Effect of mechanochemically modified MoO 3 -ZnO on Mo supply to plants when co-granulated with macronutrient fertilizers

Effect of mechanochemically modified MoO 3 -ZnO on Mo supply to plants when co-granulated with macronutrient fertilizers | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Effect of mechanochemically modified MoO 3 -ZnO on Mo supply to plants when co-granulated with macronutrient fertilizers Bo Zheng, Fien Degryse, Ivan B. Andelkovic, Roslyn Baird, Mike John McLaughlin This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4457615/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 9 You are reading this latest preprint version Abstract Molybdenum (Mo) is an essential micronutrient required for plant growth but is prone to leaching from neutral and alkaline soils. The use of slow-release Mo sources could potentially reduce leaching losses from soils and increase crop yields. In this study, we assessed mechanochemistry as a green method to produce slow-release Mo sources. Molybdenum compounds (MoO3 or (NH4)6Mo7O24·4H2O) were mechanochemically (MC) treated with ZnO to synthesize compounds with a Mo content of 1–36%. Reduced Mo solubility after MC treatment, compared to the initial Mo source, was obtained with the MoO3 source and these composites were used for co-compaction with macronutrient fertilizers. Macronutrient pellets with 0.2% Mo were compacted using the 4% Mo and 36% Mo (characterized as ZnMoO4) compounds. A column dissolution test showed that the 4% Mo compound in a macronutrient carrier (DAP and MAP) only released around 40% of the total Mo compared to 80% for a non-MC treated control over 72 h. Column leaching using two soils revealed that the release behavior of Mo was strongly related to the pH of the leachate, which was affected by both the soil pH and the macronutrient carrier. More Mo was released when the MC-treated compound was co-compacted with diammonium phosphate (DAP) compared to monoammonium phosphate (MAP). The MC-treated compound with 4% Mo showed significantly less leaching than the control without ball milling when co-compacted with both MAP and DAP. In a pot trial with simulated leaching, the uptake of Mo was greater for the MC-treated 4% Mo compound co-compacted into DAP than for the other Mo sources. Overall, our results indicate that MC-treated MoO3-ZnO could be used as a slow-release Mo source in high-rainfall areas. Mechanochemistry Slow release fertilizer molybdenum fertilizer green synthesis soil leaching Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Molybdenum (Mo) and zinc (Zn) are essential nutrients for plant growth (Kaiser et al., 2005 ). The dominant soluble Mo species in the soil is MoO 4 2− (molybdate) and this anion is adsorbed by clay minerals and Fe and Al oxides in acid soils (Goldberg et al., 1996 ; Goldberg et al., 2002 ). Unlike most other essential cationic micronutrients (e.g. Cu, Zn), Mo availability decreases with decreasing pH (Gustafsson and Tiberg, 2015 ). In acidic soils, liming usually rectifies Mo deficiency, as absorbed Mo is released into the soil solution (Anderson, 1956 ; Walker et al., 1955 ). However, in areas of high rainfall, Mo levels in soil may be low, due to losses through leaching and runoff (He et al., 2005 ). Currently, soluble molybdates (Na 2 MoO 4 .2H 2 O and (NH 4 ) 6 Mo 7 O 24 .4H 2 O) are commonly used as Mo fertilizers. Few studies have examined the use of slow-release Mo sources in fertilizers. A 1960s study reports the use of a Mo glassy frit in a field experiment (Henkens and Smilde, 1966 ) and found a greater residual effect on crop growth compared to a soluble Mo source. Bandyopadhyay et al. ( 2008 ) proposed a Mo-containing long-chain magnesium sodium polyphosphate as a slow-release Mo fertilizer and found increased crop yield over the soluble Mo treatment in a field study. More recently, a layered double hydroxide (LDH) incorporated with Mo was proposed as a slow-release Mo fertilizer, with urea being a potential carrier to allow the slow-release character of the Mo source to be maintained (Everaert et al., 2021 ). Until now, Zn deficiency remains a global health problem. It affects more than 17% of the world’s population (Myers et al., 2015 ). Zinc fertilizers can be applied by themselves, incorporated with macronutrients or applied in foliar sprays (Montalvo et al., 2016 ). Compared to separate soil or foliar applications, incorporating micronutrients with macronutrients is a more efficient way to reduce labor and spreading costs. Mechanochemistry is a green manufacturing method that has gained much attention in industrial synthesis for alloys, semiconductors, ceramics and pharmaceutical applications (Baláž et al., 2013 ; James et al., 2012). Recent mechanochemical approaches to fertilizer synthesis have mainly focused on macronutrient NPK fertilizers. Several studies have been carried out to incorporate NPK nutrients into an inorganic matrix such as a clay mineral or LDH (Borges et al., 2017 ; Lei et al., 2018 ; Tongamp et al., 2008 ; Zhang and Saito, 2009 ). Recently, mechanochemical methods have been used to combine alkaline metal salts with urea in organic co-crystals to produce more stable N fertilizers with reduced volatilization losses (Casali et al., 2018 ; Honer et al., 2017 ; Honer et al., 2018 ). Only one study reported the mechanochemical incorporation of metal or metalloid oxides in a fertilizer using a ball mill. Yuan et al. ( 2014 ) reported an amorphous glass phase of K-Si-Ca-O produced using CaO, SiO 2 , and KOH as reactants. The reactants were milled for 2 h and both the milling speed and the SiO 2 content were adjusted to achieve optimal results. The optimal SiO 2 content was chosen to perform a study of the K release rate versus the milling speed. They concluded that a slow-release K fertilizer can be obtained when the milling speed is above 300 rpm. Overall, few attempts have been made to synthesize micronutrient fertilizers using mechanochemistry (Li et al., 2017 ; Tang et al., 2021 ) and most mechanochemically synthesized products have only been tested for water solubility to indicate their effectiveness as slow-release fertilizers. However, solubility tests are not a good indicator of agronomic efficiency in soil (Chien et al., 2011; Montalvo et al., 2016 ). Therefore, it is crucial to assess newly synthesized fertilizers for their agronomic performance. Zinc oxide is one of the cheapest and high analysis sources of Zn widely used in the fertilizer industry. Zinc oxide has low water solubility and high chemical stability, but its effectiveness as a fertilizer depends largely on the application method, soil pH, and (if applicable) the macronutrient it is incorporated with (McBeath and McLaughlin, 2014 ). The efficiency of ZnO is similar or close to that of soluble Zn fertilizers such as ZnSO 4 when optimum application methods are selected (Hergert et al., 1984 ; McBeath and McLaughlin, 2014 ; Montalvo et al., 2016 ; Rehm et al., 1980 ). Molybdenum-doped ZnO and ZnMoO 4 have been synthesized by different chemical methods using ZnO and MoO 3 (Wang et al., 2016 ; Wu et al., 2015 ; Zhang et al., 2015 ) and have drawn much attention in the materials engineering industry as semiconductors and photocatalysts (Yu et al., 2012 ; Zhao et al., 2020 ). Two of the products made were mechanochemically synthesized ZnO-MoO 3 (Zazhigalov et al., 2016 ) and nickel molybdates (Klissurski et al., 2006 ). In other industries, mechanochemistry has been proposed to prepare complex metal oxides, doped metal oxide, and metal oxide nanoparticles as functional materials (Tsuzuki, 2021 ; Zdujić et al., 1992 ). In this study, we aimed to incorporate Mo into the chemically stable ZnO structure or synthesize a new complex metal oxide using mechanochemistry. We hypothesized that mechanochemically synthesized ZnO-MoO 3 variants are stable compounds with slow-release characteristics that could be useful as slow-release micronutrient compounds in fertilizers. In addition to the formulation and characterization, the resulting products were thoroughly assessed by a) co-compacting Mo products into macronutrient fertilizers (muriate of potash - MOP, MAP and DAP); b) performing column leaching using two soils; and c) evaluating the effectiveness of the Mo-incorporated fertilizers in a plant uptake experiment with simulated leaching. Methods 1.1. Mechanochemical synthesis and characterisation Zinc oxide (ZnO, 99.0% puriss) from Sigma-Aldrich (NSW, Australia), molybdenum oxide (VI) (MoO 3 , 99.5%) from Merck (VIC, Australia) and ammonium molybdate tetrahydrate ((NH 4 ) 6 Mo 7 O 24 ·4H 2 O) from Chem-Supply (SA, Australia) were used as received. Different amounts of (NH 4 ) 6 Mo 7 O 24 ·4H 2 O (AMT) or MoO 3 were mixed with ZnO to obtain 3 g mixtures in total with Mo concentrations ranging from 1 to 36% as indicated in Table S1 (AMT samples) and Table 1 (MoO 3 samples). The mixtures were milled in a 50-ml zirconia jar with six zirconia balls (15 mm diameter and 10 g per ball) to achieve a ball-to-powder weight ratio of 20. Ball milling was carried out in a planetary mill (PM200, Retsch, Haan, Germany) for 8 h at a rotation speed of 550 rpm with a break of 5 min and a change of direction every 30 min to avoid overheating. The milled products were characterized by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. X-ray diffraction patterns of products and reactants were recorded with an X'Pert Pro multipurpose diffractometer (PANalytical B.V. Almelo, Netherlands) using Fe-filtered Co Kα radiation, automatic divergence slit, 2° anti-scatter slit, and fast X'Celerator Si strip detector. The diffraction patterns were recorded in steps of 0.017° 2-theta with a counting time of 0.5 s per step for an overall counting time of approximately 30 min. The relative amounts of the major phases were determined by the Rietveld method using the Bruker TOPAS software package (Bruker BioSpinCorporation, Billerica, MA, USA). Fourier transform infrared spectroscopy measurement was carried out using the attenuated total reflectance (ATR) module on an Alpha FT-IR spectrometer (Bruker Optics, Ettlingen, Germany). The analysis was performed in the middle infrared range (wavenumber from 4000 to 400 cm − 1 ) at a resolution of 4 cm − 1 and corrected for an air background. The sample was mounted on a platinum platform and covered with a thin layer of foil paper. Each sample was scanned 100 times and the platform was cleaned with lint-free tissue and ethanol between treatments. The morphology of the synthesized products was imaged using field emission scanning electron microscopy (FE-SEM, Quanta 450, FEI, USA). Table 1 The mechanochemical treatments of MoO 3 and ZnO milled with different Zn:Mo ratios for 8 h. Treatment MoO 3 (g) ZnO (g) Mo (%) Zn (%) Zn:Mo 36% Mo 1.64 1.36 36 36 1.0 10% Mo 0.45 2.55 10 68 6.8 8% Mo 0.36 2.64 8 71 8.8 4% Mo 0.18 2.82 4 76 18.9 2% Mo 0.09 2.91 2 78 39.0 1% Mo 0.05 2.95 1 79 79.1 1.2. Batch solubility, fertilizer manufacturing, and column dissolution Batch solubility tests were conducted to assess the solubility of the mechanochemically treated Mo-ZnO products from both AMT and MoO 3 (1, 2, 4, 8, 10 and 33/36% Mo). In addition, we also tested the 4% and 36% Mo-Control, which had the same MoO 3 -ZnO reactant mixture, but without ball milling. The solubility of the samples was evaluated by weighing 0.1 g of the sample in a 50 ml digestion tube with 10 ml of reverse osmosis (RO) water. Samples were shaken on an end-to-end shaker for 1 h followed by 10 min centrifugation at 4685 g and pH was determined. Samples were filtered through a 0.2-µm syringe filter before analysis. The sediment remaining in the centrifuge tubes was digested overnight at room temperature using aqua regia (HNO 3 : HCl = 1:3 v/v), followed by 45 min of heating at 80°C and 165 min of heating at 125°C in hot block digestion. All samples were analyzed by inductively coupled plasma-optical emission spectrometry (ICP-OES, Avio 200, Perkin Elmer, Waltham, USA) to determine the total content of soluble and insoluble Mo and Zn. The compaction of micronutrient and macronutrient fertilizer powders was carried out using a pellet press. The selected micronutrient samples were the compounds made using MoO 3 and ZnO with 4% or 36% Mo. Also, mixtures of MoO 3 and ZnO without mechanochemical treatment were included for comparison, as well as a mixture of AMT and ZnSO 4 ·7H 2 O as a soluble reference treatment. Granules of MOP (muriate of potash, KCl), MAP (monoammonium phosphate) and DAP (diammonium phosphate) were ground, sieved (< 250 µm) and mixed with the Mo products (Table 2 ) before adding 1 ml of DI water to 5 g of mixed powder to form a paste. The paste was placed in a 4-cm diameter die and 9.8 MPa pressure was applied using a pellet press (Simplex 12HJ Templeton Kenlyand Co, IL, USA) to form a single pellet. The pellet was air-dried and cut into small pellets of similar size (2–3 mm square) and weights (around 40 mg). Table 2 The amount of micronutrient compound added to macronutrient fertilizers with or without mechanochemical treatment. Compound Theoretical (%) MC a treated Mo Zn 4% Mo 0.2 3.8 Yes Control 4% Mo 0.2 3.8 No 36% Mo 0.2 0.2 Yes Control 36% Mo 0.2 0.2 No AMT b and ZnSO 4 ·7H 2 O 0.2 3.8 No a MC – Mechanochemical b AMT - (NH 4 ) 6 Mo 7 O 24 ·4H 2 O Release of Mo and Zn from these products was tested using the column perfusion method described by Baird et al. ( 2019 ). This is a laboratory method that examines the dynamic release of nutrients from fertilizer formulations by continuously perfusing samples with a solution in real time. Previous studies have shown a good correlation between pot, leaching, and seedling toxicity experiments with this method (Abat et al., 2015a , b ; da Silva et al., 2018 ). Pellet samples (0.2 g) were placed between 1 g of glass wool in each polypropylene column (150 mm long × 15 mm diameter). The percolating solution (RO water) was introduced into the column from the bottom using a peristaltic pump at a constant rate of 10 ml h − 1 . The solutions released from the top of the column were collected every hour for 72 h using a fraction collector (SuperFracTM, Pharmacia, USA). At the end of the study, the residues, the glass wool and the solution remaining in each column were collected and dried in the oven at 90 ° C until all the liquid vaporized. These residues were digested using hot aqua regia , analyzed by ICP-OES, and added to all nutrients released over time to establish the total nutrient content of the sample. The nutrient release was expressed as a percentage of this total content. All column dissolutions were performed in duplicate. 1.3. Leaching in soil A column leaching experiment was performed to examine the release of Mo from the fertilizers in an acid soil and in a calcareous soil, with both considered to have low to very low fertility (for soil properties see Table S2). The columns consisted of syringes (120 mm length, 15 mm diameter) that were filled with a layer of glass wool and 30 g of soil. Around 400 mg of fertilizer (circa 10 granules) was evenly distributed throughout the soil column. Treatments were DAP or MAP alone or cogranulated with the mechanochemically treated compound (MC), the non-treated MoO 3 -ZnO mixture (C) or the soluble Mo and Zn sources (AMT) (Table 2 ). Deionized water was introduced to the column from the bottom to the top using a peristaltic pump at a constant rate. The soil was first saturated until no dry soil was observed; then 30 ml of deionized water was added to leach the column from the top on Day 1 and Day 3 followed by six leaching events with 20 ml of DI water every 2 or 3 days. After each leaching, the column was incubated at a constant temperature of 25° C. After the final leaching, the soil in each column was dried in the oven and further homogenized by grinding using a mortar and pestle. The soil was then subsampled and digested to determine total Mo concentrations. The collected and filtered leachate after each leaching and digested soil extract were analyzed using ICP-OES. 1.4. Pot trial The pot trial was conducted in a glasshouse using pure sand as a growth medium. The pure sand was used for pot trial due to low Mo plant uptake (below detection limits) in a preliminary study. Chickpea was selected due to the high demand for Mo by legumes. Plastic pots (120 mm diameter and 120 mm height) with a few layers of mesh placed at the bottom were filled with 1 kg of washed sand. For each pot, 5 granules (0.2 g of fertilizer treatments mentioned in the leaching study, containing around 0.4 mg Mo and 7.6 mg Zn), corresponding to 0.28 kg Mo ha − 1 soil assuming a bulk density of 1.4 g cm − 3 , were placed 4.5 cm equidistantly below the soil surface. Leaching was carried out two days later to allow the dissolution of the fertilizer before leaching. The initial water content of the sand, prior to leaching, was 4%. Treatments were randomized with 4 replicates of each treatment using a complete block design generated by GenStat 19th edition. The leaching procedure was performed with DI water. Each pot was leached four times with 350 ml (or a total of approximately 4 pore volumes) of water to mimic heavy rainfall events which could remove soluble Mo from the fertilizer and soil. The leachates of each pot were collected and filtered before the determination of solution pH and Mo concentrations by ICP analysis. After the leaching events, the pots were left in ambient conditions for 3 days before planting. The chickpea (anti-fungi treated) was germinated for 2 days in the dark at a constant temperature of 25° C. Germinated seeds (3 seeds per pot) were transplanted 2.5 cm below the soil surface and thinned to 1 after 2 weeks. All pots received 10 ml of basal nutrient solution 5 days after planting and every week during the growing period (7 times in total). Total amounts of nutrients supplied by the basal nutrient solution were 63 mg N kg − 1 , 198 mg P kg − 1 , 250 mg K kg − 1 90 mg Ca kg − 1 , 150 mg S kg − 1 , 15 mg Mg kg − 1 , 5 mg Mn kg − 1 , 5 mg Fe kg − 1 , 0.5 mg Cu kg − 1 , 0.05 mg B kg − 1 , and 0.05 mg Co kg − 1 . All pots were maintained at 50% field capacity by checking their weights every day and adding DI water as needed. Harvesting was carried out at flowering (stage R1) 7 weeks after planting. Plant shoots were cut 1 cm above the soil surface and roots were collected and washed with DI water. Both roots and shoots were oven dried for 72 h at 60° C for dry mass weight and further ground and digested before ICP analysis for Mo content. For statistical analysis, one-way and two-way ANOVA (analysis of variance) was used followed by Duncan's multiple range test (MRT) to check significant differences using GenStat (19th edition). Where needed, the data were log-transformed to homogenize variance. Results and discussion 1.5. Solubility of mechanochemically treated Mo-ZnO and characteristics of materials The measured total Mo content was close to the expected content for both AMT and MoO 3 treatments (Table S3). Molybdenum release was much higher for the AMT than for the MoO 3 treatments (Fig. 1 a). Molybdenum solubility increased with increasing Mo content for both MoO 3 and AMT treatments up to a Mo content of 10%, where all Mo was dissolved for the AMT treatment and ∼30% for the MoO 3 treatment. At the highest Mo content (33%), Mo in the AMT treatment was fully dissolved, while the solubility for the MoO 3 (36% Mo) treatment was lower than the treatment with 10% Mo. The 4% and 36% Mo control treatments (without mechanochemical processing) released more than twice the Mo compared to the mechanochemically treated samples. This is likely due to the formation of new compounds with higher Mo solubility in water. Given the high solubility of the AMT incorporated compounds, only compounds made with MoO 3 were further evaluated. The 4% Mo was selected because of its suitable Zn/Mo ratio for agronomic purposes (ratio similar to that of common Zn/Mo fertilizer rates) and the 36% Mo because newly formed compounds were found in this material (see below). The FTIR spectra of mechanochemically treated samples showed a different pattern compared to the reactants, ZnO and MoO 3 (Figs. 1 b, d) as increased Mo content modified the peak intensity and position. The peak at 851 cm − 1 in the 2% Mo sample shifted to 899 cm − 1 at 4% Mo and split to a shoulder peak at 909 and 806/798 cm − 1 for the 8% and 10% formulations. The peaks at 851, 899 and 909 cm − 1 are likely ascribed to the Mo-O-Mo vibration of Mo 6+ in [MoO 4 ] clusters (Chen et al., 2010 ). The observed shoulder peaks observed in the 8 and 10% Mo at 806 and 789 cm − 1 could be assigned to antisymmetric stretching of Mo-O (Yadav and Sinha, 2019 ). Characteristic peaks of MoO 3 (Fig. 1 d) and Zn-O-Mo (1100–1400 cm − 1 ) were not observed in the 2%-10% Mo samples (Yu et al., 2012 ). The FTIR spectra of the 36% Mo sample are in line with the FTIR spectra of ZnMoO 4 reported in an earlier study (Yadav and Sinha, 2019 ). It can be concluded that the chemical structure of the reactants has changed after ball milling. Changes in the XRD patterns with increased milling time further support differences in chemical structure observed with FTIR. The six clear peaks in the samples incorporated with 2–10% MoO 3 could be assigned to the wurtzite phase of ZnO (Fig. 1 c), but they were broader than in the control samples (Yu et al., 2012 ). In the control sample, the peaks assigned to MoO 3 were clearly visible even at lower Mo content (Figure S2a), but these peaks completely disappeared in the mechanochemically treated samples with 2–10% Mo (Fig. 1 c). However, a broad bump was observed around 2 theta = 31 ° when the percentage of Mo increased to 8% which was in line with the FTIR results where the shoulder peaks (between 800–900 cm − 1 ) appeared. This could be due to an increase in the Mo concentration that indicated reduction of inter-planar “d” spacing in the sample (Ali et al., 2019 ). When the Mo content increased to 36%, in addition to the identifiable ZnO peaks and minor peaks assigned to MoO 3 (Figure S2b), many new peaks assigned to several zinc molybdates and zinc molybdenum oxide were observed (Figure S2b) (Wang et al., 2018 ). A calculation using the Scherrer equation confirmed the decrease of crystallite size to approximately 1.5 to 2.0 nm for low Mo concentration samples after mechanochemical treatment (data not shown) (Patterson, 1939 ). Therefore, the much smaller crystallite size of ZnO obtained after MC treatment with MoO 3 was likely due to smaller Mo 6+ (0.065 nm) doped into and replacing Zn 2+ in the ZnO structure, thus suppressing the growth of ZnO crystals (Yu et al., 2012 ). Overall, these results indicate that the mechanochemically treated samples at a low Mo inclusion rate successfully penetrated the wurtzite crystalline lattice of ZnO, particularly at 2 and 4% Mo, where no impurity peaks were observed (Umar et al., 2015 ), while the crystal structure changed at the highest 36% Mo rate as a result of new compound formation. 1.6. Column dissolution of Mo compacted with MAP, MOP, and DAP All pelletized samples were macronutrient fertilizers containing a final Mo concentration of 0.2% as indicated in Table 2 . Both macronutrients (K and P) were quickly released from the formulations and no difference in the macronutrient release was observed between Mo treatments (Figures S3a, c). Total Mo released from DAP and MAP was twice as high in the treatments with the 36% Mo compounds, reaching 80% and 70% respectively compared to those with the 4% Mo compounds (Figs. 2 a, b). The Mo release for the 4% Mo treatments was half that of the 4% Mo-Control for both the MAP and DAP treatments. The Mo release from MAP + 4% Mo was slow and constant, while in DAP + 4% Mo, a dual release was observed where the release was fast in the initial 10 h (39%), followed by a minor release (3%) in the following 62 h. In the MOP treatments, more than 80% of the total Mo was released after 72 h of dissolution. Total Zn release was negligible in most treatments (< 6%) over 72 h, except for MOP + 36% Mo and MAP + 36% Mo where 70% and 18% of the total Zn was released, respectively. The lower percentage release of Zn in the 4% Mo treatments was likely due to (i) the 36% Mo treatments containing ZnMoO 4 had a much higher Zn solubility compared to ZnO, and a faster rate of Zn release; (ii) the higher ZnO content of the 4% Mo treatments had higher absolute amount of Zn. Overall, the column dissolution indicated that the DAP + 4% Mo and MAP + 4% Mo behaved as slow-release Mo Fertilizers. Leaching in soil and a pot trial were performed to further evaluate the agronomic effectiveness of these two treatments. 1.7. Molybdenum leaching from fertilizers in soils Leaching of Mo was assessed in two contrasting soils. For all treatments, Mo incorporated with DAP had higher Mo leaching compared to MAP (Fig. 3 ). When Mo sources were applied with MAP, the lowest Mo leaching was observed in AMT and MC treatments in both soils, both circa half that of the C treatment. The leached Mo from C was 66% in Ngarkat soil and 93% in Streaky Bay soil at the end of incubation (Figs. 3 e, f). When Mo sources were applied with DAP, the Mo release was lowest with MC treated products (Figs. 3 g, h). Molybdenum leached from MC treatments was approximately 20% lower in Ngarkat soil and 40% in Streaky Bay soil compared to C and AMT treatments. The Mo leached over time in both soils followed the same trend as the pH changes, with an increase in Mo leaching as the pH of the leachate increased (Figs. 3 a-d). Molybdenum recovery in the soil corresponded well with the leaching results except for C with DAP in the Ngarkat soil, where no residue was recovered, despite incomplete leaching. This may have been due to heterogeneity of the soil sample or residues remaining attached to the glass wool. The amount of retained Mo in the soil after leaching was higher for the MC treatments than the other treatments, except with MAP in the Ngarkat soil where AMT and MC retained a similar amount (Fig. 3 i). For the C treatment, Mo in the soil was detected only in Ngarkat soil with MAP as the carrier. Overall, Mo release was affected by the soil, most likely due to differences in the soil pH (Riley et al., 1987 ). Most treatments had lower Mo recovery in the alkaline Streaky Bay soil than in the neutral Ngarkat soil except for MC + DAP. This is consistent with the theory that typical well-drained, near-neutral sandy soils or calcareous soils with organic matter less than 50 g kg − 1 tend to retain little Mo (Goldberg and Forster, 1998 ; O'Connor et al., 2001 ). Moreover, the Mo release from the pellet is also largely affected by the pH induced by the macronutrient carrier. With the same Mo source and soil, the Mo release was higher for DAP compared to MAP due to the higher solution pH around DAP granules, except for C treatments where most of the Mo leached out within the first 3 days in the Streaky Bay soil. Due to the lower pH of the leachate in AMT compared to C, the leached Mo was higher for C in all treatments, except the DAP treatments applied in the Streaky Bay soil, where most Mo leached out by Day 3. Interestingly, the MC and C treatments had a similar pH in the leachate over the 6 leaching events, while the release of Mo was 20–50% lower for MC compared to C treatments regardless of the soil and carrier. The results, therefore, suggest that the MC treatments might be less affected by soil pH compared to the C and AMT treatments. 1.8. Pot Trail More Mo was leached from DAP treatments than from the MAP treatments (Figs. 4 a, b). The highest recovery of Mo in the leachate was observed in the DAP treatment with C, for which more than 70% of added Mo was found in the leachate (Fig. 4 b), while only 13% was leached for the corresponding treatment with MAP (Fig. 4 a). The lowest Mo recovery in leachate was observed in the MAP + MC treatment (5%). With DAP as the carrier, the Mo recovery from the MC treatment reached 39% in the leachate. The AMT treatments behaved similarly for both MAP and DAP fertilizers, with 17–25% of the added Mo leached after 4 leaching events. Surprisingly, the Mo leaching from the soluble AMT treatment was lower than that of the MC treatment for DAP (Fig. 4 d). This can perhaps be explained by the lower leachate pH for the AMT treatment than for the MC treatment. Furthermore, the pH of leachates was higher for DAP than for MAP across all treatments (Figs. 4 c, d). In agreement with column leaching, the recovery of Mo in the leachate was closely associated with the pH of the leachate. Leaching of Zn was observed only in the AMT treatment with MAP as the carrier (Figure S4a). Despite the use of soluble ZnSO 4 ·7H 2 O in the AMT treatment, leaching of Zn from the sandy medium for the AMT treatment with DAP was low, likely due to precipitation of Zn with P compounds under the higher pH environment, such as NH 4 ZnPO 4 and hopeite (Zn 3 (PO 4 ) 2 ·4H 2 O) (Milani et al., 2012 ). The shoot and root dry weights were significantly lower in the DAP + AMT treatment than in the treatment with DAP alone and the shoot dry weight of DAP + MC was significantly higher than the treatment with DAP alone (Figs. 5 a, d). The lower yield for the DAP + AMT treatment may have been due to dissolved Zn 2+ from ZnSO 4 ·7H 2 O causing toxicity (Kaur and Garg, 2021 ) as the sand had no or minimal cation exchange capacity. In the MAP treatments, there were no significant differences in yield between the treatments (Figs. 5 a, d). For both macronutrient carriers, the effect of Mo addition on Mo concentration and uptake was much higher in the root than in the shoot (Figs. 5 b, c, e and f). The highest shoot Mo concentrations were observed in MAP/DAP + MC and MAP + C treatments (Fig. 5 b). The small but detectable Mo shoot concentrations in the N treatments were likely derived from the chickpea seed itself as the pure sand did not contain a detectable amount of Mo. Concentrations of Mo in roots were highest for AMT and MC in the DAP treatments, and highest for MC and C in the MAP treatments (Fig. 5 e). The Mo uptake in roots and shoots followed the order MC > C = AMT≥N when DAP was the carrier and MC = C > AMT > N when MAP was the carrier (Figs. 5 c, f). The lower Mo uptake observed for the MAP + AMT treatment compared to the other Mo treatments was likely due to both AMT and zinc sulphate fertilizer acidifying the sand solution around roots, thus reducing Mo uptake (Gammon Jr et al., 1954 ). This is supported by the leaching results where AMT treatments had much lower pH than the control and other Mo-added treatments (Fig. 4 c). Moreover, the pure sand had a very low soil cation exchange capacity, thus the decreased soil pH will also have increased Zn bioavailability and further caused plant phytotoxicity. The availability of Mo is controlled by the pH of the soil solution. Many studies have concluded that liming along with Mo application can promote Mo availability and improve Mo uptake by plants (Hagstrom and Berger, 1963 ; McBride and Cherney, 2004 ). In soil, Mo movement or leaching is mainly affected by soil pH. Johansen et al. ( 1977 ) conducted a field trial on tropical pasture legumes using MoO 3 and sodium molybdate and reached a similar conclusion that soil pH influences Mo movement. Furthermore, they also concluded that there was no difference in residual effects on legume growth between the two Mo sources they applied. So in our study, plant uptake of Mo was likely affected by the pH of both the macronutrient carrier and the soil solution, as well as the solubility of the Mo source. Overall, the MC treatment resulted in slower Mo release and protected Mo against leaching, resulting in higher uptake than for the control (without MC treatment) when DAP was the carrier. There was no significant difference in plant uptake between the MC and control treatment when MAP was the carrier, likely because there was less Mo leaching with MAP for all the treatments (due to the lower pH induced by MAP). However, our experiments were carried out at high fertilizer rates (columns) or with a pure sand (pot trial). In field soils with higher pH buffering capacity, the fertilizer carrier would likely have less effect on soil pH and there would be less chance of Zn toxicity with more soluble treatments (e.g. AMT). Further work is therefore recommended to compare these fertilizer sources in soil systems. Conclusions The MC synthesized Mo-Zn fertilizer was found to be less prone to leaching than currently used Mo sources (MoO 3 and (NH 4 ) 6 Mo 7 O 24 ·4H 2 O). In addition, the lower leaching loss was found to result in higher Mo uptake compared to a non-treated control when DAP was the fertilizer carrier. Therefore, the mechanochemically synthesized Mo-Zn fertilizer has promise as a slow release fertilizer for application in high rainfall areas, light textured soils and/or soils with high pH. The MC method used in this study did not require water or solvent and did not produce any waste streams. To promote this green synthesis method, agronomic comparisons with conventional fertilizers are essential. This study demonstrated the importance of agronomically assessing new fertilizers, especially when examining micronutrients, as micronutrients are required in only small amounts and their availability is more likely to be affected by other nutrients applied at the same time. Informed selection of macronutrient carriers can greatly change the effectiveness of applied micronutrients. However, pot trials cannot guarantee performance in all agronomic situations. The soils used in this study were sandy with a low ability to adsorb Mo, unlike heavier soils where Mo fixation might become a dominant parameter affecting plant Mo uptake. So, further pot and field trials with different soils and climates are required to further evaluate the effectiveness of these synthesized products. Abbreviations MC mechanochemistry DAP diammonium phosphate MAP monoammonium phosphate LDH layered double hydroxide AMT (NH 4 ) 6 Mo 7 O 24 ·4H 2 O XRD X-ray diffraction FTIR fourier transform infrared FE-SEM field emission scanning electron microscopy ICP-OES inductively coupled plasma-optical emission spectrometry Declarations Ethics approval and consent to participate Not applicable Consent for publication Not applicable Availability of data and materials The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request. Competing interests The authors declare that they have no competing interests Authorship BZ, FD, IBA, RB, and MJM contributed to the study conception and design Material preparation, setting up the trial and data collection was performed by BZ The first draft of the manuscript was written by BZ and all authors commended on previous versions of the manuscript. All authors read and approved the final manuscript. Declaration of competing interest This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Acknowledgements Bo Zheng is grateful for the scholarship and support from The University of Adelaide, School of Agriculture, Food and Wine. We thank the help and support from Adelaide Microscopy and Ken Neubauer for SEM analysis. The authors acknowledge the support of The Mosaic Company LLC. The authors thank Bogumila Tomczak, Ashleigh Panagaris and Andrea Paparella for their advice and technical support. References Abat, M., Degryse, F., Baird, R., McLaughlin, M.J., 2015a. Boron Phosphates (BPO 4 ) as a Seedling-safe Boron Fertilizer Source. Plant and Soil 391(1), 153–160. 10.1007/s11104-015-2424-6 . Abat, M., Degryse, F., Baird, R., McLaughlin, M.J., 2015b. Responses of Canola to the Application of Slow-Release Boron Fertilizers and Their Residual Effect. Soil Science Society of America Journal 79(1), 97–103. 10.2136/sssaj2014.07.0280 . Ali, A., Ammar, M., Ali, M., Yahya, Z., Javaid, M.Y., Hassan, S.u., Ahmed, T., 2019. Mo-doped ZnO Nanoflakes on Ni-foam for Asymmetric Supercapacitor Applications. RSC Advances 9(47), 27432–27438. 10.1039/C9RA05051E . Amirkhanlou, S., Ketabchi, M., Parvin, N., 2012. Nanocrystalline/Nanoparticle ZnO Synthesized by High Energy Ball Milling Process. Materials Letters 86, 122–124. 10.1016/j.matlet.2012.07.041 . Anderson, A.J., 1956. Molybdenum as a Fertilizer, in: Norman, A.G. (Ed.) Advances in Agronomy. Academic Press, pp. 163–202. 10.1016/S0065-2113(08)60689-6 . Baird, R., da Silva, R.C., Degryse, F., McLaughlin, M.J., 2019. A Column Perfusion Test to Assess the Kinetics of Nutrient Release by Soluble, Sparingly Soluble and Coated Granular Fertilizers. Journal of Plant Nutrition and Soil Science 0(0). 10.1002/jpln.201800666 . Baláž, P., Achimovičová, M., Baláž, M., Billik, P., Cherkezova-Zheleva, Z., Criado, J.M., Delogu, F., Dutková, E., Gaffet, E., Gotor, F.J., Kumar, R., Mitov, I., Rojac, T., Senna, M., Streletskii, A., Wieczorek-Ciurowa, K., 2013. Hallmarks of Mechanochemistry: from Nanoparticles to Technology. Chemical Society Reviews 42(18), 7571–7637. 10.1039/C3CS35468G . Bandyopadhyay, S., Bhattacharya, I., Ghosh, K., Varadachari, C., 2008. New Slow-Releasing Molybdenum Fertilizer. Journal of Agricultural and Food Chemistry 56(4), 1343–1349. 10.1021/jf072878g . Borges, R., Prevot, V., Forano, C., Wypych, F., 2017. Design and Kinetic Study of Sustainable Potential Slow-Release Fertilizer Obtained by Mechanochemical Activation of Clay Minerals and Potassium Monohydrogen Phosphate. Industrial and Engineering Chemistry Research 56(3), 708–716. 10.1021/acs.iecr.6b04378 . Casali, L., Mazzei, L., Shemchuk, O., Honer, K., Grepioni, F., Ciurli, S., Braga, D., Baltrusaitis, J., 2018. Smart Urea Ionic Co-crystals with Enhanced Urease Inhibition Activity for Improved Nitrogen Cycle Management. Chemical Communications 54(55), 7637–7640. 10.1039/C8CC03777A . Casali, L., Mazzei, L., Shemchuk, O., Sharma, L., Honer, K., Grepioni, F., Ciurli, S., Braga, D., Baltrusaitis, J., 2019. Novel Dual-Action Plant Fertilizer and Urease Inhibitor: Urea·Catechol Cocrystal. Characterization and Environmental Reactivity. ACS Sustainable Chemistry and Engineering 7(2), 2852–2859. 10.1021/acssuschemeng.8b06293 . Chen, Y., Lu, C., Xu, L., Ma, Y., Hou, W., Zhu, J.-J., 2010. Single-crystalline Orthorhombic Molybdenum Oxide Nanobelts: Synthesis and Photocatalytic Properties. CrystEngComm 12(11), 3740–3747. 10.1039/C000744G . da Silva, R., Baird, R., Degryse, F., McLaughlin, M.J., 2018. Slow and Fast-Release Boron Sources in Potash Fertilizers: Spatial Variability, Nutrient Dissolution and Plant Uptake. Soil Science Society of America Journal 82(6), 1437–1448. 10.2136/sssaj2018.02.0065 . Everaert, M., Smolders, E., McLaughlin, M.J., Andelkovic, I., Smolders, S., Degryse, F., 2021. Layered Double Hydroxides as Slow-Release Fertilizer Compounds for the Micronutrient Molybdenum. Journal of Agricultural and Food Chemistry 69(48), 14501–14511. 10.1021/acs.jafc.1c06056 . Gammon Jr, N., Volk, G.M., McCubbin, E.N., Eddins, A.H., 1954. Soil Factors Affecting Molybdenum Uptake by Cauliflower. Soil Science Society of America Journal 18(3), 302–305. 10.2136/sssaj1954.03615995001800030018x . Glushenkov, A.M., Zhang, H.Z., Chen, Y., 2008. Reactive Ball Milling to Produce Nanocrystalline ZnO. Materials Letters 62(24), 4047–4049. 10.1016/j.matlet.2008.06.002 . Goldberg, S., Forster, H.S., 1998. Factors Affecting Molybdenum Adsorption by Soils and Minerals. Soil Science 163(2). Goldberg, S., Forster, H.S., Godfrey, C.L., 1996. Molybdenum Adsorption on Oxides, Clay Minerals, and Soils. Soil Science Society of America Journal 60(2), 425–432. 10.2136/sssaj1996.03615995006000020013x . Goldberg, S., Lesch, S.M., Suarez, D.L., 2002. Predicting Molybdenum Adsorption by Soils Using Soil Chemical Parameters in the Constant Capacitance Model. Soil Science Society of America Journal 66(6), 1836–1842. 10.2136/sssaj2002.1836 . Gustafsson, J.P., Tiberg, C., 2015. Molybdenum Binding to Soil Constituents in Acid Soils: An XAS and Modelling Study. Chemical Geology 417, 279–288. 10.1016/j.chemgeo.2015.10.016 . Hagstrom, G.R., Berger, K.C., 1963. Molybdenum Status of Three Wisconsin Soils and Its Effect on Four Legume Crops1. Agronomy Journal 55(4), 399–401. 10.2134/agronj1963.00021962005500040031x . He, Z.L., Yang, X.E., Stoffella, P.J., 2005. Trace Elements in Agroecosystems and Impacts on the Environment. Journal of Trace Elements in Medicine and Biology 19(2), 125–140. 10.1016/j.jtemb.2005.02.010 . Henkens, C.H., Smilde, K.W., 1966. Evaluation of Glassy Frits as Micronutrient Fertilizers. 1. Copper and Molybdenum Frits. Netherlands Journal of Agricultural Science 14, 165–177. Hergert, G.W., Rehm, G.W., Wiese, R.A., 1984. Field Evaluations of Zinc Sources Band Applied in Ammonium Polyphosphate Suspension. Soil Science Society of America Journal 48(5), 1190–1193. 10.2136/sssaj1984.03615995004800050048x . Honer, K., Kalfaoglu, E., Pico, C., McCann, J., Baltrusaitis, J., 2017. Mechanosynthesis of Magnesium and Calcium Salt–Urea Ionic Cocrystal Fertilizer Materials for Improved Nitrogen Management. ACS Sustainable Chemistry and Engineering 5(10), 8546–8550. 10.1021/acssuschemeng.7b02621 . Honer, K., Pico, C., Baltrusaitis, J., 2018. Reactive Mechanosynthesis of Urea Ionic Cocrystal Fertilizer Materials from Abundant Low Solubility Magnesium- and Calcium-Containing Minerals. ACS Sustainable Chemistry and Engineering 6(4), 4680–4687. 10.1021/acssuschemeng.7b03766 . James, S.L., Adams, C.J., Bolm, C., Braga, D., Collier, P., Friščić, T., Grepioni, F., Harris, K.D.M., Hyett, G., Jones, W., others, 2012. Mechanochemistry: Opportunities for New and Cleaner Synthesis. Chemical Society Reviews 41(1), 413–447. 10.1039/C1CS15171A . Johansen, C., Kerridge, P.C., Luck, P.E., Cook, B.G., Lowe, K.F., Ostrowski, H., 1977. The Residual Effect of Molybdenum Fertilizer on Growth of Tropical Pasture Legumes in a Sub-tropical Environment. Australian Journal of Experimental Agriculture 17(89), 961–968. Kaiser, B.N., Gridley, K.L., Ngaire Brady, J., Phillips, T., Tyerman, S.D., 2005. The Role of Molybdenum in Agricultural Plant Production. Ann Bot 96(5), 745–754. 10.1093/aob/mci226 . Kaur, H., Garg, N., 2021. Zinc Toxicity in Plants: A Review. Planta 253(6), 129. 10.1007/s00425-021-03642-z . Klissurski, D., Mancheva, M., Iordanova, R., Tyuliev, G., Kunev, B., 2006. Mechanochemical synthesis of nanocrystalline nickel molybdates. Journal of Alloys and Compounds 422(1), 53–57. https://doi.org/10.1016/j.jallcom.2005.11.073 . Lei, Z., Cagnetta, G., Li, X., Qu, J., Li, Z., Zhang, Q., Huang, J., 2018. Enhanced Adsorption of Potassium Nitrate with Potassium Cation on H 3 PO 4 Modified Kaolinite and Nitrate Anion into Mg-Al Layered Double Hydroxide. Applied Clay Science 154, 10–16. 10.1016/j.clay.2017.12.040 . Li, X., Lei, Z., Qu, J., Li, Z., Zhou, X., Zhang, Q., 2017. Synthesizing Slow-release Fertilizers via Mechanochemical Processing for Potentially Recycling the Waste Ferrous Sulfate from Titanium Dioxide Production. Journal of Environmental Management 186, 120–126. 10.1016/j.jenvman.2016.10.058 . McBeath, T.M., McLaughlin, M.J., 2014. Efficacy of Zinc Oxides as Fertilisers. Plant and Soil 374(1), 843–855. 10.1007/s11104-013-1919-2 . McBride, M.B., Cherney, J., 2004. Molybdenum, Sulfur, and Other Trace Elements in Farm Soils and Forages After Sewage Sludge Application. Communications in Soil Science and Plant Analysis 35(3–4), 517–535. 10.1081/CSS-120029729 . Milani, N., McLaughlin, M.J., Stacey, S.P., Kirby, J.K., Hettiarachchi, G.M., Beak, D.G., Cornelis, G., 2012. Dissolution Kinetics of Macronutrient Fertilizers Coated with Manufactured Zinc Oxide Nanoparticles. Journal of Agricultural and Food Chemistry 60(16), 3991–3998. 10.1021/jf205191y . Montalvo, D., Degryse, F., da Silva, R.C., Baird, R., McLaughlin, M.J., 2016. Chapter Five - Agronomic Effectiveness of Zinc Sources as Micronutrient Fertilizer, in: Sparks, D.L. (Ed.) Advances in Agronomy. Academic Press, pp. 215–267. 10.1016/bs.agron.2016.05.004 . Myers, S.S., Wessells, K.R., Kloog, I., Zanobetti, A., Schwartz, J., 2015. Effect of Increased Concentrations of Atmospheric Carbon Dioxide on the Global Threat of Zinc Deficiency: a Modelling Study. The Lancet. Global health 3(10), e639-645. 10.1016/s2214-109x(15)00093 – 5 . O'Connor, G.A., Brobst, R.B., Chaney, R.L., Kincaid, R.L., McDowell, L.R., Pierzynski, G.M., Rubin, A., Van Riper, G.G., 2001. A Modified Risk Assessment to Establish Molybdenum Standards for Land Application of Biosolids. Journal of Environmental Quality 30(5), 1490–1507. 10.2134/jeq2001.3051490x . Patterson, A.L., 1939. The Scherrer Formula for X-Ray Particle Size Determination. Physical Review 56(10), 978–982. 10.1103/PhysRev.56.978 . Rebafka, F.P., Ndunguru, B.J., Marschner, H., 1993. Single Superphosphate Depresses Molybdenum Uptake and Limits Yield Response to Phosphorus in Groundnut (Arachis hypogaea L.) Grown on an Acid Sandy Soil in Niger, West Africa. Fertilizer Research 34(3), 233–242. 10.1007/BF00750569 . Rehm, G.W., Wiese, R.A., Hergert, G.W., 1980. Response of Corn To Zinc Source and Rate of Zinc Band Applied with Either Orthophosphate or Polyphosphate. Soil Science 129(1). Riley, M.M., Robson, A.D., Gartrell, J.W., Jeffery, R.C., 1987. The Absence of Leaching of Molybdenum in Acidic Soils from Western Australia. Soil Research 25(2), 179–184. Tang, Y., Yang, Y., Hou, S., Cheng, D., Yao, Y., Zhang, S., Xie, J., Wang, X., Ma, X., Yu, Z., Li, S., 2021. Multifunctional Iron–Humic Acid Fertilizer from Ball Milling Double-Shelled Fe–N-doped Hollow Mesoporous Carbon Microspheres with Lignite. ACS Sustainable Chemistry and Engineering 9(2), 717–731. 10.1021/acssuschemeng.0c06406 . Tongamp, W., Zhang, Q., Saito, F., 2008. Mechanochemical Route for Synthesizing Nitrate form of Layered Double Hydroxide. Powder Technology 185(1), 43–48. 10.1016/j.powtec.2007.09.013 . Tsuzuki, T., 2021. Mechanochemical Synthesis of Metal Oxide Nanoparticles. Communications Chemistry 4(1), 143. 10.1038/s42004-021-00582-3 . Umar, K., Aris, A., Parveen, T., Jaafar, J., Abdul Majid, Z., Vijaya Bhaskar Reddy, A., Talib, J., 2015. Synthesis, Characterization of Mo and Mn Doped ZnO and Their Photocatalytic Activity for the Decolorization of Two Different Chromophoric Dyes. Applied Catalysis A: General 505, 507–514. 10.1016/j.apcata.2015.02.001 . Walker, T.W., Adams, A.F.R., Orchiston, H.D., 1955. The Effects and Interactions of Molybdenum, Lime and Phosphate Treatments on the Yield and Composition of White Clover, Grown on Acid, Molybdenum Responsive Soils. Plant and Soil 6(2), 201–220. Wang, S., Gao, W., Li, H., Xiao, L.-P., Sun, R.-C., Song, G., 2018. Selective Fragmentation of Biorefinery Corncob Lignin into p-Hydroxycinnamic Esters with a Supported Zinc Molybdate Catalyst. ChemSusChem 11(13), 2114–2123. 10.1002/cssc.201800455 . Wang, Y., Zhang, X., Meng, X., Cao, Y., Yang, F., Nan, J., Song, Q., Huang, Q., Wei, C., Zhang, J., Zhao, Y., 2016. Simulation, Fabrication, and Application of Transparent Conductive Mo-doped ZnO Film in a Solar Cell. Solar Energy Materials and Solar Cells 145, 171–179. 10.1016/j.solmat.2015.09.015 . Wu, M., Yu, S., Chen, G., He, L., Yang, L., Zhang, W., 2015. Structural, Optical, and Electrical Properties of Mo-doped ZnO Thin Films Prepared by Magnetron Sputtering. Applied Surface Science 324, 791–796. 10.1016/j.apsusc.2014.11.039 . Yadav, P., Sinha, E., 2019. Structural, Photophysical and Microwave Dielectric Properties of α-ZnMoO 4 Phosphor. Journal of Alloys and Compounds 795, 446–452. 10.1016/j.jallcom.2019.05.019 . Yu, C., Yang, K., Shu, Q., Yu, J.C., Cao, F., Li, X., Zhou, X., 2012. Preparation, Characterization and Photocatalytic Performance of Mo-doped ZnO Photocatalysts. Science China Chemistry 55(9), 1802–1810. 10.1007/s11426-012-4721-8 . Yuan, W., Solihin, Zhang, Q., Kano, J., Saito, F., 2014. Mechanochemical Formation of K–Si–Ca–O Compound as a Slow-release Fertilizer. Powder Technology 260, 22–26. 10.1016/j.powtec.2014.03.072 . Zazhigalov, V.A., Sachuk, E.V., Kopachevskaya, N.S., Bacherikova, I.V., Wieczorek-Ciurowa, K., Shcherbakov, S.N., 2016. Mechanochemical Synthesis of Nanodispersed Compounds in the ZnO-MoO 3 System. Theoretical and Experimental Chemistry 52(2), 97–103. 10.1007/s11237-016-9456-8 . Zdujić, M.V., Milošević, O.B., Karanović, L.Č., 1992. Mechanochemical Treatment of ZnO and Al 2 O 3 Powders by Ball Milling. Materials Letters 13(2), 125–129. 10.1016/0167-577X(92)90122-Z . Zhang, J.W., He, G., Li, T.S., Liu, M., Chen, X.S., Liu, Y.M., Sun, Z.Q., 2015. Modulation of Microstructure and Optical Properties of Mo-doped ZnO Thin Films by Substrate Temperature. Materials Research Bulletin 65, 7–13. 10.1016/j.materresbull.2015.01.004 . Zhang, Q., Saito, F., 2009. Mechanochemical Synthesis of Slow-Release Fertilizers through Incorporation of Alumina Composition into Potassium/Ammonium Phosphates. Journal of the American Ceramic Society 92(12), 3070–3073. 10.1111/j.1551-2916.2009.03291.x . Zhao, D., Sathasivam, S., Li, J., Carmalt, C.J., 2020. Transparent and Conductive Molybdenum-Doped ZnO Thin Films via Chemical Vapor Deposition. ACS Applied Electronic Materials 2(1), 120–125. 10.1021/acsaelm.9b00647 . Additional Declarations No competing interests reported. Supplementary Files SupportingInformation.docx Appendix A. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4457615","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":314718415,"identity":"705c5f0b-3347-4f97-9232-e41a09c113e4","order_by":0,"name":"Bo Zheng","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABDElEQVRIiWNgGAWjYBACAyBmBjH4QewHDBKMDUCOBFFaJBuA7ASStBgcAGthIKzFnL2B+XNBxR27zccPb3yQUGMh28/AfPA2D4NdYgMOLZY9BxiMZ5x5lrztTFqxQcIxCeOZDWzJ1jwMyTi1GNxIYEjmbTucbHYgx0wigU0iccMBHjNpHgZmvFoO8/47nGzc/8b8R8I/icT9B/i/AbXU49PC2MzbcNjOQCLHjCGxDWgLAw8bUMthPH452MzMc+xwgsSNZ8USiX0SxjMOsxlbzjE4boxLizl78+HPPDWH7fn7kzd++PCtTra/vfnhjTcV1bK4tEAjggHJGZBowqkeDuwJKxkFo2AUjIIRCwDd8liKu0Z4FwAAAABJRU5ErkJggg==","orcid":"","institution":"The University of Adelaide","correspondingAuthor":true,"prefix":"","firstName":"Bo","middleName":"","lastName":"Zheng","suffix":""},{"id":314718416,"identity":"2d07a21d-ca39-4078-8514-b1af8aa0d4c0","order_by":1,"name":"Fien Degryse","email":"","orcid":"","institution":"The University of Adelaide","correspondingAuthor":false,"prefix":"","firstName":"Fien","middleName":"","lastName":"Degryse","suffix":""},{"id":314718417,"identity":"791bff58-54b6-47ca-a21b-56d7784fb2e9","order_by":2,"name":"Ivan B. Andelkovic","email":"","orcid":"","institution":"The University of Adelaide","correspondingAuthor":false,"prefix":"","firstName":"Ivan","middleName":"B.","lastName":"Andelkovic","suffix":""},{"id":314718418,"identity":"90359dc3-384b-4dbe-b927-df130a627e61","order_by":3,"name":"Roslyn Baird","email":"","orcid":"","institution":"The University of Adelaide","correspondingAuthor":false,"prefix":"","firstName":"Roslyn","middleName":"","lastName":"Baird","suffix":""},{"id":314718419,"identity":"cb313526-df9f-44f8-bf42-e0693412c3f0","order_by":4,"name":"Mike John McLaughlin","email":"","orcid":"","institution":"The University of Adelaide","correspondingAuthor":false,"prefix":"","firstName":"Mike","middleName":"John","lastName":"McLaughlin","suffix":""}],"badges":[],"createdAt":"2024-05-22 02:08:17","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4457615/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4457615/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":58719798,"identity":"427ca946-8fb1-439d-b9ec-dfc1094ea600","added_by":"auto","created_at":"2024-06-20 08:46:12","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":150241,"visible":true,"origin":"","legend":"\u003cp\u003ea) Solubility of Mo for mechanochemically treated ZnO with different amounts of MoO\u003csub\u003e3\u003c/sub\u003e and (NH\u003csub\u003e4\u003c/sub\u003e)\u003csub\u003e6\u003c/sub\u003eMo\u003csub\u003e7\u003c/sub\u003eO\u003csub\u003e24\u003c/sub\u003e·4H\u003csub\u003e2\u003c/sub\u003eO after 1 h equilibration in water; b) FTIR and c) XRD spectrum of mechanochemically treated ZnO with different amounts of MoO\u003csub\u003e3\u003c/sub\u003e; d) FTIR and e) XRD of the reactants.\u003c/p\u003e","description":"","filename":"image1.png","url":"https://assets-eu.researchsquare.com/files/rs-4457615/v1/3e43e0e6cc40d4792a49031e.png"},{"id":58719794,"identity":"c8c1b6cc-9703-49a9-b0e4-759f090f7b32","added_by":"auto","created_at":"2024-06-20 08:46:11","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":50137,"visible":true,"origin":"","legend":"\u003cp\u003eThe cumulative release over 72 h of (a, b, c) Mo, and (d, e, f ) Zn (as % of added) from MAP, MOP and DAP compacted with 0.2% Mo, either as (a, d) the mechanochemically treated compounds with 36% Mo or (b, e) 4% Mo with (c, f) or the 4% Mo-Control without mechanochemical treatment. Error bars present the standard error of the mean (n = 2).\u003c/p\u003e","description":"","filename":"image2.png","url":"https://assets-eu.researchsquare.com/files/rs-4457615/v1/69f27a5a7e4161b634c173e4.png"},{"id":58719796,"identity":"f9991840-d0e9-4bbf-af53-9e9350104328","added_by":"auto","created_at":"2024-06-20 08:46:12","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":36819,"visible":true,"origin":"","legend":"\u003cp\u003eThe (a, b, c, d) pH of the leachate and (e, f, g, h) cumulative Mo (% of added Mo) leached from columns at each leaching day from Ngarkat and Streaky Bay soils; (i) digested residual Mo in the soils after the leaching events. The table shows the micronutrients added to the treatments while the letters represent the treatments. Error bars present the standard error of the mean (n = 6)\u003c/p\u003e","description":"","filename":"image3.png","url":"https://assets-eu.researchsquare.com/files/rs-4457615/v1/c059d98950d3e3ecbd2dcd24.png"},{"id":58719799,"identity":"cf173bb4-d4bb-4d0f-8f9c-af0d0535bdc2","added_by":"auto","created_at":"2024-06-20 08:46:13","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":13699,"visible":true,"origin":"","legend":"\u003cp\u003e(a,b) Amount of Mo recovered in the leachate (expressed as a percentage of added) and (c,d) pH of the leachate for MAP or DAP alone (N), or co-compacted with soluble Mo and Zn sources (AMT treatment), non-treated oxides (C treatment) or mechanochemically treated oxides (MC treatment) in the pot experiment collected after 4 consecutive leaching events of one pore volume each (L1 to L4). Error bars present the standard error of the mean (n = 4). Different letters indicate statistical (P ≤ 0.05) differences between Mo treatments using a one-way ANOVA; Duncan's MRT.\u003c/p\u003e","description":"","filename":"image4.png","url":"https://assets-eu.researchsquare.com/files/rs-4457615/v1/f54bfd0b33d02c2c03d37b3b.png"},{"id":58719795,"identity":"f37774ae-d840-4dd6-ac01-c8eb39031b60","added_by":"auto","created_at":"2024-06-20 08:46:12","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":24178,"visible":true,"origin":"","legend":"\u003cp\u003e(a, d) Shoot and root dry matter yields, (b, e) Mo concentrations in the shoots and roots, and (c, f) Mo uptake in shoots and roots of chickpea in response to application of MAP, DAP alone (N) or co-compacted with soluble Mo and Zn sources (AMT treatment), non-treated oxides (C treatment) or mechanochemically treated oxides (MC treatment). Error bars present the standard error of the mean (n = 4). Different letters indicate significant differences between treatments for a given macronutrient carrier - capital letter assigned to MAP and small letter assigned to DAP. Significance of Mo treatments (Mo) and their interactions (Carriers × Mo) are indicated by asterisks above each figure (*P ≤ 0.05; **P ≤ 0.01; ***P ≤ 0.001; ns, not significant; using two-way ANOVA; Duncan's MRT).\u003c/p\u003e","description":"","filename":"image5.png","url":"https://assets-eu.researchsquare.com/files/rs-4457615/v1/81a3b74273f52b76f23ff8e8.png"},{"id":58719800,"identity":"9b505c8e-a367-4247-ae4b-1663c8eb4b81","added_by":"auto","created_at":"2024-06-20 08:46:21","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":877026,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4457615/v1/b8c304fd-faa3-437d-beba-722ca44cc460.pdf"},{"id":58719792,"identity":"70eaf61d-bc67-4f52-90e6-0b4e1d63d420","added_by":"auto","created_at":"2024-06-20 08:46:11","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":491028,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eAppendix A. Supplementary material\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"SupportingInformation.docx","url":"https://assets-eu.researchsquare.com/files/rs-4457615/v1/dd2c6c4730a198fa97d792d3.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Effect of mechanochemically modified MoO 3 -ZnO on Mo supply to plants when co-granulated with macronutrient fertilizers","fulltext":[{"header":"Introduction","content":"\u003cp\u003eMolybdenum (Mo) and zinc (Zn) are essential nutrients for plant growth (Kaiser et al., \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2005\u003c/span\u003e). The dominant soluble Mo species in the soil is MoO\u003csub\u003e4\u003c/sub\u003e\u003csup\u003e2\u0026minus;\u003c/sup\u003e (molybdate) and this anion is adsorbed by clay minerals and Fe and Al oxides in acid soils (Goldberg et al., \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e1996\u003c/span\u003e; Goldberg et al., \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2002\u003c/span\u003e). Unlike most other essential cationic micronutrients (e.g. Cu, Zn), Mo availability decreases with decreasing pH (Gustafsson and Tiberg, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2015\u003c/span\u003e). In acidic soils, liming usually rectifies Mo deficiency, as absorbed Mo is released into the soil solution (Anderson, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e1956\u003c/span\u003e; Walker et al., \u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e1955\u003c/span\u003e). However, in areas of high rainfall, Mo levels in soil may be low, due to losses through leaching and runoff (He et al., \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2005\u003c/span\u003e). Currently, soluble molybdates (Na\u003csub\u003e2\u003c/sub\u003eMoO\u003csub\u003e4\u003c/sub\u003e.2H\u003csub\u003e2\u003c/sub\u003eO and (NH\u003csub\u003e4\u003c/sub\u003e)\u003csub\u003e6\u003c/sub\u003eMo\u003csub\u003e7\u003c/sub\u003eO\u003csub\u003e24\u003c/sub\u003e.4H\u003csub\u003e2\u003c/sub\u003eO) are commonly used as Mo fertilizers. Few studies have examined the use of slow-release Mo sources in fertilizers. A 1960s study reports the use of a Mo glassy frit in a field experiment (Henkens and Smilde, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e1966\u003c/span\u003e) and found a greater residual effect on crop growth compared to a soluble Mo source. Bandyopadhyay et al. (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2008\u003c/span\u003e) proposed a Mo-containing long-chain magnesium sodium polyphosphate as a slow-release Mo fertilizer and found increased crop yield over the soluble Mo treatment in a field study. More recently, a layered double hydroxide (LDH) incorporated with Mo was proposed as a slow-release Mo fertilizer, with urea being a potential carrier to allow the slow-release character of the Mo source to be maintained (Everaert et al., \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2021\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eUntil now, Zn deficiency remains a global health problem. It affects more than 17% of the world\u0026rsquo;s population (Myers et al., \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e2015\u003c/span\u003e). Zinc fertilizers can be applied by themselves, incorporated with macronutrients or applied in foliar sprays (Montalvo et al., \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). Compared to separate soil or foliar applications, incorporating micronutrients with macronutrients is a more efficient way to reduce labor and spreading costs.\u003c/p\u003e \u003cp\u003eMechanochemistry is a green manufacturing method that has gained much attention in industrial synthesis for alloys, semiconductors, ceramics and pharmaceutical applications (Bal\u0026aacute;ž et al., \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; James et al., 2012). Recent mechanochemical approaches to fertilizer synthesis have mainly focused on macronutrient NPK fertilizers. Several studies have been carried out to incorporate NPK nutrients into an inorganic matrix such as a clay mineral or LDH (Borges et al., \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Lei et al., \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e2018\u003c/span\u003e; Tongamp et al., \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e2008\u003c/span\u003e; Zhang and Saito, \u003cspan citationid=\"CR58\" class=\"CitationRef\"\u003e2009\u003c/span\u003e). Recently, mechanochemical methods have been used to combine alkaline metal salts with urea in organic co-crystals to produce more stable N fertilizers with reduced volatilization losses (Casali et al., \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2018\u003c/span\u003e; Honer et al., \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Honer et al., \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Only one study reported the mechanochemical incorporation of metal or metalloid oxides in a fertilizer using a ball mill. Yuan et al. (\u003cspan citationid=\"CR54\" class=\"CitationRef\"\u003e2014\u003c/span\u003e) reported an amorphous glass phase of K-Si-Ca-O produced using CaO, SiO\u003csub\u003e2\u003c/sub\u003e, and KOH as reactants. The reactants were milled for 2 h and both the milling speed and the SiO\u003csub\u003e2\u003c/sub\u003e content were adjusted to achieve optimal results. The optimal SiO\u003csub\u003e2\u003c/sub\u003e content was chosen to perform a study of the K release rate versus the milling speed. They concluded that a slow-release K fertilizer can be obtained when the milling speed is above 300 rpm. Overall, few attempts have been made to synthesize micronutrient fertilizers using mechanochemistry (Li et al., \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Tang et al., \u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e2021\u003c/span\u003e) and most mechanochemically synthesized products have only been tested for water solubility to indicate their effectiveness as slow-release fertilizers. However, solubility tests are not a good indicator of agronomic efficiency in soil (Chien et al., 2011; Montalvo et al., \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). Therefore, it is crucial to assess newly synthesized fertilizers for their agronomic performance.\u003c/p\u003e \u003cp\u003eZinc oxide is one of the cheapest and high analysis sources of Zn widely used in the fertilizer industry. Zinc oxide has low water solubility and high chemical stability, but its effectiveness as a fertilizer depends largely on the application method, soil pH, and (if applicable) the macronutrient it is incorporated with (McBeath and McLaughlin, \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e2014\u003c/span\u003e). The efficiency of ZnO is similar or close to that of soluble Zn fertilizers such as ZnSO\u003csub\u003e4\u003c/sub\u003e when optimum application methods are selected (Hergert et al., \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e1984\u003c/span\u003e; McBeath and McLaughlin, \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e2014\u003c/span\u003e; Montalvo et al., \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e2016\u003c/span\u003e; Rehm et al., \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e1980\u003c/span\u003e). Molybdenum-doped ZnO and ZnMoO\u003csub\u003e4\u003c/sub\u003e have been synthesized by different chemical methods using ZnO and MoO\u003csub\u003e3\u003c/sub\u003e (Wang et al., \u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e2016\u003c/span\u003e; Wu et al., \u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e2015\u003c/span\u003e; Zhang et al., \u003cspan citationid=\"CR57\" class=\"CitationRef\"\u003e2015\u003c/span\u003e) and have drawn much attention in the materials engineering industry as semiconductors and photocatalysts (Yu et al., \u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e2012\u003c/span\u003e; Zhao et al., \u003cspan citationid=\"CR59\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Two of the products made were mechanochemically synthesized ZnO-MoO\u003csub\u003e3\u003c/sub\u003e (Zazhigalov et al., \u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e2016\u003c/span\u003e) and nickel molybdates (Klissurski et al., \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e2006\u003c/span\u003e). In other industries, mechanochemistry has been proposed to prepare complex metal oxides, doped metal oxide, and metal oxide nanoparticles as functional materials (Tsuzuki, \u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e2021\u003c/span\u003e; Zdujić et al., \u003cspan citationid=\"CR56\" class=\"CitationRef\"\u003e1992\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn this study, we aimed to incorporate Mo into the chemically stable ZnO structure or synthesize a new complex metal oxide using mechanochemistry. We hypothesized that mechanochemically synthesized ZnO-MoO\u003csub\u003e3\u003c/sub\u003e variants are stable compounds with slow-release characteristics that could be useful as slow-release micronutrient compounds in fertilizers. In addition to the formulation and characterization, the resulting products were thoroughly assessed by a) co-compacting Mo products into macronutrient fertilizers (muriate of potash - MOP, MAP and DAP); b) performing column leaching using two soils; and c) evaluating the effectiveness of the Mo-incorporated fertilizers in a plant uptake experiment with simulated leaching.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e1.1. Mechanochemical synthesis and characterisation\u003c/h2\u003e \u003cp\u003eZinc oxide (ZnO, 99.0% puriss) from Sigma-Aldrich (NSW, Australia), molybdenum oxide (VI) (MoO\u003csub\u003e3\u003c/sub\u003e, 99.5%) from Merck (VIC, Australia) and ammonium molybdate tetrahydrate ((NH\u003csub\u003e4\u003c/sub\u003e)\u003csub\u003e6\u003c/sub\u003eMo\u003csub\u003e7\u003c/sub\u003eO\u003csub\u003e24\u003c/sub\u003e\u0026middot;4H\u003csub\u003e2\u003c/sub\u003eO) from Chem-Supply (SA, Australia) were used as received.\u003c/p\u003e \u003cp\u003eDifferent amounts of (NH\u003csub\u003e4\u003c/sub\u003e)\u003csub\u003e6\u003c/sub\u003eMo\u003csub\u003e7\u003c/sub\u003eO\u003csub\u003e24\u003c/sub\u003e\u0026middot;4H\u003csub\u003e2\u003c/sub\u003eO (AMT) or MoO\u003csub\u003e3\u003c/sub\u003e were mixed with ZnO to obtain 3 g mixtures in total with Mo concentrations ranging from 1 to 36% as indicated in Table \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e (AMT samples) and Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e (MoO\u003csub\u003e3\u003c/sub\u003e samples). The mixtures were milled in a 50-ml zirconia jar with six zirconia balls (15 mm diameter and 10 g per ball) to achieve a ball-to-powder weight ratio of 20. Ball milling was carried out in a planetary mill (PM200, Retsch, Haan, Germany) for 8 h at a rotation speed of 550 rpm with a break of 5 min and a change of direction every 30 min to avoid overheating. The milled products were characterized by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. X-ray diffraction patterns of products and reactants were recorded with an X'Pert Pro multipurpose diffractometer (PANalytical B.V. Almelo, Netherlands) using Fe-filtered Co Kα radiation, automatic divergence slit, 2\u0026deg; anti-scatter slit, and fast X'Celerator Si strip detector. The diffraction patterns were recorded in steps of 0.017\u0026deg; 2-theta with a counting time of 0.5 s per step for an overall counting time of approximately 30 min. The relative amounts of the major phases were determined by the Rietveld method using the Bruker TOPAS software package (Bruker BioSpinCorporation, Billerica, MA, USA). Fourier transform infrared spectroscopy measurement was carried out using the attenuated total reflectance (ATR) module on an Alpha FT-IR spectrometer (Bruker Optics, Ettlingen, Germany). The analysis was performed in the middle infrared range (wavenumber from 4000 to 400 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) at a resolution of 4 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and corrected for an air background. The sample was mounted on a platinum platform and covered with a thin layer of foil paper. Each sample was scanned 100 times and the platform was cleaned with lint-free tissue and ethanol between treatments. The morphology of the synthesized products was imaged using field emission scanning electron microscopy (FE-SEM, Quanta 450, FEI, USA).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eThe mechanochemical treatments of MoO\u003csub\u003e3\u003c/sub\u003e and ZnO milled with different Zn:Mo ratios for 8 h.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTreatment\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMoO\u003csub\u003e3\u003c/sub\u003e (g)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eZnO (g)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMo (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eZn (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eZn:Mo\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e36% Mo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.64\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.36\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e36\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e36\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e10% Mo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2.55\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e68\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e6.8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e8% Mo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.36\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2.64\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e71\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e8.8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4% Mo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2.82\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e76\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e18.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2% Mo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2.91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e39.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1% Mo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2.95\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e79.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e1.2. Batch solubility, fertilizer manufacturing, and column dissolution\u003c/h2\u003e \u003cp\u003eBatch solubility tests were conducted to assess the solubility of the mechanochemically treated Mo-ZnO products from both AMT and MoO\u003csub\u003e3\u003c/sub\u003e (1, 2, 4, 8, 10 and 33/36% Mo). In addition, we also tested the 4% and 36% Mo-Control, which had the same MoO\u003csub\u003e3\u003c/sub\u003e-ZnO reactant mixture, but without ball milling. The solubility of the samples was evaluated by weighing 0.1 g of the sample in a 50 ml digestion tube with 10 ml of reverse osmosis (RO) water. Samples were shaken on an end-to-end shaker for 1 h followed by 10 min centrifugation at 4685 g and pH was determined. Samples were filtered through a 0.2-\u0026micro;m syringe filter before analysis. The sediment remaining in the centrifuge tubes was digested overnight at room temperature using \u003cem\u003eaqua regia\u003c/em\u003e (HNO\u003csub\u003e3\u003c/sub\u003e: HCl\u0026thinsp;=\u0026thinsp;1:3 v/v), followed by 45 min of heating at 80\u0026deg;C and 165 min of heating at 125\u0026deg;C in hot block digestion. All samples were analyzed by inductively coupled plasma-optical emission spectrometry (ICP-OES, Avio 200, Perkin Elmer, Waltham, USA) to determine the total content of soluble and insoluble Mo and Zn.\u003c/p\u003e \u003cp\u003eThe compaction of micronutrient and macronutrient fertilizer powders was carried out using a pellet press. The selected micronutrient samples were the compounds made using MoO\u003csub\u003e3\u003c/sub\u003e and ZnO with 4% or 36% Mo. Also, mixtures of MoO\u003csub\u003e3\u003c/sub\u003e and ZnO without mechanochemical treatment were included for comparison, as well as a mixture of AMT and ZnSO\u003csub\u003e4\u003c/sub\u003e\u0026middot;7H\u003csub\u003e2\u003c/sub\u003eO as a soluble reference treatment. Granules of MOP (muriate of potash, KCl), MAP (monoammonium phosphate) and DAP (diammonium phosphate) were ground, sieved (\u0026lt;\u0026thinsp;250 \u0026micro;m) and mixed with the Mo products (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e) before adding 1 ml of DI water to 5 g of mixed powder to form a paste. The paste was placed in a 4-cm diameter die and 9.8 MPa pressure was applied using a pellet press (Simplex 12HJ Templeton Kenlyand Co, IL, USA) to form a single pellet. The pellet was air-dried and cut into small pellets of similar size (2\u0026ndash;3 mm square) and weights (around 40 mg).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eThe amount of micronutrient compound added to macronutrient fertilizers with or without mechanochemical treatment.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eCompound\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eTheoretical (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eMC\u003csup\u003ea\u003c/sup\u003e treated\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMo\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eZn\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4% Mo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e3.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eControl 4% Mo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e3.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e36% Mo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eControl 36% Mo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAMT\u003csup\u003eb\u003c/sup\u003e and ZnSO\u003csub\u003e4\u003c/sub\u003e\u0026middot;7H\u003csub\u003e2\u003c/sub\u003eO\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e3.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003e\u003csup\u003ea\u003c/sup\u003e MC \u0026ndash; Mechanochemical\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003e\u003csup\u003eb\u003c/sup\u003e AMT - (NH\u003csub\u003e4\u003c/sub\u003e)\u003csub\u003e6\u003c/sub\u003eMo\u003csub\u003e7\u003c/sub\u003eO\u003csub\u003e24\u003c/sub\u003e\u0026middot;4H\u003csub\u003e2\u003c/sub\u003eO\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eRelease of Mo and Zn from these products was tested using the column perfusion method described by Baird et al. (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). This is a laboratory method that examines the dynamic release of nutrients from fertilizer formulations by continuously perfusing samples with a solution in real time. Previous studies have shown a good correlation between pot, leaching, and seedling toxicity experiments with this method (Abat et al., \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2015a\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003eb\u003c/span\u003e; da Silva et al., \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Pellet samples (0.2 g) were placed between 1 g of glass wool in each polypropylene column (150 mm long \u0026times; 15 mm diameter). The percolating solution (RO water) was introduced into the column from the bottom using a peristaltic pump at a constant rate of 10 ml h\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. The solutions released from the top of the column were collected every hour for 72 h using a fraction collector (SuperFracTM, Pharmacia, USA). At the end of the study, the residues, the glass wool and the solution remaining in each column were collected and dried in the oven at 90 \u0026deg; C until all the liquid vaporized. These residues were digested using hot \u003cem\u003eaqua regia\u003c/em\u003e, analyzed by ICP-OES, and added to all nutrients released over time to establish the total nutrient content of the sample. The nutrient release was expressed as a percentage of this total content. All column dissolutions were performed in duplicate.\u003c/p\u003e \u003cdiv id=\"Sec5\" class=\"Section3\"\u003e \u003ch2\u003e1.3. Leaching in soil\u003c/h2\u003e \u003cp\u003eA column leaching experiment was performed to examine the release of Mo from the fertilizers in an acid soil and in a calcareous soil, with both considered to have low to very low fertility (for soil properties see Table S2). The columns consisted of syringes (120 mm length, 15 mm diameter) that were filled with a layer of glass wool and 30 g of soil. Around 400 mg of fertilizer (circa 10 granules) was evenly distributed throughout the soil column. Treatments were DAP or MAP alone or cogranulated with the mechanochemically treated compound (MC), the non-treated MoO\u003csub\u003e3\u003c/sub\u003e-ZnO mixture (C) or the soluble Mo and Zn sources (AMT) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Deionized water was introduced to the column from the bottom to the top using a peristaltic pump at a constant rate. The soil was first saturated until no dry soil was observed; then 30 ml of deionized water was added to leach the column from the top on Day 1 and Day 3 followed by six leaching events with 20 ml of DI water every 2 or 3 days. After each leaching, the column was incubated at a constant temperature of 25\u0026deg; C. After the final leaching, the soil in each column was dried in the oven and further homogenized by grinding using a mortar and pestle. The soil was then subsampled and digested to determine total Mo concentrations. The collected and filtered leachate after each leaching and digested soil extract were analyzed using ICP-OES.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e1.4. Pot trial\u003c/h2\u003e \u003cp\u003eThe pot trial was conducted in a glasshouse using pure sand as a growth medium. The pure sand was used for pot trial due to low Mo plant uptake (below detection limits) in a preliminary study. Chickpea was selected due to the high demand for Mo by legumes. Plastic pots (120 mm diameter and 120 mm height) with a few layers of mesh placed at the bottom were filled with 1 kg of washed sand. For each pot, 5 granules (0.2 g of fertilizer treatments mentioned in the leaching study, containing around 0.4 mg Mo and 7.6 mg Zn), corresponding to 0.28 kg Mo ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e soil assuming a bulk density of 1.4 g cm\u003csup\u003e\u0026minus;\u0026thinsp;3\u003c/sup\u003e, were placed 4.5 cm equidistantly below the soil surface. Leaching was carried out two days later to allow the dissolution of the fertilizer before leaching. The initial water content of the sand, prior to leaching, was 4%. Treatments were randomized with 4 replicates of each treatment using a complete block design generated by GenStat 19th edition. The leaching procedure was performed with DI water. Each pot was leached four times with 350 ml (or a total of approximately 4 pore volumes) of water to mimic heavy rainfall events which could remove soluble Mo from the fertilizer and soil. The leachates of each pot were collected and filtered before the determination of solution pH and Mo concentrations by ICP analysis. After the leaching events, the pots were left in ambient conditions for 3 days before planting. The chickpea (anti-fungi treated) was germinated for 2 days in the dark at a constant temperature of 25\u0026deg; C. Germinated seeds (3 seeds per pot) were transplanted 2.5 cm below the soil surface and thinned to 1 after 2 weeks. All pots received 10 ml of basal nutrient solution 5 days after planting and every week during the growing period (7 times in total). Total amounts of nutrients supplied by the basal nutrient solution were 63 mg N kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 198 mg P kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 250 mg K kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e 90 mg Ca kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 150 mg S kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 15 mg Mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 5 mg Mn kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 5 mg Fe kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 0.5 mg Cu kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 0.05 mg B kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, and 0.05 mg Co kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. All pots were maintained at 50% field capacity by checking their weights every day and adding DI water as needed. Harvesting was carried out at flowering (stage R1) 7 weeks after planting. Plant shoots were cut 1 cm above the soil surface and roots were collected and washed with DI water. Both roots and shoots were oven dried for 72 h at 60\u0026deg; C for dry mass weight and further ground and digested before ICP analysis for Mo content.\u003c/p\u003e \u003cp\u003eFor statistical analysis, one-way and two-way ANOVA (analysis of variance) was used followed by Duncan's multiple range test (MRT) to check significant differences using GenStat (19th edition). Where needed, the data were log-transformed to homogenize variance.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results and discussion","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003e1.5. Solubility of mechanochemically treated Mo-ZnO and characteristics of materials\u003c/h2\u003e \u003cp\u003eThe measured total Mo content was close to the expected content for both AMT and MoO\u003csub\u003e3\u003c/sub\u003e treatments (Table S3). Molybdenum release was much higher for the AMT than for the MoO\u003csub\u003e3\u003c/sub\u003e treatments (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea). Molybdenum solubility increased with increasing Mo content for both MoO\u003csub\u003e3\u003c/sub\u003e and AMT treatments up to a Mo content of 10%, where all Mo was dissolved for the AMT treatment and \u0026sim;30% for the MoO\u003csub\u003e3\u003c/sub\u003e treatment. At the highest Mo content (33%), Mo in the AMT treatment was fully dissolved, while the solubility for the MoO\u003csub\u003e3\u003c/sub\u003e (36% Mo) treatment was lower than the treatment with 10% Mo. The 4% and 36% Mo control treatments (without mechanochemical processing) released more than twice the Mo compared to the mechanochemically treated samples. This is likely due to the formation of new compounds with higher Mo solubility in water. Given the high solubility of the AMT incorporated compounds, only compounds made with MoO\u003csub\u003e3\u003c/sub\u003e were further evaluated. The 4% Mo was selected because of its suitable Zn/Mo ratio for agronomic purposes (ratio similar to that of common Zn/Mo fertilizer rates) and the 36% Mo because newly formed compounds were found in this material (see below).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Taba\" border=\"1\"\u003e \u003ccolgroup cols=\"1\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe FTIR spectra of mechanochemically treated samples showed a different pattern compared to the reactants, ZnO and MoO\u003csub\u003e3\u003c/sub\u003e (Figs.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eb, d) as increased Mo content modified the peak intensity and position. The peak at 851 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e in the 2% Mo sample shifted to 899 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e at 4% Mo and split to a shoulder peak at 909 and 806/798 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e for the 8% and 10% formulations. The peaks at 851, 899 and 909 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e are likely ascribed to the Mo-O-Mo vibration of Mo\u003csup\u003e6+\u003c/sup\u003e in [MoO\u003csub\u003e4\u003c/sub\u003e] clusters (Chen et al., \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2010\u003c/span\u003e). The observed shoulder peaks observed in the 8 and 10% Mo at 806 and 789 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e could be assigned to antisymmetric stretching of Mo-O (Yadav and Sinha, \u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Characteristic peaks of MoO\u003csub\u003e3\u003c/sub\u003e (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ed) and Zn-O-Mo (1100\u0026ndash;1400 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) were not observed in the 2%-10% Mo samples (Yu et al., \u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). The FTIR spectra of the 36% Mo sample are in line with the FTIR spectra of ZnMoO\u003csub\u003e4\u003c/sub\u003e reported in an earlier study (Yadav and Sinha, \u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). It can be concluded that the chemical structure of the reactants has changed after ball milling.\u003c/p\u003e \u003cp\u003eChanges in the XRD patterns with increased milling time further support differences in chemical structure observed with FTIR. The six clear peaks in the samples incorporated with 2\u0026ndash;10% MoO\u003csub\u003e3\u003c/sub\u003e could be assigned to the wurtzite phase of ZnO (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ec), but they were broader than in the control samples (Yu et al., \u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). In the control sample, the peaks assigned to MoO\u003csub\u003e3\u003c/sub\u003e were clearly visible even at lower Mo content (Figure S2a), but these peaks completely disappeared in the mechanochemically treated samples with 2\u0026ndash;10% Mo (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ec). However, a broad bump was observed around 2 theta\u0026thinsp;=\u0026thinsp;31 \u0026deg; when the percentage of Mo increased to 8% which was in line with the FTIR results where the shoulder peaks (between 800\u0026ndash;900 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) appeared. This could be due to an increase in the Mo concentration that indicated reduction of inter-planar \u0026ldquo;d\u0026rdquo; spacing in the sample (Ali et al., \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). When the Mo content increased to 36%, in addition to the identifiable ZnO peaks and minor peaks assigned to MoO\u003csub\u003e3\u003c/sub\u003e (Figure S2b), many new peaks assigned to several zinc molybdates and zinc molybdenum oxide were observed (Figure S2b) (Wang et al., \u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). A calculation using the Scherrer equation confirmed the decrease of crystallite size to approximately 1.5 to 2.0 nm for low Mo concentration samples after mechanochemical treatment (data not shown) (Patterson, \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e1939\u003c/span\u003e). Therefore, the much smaller crystallite size of ZnO obtained after MC treatment with MoO\u003csub\u003e3\u003c/sub\u003e was likely due to smaller Mo\u003csup\u003e6+\u003c/sup\u003e (0.065 nm) doped into and replacing Zn\u003csup\u003e2+\u003c/sup\u003e in the ZnO structure, thus suppressing the growth of ZnO crystals (Yu et al., \u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). Overall, these results indicate that the mechanochemically treated samples at a low Mo inclusion rate successfully penetrated the wurtzite crystalline lattice of ZnO, particularly at 2 and 4% Mo, where no impurity peaks were observed (Umar et al., \u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e2015\u003c/span\u003e), while the crystal structure changed at the highest 36% Mo rate as a result of new compound formation.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003e1.6. Column dissolution of Mo compacted with MAP, MOP, and DAP\u003c/h3\u003e\n\u003cp\u003eAll pelletized samples were macronutrient fertilizers containing a final Mo concentration of 0.2% as indicated in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. Both macronutrients (K and P) were quickly released from the formulations and no difference in the macronutrient release was observed between Mo treatments (Figures S3a, c). Total Mo released from DAP and MAP was twice as high in the treatments with the 36% Mo compounds, reaching 80% and 70% respectively compared to those with the 4% Mo compounds (Figs.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ea, b). The Mo release for the 4% Mo treatments was half that of the 4% Mo-Control for both the MAP and DAP treatments. The Mo release from MAP\u0026thinsp;+\u0026thinsp;4% Mo was slow and constant, while in DAP\u0026thinsp;+\u0026thinsp;4% Mo, a dual release was observed where the release was fast in the initial 10 h (39%), followed by a minor release (3%) in the following 62 h. In the MOP treatments, more than 80% of the total Mo was released after 72 h of dissolution. Total Zn release was negligible in most treatments (\u0026lt;\u0026thinsp;6%) over 72 h, except for MOP\u0026thinsp;+\u0026thinsp;36% Mo and MAP\u0026thinsp;+\u0026thinsp;36% Mo where 70% and 18% of the total Zn was released, respectively. The lower percentage release of Zn in the 4% Mo treatments was likely due to (i) the 36% Mo treatments containing ZnMoO\u003csub\u003e4\u003c/sub\u003e had a much higher Zn solubility compared to ZnO, and a faster rate of Zn release; (ii) the higher ZnO content of the 4% Mo treatments had higher absolute amount of Zn. Overall, the column dissolution indicated that the DAP\u0026thinsp;+\u0026thinsp;4% Mo and MAP\u0026thinsp;+\u0026thinsp;4% Mo behaved as slow-release Mo Fertilizers. Leaching in soil and a pot trial were performed to further evaluate the agronomic effectiveness of these two treatments.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003e1.7. Molybdenum leaching from fertilizers in soils\u003c/h2\u003e \u003cp\u003eLeaching of Mo was assessed in two contrasting soils. For all treatments, Mo incorporated with DAP had higher Mo leaching compared to MAP (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). When Mo sources were applied with MAP, the lowest Mo leaching was observed in AMT and MC treatments in both soils, both circa half that of the C treatment. The leached Mo from C was 66% in Ngarkat soil and 93% in Streaky Bay soil at the end of incubation (Figs.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ee, f). When Mo sources were applied with DAP, the Mo release was lowest with MC treated products (Figs.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eg, h). Molybdenum leached from MC treatments was approximately 20% lower in Ngarkat soil and 40% in Streaky Bay soil compared to C and AMT treatments. The Mo leached over time in both soils followed the same trend as the pH changes, with an increase in Mo leaching as the pH of the leachate increased (Figs.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ea-d). Molybdenum recovery in the soil corresponded well with the leaching results except for C with DAP in the Ngarkat soil, where no residue was recovered, despite incomplete leaching. This may have been due to heterogeneity of the soil sample or residues remaining attached to the glass wool. The amount of retained Mo in the soil after leaching was higher for the MC treatments than the other treatments, except with MAP in the Ngarkat soil where AMT and MC retained a similar amount (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ei). For the C treatment, Mo in the soil was detected only in Ngarkat soil with MAP as the carrier.\u003c/p\u003e \u003cp\u003eOverall, Mo release was affected by the soil, most likely due to differences in the soil pH (Riley et al., \u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e1987\u003c/span\u003e). Most treatments had lower Mo recovery in the alkaline Streaky Bay soil than in the neutral Ngarkat soil except for MC\u0026thinsp;+\u0026thinsp;DAP. This is consistent with the theory that typical well-drained, near-neutral sandy soils or calcareous soils with organic matter less than 50 g kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e tend to retain little Mo (Goldberg and Forster, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e1998\u003c/span\u003e; O'Connor et al., \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e2001\u003c/span\u003e). Moreover, the Mo release from the pellet is also largely affected by the pH induced by the macronutrient carrier. With the same Mo source and soil, the Mo release was higher for DAP compared to MAP due to the higher solution pH around DAP granules, except for C treatments where most of the Mo leached out within the first 3 days in the Streaky Bay soil. Due to the lower pH of the leachate in AMT compared to C, the leached Mo was higher for C in all treatments, except the DAP treatments applied in the Streaky Bay soil, where most Mo leached out by Day 3. Interestingly, the MC and C treatments had a similar pH in the leachate over the 6 leaching events, while the release of Mo was 20\u0026ndash;50% lower for MC compared to C treatments regardless of the soil and carrier. The results, therefore, suggest that the MC treatments might be less affected by soil pH compared to the C and AMT treatments.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003e1.8. Pot Trail\u003c/h2\u003e \u003cp\u003eMore Mo was leached from DAP treatments than from the MAP treatments (Figs.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ea, b). The highest recovery of Mo in the leachate was observed in the DAP treatment with C, for which more than 70% of added Mo was found in the leachate (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eb), while only 13% was leached for the corresponding treatment with MAP (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ea). The lowest Mo recovery in leachate was observed in the MAP\u0026thinsp;+\u0026thinsp;MC treatment (5%). With DAP as the carrier, the Mo recovery from the MC treatment reached 39% in the leachate. The AMT treatments behaved similarly for both MAP and DAP fertilizers, with 17\u0026ndash;25% of the added Mo leached after 4 leaching events. Surprisingly, the Mo leaching from the soluble AMT treatment was lower than that of the MC treatment for DAP (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ed). This can perhaps be explained by the lower leachate pH for the AMT treatment than for the MC treatment. Furthermore, the pH of leachates was higher for DAP than for MAP across all treatments (Figs.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ec, d). In agreement with column leaching, the recovery of Mo in the leachate was closely associated with the pH of the leachate. Leaching of Zn was observed only in the AMT treatment with MAP as the carrier (Figure S4a). Despite the use of soluble ZnSO\u003csub\u003e4\u003c/sub\u003e\u0026middot;7H\u003csub\u003e2\u003c/sub\u003eO in the AMT treatment, leaching of Zn from the sandy medium for the AMT treatment with DAP was low, likely due to precipitation of Zn with P compounds under the higher pH environment, such as NH\u003csub\u003e4\u003c/sub\u003eZnPO\u003csub\u003e4\u003c/sub\u003e and hopeite (Zn\u003csub\u003e3\u003c/sub\u003e(PO\u003csub\u003e4\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e\u0026middot;4H\u003csub\u003e2\u003c/sub\u003eO) (Milani et al., \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e2012\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe shoot and root dry weights were significantly lower in the DAP\u0026thinsp;+\u0026thinsp;AMT treatment than in the treatment with DAP alone and the shoot dry weight of DAP\u0026thinsp;+\u0026thinsp;MC was significantly higher than the treatment with DAP alone (Figs.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ea, d). The lower yield for the DAP\u0026thinsp;+\u0026thinsp;AMT treatment may have been due to dissolved Zn\u003csup\u003e2+\u003c/sup\u003e from ZnSO\u003csub\u003e4\u003c/sub\u003e\u0026middot;7H\u003csub\u003e2\u003c/sub\u003eO causing toxicity (Kaur and Garg, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2021\u003c/span\u003e) as the sand had no or minimal cation exchange capacity. In the MAP treatments, there were no significant differences in yield between the treatments (Figs.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ea, d).\u003c/p\u003e \u003cp\u003eFor both macronutrient carriers, the effect of Mo addition on Mo concentration and uptake was much higher in the root than in the shoot (Figs.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003eb, c, e and f). The highest shoot Mo concentrations were observed in MAP/DAP\u0026thinsp;+\u0026thinsp;MC and MAP\u0026thinsp;+\u0026thinsp;C treatments (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003eb). The small but detectable Mo shoot concentrations in the N treatments were likely derived from the chickpea seed itself as the pure sand did not contain a detectable amount of Mo. Concentrations of Mo in roots were highest for AMT and MC in the DAP treatments, and highest for MC and C in the MAP treatments (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ee). The Mo uptake in roots and shoots followed the order MC\u0026thinsp;\u0026gt;\u0026thinsp;C\u0026thinsp;=\u0026thinsp;AMT\u0026ge;N when DAP was the carrier and MC\u0026thinsp;=\u0026thinsp;C\u0026thinsp;\u0026gt;\u0026thinsp;AMT\u0026thinsp;\u0026gt;\u0026thinsp;N when MAP was the carrier (Figs.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ec, f). The lower Mo uptake observed for the MAP\u0026thinsp;+\u0026thinsp;AMT treatment compared to the other Mo treatments was likely due to both AMT and zinc sulphate fertilizer acidifying the sand solution around roots, thus reducing Mo uptake (Gammon Jr et al., \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e1954\u003c/span\u003e). This is supported by the leaching results where AMT treatments had much lower pH than the control and other Mo-added treatments (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ec). Moreover, the pure sand had a very low soil cation exchange capacity, thus the decreased soil pH will also have increased Zn bioavailability and further caused plant phytotoxicity.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe availability of Mo is controlled by the pH of the soil solution. Many studies have concluded that liming along with Mo application can promote Mo availability and improve Mo uptake by plants (Hagstrom and Berger, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e1963\u003c/span\u003e; McBride and Cherney, \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2004\u003c/span\u003e). In soil, Mo movement or leaching is mainly affected by soil pH. Johansen et al. (\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e1977\u003c/span\u003e) conducted a field trial on tropical pasture legumes using MoO\u003csub\u003e3\u003c/sub\u003e and sodium molybdate and reached a similar conclusion that soil pH influences Mo movement. Furthermore, they also concluded that there was no difference in residual effects on legume growth between the two Mo sources they applied. So in our study, plant uptake of Mo was likely affected by the pH of both the macronutrient carrier and the soil solution, as well as the solubility of the Mo source.\u003c/p\u003e \u003cp\u003eOverall, the MC treatment resulted in slower Mo release and protected Mo against leaching, resulting in higher uptake than for the control (without MC treatment) when DAP was the carrier. There was no significant difference in plant uptake between the MC and control treatment when MAP was the carrier, likely because there was less Mo leaching with MAP for all the treatments (due to the lower pH induced by MAP). However, our experiments were carried out at high fertilizer rates (columns) or with a pure sand (pot trial). In field soils with higher pH buffering capacity, the fertilizer carrier would likely have less effect on soil pH and there would be less chance of Zn toxicity with more soluble treatments (e.g. AMT). Further work is therefore recommended to compare these fertilizer sources in soil systems.\u003c/p\u003e \u003c/div\u003e"},{"header":"Conclusions","content":"\u003cp\u003eThe MC synthesized Mo-Zn fertilizer was found to be less prone to leaching than currently used Mo sources (MoO\u003csub\u003e3\u003c/sub\u003e and (NH\u003csub\u003e4\u003c/sub\u003e)\u003csub\u003e6\u003c/sub\u003eMo\u003csub\u003e7\u003c/sub\u003eO\u003csub\u003e24\u003c/sub\u003e\u0026middot;4H\u003csub\u003e2\u003c/sub\u003eO). In addition, the lower leaching loss was found to result in higher Mo uptake compared to a non-treated control when DAP was the fertilizer carrier. Therefore, the mechanochemically synthesized Mo-Zn fertilizer has promise as a slow release fertilizer for application in high rainfall areas, light textured soils and/or soils with high pH. The MC method used in this study did not require water or solvent and did not produce any waste streams. To promote this green synthesis method, agronomic comparisons with conventional fertilizers are essential. This study demonstrated the importance of agronomically assessing new fertilizers, especially when examining micronutrients, as micronutrients are required in only small amounts and their availability is more likely to be affected by other nutrients applied at the same time. Informed selection of macronutrient carriers can greatly change the effectiveness of applied micronutrients. However, pot trials cannot guarantee performance in all agronomic situations. The soils used in this study were sandy with a low ability to adsorb Mo, unlike heavier soils where Mo fixation might become a dominant parameter affecting plant Mo uptake. So, further pot and field trials with different soils and climates are required to further evaluate the effectiveness of these synthesized products.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eMC\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003emechanochemistry\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eDAP\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ediammonium phosphate\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eMAP\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003emonoammonium phosphate\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eLDH\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003elayered double hydroxide\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eAMT\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003e(NH\u003csub\u003e4\u003c/sub\u003e)\u003csub\u003e6\u003c/sub\u003eMo\u003csub\u003e7\u003c/sub\u003eO\u003csub\u003e24\u003c/sub\u003e\u0026middot;4H\u003csub\u003e2\u003c/sub\u003eO\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eXRD\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eX-ray diffraction\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eFTIR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003efourier transform infrared\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eFE-SEM\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003efield emission scanning electron microscopy\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eICP-OES\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003einductively coupled plasma-optical emission spectrometry\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthorship\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;BZ, FD, IBA, RB, and MJM contributed to the study conception and design \u0026nbsp;Material preparation, setting up the trial and data collection was performed by BZ\u0026nbsp;The first draft of the manuscript was written by BZ and all authors commended on previous versions of the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDeclaration of competing interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eBo Zheng is grateful for the scholarship and support from The University of Adelaide, School of Agriculture, Food and Wine. We thank the help and support from Adelaide Microscopy and Ken Neubauer for SEM analysis. The authors acknowledge the support of The Mosaic Company LLC. The authors thank Bogumila Tomczak, Ashleigh Panagaris and Andrea Paparella for their advice and technical support.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAbat, M., Degryse, F., Baird, R., McLaughlin, M.J., 2015a. Boron Phosphates (BPO\u003csub\u003e4\u003c/sub\u003e) as a Seedling-safe Boron Fertilizer Source. Plant and Soil 391(1), 153\u0026ndash;160. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s11104-015-2424-6\u003c/span\u003e\u003cspan address=\"10.1007/s11104-015-2424-6\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAbat, M., Degryse, F., Baird, R., McLaughlin, M.J., 2015b. Responses of Canola to the Application of Slow-Release Boron Fertilizers and Their Residual Effect. Soil Science Society of America Journal 79(1), 97\u0026ndash;103. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.2136/sssaj2014.07.0280\u003c/span\u003e\u003cspan address=\"10.2136/sssaj2014.07.0280\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAli, A., Ammar, M., Ali, M., Yahya, Z., Javaid, M.Y., Hassan, S.u., Ahmed, T., 2019. Mo-doped ZnO Nanoflakes on Ni-foam for Asymmetric Supercapacitor Applications. RSC Advances 9(47), 27432\u0026ndash;27438. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1039/C9RA05051E\u003c/span\u003e\u003cspan address=\"10.1039/C9RA05051E\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAmirkhanlou, S., Ketabchi, M., Parvin, N., 2012. Nanocrystalline/Nanoparticle ZnO Synthesized by High Energy Ball Milling Process. Materials Letters 86, 122\u0026ndash;124. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.matlet.2012.07.041\u003c/span\u003e\u003cspan address=\"10.1016/j.matlet.2012.07.041\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAnderson, A.J., 1956. Molybdenum as a Fertilizer, in: Norman, A.G. (Ed.) Advances in Agronomy. Academic Press, pp. 163\u0026ndash;202. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/S0065-2113(08)60689-6\u003c/span\u003e\u003cspan address=\"10.1016/S0065-2113(08)60689-6\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBaird, R., da Silva, R.C., Degryse, F., McLaughlin, M.J., 2019. A Column Perfusion Test to Assess the Kinetics of Nutrient Release by Soluble, Sparingly Soluble and Coated Granular Fertilizers. Journal of Plant Nutrition and Soil Science 0(0). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1002/jpln.201800666\u003c/span\u003e\u003cspan address=\"10.1002/jpln.201800666\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBal\u0026aacute;ž, P., Achimovičov\u0026aacute;, M., Bal\u0026aacute;ž, M., Billik, P., Cherkezova-Zheleva, Z., Criado, J.M., Delogu, F., Dutkov\u0026aacute;, E., Gaffet, E., Gotor, F.J., Kumar, R., Mitov, I., Rojac, T., Senna, M., Streletskii, A., Wieczorek-Ciurowa, K., 2013. Hallmarks of Mechanochemistry: from Nanoparticles to Technology. Chemical Society Reviews 42(18), 7571\u0026ndash;7637. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1039/C3CS35468G\u003c/span\u003e\u003cspan address=\"10.1039/C3CS35468G\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBandyopadhyay, S., Bhattacharya, I., Ghosh, K., Varadachari, C., 2008. New Slow-Releasing Molybdenum Fertilizer. Journal of Agricultural and Food Chemistry 56(4), 1343\u0026ndash;1349. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/jf072878g\u003c/span\u003e\u003cspan address=\"10.1021/jf072878g\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBorges, R., Prevot, V., Forano, C., Wypych, F., 2017. Design and Kinetic Study of Sustainable Potential Slow-Release Fertilizer Obtained by Mechanochemical Activation of Clay Minerals and Potassium Monohydrogen Phosphate. Industrial and Engineering Chemistry Research 56(3), 708\u0026ndash;716. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/acs.iecr.6b04378\u003c/span\u003e\u003cspan address=\"10.1021/acs.iecr.6b04378\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCasali, L., Mazzei, L., Shemchuk, O., Honer, K., Grepioni, F., Ciurli, S., Braga, D., Baltrusaitis, J., 2018. Smart Urea Ionic Co-crystals with Enhanced Urease Inhibition Activity for Improved Nitrogen Cycle Management. Chemical Communications 54(55), 7637\u0026ndash;7640. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1039/C8CC03777A\u003c/span\u003e\u003cspan address=\"10.1039/C8CC03777A\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCasali, L., Mazzei, L., Shemchuk, O., Sharma, L., Honer, K., Grepioni, F., Ciurli, S., Braga, D., Baltrusaitis, J., 2019. Novel Dual-Action Plant Fertilizer and Urease Inhibitor: Urea\u0026middot;Catechol Cocrystal. Characterization and Environmental Reactivity. ACS Sustainable Chemistry and Engineering 7(2), 2852\u0026ndash;2859. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/acssuschemeng.8b06293\u003c/span\u003e\u003cspan address=\"10.1021/acssuschemeng.8b06293\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChen, Y., Lu, C., Xu, L., Ma, Y., Hou, W., Zhu, J.-J., 2010. Single-crystalline Orthorhombic Molybdenum Oxide Nanobelts: Synthesis and Photocatalytic Properties. CrystEngComm 12(11), 3740\u0026ndash;3747. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1039/C000744G\u003c/span\u003e\u003cspan address=\"10.1039/C000744G\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eda Silva, R., Baird, R., Degryse, F., McLaughlin, M.J., 2018. Slow and Fast-Release Boron Sources in Potash Fertilizers: Spatial Variability, Nutrient Dissolution and Plant Uptake. Soil Science Society of America Journal 82(6), 1437\u0026ndash;1448. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.2136/sssaj2018.02.0065\u003c/span\u003e\u003cspan address=\"10.2136/sssaj2018.02.0065\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEveraert, M., Smolders, E., McLaughlin, M.J., Andelkovic, I., Smolders, S., Degryse, F., 2021. Layered Double Hydroxides as Slow-Release Fertilizer Compounds for the Micronutrient Molybdenum. Journal of Agricultural and Food Chemistry 69(48), 14501\u0026ndash;14511. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/acs.jafc.1c06056\u003c/span\u003e\u003cspan address=\"10.1021/acs.jafc.1c06056\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGammon Jr, N., Volk, G.M., McCubbin, E.N., Eddins, A.H., 1954. Soil Factors Affecting Molybdenum Uptake by Cauliflower. Soil Science Society of America Journal 18(3), 302\u0026ndash;305. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.2136/sssaj1954.03615995001800030018x\u003c/span\u003e\u003cspan address=\"10.2136/sssaj1954.03615995001800030018x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGlushenkov, A.M., Zhang, H.Z., Chen, Y., 2008. Reactive Ball Milling to Produce Nanocrystalline ZnO. Materials Letters 62(24), 4047\u0026ndash;4049. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.matlet.2008.06.002\u003c/span\u003e\u003cspan address=\"10.1016/j.matlet.2008.06.002\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGoldberg, S., Forster, H.S., 1998. Factors Affecting Molybdenum Adsorption by Soils and Minerals. Soil Science 163(2).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGoldberg, S., Forster, H.S., Godfrey, C.L., 1996. Molybdenum Adsorption on Oxides, Clay Minerals, and Soils. Soil Science Society of America Journal 60(2), 425\u0026ndash;432. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.2136/sssaj1996.03615995006000020013x\u003c/span\u003e\u003cspan address=\"10.2136/sssaj1996.03615995006000020013x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGoldberg, S., Lesch, S.M., Suarez, D.L., 2002. Predicting Molybdenum Adsorption by Soils Using Soil Chemical Parameters in the Constant Capacitance Model. Soil Science Society of America Journal 66(6), 1836\u0026ndash;1842. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.2136/sssaj2002.1836\u003c/span\u003e\u003cspan address=\"10.2136/sssaj2002.1836\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGustafsson, J.P., Tiberg, C., 2015. Molybdenum Binding to Soil Constituents in Acid Soils: An XAS and Modelling Study. Chemical Geology 417, 279\u0026ndash;288. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.chemgeo.2015.10.016\u003c/span\u003e\u003cspan address=\"10.1016/j.chemgeo.2015.10.016\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHagstrom, G.R., Berger, K.C., 1963. Molybdenum Status of Three Wisconsin Soils and Its Effect on Four Legume Crops1. Agronomy Journal 55(4), 399\u0026ndash;401. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.2134/agronj1963.00021962005500040031x\u003c/span\u003e\u003cspan address=\"10.2134/agronj1963.00021962005500040031x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHe, Z.L., Yang, X.E., Stoffella, P.J., 2005. Trace Elements in Agroecosystems and Impacts on the Environment. Journal of Trace Elements in Medicine and Biology 19(2), 125\u0026ndash;140. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.jtemb.2005.02.010\u003c/span\u003e\u003cspan address=\"10.1016/j.jtemb.2005.02.010\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHenkens, C.H., Smilde, K.W., 1966. Evaluation of Glassy Frits as Micronutrient Fertilizers. 1. Copper and Molybdenum Frits. Netherlands Journal of Agricultural Science 14, 165\u0026ndash;177.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHergert, G.W., Rehm, G.W., Wiese, R.A., 1984. Field Evaluations of Zinc Sources Band Applied in Ammonium Polyphosphate Suspension. Soil Science Society of America Journal 48(5), 1190\u0026ndash;1193. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.2136/sssaj1984.03615995004800050048x\u003c/span\u003e\u003cspan address=\"10.2136/sssaj1984.03615995004800050048x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHoner, K., Kalfaoglu, E., Pico, C., McCann, J., Baltrusaitis, J., 2017. Mechanosynthesis of Magnesium and Calcium Salt\u0026ndash;Urea Ionic Cocrystal Fertilizer Materials for Improved Nitrogen Management. ACS Sustainable Chemistry and Engineering 5(10), 8546\u0026ndash;8550. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/acssuschemeng.7b02621\u003c/span\u003e\u003cspan address=\"10.1021/acssuschemeng.7b02621\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHoner, K., Pico, C., Baltrusaitis, J., 2018. Reactive Mechanosynthesis of Urea Ionic Cocrystal Fertilizer Materials from Abundant Low Solubility Magnesium- and Calcium-Containing Minerals. ACS Sustainable Chemistry and Engineering 6(4), 4680\u0026ndash;4687. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/acssuschemeng.7b03766\u003c/span\u003e\u003cspan address=\"10.1021/acssuschemeng.7b03766\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJames, S.L., Adams, C.J., Bolm, C., Braga, D., Collier, P., Friščić, T., Grepioni, F., Harris, K.D.M., Hyett, G., Jones, W., others, 2012. Mechanochemistry: Opportunities for New and Cleaner Synthesis. Chemical Society Reviews 41(1), 413\u0026ndash;447. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1039/C1CS15171A\u003c/span\u003e\u003cspan address=\"10.1039/C1CS15171A\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJohansen, C., Kerridge, P.C., Luck, P.E., Cook, B.G., Lowe, K.F., Ostrowski, H., 1977. The Residual Effect of Molybdenum Fertilizer on Growth of Tropical Pasture Legumes in a Sub-tropical Environment. Australian Journal of Experimental Agriculture 17(89), 961\u0026ndash;968.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKaiser, B.N., Gridley, K.L., Ngaire Brady, J., Phillips, T., Tyerman, S.D., 2005. The Role of Molybdenum in Agricultural Plant Production. Ann Bot 96(5), 745\u0026ndash;754. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1093/aob/mci226\u003c/span\u003e\u003cspan address=\"10.1093/aob/mci226\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKaur, H., Garg, N., 2021. Zinc Toxicity in Plants: A Review. Planta 253(6), 129. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s00425-021-03642-z\u003c/span\u003e\u003cspan address=\"10.1007/s00425-021-03642-z\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKlissurski, D., Mancheva, M., Iordanova, R., Tyuliev, G., Kunev, B., 2006. Mechanochemical synthesis of nanocrystalline nickel molybdates. Journal of Alloys and Compounds 422(1), 53\u0026ndash;57. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jallcom.2005.11.073\u003c/span\u003e\u003cspan address=\"10.1016/j.jallcom.2005.11.073\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLei, Z., Cagnetta, G., Li, X., Qu, J., Li, Z., Zhang, Q., Huang, J., 2018. Enhanced Adsorption of Potassium Nitrate with Potassium Cation on H\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e Modified Kaolinite and Nitrate Anion into Mg-Al Layered Double Hydroxide. Applied Clay Science 154, 10\u0026ndash;16. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.clay.2017.12.040\u003c/span\u003e\u003cspan address=\"10.1016/j.clay.2017.12.040\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi, X., Lei, Z., Qu, J., Li, Z., Zhou, X., Zhang, Q., 2017. Synthesizing Slow-release Fertilizers via Mechanochemical Processing for Potentially Recycling the Waste Ferrous Sulfate from Titanium Dioxide Production. Journal of Environmental Management 186, 120\u0026ndash;126. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.jenvman.2016.10.058\u003c/span\u003e\u003cspan address=\"10.1016/j.jenvman.2016.10.058\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMcBeath, T.M., McLaughlin, M.J., 2014. Efficacy of Zinc Oxides as Fertilisers. Plant and Soil 374(1), 843\u0026ndash;855. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s11104-013-1919-2\u003c/span\u003e\u003cspan address=\"10.1007/s11104-013-1919-2\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMcBride, M.B., Cherney, J., 2004. Molybdenum, Sulfur, and Other Trace Elements in Farm Soils and Forages After Sewage Sludge Application. Communications in Soil Science and Plant Analysis 35(3\u0026ndash;4), 517\u0026ndash;535. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1081/CSS-120029729\u003c/span\u003e\u003cspan address=\"10.1081/CSS-120029729\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMilani, N., McLaughlin, M.J., Stacey, S.P., Kirby, J.K., Hettiarachchi, G.M., Beak, D.G., Cornelis, G., 2012. Dissolution Kinetics of Macronutrient Fertilizers Coated with Manufactured Zinc Oxide Nanoparticles. Journal of Agricultural and Food Chemistry 60(16), 3991\u0026ndash;3998. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/jf205191y\u003c/span\u003e\u003cspan address=\"10.1021/jf205191y\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMontalvo, D., Degryse, F., da Silva, R.C., Baird, R., McLaughlin, M.J., 2016. Chapter Five - Agronomic Effectiveness of Zinc Sources as Micronutrient Fertilizer, in: Sparks, D.L. (Ed.) Advances in Agronomy. Academic Press, pp. 215\u0026ndash;267. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/bs.agron.2016.05.004\u003c/span\u003e\u003cspan address=\"10.1016/bs.agron.2016.05.004\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMyers, S.S., Wessells, K.R., Kloog, I., Zanobetti, A., Schwartz, J., 2015. Effect of Increased Concentrations of Atmospheric Carbon Dioxide on the Global Threat of Zinc Deficiency: a Modelling Study. The Lancet. Global health 3(10), e639-645. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/s2214-109x(15)00093\u0026thinsp;\u0026ndash;\u0026thinsp;5\u003c/span\u003e\u003cspan address=\"10.1016/s2214-109x(15)00093\u0026thinsp;\u0026ndash;\u0026thinsp;5\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eO'Connor, G.A., Brobst, R.B., Chaney, R.L., Kincaid, R.L., McDowell, L.R., Pierzynski, G.M., Rubin, A., Van Riper, G.G., 2001. A Modified Risk Assessment to Establish Molybdenum Standards for Land Application of Biosolids. Journal of Environmental Quality 30(5), 1490\u0026ndash;1507. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.2134/jeq2001.3051490x\u003c/span\u003e\u003cspan address=\"10.2134/jeq2001.3051490x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePatterson, A.L., 1939. The Scherrer Formula for X-Ray Particle Size Determination. Physical Review 56(10), 978\u0026ndash;982. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1103/PhysRev.56.978\u003c/span\u003e\u003cspan address=\"10.1103/PhysRev.56.978\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRebafka, F.P., Ndunguru, B.J., Marschner, H., 1993. Single Superphosphate Depresses Molybdenum Uptake and Limits Yield Response to Phosphorus in Groundnut (Arachis hypogaea L.) Grown on an Acid Sandy Soil in Niger, West Africa. Fertilizer Research 34(3), 233\u0026ndash;242. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/BF00750569\u003c/span\u003e\u003cspan address=\"10.1007/BF00750569\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRehm, G.W., Wiese, R.A., Hergert, G.W., 1980. Response of Corn To Zinc Source and Rate of Zinc Band Applied with Either Orthophosphate or Polyphosphate. Soil Science 129(1).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRiley, M.M., Robson, A.D., Gartrell, J.W., Jeffery, R.C., 1987. The Absence of Leaching of Molybdenum in Acidic Soils from Western Australia. Soil Research 25(2), 179\u0026ndash;184.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTang, Y., Yang, Y., Hou, S., Cheng, D., Yao, Y., Zhang, S., Xie, J., Wang, X., Ma, X., Yu, Z., Li, S., 2021. Multifunctional Iron\u0026ndash;Humic Acid Fertilizer from Ball Milling Double-Shelled Fe\u0026ndash;N-doped Hollow Mesoporous Carbon Microspheres with Lignite. ACS Sustainable Chemistry and Engineering 9(2), 717\u0026ndash;731. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/acssuschemeng.0c06406\u003c/span\u003e\u003cspan address=\"10.1021/acssuschemeng.0c06406\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTongamp, W., Zhang, Q., Saito, F., 2008. Mechanochemical Route for Synthesizing Nitrate form of Layered Double Hydroxide. Powder Technology 185(1), 43\u0026ndash;48. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.powtec.2007.09.013\u003c/span\u003e\u003cspan address=\"10.1016/j.powtec.2007.09.013\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTsuzuki, T., 2021. Mechanochemical Synthesis of Metal Oxide Nanoparticles. Communications Chemistry 4(1), 143. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/s42004-021-00582-3\u003c/span\u003e\u003cspan address=\"10.1038/s42004-021-00582-3\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eUmar, K., Aris, A., Parveen, T., Jaafar, J., Abdul Majid, Z., Vijaya Bhaskar Reddy, A., Talib, J., 2015. Synthesis, Characterization of Mo and Mn Doped ZnO and Their Photocatalytic Activity for the Decolorization of Two Different Chromophoric Dyes. Applied Catalysis A: General 505, 507\u0026ndash;514. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.apcata.2015.02.001\u003c/span\u003e\u003cspan address=\"10.1016/j.apcata.2015.02.001\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWalker, T.W., Adams, A.F.R., Orchiston, H.D., 1955. The Effects and Interactions of Molybdenum, Lime and Phosphate Treatments on the Yield and Composition of White Clover, Grown on Acid, Molybdenum Responsive Soils. Plant and Soil 6(2), 201\u0026ndash;220.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang, S., Gao, W., Li, H., Xiao, L.-P., Sun, R.-C., Song, G., 2018. Selective Fragmentation of Biorefinery Corncob Lignin into p-Hydroxycinnamic Esters with a Supported Zinc Molybdate Catalyst. ChemSusChem 11(13), 2114\u0026ndash;2123. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1002/cssc.201800455\u003c/span\u003e\u003cspan address=\"10.1002/cssc.201800455\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang, Y., Zhang, X., Meng, X., Cao, Y., Yang, F., Nan, J., Song, Q., Huang, Q., Wei, C., Zhang, J., Zhao, Y., 2016. Simulation, Fabrication, and Application of Transparent Conductive Mo-doped ZnO Film in a Solar Cell. Solar Energy Materials and Solar Cells 145, 171\u0026ndash;179. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.solmat.2015.09.015\u003c/span\u003e\u003cspan address=\"10.1016/j.solmat.2015.09.015\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWu, M., Yu, S., Chen, G., He, L., Yang, L., Zhang, W., 2015. Structural, Optical, and Electrical Properties of Mo-doped ZnO Thin Films Prepared by Magnetron Sputtering. Applied Surface Science 324, 791\u0026ndash;796. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.apsusc.2014.11.039\u003c/span\u003e\u003cspan address=\"10.1016/j.apsusc.2014.11.039\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYadav, P., Sinha, E., 2019. Structural, Photophysical and Microwave Dielectric Properties of α-ZnMoO\u003csub\u003e4\u003c/sub\u003e Phosphor. Journal of Alloys and Compounds 795, 446\u0026ndash;452. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.jallcom.2019.05.019\u003c/span\u003e\u003cspan address=\"10.1016/j.jallcom.2019.05.019\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYu, C., Yang, K., Shu, Q., Yu, J.C., Cao, F., Li, X., Zhou, X., 2012. Preparation, Characterization and Photocatalytic Performance of Mo-doped ZnO Photocatalysts. Science China Chemistry 55(9), 1802\u0026ndash;1810. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s11426-012-4721-8\u003c/span\u003e\u003cspan address=\"10.1007/s11426-012-4721-8\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYuan, W., Solihin, Zhang, Q., Kano, J., Saito, F., 2014. Mechanochemical Formation of K\u0026ndash;Si\u0026ndash;Ca\u0026ndash;O Compound as a Slow-release Fertilizer. Powder Technology 260, 22\u0026ndash;26. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.powtec.2014.03.072\u003c/span\u003e\u003cspan address=\"10.1016/j.powtec.2014.03.072\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZazhigalov, V.A., Sachuk, E.V., Kopachevskaya, N.S., Bacherikova, I.V., Wieczorek-Ciurowa, K., Shcherbakov, S.N., 2016. Mechanochemical Synthesis of Nanodispersed Compounds in the ZnO-MoO\u003csub\u003e3\u003c/sub\u003e System. Theoretical and Experimental Chemistry 52(2), 97\u0026ndash;103. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s11237-016-9456-8\u003c/span\u003e\u003cspan address=\"10.1007/s11237-016-9456-8\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZdujić, M.V., Milošević, O.B., Karanović, L.Č., 1992. Mechanochemical Treatment of ZnO and Al\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e Powders by Ball Milling. Materials Letters 13(2), 125\u0026ndash;129. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/0167-577X(92)90122-Z\u003c/span\u003e\u003cspan address=\"10.1016/0167-577X(92)90122-Z\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang, J.W., He, G., Li, T.S., Liu, M., Chen, X.S., Liu, Y.M., Sun, Z.Q., 2015. Modulation of Microstructure and Optical Properties of Mo-doped ZnO Thin Films by Substrate Temperature. Materials Research Bulletin 65, 7\u0026ndash;13. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.materresbull.2015.01.004\u003c/span\u003e\u003cspan address=\"10.1016/j.materresbull.2015.01.004\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang, Q., Saito, F., 2009. Mechanochemical Synthesis of Slow-Release Fertilizers through Incorporation of Alumina Composition into Potassium/Ammonium Phosphates. Journal of the American Ceramic Society 92(12), 3070\u0026ndash;3073. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1111/j.1551-2916.2009.03291.x\u003c/span\u003e\u003cspan address=\"10.1111/j.1551-2916.2009.03291.x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhao, D., Sathasivam, S., Li, J., Carmalt, C.J., 2020. Transparent and Conductive Molybdenum-Doped ZnO Thin Films via Chemical Vapor Deposition. ACS Applied Electronic Materials 2(1), 120\u0026ndash;125. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/acsaelm.9b00647\u003c/span\u003e\u003cspan address=\"10.1021/acsaelm.9b00647\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"chemical-and-biological-technologies-in-agriculture","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"Learn more about [Chemical and Biological Technologies in Agriculture](https://chembioagro.springeropen.com/)","snPcode":"40538","submissionUrl":"https://submission.nature.com/new-submission/40538/3","title":"Chemical and Biological Technologies in Agriculture","twitterHandle":"@SpringerPlants","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Mechanochemistry, Slow release fertilizer, molybdenum fertilizer, green synthesis, soil leaching","lastPublishedDoi":"10.21203/rs.3.rs-4457615/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4457615/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eMolybdenum (Mo) is an essential micronutrient required for plant growth but is prone to leaching from neutral and alkaline soils. The use of slow-release Mo sources could potentially reduce leaching losses from soils and increase crop yields. In this study, we assessed mechanochemistry as a green method to produce slow-release Mo sources. Molybdenum compounds (MoO3 or (NH4)6Mo7O24\u0026middot;4H2O) were mechanochemically (MC) treated with ZnO to synthesize compounds with a Mo content of 1\u0026ndash;36%. Reduced Mo solubility after MC treatment, compared to the initial Mo source, was obtained with the MoO3 source and these composites were used for co-compaction with macronutrient fertilizers. Macronutrient pellets with 0.2% Mo were compacted using the 4% Mo and 36% Mo (characterized as ZnMoO4) compounds. A column dissolution test showed that the 4% Mo compound in a macronutrient carrier (DAP and MAP) only released around 40% of the total Mo compared to 80% for a non-MC treated control over 72 h. Column leaching using two soils revealed that the release behavior of Mo was strongly related to the pH of the leachate, which was affected by both the soil pH and the macronutrient carrier. More Mo was released when the MC-treated compound was co-compacted with diammonium phosphate (DAP) compared to monoammonium phosphate (MAP). The MC-treated compound with 4% Mo showed significantly less leaching than the control without ball milling when co-compacted with both MAP and DAP. In a pot trial with simulated leaching, the uptake of Mo was greater for the MC-treated 4% Mo compound co-compacted into DAP than for the other Mo sources. Overall, our results indicate that MC-treated MoO3-ZnO could be used as a slow-release Mo source in high-rainfall areas.\u003c/p\u003e","manuscriptTitle":"Effect of mechanochemically modified MoO 3 -ZnO on Mo supply to plants when co-granulated with macronutrient fertilizers","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-06-20 08:46:04","doi":"10.21203/rs.3.rs-4457615/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-06-23T10:50:00+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-06-21T05:27:10+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-06-15T06:13:31+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"333021697898037104329615661562913999680","date":"2024-06-07T11:44:27+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"48046111460189062859775140199248731318","date":"2024-06-07T07:53:45+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-06-07T07:43:36+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-06-06T13:58:35+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-06-06T13:57:32+00:00","index":"","fulltext":""},{"type":"submitted","content":"Chemical and Biological Technologies in Agriculture","date":"2024-05-22T02:03:56+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"chemical-and-biological-technologies-in-agriculture","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"Learn more about [Chemical and Biological Technologies in Agriculture](https://chembioagro.springeropen.com/)","snPcode":"40538","submissionUrl":"https://submission.nature.com/new-submission/40538/3","title":"Chemical and Biological Technologies in Agriculture","twitterHandle":"@SpringerPlants","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"bb8abc6c-fe9f-4c18-b46c-e66b1e40934f","owner":[],"postedDate":"June 20th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2024-07-22T11:14:20+00:00","versionOfRecord":[],"versionCreatedAt":"2024-06-20 08:46:04","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4457615","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4457615","identity":"rs-4457615","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}