The Effect of Potassium Humate on the Morphophysiological Indicators and Yield of Soybean Growing in Different Ecological Conditions of Azerbaijan

The Effect of Potassium Humate on the Morphophysiological Indicators and Yield of Soybean Growing in Different Ecological Conditions of Azerbaijan | 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 Article The Effect of Potassium Humate on the Morphophysiological Indicators and Yield of Soybean Growing in Different Ecological Conditions of Azerbaijan A.H. Gadimov, S.N. Ragimova, K.F. Bakhshaliyeva, P.Z. Muradov, and 6 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8258686/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 5 You are reading this latest preprint version Abstract In the research, an attempt was made to theoretically substantiate the use of potassium humate (k-humate) preparation in improving the morphophysiological indicators and productivity of soybean plants of the “Bravo” variety infected with rhizotorphine, which is prepared based on the root nodule bacterium Bradyrhizibium japonicum (strains 634), in two different ecologically distinct regions (Kurdamir and Ganja) of the Republic of Azerbaijan. The role of rhizotorphin and potassium humate in changing the values of some morphological and physiological parameters of soybean plants was determined and the response of soybean plants to these factors was studied. The dynamics of nitrogen fixation activity and total nitrogen accumulation in soybean plants were studied. The results obtained indicate that k-humate increases the tolerance of soybean plants to environmental stress factors by improving their metabolic processes under unfavorable conditions. In both regions, k-humate plays a positive role in improving morphological parameters, forming the photosynthetic apparatus and symbiotic system, accumulating dry matter and total nitrogen, and also increasing productivity. The k-humate preparation works more effectively in Kurdamir, where soil and climatic conditions are more stressful than in Ganja. Biological sciences/Ecology Earth and environmental sciences/Ecology Biological sciences/Plant sciences nodule bacterium rhizotorphine nitrogen fixation activity photosynthetic apparatus productivity Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Introduction Soybean is one of the leading legumes in terms of the quantity and quality of proteins in its beans. Considering the worsening ecological situation and the increasing demand for protein by the world's population, soybean can be considered an indispensable plant in solving this problem. One of the ways to effectively grow this plant is to infect it with rhizobial bacteria, since the treatment of seeds with highly effective strains of rhizobium bacteria, in addition to the use of new territories, significantly increases the productivity of the plant. Another way to affect the productivity and quality of soybeans is the use of biopreparations of natural origin, as well as beneficial microorganisms and preparations derived from them. They increase the yield and improve the quality of soybeans and other leguminous plants by enhancing their adaptation to environmental stress conditions (Hayam et al., 2022, Olaetxea et al., 2020, Schmidt and Santi, 2007). Although biological products are widely used in modern crop production as an alternative to chemical products, they cannot completely replace chemical products. However, they play a role in increasing productivity by reducing ecological pressure on the environment and minimizing the development of pest resistance and populations in this area (Kalogiannidis et al., 2022). Many world scientists in their studies note the role of humic substances, including potassium humate (KH), in plant productivity (Canellas et al., 2023, Shahriyari et al., 2009 , Da Silva et al., 2021, Davoud, Gao et al., 2015). Potassium humate, like other organic compounds, is very effectively absorbed by the root system and above-ground part of the plant. The use of humate stimulates better root system development, ensures effective plant nutrition, activation of biochemical processes and increases the productivity of agricultural crops (Ampong et al., 2022). The ability of humate to increase the adaptation of plants to stress conditions such as drought (Benito et al., 2024) and salinity (Alhardi et al., 2022, Canavar et al., 2023, Ma et al., 2020) is manifested in an increase in productivity. That is, this preparation, like all organic fertilizers, serves as a producer of soil fertility. The richness of biogenic elements in its composition plays an important role in improving the amount of soil nutrients and the development of saprophytic microflora in the environment, which significantly improves the process of soil formation. That is, the effect of humate on soil fertility and productivity is realized as a result of the complex activity of interconnected processes. These include 1) the effect of humate on the physical and chemical properties of the soil; 2) the direct effect of humate on the vital activity of higher plants and microorganisms; 3) the acceleration of the exchange of internal soil processes, i.e., the strengthening of biological activity and the adsorption of soil nutrients by fertilizers with the improvement of the plant nutrition regime (Bezuglova et al., 2021, Ampong et al., 2022). Despite the large number of research studies on the effect of potassium humate on morphophysiological, biochemical indicators, productivity and product quality of agriculturally important plants under salinity, drought and different nutritional regimes at different stages of ontogenesis (Bashandy and Sarhan, 2021, El-Nwehy et al., 2020, El-Beltagi et al., 2023, Shahryari et al., 2008, 2013), research studies on soybean plants under different ecological and soil-climatic conditions are very rare. For this, one of the main ways may be to develop the theoretical and practical foundations of the combined use of rhizobium bacteria and potassium humate preparations in order to achieve high and quality yields by cultivating soybeans in various ecological and soil-climatic conditions. Therefore, the purpose of the research work is to study the effect of rhizotorphin and potassium humate on the morphological indicators of soybean plants, the formation of the symbiotic system, nitrogen metabolism, and grain yield in ecologically distinct areas of our republic. Materials and Methods The soybean plant variety “Bravo” was used as the research material. The seeds of the plant were purchased from the Scientific Research Institute of Agriculture of the Republic of Azerbaijan. Field experiments were conducted for two consecutive years, in 2022-2023, in various regions of the Republic of Azerbaijan, which differ in ecological and soil-climatic conditions, at the experimental field of the Azerbaijan State Agrarian University in Ganja and at the agricultural research stations located in the Karrar Experiment Station of Kurdamir district of the Institute of Botany of the Ministry of Science and Education of the Republic of Azerbaijan. The experiments were set up in both areas at the same time by random selection, with an area of 16 m 2 (3 replicates) in both regions at the same time every year on April 20, according to the following scheme: 1) Ganja Control (GC); 2) Ganja K-Humate (G-Kh); 3) Kurdamir Control (K-C); 4) Kurdamir K-humate (K-Kh). Seeds of the G-Kh and K-Kh variants were soaked in K-humate for 2 hours. After the seeds were dried, before sowing, the seeds of all variants were treated with rhizotorphin, a preparation based on the rhizome bacterium Bradyrhizibium japonicum (strain 634). Agrochemical indicators of the soils of the experimental plots were determined: Agrochemical indicators of the soil of Ganja experimental plot: pH -7.3, EC 25 -0.45, CaCO 3 -8.2%, humus -3.4%, N -0.11%, P 2 O 5 -41 ppm, K 2 O -269 kg/h, Ca -1372 ppm, Mg -210 ppm, Na -276 ppm, Fe -6.1 ppm, Mn -3.8 ppm, Zn -1.7 ppm. In the Karrar Experiment Station of Kurdamir district - pH 7.9, EC 25 -0.67, CaCO 3 -5.9%, humus -1.9%, N -0.062%, P 2 O 5 -28 ppm, K 2 O- 143 kq/h, Ca -1250 ppm, Mg -182 ppm, Na -249 ppm, Fe -5.6 ppm, Mn -3.7 ppm, Zn -0.8 ppm. As can be seen, they have different agrochemical indicators, and the soils of the Karrar base are very poor in humus content and the amount of essential nutrients. The meteorological indicators are different. The average monthly air temperature in Ganja during the research years was 15.5 0 C in April, 18 0 C in May, 24.5 0 C in June, 27 0 C in July, and 28 0 C in August, while in Kurdamir it was 17.5; 20.0; 27.5; 30.0; 30.5 0 C, respectively. The amount of precipitation in Ganja during the research years was 51.73-128.6 mm in April-June, and 21.23-44.69 mm in July-September, and 38.87-56.35 mm in April-June, and 13.13-35.9 mm in July-September. In both experimental plots, the same amount of mineral fertilizers N-ammonium sulfate (20.5%), P-superphosphate P 2 O 2 (18.7%) and K-potassium sulfate K 2 O (48%) were used. The fertilizers were applied under the plow before sowing. Phenological observations of plant growth and development were conducted throughout ontogenesis, and the dates of germination, budding, flowering, onset of ripening, and full ripening phases were recorded and samples were taken for experiments (Lukomca, 2010, Melgar and Zelada, 2021). The leaf area per 1 m 2 of planting area was calculated using the generally accepted method based on the absolute dry mass of leaves and cuttings (Nichiporovich, 1988). Active symbiotic potential (ASP ). The activity of soybean nodules is confirmed by the presence of leghemoglobin in their composition. Leghemoglobin gives the nodules a pink and red color. Gray and green nodules are not symbiotically active, that is, they do not contain leghemoglobin. To determine the active symbiotic potential, pink and red nodules are selected and weighed on a scale. The ASP of the plant was calculated according to the following formula. t (M 1 + M 2 )/2 t- time between two analyses (days) (M1 + M2)/2 – average mass of pink nodules (for ASP) ASP for the period of branching-pod formation was calculated based on the sum of ASPs of individual periods (Posypanov, 1991). At different stages of development the total nitrogen content and protein content in grains were determined by the Keldal method (Gadzhimamedov et al., 2016). Results and Discussion The course of vegetative development (the time of onset of development phases and the duration of interphase periods), which varies depending on natural climatic conditions, is one of the main factors affecting the productivity indicators of soybean plants (Kumudini, 2010). Different climatic conditions were observed in Kurdamir district and Ganja city during the study year. The difference in the vegetation period of soybean, especially the difference in the duration between the transitions to phases, depending on the environment in which it is cultivated, can be attributed to the climatic differences in these regions (Kurdamir, Ganja). Our phenological observations partially confirmed these assumptions. In both regions, seed germination began 4 days after sowing. Full germination occurred 3 days after germination in Kurdamir region and 4 days after germination in Ganja. K-humate treatment did not cause any changes in the germination period compared to the control. In general, this slight difference continued until the flowering phase (Figure 1). Although the indicators were equalized in the flowering phase, differences began to be observed in the transition period between phases in the region during the bean formation phase, especially in plants treated with k-humate. The effect of k-humate on the duration of the interphase transition of soybean development, the formation and full ripening of beans was observed both in Kurdamir district and in Ganja city. Depending on the climatic conditions, the vegetation period of soybean grown in Ganja city was 3 days longer than the control under the influence of k-humate and in Kurdamir district by 2 days. Plant height. In modern agriculture, biological preparations of various purposes are widely used to increase the productivity of soybean plants in various ecological conditions. The results of the effect of k-humate on the height of soybean plants grown in Kurdamir and Ganja are given in Figure 2. Observations were made in the phases of branching, flowering and bean formation of soybean development (Figure 2). K-hummate had a positive effect on the height of soybean plants grown in both Kurdamir and Ganja. Different heights were recorded depending on the phenological phases. In the branching phase, the height of soybean plants grown in Kurdamir was 2.4 cm higher than the control variant, and in Ganja - 1.6 cm. This indicator increased slightly in the flowering phase, equaling 3.1 and 2.2 cm, respectively. That is, the positive effect of k-humate continued to manifest itself, and in the pod formation phase, the difference between the variants increased, reaching 3.8 cm in Kurdamir and 5.9 cm in Ganja. Comparison of the heights of soybean plants grown in Kurdamir and Ganja showed that the plants grown in Ganja were taller (Figure 2). The highest height increase was recorded in the k-humate variant in Ganja, 5.9 cm more than the control. Thus, as can be seen from Figure 2, the use of k-humate significantly increases the height of soybean plants in both environmental conditions and in all phases of development. Formation of the photosynthetic apparatus and accumulation of dry mass. The productivity and quality of agricultural crops depend to a certain extent on the formation of the photosynthetic apparatus, its productivity and factors that positively affect these processes. The main signs characterizing the photosynthetic activity of a plant are the leaf surface, photosynthetic potential and photosynthesis productivity (Nichiporovich, 1988, Hussain et al., 2021). The main photosynthetic power in the formation of productivity falls on the leaves. For example, in peas, the role of the leaf in the formation of productivity is up to 86% (Amelin, 1998), in field beans up to 94% (Juraev et al., 2023), etc. The photosynthetic role of other organs increases significantly in the late stages of plant development (Song et al., 2022). Analysis of studies shows that in the early stages of plant development, the surface of the leaves increases, and in the later stages of development they decrease in connection with the formation of reproductive organs (Nichiporovich, 1988). Our results showed that, regardless of the environmental conditions in which they were grown, in all variants, although different, the leaf surface increases from the beginning of flowering to the beginning of fruiting, and decreases from the beginning of fruit formation to fruit collection (Fig. 3). The leaf surface of soybean plants grown in both Kurdamir and Gandja districts was larger than that of control plants regardless of the development phase due to the effect of k-humate. The largest leaf surface was observed at the beginning of fruiting. In this phase, it was observed that the leaf surface increased by 12.43% in Kurdamir variant and 7.73% in Ganja variant compared to the control plants due to the effect of k-humate. In general, the leaf surface of soybean plants grown in Ganja was larger in all development phases. The maximum leaf surface was recorded at the beginning of fruiting in Ganja variant with the participation of k-humate, 4.34 m 2 per 1 square meter (Figure 3). Figure 4 A, B and C show the photosynthetic indicators of soybean plants treated with k-humate in the pod formation phase. It was found that pre-sowing treatment of seeds with k-humate preparation leads to an increase in the photosynthetic potential of the plant. This increase was 26.84% in Kurdamir variant and 12.14% in Ganja variant. The pure photosynthetic potential was measured in the pod formation phase. When comparing the value of the photosynthetic potential with the value of the pure photosynthetic potential, no dependence on the photosynthetic potential was observed. The accumulation of dry matter in plants depends on environmental conditions, in particular, on weather conditions, mineral nutrition and agrochemical composition of the soil. At the initial stages of growth and development, the accumulation of dry matter in plants is very weak. In the later stages of ontogenesis, with the formation of new leaves, the growth of dry matter in plants intensifies and reaches its maximum value with the complete formation of the leaf surface, which is accompanied by the activity of photosynthetic indicators. One of the signs that determine the productivity of plants is the accumulation of its aboveground mass. Therefore, we determined the dry mass of soybean plants in ecologically different regions using rhizotorphine and potassium humate preparations (Figure 5). Our results showed that the accumulation of dry matter of soybean plants varies depending on the growing conditions and the preparations used. In both Kurdamir and Ganja conditions, the increase in the dry matter of the plant changed positively in parallel with the increase in photosynthetic activity. In both conditions, the highest increase was recorded in fruit harvest. The K-hummate preparation stimulated the accumulation of dry matter more. Thus, in Kurdamir variant, the increase in dry matter due to the influence of k-hummate was 22.44% in the flowering phase, 30.79% in the fruiting phase, and 27.57% in the fruit harvest phase. Accordingly, in Ganja variant, it was 21.56; 30.00 and 26.06%. As can be seen, the k-hummate preparation works more effectively in Kurdamir variant. Development of the symbiotic apparatus. One of the important factors affecting the symbiosis of leguminous plants with rhizobium bacteria and nitrogen fixation activity is soil-climatic conditions, especially soil moisture. Thus, rhizobium bacteria multiply very poorly in arid areas. Unstable soil-climatic conditions during the reproduction and movement of rhizobium bacteria at the beginning of vegetation delay the formation of rhizobium, weakening the intensity of nitrogen fixation (Cerezini et al., 2014, Li et al., 2020, Rodrigo et al., 2017). Therefore, in our studies, the effect of k-hummate on the amount and symbiotic potential of rhizobium bacteria formed as a result of symbiosis of soybean plants grown under different ecological conditions was studied. Experiments showed that in all development phases, from the beginning of vegetation to the formation of beans, the wet mass of rhizobium in plants grown in Ganja was higher than in Kurdamir. This correspondence was also reflected in the number of rhizobium (Figure 6). The effect of potassium humate on the symbiotic potential of root nodules of soybean plants grown in different natural ecological conditions is shown in Figure 7. As can be seen, the symbiotic potential of root nodules formed in the roots significantly depends on the ecological conditions of the environment in which they grow. Infection of seeds with rhizobium bacteria before sowing and treatment with k-hummate preparation have different effects on the formation of the symbiotic apparatus depending on the weather conditions. In this sense, we see that the number, size and mass of leghemoglobin root nodules formed in the roots of soybean plants grown in the territory of Ganja are greater (Figure 7). The large number and weight of nodules does not at all indicate the formation of an active symbiotic system. The active symbiotic potential of legumes depends on the number of leguminous nodules formed in their roots. Leguminous nodules give their roots a pink or red color. This pigment not only provides the energy centers of the nodules with oxygen, but also protects them from high concentrations of oxygen, causing the release of energy for the fixation of atmospheric nitrogen (Topunov, 1996). Transparent nodules do not fix atmospheric nitrogen. The formation of effective symbiosis and nitrogen fixation activity of legumes with rhizobium bacteria depends on a number of factors. These include soil-climatic conditions, plant characteristics, agrotechnical rules, etc. (Evans et al., 1989). The active symbiotic potential of legumes is based on the relative stability of the mass of rhizomes during a certain period of development phases and the dependence of the activity of the legume-rhizobium symbiotic system on the mass of legume-hemoglobin rhizomes. It is known that active formation of rhizomes occurs during the branching phase of soybean development and the phase of pod formation. We determined the active symbiotic potential during this period. In Ganja, where the amount of precipitation is relatively high, it was observed that the active symbiotic potential of rhizomes of plants treated with k-humate was higher (Figure 7). The active symbiotic potential of plants grown in Ganja was 939 kg day/ha higher than the control variant of plants in Kurdamir by 939 kg day/ha. In the K-humate variant, this increase was equal to 1183 kg day/ha. In Kurdamir, where the amount of precipitation is not very high and the temperature is higher than in Ganja, the treatment of soybean seeds with the k-humate preparation had a slightly better effect on the formation of active symbiotic potential than in Ganja, although in percentage terms. During the period of branching and pod formation, the active symbiotic potential increased by 30.08% in Kurdamir compared to the control plants, and by 29.25% in Ganja variant. Based on the results obtained, it was determined that, regardless of the growing environment, the infection of soybean seeds with rhizobium bacteria before sowing and the treatment with the k-humate preparation have a positive effect on the symbiotic activity of the plant. As a result of the combined effect of the two factors, a high increase in the number, mass and formation of the symbiotic apparatus of soybean plants grown under different environmental conditions is noted. Nitrogen metabolism. The accumulation of combined nitrogen in the soil occurs due to irrigation, precipitation, fertilization, symbiotic and associative nitrogen fixation. Among these, symbiotic nitrogen fixation is considered the most efficient and effective in both ecological and economic approaches (Sinclair and Vades, 2012). Unfavorable environmental conditions (temperature, drought, salinity, radiation, etc.) weaken the assimilation of combined and free nitrogen by plants. Therefore, the study of factors that can reduce the negative effects of the environment on the ability of plants to assimilate nitrogen remains always relevant. In order to increase the resistance of plants and improve nitrogen metabolism in such conditions, recently, in order to increase the resistance of plants and improve nitrogen metabolism, the use of plant-derived phytohormones (Zeng et al., 2023, 2023a), other physiologically active substances, microorganisms (bacteria and micromycetes) and their products, which are safer in ecological and economic terms, has been widely used (Nassar et al., 2021). Therefore, the use of biological preparations such as rhizotorphin and k-hummate is of interest in improving the development of legumes under various environmental stress conditions and increasing productivity by increasing the efficiency of nitrogen metabolism. Soybean plants accumulate dry matter and nitrogen relatively weakly in the early stages of their development, but with high intensity during the fruit formation phase (Hangway and Weber, 1971, Gadimov et al., 2024). Table 1 shows the results obtained from the distribution (mg/plant) of various forms of nitrogen (total, non-protein and protein) in order to study the effect of environmental soil-climatic conditions on soybean nitrogen metabolism in Kurdamir and Ganja districts. As can be seen from Table 1, although k-humate has a positive effect on nitrogen metabolism in plants until the branching stage of vegetation, nitrogen accumulation is weak compared to other stages, and these indicators are approximately the same in all variants in both regions (Kurdamir and Ganja). At this stage, an increase in non-protein nitrogen under the influence of k-humate is observed in both regions (19% and 27%). The assimilation and distribution of nitrogenous compounds in a plant is considered one of the important processes of its coloring and development. It is known that the amount of protein nitrogen is an indicator of the biosynthetic activity of nitrogen in protein synthesis in the cell. This, in turn, indicates the activation of active defense mechanisms in the process of nitrogen exchange under unfavorable conditions. Analysis of the amount of protein nitrogen at the branching stage shows that it increased by approximately the same level (9% and 8%) in plants of both regions compared to the control. A significant increase in the accumulation of total nitrogen is observed in the flowering phase. In both regions, under the influence of the k-humate preparation, total nitrogen accumulates by approximately the same amount compared to the control variant (6.27% and 6.67%). Despite the increase in total nitrogen during the flowering stage, a decrease in non-protein nitrogen (15% and 17%, respectively), and an increase in protein nitrogen (11% and 13%) are observed in plants of both regions. This trend continues until the beginning of fruit formation. The intensity of total nitrogen accumulation increases further in the fruit formation phase and compared to the flowering phase, the amount of total nitrogen in Kurdamir variant in the control plants is 79.94% higher, and under the influence of k-humate - 87.82% higher than in the control. The same situation is observed in Ganja variant, this increase in the control variant plants is 81.06%, respectively, and under the influence of potassium humate - 91.36%. As can be seen, the increase in total nitrogen accumulation in the plants grown in Ganja is approximately 1-2% higher than in Kurdamir variant. As a result of the analysis of pure seeds, it was found that in Kurdamir and Ganja variant plants, the effect of k-humate caused a decrease in non-protein nitrogen (21% and 3%), as a result, the amount of protein nitrogen increased (5% and 3%). Starting from the flowering phase, the increase in the intensity of total nitrogen accumulation in soybean plants with the participation of rhizobium root nodule bacteria and k-humate can be explained by the complete formation of the symbiotic system. The results of the formation of the symbiotic system and the active symbiotic potential confirm this idea (Figures 6. and 7.). From the flowering phase to the legume phase, a high increase in the number, mass and color (brown) of nitrogen-fixing root nodules is observed. It can be concluded that the increase in the amount of total nitrogen in these phases is mainly due to the nitrogen absorbed symbiotically along with k-humate. The high nitrogen content in seeds in Kurdamir experimental variant plants at the final stage of ontogenesis can be understood as the result of the activation of defense-adaptation mechanisms in plants at this phase, the synthesis of active functional proteins (stress proteins), and the formation of stable adaptation of plants to stress factors. That is, the positive effect of K-hummate on the increase in the concentration of protein nitrogen against the background of an increase in total nitrogen in soybean seeds under unfavorable soil-climatic conditions results in an increase in the defense-adaptation reaction of the plant to stress conditions. Grain yield and quality. Analysis of the yield and protein content of soybeans infected with rhizotorphine and treated with k-humate showed different values in the experimental regions. In Kurdamir, which is considered a relatively arid region, the k-humate preparation was more effective. This effectiveness was manifested both in the grain yield of the plant and in the amount of protein. The results we obtained once again confirmed the idea that the k-humate preparation is more effective in stress conditions (Bezuglova, 2021, Hasanpanah et al., 2008). The grain yield of soybean plants and the amount of protein in their grains in Kurdamir and Ganja districts are given in the table. As can be seen, k-humate has a more effective effect on both grain yield and protein content of plants in Kurdamir, where soil and climatic conditions are less favorable than in Ganja city. When considering the overall yield, we see that the grain yield of plants grown in Ganja environment is higher than in Kurdamir both in the control variant and in the k-humate variant. Thus, we see that the grain yield of soybeans in control plants is 19.4% higher, and in plants treated with potassium humate - 7.55%. In the results related to the amount of protein in soybean grains, although the amount of proteins in the control variant was 5.02% higher in plants grown in Ganja environment than in plants grown in Kurdamir, in the k-humate variant, on the contrary, the amount of proteins in the grains of plants grown in Kurdamir was 1.98% higher than in Ganja plants (Table 2). The results of the effect of K-humate on soybean grain yield and grain protein content show that this preparation works more effectively in Kurdamir. K-humate increases grain yield by 18.66% compared to the control variant, and by 6.86% in Ganja city area. The same trend is observed in the increase in grain protein content, 8.72% and 6.57%, respectively. CONCLUSION Thus, in both regions, a positive role of k-humates in the formation of the symbiotic system and the accumulation of total nitrogen is observed. With the help of its richness in humus, macro- and microelement composition, they positively affect metabolic processes in soybean plants in various environmental conditions, increase their tolerance to environmental stress factors, improve nitrogen metabolism, and participate in the formation of the photosynthetic apparatus and the symbiotic system. Declarations FUNDING This work was supported by the Azerbaijan Science Foundation – Grant AEF-MCG-2023-1(43)-13/10/3-M-10 DECLARATION OF COMPETING INTEREST : The authors declare they have no conflict of interest to declare. AUTHOR CONTRIBUTION AG and PM - general guidance and writing and submitting the article for publication, SR, ZA, NI and NG- Establishing experiments and collecting data in the Ganja zone, KB, ST, GG and SA- Establishing experiments and collecting data in the Kurdamir zone References Alhardi K., Rashwan E., Hafes E. and et al. (2022) Potassium Humate and plant growth-promoting microbes jointly mitigate water deficit stress in soybean cultivated in salt-affected soil. Plant (Basel). Nov 8-11(22),3016. Doi:10.3390/plants11223016 Amelin A.B. (1998). Physiological aspects of creating highly productive varieties of whiskered peas. Bulletin of the Russian Academy of Agricultural Sciences. 1998. No. 1. P. 54-56. Ampong K., Thilakaranthna MS., Gorim LY. (2022) Understanding the role of humic acids on crop performance and soil health. Front Agron. 4:848621. doi.10.3389/fagro.2022.848621 Bashandy S.O., Sarhan M. (2021) Response of soybean (Glycine max L.) plant and soil properties to NPK fertilization and and humate substances application under differerent tillage systems. Art. 4, Vol. 12, Issure 7, p. 469-479. DOI:10.21608/JSSAE.2021.83672.1018 Benito P, Bellón J, Porcel R, Yenush L, Mulet JM. (2023) The Biostimulant, Potassium Humate Ameliorates Abiotic Stress in Arabidopsis thaliana by Increasing Starch Availability. Int J Mol Sci., 28;24(15):12140. doi: 10.3390/ijms241512140. Bezuglova O., Gorovotsov A., Grinko A. Et al. (2021). Effect of pesticide and humic preparation on the soil structure during pea and chickpea cultivation. Agronomy, 11(10), 2053; https://doi.org/10.10.3390/agronomy11102053 Canavar O., Goren H.K., Kucuk Kaya S., Oncan Sumer F. (2023) Effect of potassium Humate on Soybean Germination Traits Under Salinity Stress Conditions. Turkish Journal of Agricultur – Food Science an Technology, 11(10). 1889-1891, 2023 DOI: https://org/10.24925/turjaf,v11i10.1889-1891.6223 Canellas, L.P., Silva R.M., Barbosa L.J.d.S., et al. (2023). Co-Inoculation with Bradyrhisobium and Humic Substances Combined with Herbstances Seropedicae Promotes Soybean vegetative growth and nodulation. Agronomy, 13, 2660. https://doi.org/10.3390/agronomy13102660 Cerezini P., Pipolo A., Hungria M. and Noguera M. (2014) Gaz exchanges and biological nitrogen fixation in soybean under water restriction. American Journal of Plant Sciences, 5, 4011-4017. doi:10.4236/ajps.2014.526419 Da Silva M.S.R. d., De Melo Silveira dos Santos B., Hidalgo Chavez D.W., et al. (2021) K-humate as an agricultural alternative to increase nodulation of soybeans inoculated with Bradyrhizobium. Biocatalysis Agricultural Biotechnology. 36. 102129. DOI: 10.16/j.bcab.2021.102129 El-Beltagi H.S., Al-Otaibi H.H., Pamar A., et al. (2023). Application of potassium humate and salicylic acid to mitigate salinity stress of common bean. Life 2023,13,449. https://doi.org/3390/life13020448 El-Nwehy S.S., Sary D.H., Afify R.M.M. (2020) Effect of potassium humate follar application on yield and quality of soybean ( Glycine Max L.) grown on calcareous soil under irrigation water regime. Plant Archives Vol 20, № 1. P. 1495-1502. https//www.researchgate.net/publication/355168606 Evans I., O’Connor G.E., Turnen G.L. et al. (1989). N 2 -fixation and its value to soil N increase in lupin, field pea and other legumes in south-eastern Australia. Agricultural and food sciences, environmental science. DOI:10.1071/AR9890791 Gadimov A.G., Ragimova S.N., Bakshaliyeva K.F., et al. (2024). Effect of Trichoderma and potassium humate on symbiotic characteristics of soybean. Inter. Scientific Journal. Science and innovation. https://doi.org/10.5281/zenodo.13837901 Gadzhimamedov I.M., Talai S.M., Kosayev E.M. (2016). Methods of agrochemical analysis of soil, plants and fertilizers. Baku. Author Publishing House, 131 p. Gao T.G., Xu Y.Y., Feng J., et al. (2015) Nodulation characterization and proteomic profiling of Bradyrhizobium liaoningense CCBAU05525 in response to water-soluble humic materials. Sci. Rep. 5, 10836. DOI:10.1038/srep10836 Hayam A. El-Shabouty, E.A.E.Elnefili (2022). Effect of biofertilization, potassium humate and rates of NPK fertilization on growth, Yield and Economic Indicators of soybean. Journal of soil sciences and agricultural engineering. Art. 4, Vol. 13, Issue 12, P. 413-420. DOI: 10.21608/JSSAE.2023.182034.1123 Hangway J.J., Weber C.R. (1971). Accumulation of N, P and K by soybean (Glycine max (L) Merrill) plants. Agronomy Journal, 63, p.406-408. Hassanpanah D., Gurbanov E., Gadimov A., Shahriari R. (2008) Shortening transplantation periods of potato plantlets by use of potassium humate and kadostim and their effects on mini-tuber production. Pak J Biol Sci. 15; 11 (10):1370-4. Doi:103923/pjbs.2008.1370.1374. Hussain S., Ulhassan Z., Brestic M. et al. (2021). Photosynthesis research under climate change. Photosynth Res. 150 (1-3):5-19. doi: 10.1007/s11120-021-00861-z. Juraev S.T., Bakhramova N.N. & Jumanova M.B. (2023). Selection Of High Photosynthetic Productivity Of Broad Bean (Vicia Faba L.) Lines. Diversity Research: Journal of Analysis and Trends , 1 (4), 6–9. Retrieved from https://academiaone.org/index.php/2/article/view/173 Kumudini S. Soybean growth and development. (2010). In book: The soybean: botany, production and uses pp. 48-73. DOI: 10.1079/9781845936440.0048 Kaligiannidis S., Kalfas D., Chatzitheodoridis., Papaevangelou O. (2022). Role of Crop-Protection Technologies in Sustainable Agricultural Productivity and management. Land. 11(10), 1680. https://doi.org/10.3390/land11101680 Li R., Chen H., Yang Z. et al (2020). Research status of soybean symbiosis nitrogen fixation. Oil Crop Science Vol.5, Issue 1, p.6-10. https://doi.org/10.1016/j.ocsci.2020.03.005 Ma Y, Dias MC and Freitas H (2020) Drought and Salinity Stress Responses and Microbe-Induced Tolerance in Plants. Front. Plant Sci . 11:591911. doi: 10.3389/fpls.2020.591911 Melgar, A.E., Zelada, A.M. (2021) Evolutionary analysis of angiosperm dehydrin gene family reveals three orthologues groups associated to specific protein domains. Sci Rep 11 , 23869. https://doi.org/10.1038/s41598-021-03066-5 Lukomets V.M. (2010) Methodology for conducting field agrotechnical experiments with oil crops. - Krasnodar: OOO RIA "Alvi-Design", 328p. Nassar K.E.M., Hayam A. El-Shaboury, Amany E. El-Sonbaty (2021). Influence of some potassium hummate application methods and mineral fertilization of nitrogen and posphorus on soybean yeld and quality. Menoufia J. Soil Sci., Vol. 6. Issue 4. P. 133-145. DOI:10.21608/MJSS.2021.175597 Nichiporovich A.A. (1988). Photosynthetic activity of plants as the basis of their productivity in the biosphere and agriculture. Photosynthesis and production process. Moscow: Nauka, P. 5-28. Olaetxea M., Mora V., Baigorri R., Zamarreno A. M., and Garcia-Mina J.M. (2020). The singular molecular conformation of humic acids in solution influences their ability to enhance root hydraulic conductivity and plant growth. Molecules 26, 7-10. doi:10.3390/molecules26010003 Posypanov G.S. (1991) Methods for studying biological fixation of atmospheric nitrogen. Moscow: Agropromizdat, 300 p. Rodrigo sa-Silva, Alexandre A., Brigido S., Oliveira S. (2017) Can stress response genes be used to improve the symbiotic performance of rhizobia. AIMS Microbiology., 3, pp.365-382. Doi:10.3934/microbiol.2017.3.365 Schmidt W., Santi S. (2007). Water-extractable humic substances alter root development and epidermal cell patten in Arabidopsis. Plant Soil 300, 259-267. doi:10.1007/s11104-007-9411-5 Shahryari R., Gadimov A., Elshad Gurbanov, Valizadeh M. (2009). Application of potassium humate to wheat for organic agriculture in Iran. Asian Journal of Food and Agro-Industry, Special Issue, S164-S168. Shahryari R., Gurbanov E., Gadimov A., Hassanpanah D. (2008). Tolerance of 42 bread wheat genotypes to drought stress after anthesis. 15; 11 (10):1330-5. doi:10.3923/pjbs.2008.1330.1335 Shahryari R., Valizadeh M., Gadimov A., Gurbanov E. (2013) In vitro effect of humic fertilizer on activity of nitrate reductase, under drought stress mediated through polyetilene glycole in wheat. Romanian agricultural research, 30 (30): 213-218 Sinclair T.R. and Vadez V. (2012) The future of grain legumes in cropping systems. Crop Pasture Science, 63, 501-512. http://dx.doi.org/10.1071/CP12128 Song Q., Van Rie J., Den Boer B. et al. (2022) Diurnal and Seasonal Variations of Photosynthetic Energy Conversion Efficiency of Field Grown Wheat. Front. Plant Sci. 13:817654. doi: 10.3389/fpls.2022.817654 Topunov A.F. (1996). Functioning of legume and regulation of oxygen regime in legume nodules: author's abstract. Dis. Dr. of Biol. Sci. M. - 46 p. Zhang W., Li J., Li H., et al. (2023) Transcriptomic analysis of humic acid in relieving the inhibitory effect of high nitrogen on soybean nodulation. Front. Plant Sci. 14:1196939. doi.10.3389/fpls.2023.1196939 Zheng Y., Wang X., Cui X. et all (2023a). Phytohormones regulate the abiotic stress: An overview of physiological, biochemical, and molecular responses in hortictural crops. Front. Plant Sci. 13:1095363. doi: 10.3389/fpls.2022.1095363 Tables Table 1 and 2 are available in the Supplementary Files section. Additional Declarations No competing interests reported. Supplementary Files Table12.docx Cite Share Download PDF Status: Under Review Version 1 posted Reviewers invited by journal 17 Feb, 2026 Editor assigned by journal 16 Feb, 2026 Editor invited by journal 16 Jan, 2026 Submission checks completed at journal 08 Jan, 2026 First submitted to journal 08 Jan, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-8258686","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":592647162,"identity":"f082e5dd-6546-44c2-a0c4-416409b0d7f3","order_by":0,"name":"A.H. Gadimov","email":"","orcid":"","institution":"Ministry of Science and Education of the Republic of Azerbaijan, Institute of Botany","correspondingAuthor":false,"prefix":"","firstName":"A.H.","middleName":"","lastName":"Gadimov","suffix":""},{"id":592647163,"identity":"5e0a9f0a-eedc-4940-a0f6-084889a50c93","order_by":1,"name":"S.N. Ragimova","email":"","orcid":"","institution":"Azerbaijan State Agrarian University","correspondingAuthor":false,"prefix":"","firstName":"S.N.","middleName":"","lastName":"Ragimova","suffix":""},{"id":592647164,"identity":"f787fec9-ab8a-422a-baf4-3bd116f84483","order_by":2,"name":"K.F. Bakhshaliyeva","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAzklEQVRIiWNgGAWjYBACCRDxgOEAkORhfADkyxCnJQGihdkAyOchSQsbiENYi2R77zGJBIY78gbnzx6rulFjwcMgfcYArxZpnnNpQC3PDGfOyEu7nXMM6DC+HPxa5CRyzIBaDjP2S/CY3c5hA2rh4SFOi30b/xmz4px/RGiRhmpJ7GfIMWPObSNCi2TPGWOLBINnyTNn5BhL5/ZJ8LDxsBXg1SJxvMfwxoeKO7Ybzp8x/JzzrU6On4d5A14tEIDsEjYi1I+CUTAKRsEoIAAA7Rs5ZxEQFLwAAAAASUVORK5CYII=","orcid":"","institution":"Ministry of Science and Education of the Republic of Azerbaijan, Institute of Microbiology,","correspondingAuthor":true,"prefix":"","firstName":"K.F.","middleName":"","lastName":"Bakhshaliyeva","suffix":""},{"id":592647165,"identity":"d3ec3e82-ca7f-4bdb-bdf2-90a3ca6f1cb6","order_by":3,"name":"P.Z. Muradov","email":"","orcid":"","institution":"Ministry of Science and Education of the Republic of Azerbaijan, Institute of Microbiology,","correspondingAuthor":false,"prefix":"","firstName":"P.Z.","middleName":"","lastName":"Muradov","suffix":""},{"id":592647166,"identity":"75ba6db7-724b-45ec-9fb1-8eabc4a73cd5","order_by":4,"name":"S.M. Tahirli","email":"","orcid":"","institution":"Baku State University","correspondingAuthor":false,"prefix":"","firstName":"S.M.","middleName":"","lastName":"Tahirli","suffix":""},{"id":592647167,"identity":"271bd1da-e1ac-4ae6-9d2e-5de2326d921d","order_by":5,"name":"Z.I. Abbasova","email":"","orcid":"","institution":"Ministry of Science and Education of the Republic of Azerbaijan, Institute of Botany","correspondingAuthor":false,"prefix":"","firstName":"Z.I.","middleName":"","lastName":"Abbasova","suffix":""},{"id":592647168,"identity":"ddf72ee2-ba6d-41f6-a9cb-c8e319e24957","order_by":6,"name":"G. J. Gasimova","email":"","orcid":"","institution":"Ministry of Science and Education of the Republic of Azerbaijan, Institute of Botany","correspondingAuthor":false,"prefix":"","firstName":"G.","middleName":"J.","lastName":"Gasimova","suffix":""},{"id":592647169,"identity":"c517d101-5023-45b1-ba03-cf76ca23857d","order_by":7,"name":"N.B. Guseynova","email":"","orcid":"","institution":"Ministry of Science and Education of the Republic of Azerbaijan, Institute of Botany","correspondingAuthor":false,"prefix":"","firstName":"N.B.","middleName":"","lastName":"Guseynova","suffix":""},{"id":592647170,"identity":"45881d98-17c7-49a8-bb96-3532514863ca","order_by":8,"name":"S.F. Azadaliyeva","email":"","orcid":"","institution":"Sumqayit State University","correspondingAuthor":false,"prefix":"","firstName":"S.F.","middleName":"","lastName":"Azadaliyeva","suffix":""},{"id":592647171,"identity":"70f405c0-16e5-437b-89c9-b26e443e216c","order_by":9,"name":"N.D. Imamkhuliyev","email":"","orcid":"","institution":"Azerbaijan State Agrarian University","correspondingAuthor":false,"prefix":"","firstName":"N.D.","middleName":"","lastName":"Imamkhuliyev","suffix":""}],"badges":[],"createdAt":"2025-12-02 09:38:10","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8258686/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8258686/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":103506626,"identity":"77aef7de-139d-411f-9021-1d6e64f40dbf","added_by":"auto","created_at":"2026-02-26 13:38:12","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":81119,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eEffect of potassium humate on the duration of interphase transition of soybean grow undert different conditions(days)\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-8258686/v1/9ce63bf17a94c76d453d601d.png"},{"id":103505930,"identity":"36970a7b-d6c1-42cf-bf9a-9dd6dd15567b","added_by":"auto","created_at":"2026-02-26 13:33:33","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":23514,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eHeight of soybean plants treated with potassium humate in development phases\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-8258686/v1/b17fb7013389b47c87c854b7.png"},{"id":103288057,"identity":"fddf976b-afa6-49f2-8006-bd8b5878a4c8","added_by":"auto","created_at":"2026-02-24 05:31:08","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":56094,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eLeaf surface area of ​​soybean plants treated with potassium humate by phase\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-8258686/v1/18980928d669bc680440e7e2.png"},{"id":103506183,"identity":"0d7816b7-d3a1-42ec-8287-fb95fd5f21b9","added_by":"auto","created_at":"2026-02-26 13:34:27","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":5713,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eChanges in photosynthetic activity of soybean plants grown under different conditions depending on potassium humate.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"placeholderimage.png","url":"https://assets-eu.researchsquare.com/files/rs-8258686/v1/98f5a467ec3f9002117fd085.png"},{"id":103506021,"identity":"6d8949c1-28ed-4ff4-858c-82db151ed7a3","added_by":"auto","created_at":"2026-02-26 13:33:50","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":30795,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eDry matter accumulation of soybean plants treated with rhizotorphine and k-hummate preparations and grown under different conditions\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-8258686/v1/45c3bd63d7bd4ba15d938983.png"},{"id":103505794,"identity":"50d90101-dcf2-4fbd-9f4d-3fd018496ace","added_by":"auto","created_at":"2026-02-26 13:33:03","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":5713,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eEffect of K-hummate on the number of A-root nodules (numbers/m2) and B-wet mass (g/m2) of soybean plants infected with rhizotorphin\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"placeholderimageCopy.png","url":"https://assets-eu.researchsquare.com/files/rs-8258686/v1/c9c3c6430ee9298bf352a033.png"},{"id":103288064,"identity":"6bd6f284-18ea-4575-9024-71661a3a53ae","added_by":"auto","created_at":"2026-02-24 05:31:08","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":24182,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eThe effect of seed treatment with potassium humate on the formation of active symbiotic potential of soybean plants\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-8258686/v1/7ca7f941d3b44fc21e6c7150.png"},{"id":103510037,"identity":"9c142502-9680-4be4-815b-eabcc54f0b2a","added_by":"auto","created_at":"2026-02-26 14:03:09","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":984534,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8258686/v1/5c3c3037-679d-4ddb-b2ac-e0af4c5ef024.pdf"},{"id":103506304,"identity":"40284d2b-ba18-4c18-92c8-101ff4e19c23","added_by":"auto","created_at":"2026-02-26 13:35:04","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":16339,"visible":true,"origin":"","legend":"","description":"","filename":"Table12.docx","url":"https://assets-eu.researchsquare.com/files/rs-8258686/v1/cd5f88fbc63bea90c321e1c0.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eThe Effect of Potassium Humate on the Morphophysiological Indicators and Yield of Soybean Growing in Different Ecological Conditions of Azerbaijan\u003c/p\u003e","fulltext":[{"header":"Introduction","content":"\u003cp\u003eSoybean is one of the leading legumes in terms of the quantity and quality of proteins in its beans. Considering the worsening ecological situation and the increasing demand for protein by the world\u0026apos;s population, soybean can be considered an indispensable plant in solving this problem. One of the ways to effectively grow this plant is to infect it with rhizobial bacteria, since the treatment of seeds with highly effective strains of rhizobium bacteria, in addition to the use of new territories, significantly increases the productivity of the plant. Another way to affect the productivity and quality of soybeans is the use of biopreparations of natural origin, as well as beneficial microorganisms and preparations derived from them. They increase the yield and improve the quality of soybeans and other leguminous plants by enhancing their adaptation to environmental stress conditions (Hayam et al., 2022, Olaetxea et al., 2020, \u0026nbsp;Schmidt and Santi, 2007).\u003c/p\u003e\n\u003cp\u003eAlthough biological products are widely used in modern crop production as an alternative to chemical products, they cannot completely replace chemical products. However, they play a role in increasing productivity by reducing ecological pressure on the environment and minimizing the development of pest resistance and populations in this area (Kalogiannidis et al., 2022).\u003c/p\u003e\n\u003cp\u003eMany world scientists in their studies note the role of humic substances, including potassium humate (KH), in plant productivity (Canellas et al., 2023, Shahriyari et al., 2009 , Da Silva et al., 2021, Davoud, Gao et al., 2015). Potassium humate, like other organic compounds, is very effectively absorbed by the root system and above-ground part of the plant. The use of humate stimulates better root system development, ensures effective plant nutrition, activation of biochemical processes and increases the productivity of agricultural crops (Ampong et al., 2022). The ability of humate to increase the adaptation of plants to stress conditions such as drought (Benito et al., 2024) and salinity (Alhardi et al., 2022, Canavar et al., 2023, Ma et al., 2020) \u0026nbsp;is manifested in an increase in productivity. That is, this preparation, like all organic fertilizers, serves as a producer of soil fertility. The richness of biogenic elements in its composition plays an important role in improving the amount of soil nutrients and the development of saprophytic microflora in the environment, which significantly improves the process of soil formation. That is, the effect of humate on soil fertility and productivity is realized as a result of the complex activity of interconnected processes. These include 1) the effect of humate on the physical and chemical properties of the soil; 2) the direct effect of humate on the vital activity of higher plants and microorganisms; 3) the acceleration of the exchange of internal soil processes, i.e., the strengthening of biological activity and the adsorption of soil nutrients by fertilizers with the improvement of the plant nutrition regime (Bezuglova et al., 2021, Ampong et al., 2022).\u003c/p\u003e\n\u003cp\u003eDespite the large number of research studies on the effect of potassium humate on morphophysiological, biochemical indicators, productivity and product quality of agriculturally important plants under salinity, drought and different nutritional regimes at different stages of ontogenesis (Bashandy and Sarhan, 2021, El-Nwehy et al., 2020, El-Beltagi et al., 2023, Shahryari et al., 2008, 2013), research studies on soybean plants under different ecological and soil-climatic conditions are very rare.\u003c/p\u003e\n\u003cp\u003eFor this, one of the main ways may be to develop the theoretical and practical foundations of the combined use of rhizobium bacteria and potassium humate preparations in order to achieve high and quality yields by cultivating soybeans in various ecological and soil-climatic conditions.\u003c/p\u003e\n\u003cp\u003eTherefore, the purpose of the research work is to study the effect of rhizotorphin and potassium humate on the morphological indicators of soybean plants, the formation of the symbiotic system, nitrogen metabolism, and grain yield in ecologically distinct areas of our republic.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cp\u003eThe soybean plant variety \u0026ldquo;Bravo\u0026rdquo; was used as the research material. The seeds of the plant were purchased from the Scientific Research Institute of Agriculture of the Republic of Azerbaijan.\u003c/p\u003e\n\u003cp\u003eField experiments were conducted for two consecutive years, in 2022-2023, in various regions of the Republic of Azerbaijan, which differ in ecological and soil-climatic conditions, at the experimental field of the Azerbaijan State Agrarian University in Ganja and at the agricultural research stations located in the Karrar Experiment Station\u0026nbsp;of Kurdamir district of the Institute of Botany of the Ministry of Science and Education of the Republic of Azerbaijan.\u003c/p\u003e\n\u003cp\u003eThe experiments were set up in both areas at the same time by random selection, with an area of 16 m\u003csup\u003e2\u003c/sup\u003e (3 replicates) in both regions at the same time every year on April 20, according to the following scheme: 1) Ganja Control (GC); 2) Ganja K-Humate (G-Kh); 3) Kurdamir Control (K-C); 4) Kurdamir K-humate (K-Kh).\u003c/p\u003e\n\u003cp\u003eSeeds of the G-Kh and K-Kh variants were soaked in K-humate for 2 hours. After the seeds were dried, before sowing, the seeds of all variants were treated with rhizotorphin, a preparation based on the rhizome bacterium Bradyrhizibium japonicum (strain 634).\u003c/p\u003e\n\u003cp\u003eAgrochemical indicators of the soils of the experimental plots were determined: Agrochemical indicators of the soil of Ganja experimental plot: pH -7.3, EC\u003csub\u003e25\u003c/sub\u003e -0.45, CaCO\u003csub\u003e3\u003c/sub\u003e -8.2%, humus -3.4%, N -0.11%, P\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e -41 ppm, K\u003csub\u003e2\u003c/sub\u003eO -269 kg/h, Ca -1372 ppm, Mg -210 ppm, Na -276 ppm, Fe -6.1 ppm, Mn -3.8 ppm, Zn -1.7 ppm. In the Karrar Experiment Station of Kurdamir district - pH 7.9, EC\u003csub\u003e25\u003c/sub\u003e -0.67, CaCO\u003csub\u003e3\u003c/sub\u003e -5.9%, humus -1.9%, N -0.062%, P\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e -28 ppm, K\u003csub\u003e2\u003c/sub\u003eO- 143 kq/h, Ca -1250 ppm, Mg -182 ppm, Na -249 ppm, Fe -5.6 ppm, Mn -3.7 ppm, Zn -0.8 ppm.\u003c/p\u003e\n\u003cp\u003eAs can be seen, they have different agrochemical indicators, and the soils of the Karrar base are very poor in humus content and the amount of essential nutrients.\u003c/p\u003e\n\u003cp\u003eThe meteorological indicators are different. The average monthly air temperature in Ganja during the research years was 15.5\u003csup\u003e0\u003c/sup\u003eC in April, 18\u003csup\u003e0\u003c/sup\u003eC in May, 24.5\u003csup\u003e0\u003c/sup\u003eC in June, 27\u003csup\u003e0\u003c/sup\u003eC in July, and 28\u003csup\u003e0\u003c/sup\u003eC in August, while in Kurdamir it was 17.5; 20.0; 27.5; 30.0; 30.5\u003csup\u003e0\u003c/sup\u003eC, respectively. The amount of precipitation in Ganja during the research years was 51.73-128.6 mm in April-June, and 21.23-44.69 mm in July-September, and 38.87-56.35 mm in April-June, and 13.13-35.9 mm in July-September.\u003c/p\u003e\n\u003cp\u003eIn both experimental plots, the same amount of mineral fertilizers N-ammonium sulfate (20.5%), P-superphosphate P\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e2\u003c/sub\u003e (18.7%) and K-potassium sulfate K\u003csub\u003e2\u003c/sub\u003eO (48%) were used. The fertilizers were applied under the plow before sowing.\u003c/p\u003e\n\u003cp\u003ePhenological observations of plant growth and development were conducted throughout ontogenesis, and the dates of germination, budding, flowering, onset of ripening, and full ripening phases were recorded and samples were taken for experiments (Lukomca, 2010,\u0026nbsp;Melgar and Zelada, 2021).\u003c/p\u003e\n\u003cp\u003eThe leaf area per 1 m\u003csup\u003e2\u003c/sup\u003e of planting area was calculated using the generally accepted method based on the absolute dry mass of leaves and cuttings (Nichiporovich, 1988).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eActive symbiotic potential (ASP\u003c/strong\u003e). The activity of soybean nodules is confirmed by the presence of leghemoglobin in their composition. Leghemoglobin gives the nodules a pink and red color. Gray and green nodules are not symbiotically active, that is, they do not contain leghemoglobin. To determine the active symbiotic potential, pink and red nodules are selected and weighed on a scale.\u003c/p\u003e\n\u003cp\u003eThe ASP of the plant was calculated according to the following formula.\u003c/p\u003e\n\u003cp\u003et (M\u003csub\u003e1\u003c/sub\u003e + M\u003csub\u003e2\u003c/sub\u003e)/2\u003c/p\u003e\n\u003cp\u003et- time between two analyses (days)\u003c/p\u003e\n\u003cp\u003e(M1 + M2)/2 \u0026ndash; average mass of pink nodules (for ASP)\u003c/p\u003e\n\u003cp\u003eASP for the period of branching-pod formation was calculated based on the sum of ASPs of individual periods (Posypanov, 1991).\u003c/p\u003e\n\u003cp\u003eAt different stages of development the total nitrogen content and protein content in grains were determined by the Keldal method (Gadzhimamedov et al., 2016).\u003c/p\u003e"},{"header":"Results and Discussion","content":"\u003cp\u003eThe course of vegetative development (the time of onset of development phases and the duration of interphase periods), which varies depending on natural climatic conditions, is one of the main factors affecting the productivity indicators of soybean plants (Kumudini, 2010).\u003c/p\u003e\n\u003cp\u003eDifferent climatic conditions were observed in Kurdamir district and Ganja city during the study year. The difference in the vegetation period of soybean, especially the difference in the duration between the transitions to phases, depending on the environment in which it is cultivated, can be attributed to the climatic differences in these regions (Kurdamir, Ganja).\u003c/p\u003e\n\u003cp\u003eOur phenological observations partially confirmed these assumptions. In both regions, seed germination began 4 days after sowing. Full germination occurred 3 days after germination in Kurdamir region and 4 days after germination in Ganja. K-humate treatment did not cause any changes in the germination period compared to the control. In general, this slight difference continued until the flowering phase (Figure 1). Although the indicators were equalized in the flowering phase, differences began to be observed in the transition period between phases in the region during the bean formation phase, especially in plants treated with k-humate.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe effect of k-humate on the duration of the interphase transition of soybean development, the formation and full ripening of beans was observed both in Kurdamir district and in Ganja city. Depending on the climatic conditions, the vegetation period of soybean grown in Ganja city was 3 days longer than the control under the influence of k-humate and in Kurdamir district by 2 days.\u003c/p\u003e\n\u003cp\u003ePlant height. In modern agriculture, biological preparations of various purposes are widely used to increase the productivity of soybean plants in various ecological conditions. The results of the effect of k-humate on the height of soybean plants grown in Kurdamir and Ganja are given in Figure 2. Observations were made in the phases of branching, flowering and bean formation of soybean development (Figure 2).\u003c/p\u003e\n\u003cp\u003eK-hummate had a positive effect on the height of soybean plants grown in both Kurdamir and Ganja. Different heights were recorded depending on the phenological phases. In the branching phase, the height of soybean plants grown in Kurdamir was 2.4 cm higher than the control variant, and in Ganja - 1.6 cm. This indicator increased slightly in the flowering phase, equaling 3.1 and 2.2 cm, respectively. That is, the positive effect of k-humate continued to manifest itself, and in the pod formation phase, the difference between the variants increased, reaching 3.8 cm in Kurdamir and 5.9 cm in Ganja.\u003c/p\u003e\n\u003cp\u003eComparison of the heights of soybean plants grown in Kurdamir and Ganja showed that the plants grown in Ganja were taller (Figure 2). The highest height increase was recorded in the k-humate variant in Ganja, 5.9 cm more than the control.\u003c/p\u003e\n\u003cp\u003eThus, as can be seen from Figure 2, the use of k-humate significantly increases the height of soybean plants in both environmental conditions and in all phases of development.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFormation of the photosynthetic apparatus and accumulation of dry mass.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe productivity and quality of agricultural crops depend to a certain extent on the formation of the photosynthetic apparatus, its productivity and factors that positively affect these processes. The main signs characterizing the photosynthetic activity of a plant are the leaf surface, photosynthetic potential and photosynthesis productivity (Nichiporovich, 1988, Hussain et al., 2021).\u003c/p\u003e\n\u003cp\u003eThe main photosynthetic power in the formation of productivity falls on the leaves. For example, in peas, the role of the leaf in the formation of productivity is up to 86% (Amelin, 1998), in field beans up to 94% (Juraev et al., 2023), etc. The photosynthetic role of other organs increases significantly in the late stages of plant development (Song et al., 2022). Analysis of studies shows that in the early stages of plant development, the surface of the leaves increases, and in the later stages of development they decrease in connection with the formation of reproductive organs (Nichiporovich, 1988). Our results showed that, regardless of the environmental conditions in which they were grown, in all variants, although different, the leaf surface increases from the beginning of flowering to the beginning of fruiting, and decreases from the beginning of fruit formation to fruit collection (Fig. 3).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe leaf surface of soybean plants grown in both Kurdamir and Gandja districts was larger than that of control plants regardless of the development phase due to the effect of k-humate. The largest leaf surface was observed at the beginning of fruiting. In this phase, it was observed that the leaf surface increased by 12.43% in Kurdamir variant and 7.73% in Ganja variant compared to the control plants due to the effect of k-humate. In general, the leaf surface of soybean plants grown in Ganja was larger in all development phases. The maximum leaf surface was recorded at the beginning of fruiting in Ganja variant with the participation of k-humate, 4.34 m\u003csup\u003e2\u003c/sup\u003e per 1 square meter (Figure 3).\u003c/p\u003e\n\u003cp\u003eFigure 4 A, B and C show the photosynthetic indicators of soybean plants treated with k-humate in the pod formation phase. It was found that pre-sowing treatment of seeds with k-humate preparation leads to an increase in the photosynthetic potential of the plant. This increase was 26.84% in Kurdamir variant and 12.14% in Ganja variant. The pure photosynthetic potential was measured in the pod formation phase. When comparing the value of the photosynthetic potential with the value of the pure photosynthetic potential, no dependence on the photosynthetic potential was observed.\u003c/p\u003e\n\u003cp\u003eThe accumulation of dry matter in plants depends on environmental conditions, in particular, on weather conditions, mineral nutrition and agrochemical composition of the soil. At the initial stages of growth and development, the accumulation of dry matter in plants is very weak. In the later stages of ontogenesis, with the formation of new leaves, the growth of dry matter in plants intensifies and reaches its maximum value with the complete formation of the leaf surface, which is accompanied by the activity of photosynthetic indicators.\u003c/p\u003e\n\u003cp\u003eOne of the signs that determine the productivity of plants is the accumulation of its aboveground mass. Therefore, we determined the dry mass of soybean plants in ecologically different regions using rhizotorphine and potassium humate preparations (Figure 5).\u003c/p\u003e\n\u003cp\u003eOur results showed that the accumulation of dry matter of soybean plants varies depending on the growing conditions and the preparations used. In both Kurdamir and Ganja conditions, the increase in the dry matter of the plant changed positively in parallel with the increase in photosynthetic activity. In both conditions, the highest increase was recorded in fruit harvest. The K-hummate preparation stimulated the accumulation of dry matter more. Thus, in Kurdamir variant, the increase in dry matter due to the influence of k-hummate was 22.44% in the flowering phase, 30.79% in the fruiting phase, and 27.57% in the fruit harvest phase. Accordingly, in Ganja variant, it was 21.56; 30.00 and 26.06%. As can be seen, the k-hummate preparation works more effectively in Kurdamir variant.\u003c/p\u003e\n\u003cp\u003eDevelopment of the symbiotic apparatus. One of the important factors affecting the symbiosis of leguminous plants with rhizobium bacteria and nitrogen fixation activity is soil-climatic conditions, especially soil moisture. Thus, rhizobium bacteria multiply very poorly in arid areas. Unstable soil-climatic conditions during the reproduction and movement of rhizobium bacteria at the beginning of vegetation delay the formation of rhizobium, weakening the intensity of nitrogen fixation (Cerezini et al., 2014, Li et al., 2020, Rodrigo et al., 2017). Therefore, in our studies, the effect of k-hummate on the amount and symbiotic potential of rhizobium bacteria formed as a result of symbiosis of soybean plants grown under different ecological conditions was studied. Experiments showed that in all development phases, from the beginning of vegetation to the formation of beans, the wet mass of rhizobium in plants grown in Ganja was higher than in Kurdamir. This correspondence was also reflected in the number of rhizobium (Figure 6).\u003c/p\u003e\n\u003cp\u003eThe effect of potassium humate on the symbiotic potential of root nodules of soybean plants grown in different natural ecological conditions is shown in Figure 7. As can be seen, the symbiotic potential of root nodules formed in the roots significantly depends on the ecological conditions of the environment in which they grow. Infection of seeds with rhizobium bacteria before sowing and treatment with k-hummate preparation have different effects on the formation of the symbiotic apparatus depending on the weather conditions. In this sense, we see that the number, size and mass of leghemoglobin root nodules formed in the roots of soybean plants grown in the territory of Ganja are greater (Figure 7).\u003c/p\u003e\n\u003cp\u003eThe large number and weight of nodules does not at all indicate the formation of an active symbiotic system. The active symbiotic potential of legumes depends on the number of leguminous nodules formed in their roots. Leguminous nodules give their roots a pink or red color. This pigment not only provides the energy centers of the nodules with oxygen, but also protects them from high concentrations of oxygen, causing the release of energy for the fixation of atmospheric nitrogen (Topunov, 1996). Transparent nodules do not fix atmospheric nitrogen.\u003c/p\u003e\n\u003cp\u003eThe formation of effective symbiosis and nitrogen fixation activity of legumes with rhizobium bacteria depends on a number of factors. These include soil-climatic conditions, plant characteristics, agrotechnical rules, etc. (Evans et al., 1989).\u003c/p\u003e\n\u003cp\u003eThe active symbiotic potential of legumes is based on the relative stability of the mass of rhizomes during a certain period of development phases and the dependence of the activity of the legume-rhizobium symbiotic system on the mass of legume-hemoglobin rhizomes. It is known that active formation of rhizomes occurs during the branching phase of soybean development and the phase of pod formation. We determined the active symbiotic potential during this period. In Ganja, where the amount of precipitation is relatively high, it was observed that the active symbiotic potential of rhizomes of plants treated with k-humate was higher (Figure 7).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe active symbiotic potential of plants grown in Ganja was 939 kg day/ha higher than the control variant of plants in Kurdamir by 939 kg day/ha. In the K-humate variant, this increase was equal to 1183 kg day/ha.\u003c/p\u003e\n\u003cp\u003eIn Kurdamir, where the amount of precipitation is not very high and the temperature is higher than in Ganja, the treatment of soybean seeds with the k-humate preparation had a slightly better effect on the formation of active symbiotic potential than in Ganja, although in percentage terms. During the period of branching and pod formation, the active symbiotic potential increased by 30.08% in Kurdamir compared to the control plants, and by 29.25% in Ganja variant.\u003c/p\u003e\n\u003cp\u003eBased on the results obtained, it was determined that, regardless of the growing environment, the infection of soybean seeds with rhizobium bacteria before sowing and the treatment with the k-humate preparation have a positive effect on the symbiotic activity of the plant. As a result of the combined effect of the two factors, a high increase in the number, mass and formation of the symbiotic apparatus of soybean plants grown under different environmental conditions is noted.\u003c/p\u003e\n\u003cp\u003eNitrogen metabolism. The accumulation of combined nitrogen in the soil occurs due to irrigation, precipitation, fertilization, symbiotic and associative nitrogen fixation. Among these, symbiotic nitrogen fixation is considered the most efficient and effective in both ecological and economic approaches (Sinclair and Vades, 2012). Unfavorable environmental conditions (temperature, drought, salinity, radiation, etc.) weaken the assimilation of combined and free nitrogen by plants. Therefore, the study of factors that can reduce the negative effects of the environment on the ability of plants to assimilate nitrogen remains always relevant. In order to increase the resistance of plants and improve nitrogen metabolism in such conditions, recently, in order to increase the resistance of plants and improve nitrogen metabolism, the use of plant-derived phytohormones (Zeng et al., 2023, 2023a), other physiologically active substances, microorganisms (bacteria and micromycetes) and their products, which are safer in ecological and economic terms, has been widely used (Nassar et al., 2021).\u003c/p\u003e\n\u003cp\u003eTherefore, the use of biological preparations such as rhizotorphin and k-hummate is of interest in improving the development of legumes under various environmental stress conditions and increasing productivity by increasing the efficiency of nitrogen metabolism.\u003c/p\u003e\n\u003cp\u003eSoybean plants accumulate dry matter and nitrogen relatively weakly in the early stages of their development, but with high intensity during the fruit formation phase (Hangway and Weber, 1971, Gadimov et al., 2024).\u003c/p\u003e\n\u003cp\u003eTable 1 shows the results obtained from the distribution (mg/plant) of various forms of nitrogen (total, non-protein and protein) in order to study the effect of environmental soil-climatic conditions on soybean nitrogen metabolism in Kurdamir and Ganja districts.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAs can be seen from Table 1, although k-humate has a positive effect on nitrogen metabolism in plants until the branching stage of vegetation, nitrogen accumulation is weak compared to other stages, and these indicators are approximately the same in all variants in both regions (Kurdamir and Ganja). At this stage, an increase in non-protein nitrogen under the influence of k-humate is observed in both regions (19% and 27%).\u003c/p\u003e\n\u003cp\u003eThe assimilation and distribution of nitrogenous compounds in a plant is considered one of the important processes of its coloring and development. It is known that the amount of protein nitrogen is an indicator of the biosynthetic activity of nitrogen in protein synthesis in the cell. This, in turn, indicates the activation of active defense mechanisms in the process of nitrogen exchange under unfavorable conditions. Analysis of the amount of protein nitrogen at the branching stage shows that it increased by approximately the same level (9% and 8%) in plants of both regions compared to the control.\u003c/p\u003e\n\u003cp\u003eA significant increase in the accumulation of total nitrogen is observed in the flowering phase. In both regions, under the influence of the k-humate preparation, total nitrogen accumulates by approximately the same amount compared to the control variant (6.27% and 6.67%). Despite the increase in total nitrogen during the flowering stage, a decrease in non-protein nitrogen (15% and 17%, respectively), and an increase in protein nitrogen (11% and 13%) are observed in plants of both regions. This trend continues until the beginning of fruit formation.\u003c/p\u003e\n\u003cp\u003eThe intensity of total nitrogen accumulation increases further in the fruit formation phase and compared to the flowering phase, the amount of total nitrogen in Kurdamir variant in the control plants is 79.94% higher, and under the influence of k-humate - 87.82% higher than in the control. The same situation is observed in Ganja variant, this increase in the control variant plants is 81.06%, respectively, and under the influence of potassium humate - 91.36%. As can be seen, the increase in total nitrogen accumulation in the plants grown in Ganja is approximately 1-2% higher than in Kurdamir variant.\u003c/p\u003e\n\u003cp\u003eAs a result of the analysis of pure seeds, it was found that in Kurdamir and Ganja variant plants, the effect of k-humate caused a decrease in non-protein nitrogen (21% and 3%), as a result, the amount of protein nitrogen increased (5% and 3%).\u003c/p\u003e\n\u003cp\u003eStarting from the flowering phase, the increase in the intensity of total nitrogen accumulation in soybean plants with the participation of rhizobium root nodule bacteria and k-humate can be explained by the complete formation of the symbiotic system. The results of the formation of the symbiotic system and the active symbiotic potential confirm this idea (Figures 6. and 7.). From the flowering phase to the legume phase, a high increase in the number, mass and color (brown) of nitrogen-fixing root nodules is observed. It can be concluded that the increase in the amount of total nitrogen in these phases is mainly due to the nitrogen absorbed symbiotically along with k-humate.\u003c/p\u003e\n\u003cp\u003eThe high nitrogen content in seeds in Kurdamir experimental variant plants at the final stage of ontogenesis can be understood as the result of the activation of defense-adaptation mechanisms in plants at this phase, the synthesis of active functional proteins (stress proteins), and the formation of stable adaptation of plants to stress factors. That is, the positive effect of K-hummate on the increase in the concentration of protein nitrogen against the background of an increase in total nitrogen in soybean seeds under unfavorable soil-climatic conditions results in an increase in the defense-adaptation reaction of the plant to stress conditions.\u003c/p\u003e\n\u003cp\u003eGrain yield and quality. Analysis of the yield and protein content of soybeans infected with rhizotorphine and treated with k-humate showed different values in the experimental regions. In Kurdamir, which is considered a relatively arid region, the k-humate preparation was more effective. This effectiveness was manifested both in the grain yield of the plant and in the amount of protein. The results we obtained once again confirmed the idea that the k-humate preparation is more effective in stress conditions (Bezuglova, 2021, Hasanpanah et al., 2008). The grain yield of soybean plants and the amount of protein in their grains in Kurdamir and Ganja districts are given in the table.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAs can be seen, k-humate has a more effective effect on both grain yield and protein content of plants in Kurdamir, where soil and climatic conditions are less favorable than in Ganja city. When considering the overall yield, we see that the grain yield of plants grown in Ganja environment is higher than in Kurdamir both in the control variant and in the k-humate variant. Thus, we see that the grain yield of soybeans in control plants is 19.4% higher, and in plants treated with potassium humate - 7.55%. In the results related to the amount of protein in soybean grains, although the amount of proteins in the control variant was 5.02% higher in plants grown in Ganja environment than in plants grown in Kurdamir, in the k-humate variant, on the contrary, the amount of proteins in the grains of plants grown in Kurdamir was 1.98% higher than in Ganja plants (Table 2).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe results of the effect of K-humate on soybean grain yield and grain protein content show that this preparation works more effectively in Kurdamir. K-humate increases grain yield by 18.66% compared to the control variant, and by 6.86% in Ganja city area. The same trend is observed in the increase in grain protein content, 8.72% and 6.57%, respectively.\u0026nbsp;\u003c/p\u003e"},{"header":"CONCLUSION","content":"\u003cp\u003eThus, in both regions, a positive role of k-humates in the formation of the symbiotic system and the accumulation of total nitrogen is observed. With the help of its richness in humus, macro- and microelement composition, they positively affect metabolic processes in soybean plants in various environmental conditions, increase their tolerance to environmental stress factors, improve nitrogen metabolism, and participate in the formation of the photosynthetic apparatus and the symbiotic system.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eFUNDING\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by the Azerbaijan Science Foundation \u0026ndash; Grant AEF-MCG-2023-1(43)-13/10/3-M-10\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDECLARATION OF COMPETING INTEREST\u003c/strong\u003e\u003cstrong\u003e:\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare they have no conflict of interest to declare.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;AUTHOR CONTRIBUTION\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAG \u0026nbsp;and PM - general guidance and writing and submitting the article for publication,\u003c/p\u003e\n\u003cp\u003eSR, \u0026nbsp;ZA, NI and NG- Establishing experiments and collecting data in the Ganja zone,\u003c/p\u003e\n\u003cp\u003eKB, ST, GG and \u0026nbsp; SA- Establishing experiments and collecting data in the Kurdamir zone\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eAlhardi K., Rashwan E., Hafes E. and et al. (2022) Potassium Humate and plant growth-promoting microbes jointly mitigate water deficit stress in soybean cultivated in salt-affected soil. Plant (Basel). Nov 8-11(22),3016. Doi:10.3390/plants11223016\u003c/li\u003e\n\u003cli\u003eAmelin A.B. (1998). Physiological aspects of creating highly productive varieties of whiskered peas. Bulletin of the Russian Academy of Agricultural Sciences. 1998. No. 1. P. 54-56.\u003c/li\u003e\n\u003cli\u003eAmpong K., Thilakaranthna MS., Gorim LY. (2022) Understanding the role of humic acids on crop performance and soil health. Front Agron. 4:848621. doi.10.3389/fagro.2022.848621\u003c/li\u003e\n\u003cli\u003eBashandy S.O., Sarhan M. (2021) Response of soybean (Glycine max L.) plant and soil properties to NPK fertilization and and humate substances application under differerent tillage systems. Art. 4, Vol. 12, Issure 7, p. 469-479. DOI:10.21608/JSSAE.2021.83672.1018\u003c/li\u003e\n\u003cli\u003eBenito P, Bell\u0026oacute;n J, Porcel R, Yenush L, Mulet JM. (2023) The Biostimulant, Potassium Humate Ameliorates Abiotic Stress in \u003cem\u003eArabidopsis thaliana\u003c/em\u003e by Increasing Starch Availability. Int J Mol Sci., 28;24(15):12140. doi: 10.3390/ijms241512140. \u003c/li\u003e\n\u003cli\u003eBezuglova O., Gorovotsov A., Grinko A. Et al. (2021). Effect of pesticide and humic preparation on the soil structure during pea and chickpea cultivation. Agronomy, 11(10), 2053; https://doi.org/10.10.3390/agronomy11102053\u003c/li\u003e\n\u003cli\u003eCanavar O., Goren H.K., Kucuk Kaya S., Oncan Sumer F. (2023) Effect of potassium Humate on Soybean Germination Traits Under Salinity Stress Conditions. Turkish Journal of Agricultur \u0026ndash; Food Science an Technology, 11(10). 1889-1891, 2023 DOI: https://org/10.24925/turjaf,v11i10.1889-1891.6223\u003c/li\u003e\n\u003cli\u003eCanellas, L.P., Silva R.M., Barbosa L.J.d.S., et al. (2023). Co-Inoculation with \u003cem\u003eBradyrhisobium\u003c/em\u003e and Humic Substances Combined with Herbstances Seropedicae Promotes Soybean vegetative growth and nodulation. Agronomy, 13, 2660. https://doi.org/10.3390/agronomy13102660\u003c/li\u003e\n\u003cli\u003eCerezini P., Pipolo A., Hungria M. and Noguera M. (2014) Gaz exchanges and biological nitrogen fixation in soybean under water restriction. American Journal of Plant Sciences, 5, 4011-4017. doi:10.4236/ajps.2014.526419\u003c/li\u003e\n\u003cli\u003eDa Silva M.S.R. d., De Melo Silveira dos Santos B., Hidalgo Chavez D.W., et al. (2021) K-humate as an agricultural alternative to increase nodulation of soybeans inoculated with Bradyrhizobium. Biocatalysis Agricultural Biotechnology. 36. 102129. DOI: 10.16/j.bcab.2021.102129 \u003c/li\u003e\n\u003cli\u003eEl-Beltagi H.S., Al-Otaibi H.H., Pamar A., et al. (2023). Application of potassium humate and salicylic acid to mitigate salinity stress of common bean. Life 2023,13,449. https://doi.org/3390/life13020448\u003c/li\u003e\n\u003cli\u003eEl-Nwehy S.S., Sary D.H., Afify R.M.M. (2020) Effect of potassium humate follar application on yield and quality of soybean (\u003cem\u003eGlycine Max\u003c/em\u003e L.) grown on calcareous soil under irrigation water regime. Plant Archives Vol 20, № 1. P. 1495-1502. https//www.researchgate.net/publication/355168606\u003c/li\u003e\n\u003cli\u003eEvans I., O\u0026rsquo;Connor G.E., Turnen G.L. et al. (1989). N\u003csub\u003e2\u003c/sub\u003e-fixation and its value to soil N increase in lupin, field pea and other legumes in south-eastern Australia. Agricultural and food sciences, environmental science. DOI:10.1071/AR9890791\u003c/li\u003e\n\u003cli\u003eGadimov A.G., Ragimova S.N., Bakshaliyeva K.F., et al. (2024). Effect of Trichoderma and potassium humate on symbiotic characteristics of soybean. Inter. Scientific Journal. Science and innovation. https://doi.org/10.5281/zenodo.13837901\u003c/li\u003e\n\u003cli\u003eGadzhimamedov I.M., Talai S.M., Kosayev E.M. (2016). Methods of agrochemical analysis of soil, plants and fertilizers. Baku. Author Publishing House, 131 p.\u003c/li\u003e\n\u003cli\u003eGao T.G., Xu Y.Y., Feng J., et al. (2015) Nodulation characterization and proteomic profiling of Bradyrhizobium liaoningense CCBAU05525 in response to water-soluble humic materials. Sci. Rep. 5, 10836. DOI:10.1038/srep10836\u003c/li\u003e\n\u003cli\u003eHayam A. El-Shabouty, E.A.E.Elnefili (2022). Effect of biofertilization, potassium humate and rates of NPK fertilization on growth, Yield and Economic Indicators of soybean. Journal of soil sciences and agricultural engineering. Art. 4, Vol. 13, Issue 12, P. 413-420. DOI: 10.21608/JSSAE.2023.182034.1123\u003c/li\u003e\n\u003cli\u003eHangway J.J., Weber C.R. (1971). Accumulation of N, P and K by soybean (Glycine max (L) Merrill) plants. Agronomy Journal, 63, p.406-408.\u003c/li\u003e\n\u003cli\u003eHassanpanah D., Gurbanov E., Gadimov A., Shahriari R. (2008) Shortening transplantation periods of potato plantlets by use of potassium humate and kadostim and their effects on mini-tuber production. Pak J Biol Sci. 15; 11 (10):1370-4. Doi:103923/pjbs.2008.1370.1374. \u003c/li\u003e\n\u003cli\u003eHussain S., Ulhassan Z., Brestic M. et al. (2021). Photosynthesis research under climate change. Photosynth Res. 150 (1-3):5-19. doi: 10.1007/s11120-021-00861-z.\u003c/li\u003e\n\u003cli\u003eJuraev S.T., Bakhramova N.N. \u0026amp; Jumanova M.B. (2023). Selection Of High Photosynthetic Productivity Of Broad Bean (Vicia Faba L.) Lines. \u003cem\u003eDiversity Research: Journal of Analysis and Trends\u003c/em\u003e, \u003cem\u003e1\u003c/em\u003e(4), 6\u0026ndash;9. Retrieved from https://academiaone.org/index.php/2/article/view/173\u003c/li\u003e\n\u003cli\u003eKumudini S. Soybean growth and development. (2010). In book: The soybean: botany, production and uses pp. 48-73. DOI: 10.1079/9781845936440.0048\u003c/li\u003e\n\u003cli\u003eKaligiannidis S., Kalfas D., Chatzitheodoridis., Papaevangelou O. (2022). Role of Crop-Protection Technologies in Sustainable Agricultural Productivity and management. Land. 11(10), 1680. https://doi.org/10.3390/land11101680\u003c/li\u003e\n\u003cli\u003eLi R., Chen H., Yang Z. et al (2020). Research status of soybean symbiosis nitrogen fixation. Oil Crop Science Vol.5, Issue 1, p.6-10. https://doi.org/10.1016/j.ocsci.2020.03.005\u003c/li\u003e\n\u003cli\u003eMa Y, Dias MC and Freitas H (2020) Drought and Salinity Stress Responses and Microbe-Induced Tolerance in Plants. \u003cem\u003eFront. Plant Sci\u003c/em\u003e. 11:591911. doi: 10.3389/fpls.2020.591911\u003c/li\u003e\n\u003cli\u003eMelgar, A.E., Zelada, A.M. (2021) Evolutionary analysis of angiosperm dehydrin gene family reveals three orthologues groups associated to specific protein domains. \u003cem\u003eSci Rep\u003c/em\u003e \u003cstrong\u003e11\u003c/strong\u003e, 23869. https://doi.org/10.1038/s41598-021-03066-5 \u003c/li\u003e\n\u003cli\u003eLukomets V.M. (2010) Methodology for conducting field agrotechnical experiments with oil crops. - Krasnodar: OOO RIA \u0026quot;Alvi-Design\u0026quot;, 328p.\u003c/li\u003e\n\u003cli\u003eNassar K.E.M., Hayam A. El-Shaboury, Amany E. El-Sonbaty (2021). Influence of some potassium hummate application methods and mineral fertilization of nitrogen and posphorus on soybean yeld and quality. Menoufia J. Soil Sci., Vol. 6. Issue 4. P. 133-145. DOI:10.21608/MJSS.2021.175597\u003c/li\u003e\n\u003cli\u003eNichiporovich A.A. (1988). Photosynthetic activity of plants as the basis of their productivity in the biosphere and agriculture. Photosynthesis and production process. Moscow: Nauka, P. 5-28.\u003c/li\u003e\n\u003cli\u003eOlaetxea M., Mora V., Baigorri R., Zamarreno A. M., and Garcia-Mina J.M. (2020). The singular molecular conformation of humic acids in solution influences their ability to enhance root hydraulic conductivity and plant growth. Molecules 26, 7-10. doi:10.3390/molecules26010003\u003c/li\u003e\n\u003cli\u003ePosypanov G.S. (1991) Methods for studying biological fixation of atmospheric nitrogen. Moscow: Agropromizdat, 300 p.\u003c/li\u003e\n\u003cli\u003eRodrigo sa-Silva, Alexandre A., Brigido S., Oliveira S. (2017) Can stress response genes be used to improve the symbiotic performance of rhizobia. AIMS Microbiology., 3, pp.365-382. Doi:10.3934/microbiol.2017.3.365\u003c/li\u003e\n\u003cli\u003eSchmidt W., Santi S. (2007). Water-extractable humic substances alter root development and epidermal cell patten in Arabidopsis. Plant Soil 300, 259-267. doi:10.1007/s11104-007-9411-5\u003c/li\u003e\n\u003cli\u003eShahryari R., Gadimov A., Elshad Gurbanov, Valizadeh M. (2009). Application of potassium humate to wheat for organic agriculture in Iran. Asian Journal of Food and Agro-Industry, Special Issue, S164-S168.\u003c/li\u003e\n\u003cli\u003eShahryari R., Gurbanov E., Gadimov A., Hassanpanah D. (2008). Tolerance of 42 bread wheat genotypes to drought stress after anthesis. 15; 11 (10):1330-5. doi:10.3923/pjbs.2008.1330.1335\u003c/li\u003e\n\u003cli\u003eShahryari R., Valizadeh M., Gadimov A., Gurbanov E. (2013) In vitro effect of humic fertilizer on activity of nitrate reductase, under drought stress mediated through polyetilene glycole in wheat. Romanian agricultural research, 30 (30): 213-218\u003c/li\u003e\n\u003cli\u003eSinclair T.R. and Vadez V. (2012) The future of grain legumes in cropping systems. Crop Pasture Science, 63, 501-512. http://dx.doi.org/10.1071/CP12128\u003c/li\u003e\n\u003cli\u003eSong Q., Van Rie J., Den Boer B. et al. (2022) Diurnal and Seasonal Variations of Photosynthetic Energy Conversion Efficiency of Field Grown Wheat. Front. Plant Sci. 13:817654. doi: 10.3389/fpls.2022.817654 \u003c/li\u003e\n\u003cli\u003eTopunov A.F. (1996). Functioning of legume and regulation of oxygen regime in legume nodules: author\u0026apos;s abstract. Dis. Dr. of Biol. Sci. M. - 46 p.\u003c/li\u003e\n\u003cli\u003eZhang W., Li J., Li H., et al. (2023) Transcriptomic analysis of humic acid in relieving the inhibitory effect of high nitrogen on soybean nodulation. Front. Plant Sci. 14:1196939. doi.10.3389/fpls.2023.1196939\u003c/li\u003e\n\u003cli\u003eZheng Y., Wang X., Cui X. et all (2023a). Phytohormones regulate the abiotic stress: An overview of physiological, biochemical, and molecular responses in hortictural crops. Front. Plant Sci. 13:1095363. doi: 10.3389/fpls.2022.1095363\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTable 1 and 2 are available in the Supplementary Files section.\u003c/p\u003e\n"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"nodule bacterium, rhizotorphine, nitrogen fixation activity, photosynthetic apparatus, productivity","lastPublishedDoi":"10.21203/rs.3.rs-8258686/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8258686/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eIn the research, an attempt was made to theoretically substantiate the use of potassium humate (k-humate) preparation in improving the morphophysiological indicators and productivity of soybean plants of the “Bravo” variety infected with rhizotorphine, which is prepared based on the root nodule bacterium Bradyrhizibium japonicum (strains 634), in two different ecologically distinct regions (Kurdamir and Ganja) of the Republic of Azerbaijan. The role of rhizotorphin and potassium humate in changing the values of some morphological and physiological parameters of soybean plants was determined and the response of soybean plants to these factors was studied. The dynamics of nitrogen fixation activity and total nitrogen accumulation in soybean plants were studied. The results obtained indicate that k-humate increases the tolerance of soybean plants to environmental stress factors by improving their metabolic processes under unfavorable conditions. In both regions, k-humate plays a positive role in improving morphological parameters, forming the photosynthetic apparatus and symbiotic system, accumulating dry matter and total nitrogen, and also increasing productivity. The k-humate preparation works more effectively in Kurdamir, where soil and climatic conditions are more stressful than in Ganja.\u003c/p\u003e","manuscriptTitle":"The Effect of Potassium Humate on the Morphophysiological Indicators and Yield of Soybean Growing in Different Ecological Conditions of Azerbaijan","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-24 05:31:00","doi":"10.21203/rs.3.rs-8258686/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewersInvited","content":"","date":"2026-02-17T09:58:04+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-02-16T10:52:52+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-01-16T06:57:39+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-01-08T11:19:28+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2026-01-08T11:08:51+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"67cf4499-ea52-4ab6-9f9a-c33f6c5c426f","owner":[],"postedDate":"February 24th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":63230228,"name":"Biological sciences/Ecology"},{"id":63230229,"name":"Earth and environmental sciences/Ecology"},{"id":63230230,"name":"Biological sciences/Plant sciences"}],"tags":[],"updatedAt":"2026-02-24T05:31:00+00:00","versionOfRecord":[],"versionCreatedAt":"2026-02-24 05:31:00","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8258686","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8258686","identity":"rs-8258686","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}