Distribution of Phosphorus Fractions in Soils Developed From Two Geological Formations in Ogun State, Nigeria

Distribution of Phosphorus Fractions in Soils Developed From Two Geological Formations in Ogun State, Nigeria | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Distribution of Phosphorus Fractions in Soils Developed From Two Geological Formations in Ogun State, Nigeria Achile Blessed-Amos Kadiri, Ejike Charles Basil, Iduh Jonathan Joseph Otene This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9215421/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 8 You are reading this latest preprint version Abstract This study was carried to investigate the phosphorus distribution pattern in the soils developed from major geological formations in Ogun State Nigeria. Four locations were selected from the two geological formations that was used in this study and consequent of the land use types (cultivated and uncultivated). Soil profile were sunk in each of the four locations, making a total of four soil profile pits and a total of 27 soil samples collected according to pedogenic horizons were used in this study. Data obtained were subjected to Analysis of Variance (ANOVA) of GENSTAT discovering software and means were separated using Least Significant Difference at 5% level of probability. Results showed that the soils of the three geological formations were similar in texture (Loamy sand at the surface and Sandy clay loam at the sub-surface) while the soil pH (4.75–7.15), calcium (2.60–9.70 cmol kg − 1 ), magnesium (3.60–11.40 cmol kg − 1 ) and organic content (0.40–18.00 g/kg) varied across formations. The soils of Oshosun and Abeokuta Formations were deeper (> 180 cm) with soil colour that ranged from dark brown (epipedon) to yellowish red (endopedon). Al-P and water-soluble-P were significantly affected by geology and soil depth. However, the interactions of geology, land use and soil depths were seen to have been significant effect on Labile-P. Also, this study showed that Al-P, Fe-P and Labile-P was significantly affected by geology and Land use. The P forms distribution in the geology was as follows; Iron-P (40.94 mg/kg) > Labile-P (35.17 mg/kg) > Water soluble-P (9.98 mg/kg) > Calcium-P (9.34 mg/kg) > Aluminium-P (8.39 mg/kg). The study concluded that P distribution varied across the geological formations and had Fe-P as the most abundance and Al-P as the least. Phosphorus forms geology soil depth and land use INTRODUCTION Phosphorus (P) is one of the most essential macronutrients required for plant growth, playing a fundamental role in energy transfer, photosynthesis, nucleic acid synthesis, and overall metabolic processes in plants. Despite its importance, phosphorus is often a limiting nutrient in many tropical soils due to its low solubility and strong fixation reactions, which reduce its availability to plants (Brady & Weil, 2016 ). In highly weathered soils of the humid tropics, phosphorus is predominantly bound to iron (Fe) and aluminum (Al) oxides and hydroxides, forming stable complexes that are not readily accessible for plant uptake (Hinsinger, 2001 ). The concept of phosphorus fractionation has been widely used to understand the distribution and transformation of P in soils. Phosphorus exists in multiple pools, including labile, moderately labile, and non-labile fractions, each differing in their availability to plants and susceptibility to environmental changes. Sequential extraction procedures, such as the widely used Hedley fractionation method, provide insights into these P pools and their relative contributions to soil fertility (Hedley et al., 1982 ). The distribution of these fractions is influenced by several soil-forming factors, including parent material, climate, topography, biological activity, and time. Among these factors, parent material, as expressed through geological formation, exerts a strong control on soil mineralogy and chemical composition, thereby influencing phosphorus dynamics. Soils derived from different geological formations often exhibit significant variations in clay mineral types, Fe and Al oxide contents, and organic matter levels, all of which affect phosphorus retention and transformation processes (Sanchez, 2019 ). In tropical regions, highly weathered soils such as Ultisols and Oxisols typically have high P sorption capacities due to the dominance of sesquioxides, resulting in reduced P availability. Soil depth is another important factor affecting phosphorus distribution. Surface soils generally contain higher concentrations of organic matter and biologically active phosphorus fractions due to litter deposition and microbial activity, whereas subsoils tend to be dominated by more stable and occluded forms of phosphorus (Cross & Schlesinger, 1995 ). Additionally, land use practices such as cultivation, fallowing, and forest cover significantly influence phosphorus cycling by altering soil structure, organic matter content, and microbial processes. Continuous cultivation often leads to depletion of labile P fractions, while natural vegetation systems enhance P recycling and retention. In southwestern Nigeria, particularly in Ogun State, soils are formed from diverse geological formations, including basement complex rocks and sedimentary materials, which contribute to spatial variability in soil properties. However, there is limited information on how these geological formations influence the distribution of phosphorus fractions under varying soil depths and land use systems. Understanding these interactions is critical for developing efficient and site-specific phosphorus management strategies aimed at improving soil fertility and crop productivity in the region. Therefore, this study aims to evaluate the distribution of phosphorus fractions in soils developed from major geological formations in Ogun State, Nigeria. MATERIALS AND METHODS Study Area This study was carried out in Ogun State, Nigeria, on the soils of Abeokuta geological formation and Oshosun geological formation. Ogun State of Nigeria is located between Latitude 6.2 0 N and 7.8 0 N and Longitude 3.0 0 E, and 5.0 0 E, and has a total land mass of 16,409.2 km 2 . The State shares interstate boundaries with Oyo State to the north, Lagos and Atlantic Ocean to the south and Ondo State to the east and an international border with the Republic of Benin to the West. The northern part of the state lies within the derived savanna ecology, while the central part falls within the rain forest belt and the Southern part of the state falls into mangrove swamp. The climate of Ogun state is of typical tropical pattern with the rainy season starting about March and end in November, followed by dry season. The mean annual rainfall varies from 1280 mm in the Southern parts of the State to 1050 mm in the northern areas. Field Work Two locations were selected in each of the two geological formations (Abeokuta and Oshosun formations). In the Abeokuta formation, the study was carried out in Odogbolu and Ayetoro village. Meanwhile, in Oshosun formation, Ibese and Ijebu-Ife Village was the study area. In Odogbolu village, two soil profile were sunk, first was on a cultivated land (6.83165 0 N, 3.79448 0 E) and the second on an uncultivated land (6.83161 0 N, 3.79443 0 E). Similarly, in Ayetoro, first soil profile pit was located on a cultivated land (7.25722 0 N, 3.05519 0 E) while, the second soil profile was an uncultivated land (7.25701 0 N, 3.05526 0 E). Also, in Ibese village, a soil profile pit was sunk on two land use types; cultivated (7.05162 0 N, 3.04562 0 E) and uncultivated (7.05128 0 N, 3.04378 0 E). In the same manner, two soil profile pits were sunk on cultivated land (6.77644 0 N, 4.03095 0 E) and uncultivated land (6.77666 0 N, 4.03027 0 E) respectively. The profile pits were described according to the FAO ( 2006 ) guideline on soil profile description, a total of 27 soil samples were collected according to the pedogenic horizons of the profiles in a well labeled sample bag. All the samples collected were air dried and sieved using 2 mm sieve before taking to the Laboratory for the forms of phosphorus studies. LABORATORY ANALYSIS Soil pH was determined electrometrically in 1:2 (soil: water ratio) suspension (Mclean, 1965 ). Particle size analysis was determined using the hydrometer method as described by Bouyocous (1962). Total soil organic carbon was determined using acid dichromate wet-oxidation procedure of Walkley and Black method as described by Nelson and Sommers (1982). The available P was extracted using Bray-1 extractant at a soil: extractant ratio of 1:5, while the concentration of the available P in the extract was determined by vanado-molybdate blue method of Murphy and Riley (1962) using spectrophotometer at 882 nm wavelength. Finally, the phosphorus forms in the soil were determined by sequential fractionation method of Chang and Jackson (1957) as modified by Manojlovic et al. ( 2007 ). STATISTICAL ANALYSIS Data obtained were subjected to Analysis of Variance (ANOVA) of GENSTAT discovering software and means were separated using Least Significant Difference at 5% level of probability. RESULTS Morphological and physical Properties of Soils of the study areas Oshosun Formation The soils of Oshosun formation were very deep with depths greater than 150 cm at Ibese and Ijebu-Ife which were the two locations studied on this geological formation (Table 1). The colour varied between Yellowish red (5YR) and Red (2.5YR) range. The surface horizons had colours that ranged from very dark red (10YR) to very dusky red (10R). While, the profiles dug at Ibese had very dusky red epipedon, those of Ijebu-Ife had colours variation between Dark reddish brown (5YR3/4) and very dark brown (10YR2/2) in the epipedon. In terms of land use, uncultivated soil at Oshosun formation, had a dark brown (7.5YR3/4) epipedon while the cultivated soil was dark reddish brown (5YR3/4). The sub-surface colours, especially at depths below 30 cm were dark red (10R3/6) in all the profiles irrespective of the location (Table 1). The texture of all the surface soils of Oshosun formation were loamy sand (LS), while the sub-surface horizons had sandy clay loam (SCL) texture. In term of soil textural characteristics, the soil of Oshosun formation were uniform across the locations. Furthermore, the soils had structure that ranged from granular, crumb to fine sub-angular block (fsbk) on the surface but predominantly coarse-angular block (Cak) structure in the subsurface. The structures of the subsurface horizons were more uniform across the location and varied directly with the clay content of the soil. In terms of the soils ability to resist deformation under an externally applied force (consistency), all the soils sampled at Ijebu-Ife profiles had loose (L) consistency, while, those of Ibese were loose in the surface but were moderately firm at the subsurface horizons. The pattern of distribution of the sand particle fraction was similar in the two profiles dug at Ibese. The profiles had sand content that decreased with increasing soil depth. Conversely, the clay content of the soils increased with increasing soil depth with the subsurface argilluviation. However, the distribution pattern of silt content in Ibese was irregular within the profiles. The sand content in the surface soils ( 30 cm) had sand content that ranged from 533.60 g/kg to 703.60 g/kg. The clay content in this region ranged between 270.0 g/kg and 274.30 g/kg at the surface, while, the sub-surface (> 30 cm), clay content ranged between 285.40 g/kg and 452.2 g/kg within the profiles. The silt contents in the soils of Ibese ranged from 0.6 g/kg to 15.00 g/kg in the surface, while the subsurface horizons had silt contents that ranged from 35.00 g/kg to 15.00 g/kg. Similar to Ibese particle size distribution pattern, the Ijebu-Ife had particle size distribution that was similar in the two profiles. The sand contents in the two profiles decreased with increasing soil depth, while, the clay contents increased with increasing soil depth. The sand contents in the surface soils ranged from 635.00 g/kg to 685.00 g/kg, while, the sub-surface soils had sand content that ranged from 473.60 g/kg to 635.00 g/kg within the profile. The clay contents in the surface and subsurface soils ranged from 302.20 g/kg to 321.40 g/kg and from 331.4 g/kg to 522.2 g/kg respectively. The silt content in Ijebu-Ife had an irregular pattern of distribution within the two profiles. The surface soils had silt content that ranged from 35.00 g/kg to 12.8 g/kg, while the subsurface soils had silt contents that ranged between 42.00 g/kg and 28.00 g/kg. Abeokuta Formation The soils of Ayetoro in Abeokuta formation were generally shallow with maximum depth 100 cm in all the profiles. The soils of Ayetoro had colours that varied from dark brown (7.5YR3/4) at the surface (epipedon) to yellowish red (5YR4/6) at the subsurface, while, Odogbolu soil had very dark greyish brown (10YR3/2) colour at the surface horizons and red (2.5YR4/6) at the subsurface horizons. The subsurface soil colour in Ayetoro profile 2 and Odogbolu profiles were generally yellowish red (5YR4/6) to red (Table 1). Generally, the textures of the soils of this formation were Loamy sand on the surface and sandy clay loam at the subsurface. The structure of the soils varied among the profiles, Ayetoro pedon 1 had coarse sub-angular blocky down the profile, while, pedon 2 had crumbly structure at the surface and granular on the subsurface. Odogbolu profiles had fine sub-angular blocky structure in the surface horizons and fine sub-angular blocky to medium fine blocky at the subsurface horizons. The consistency of the soils in this formation varied in all the locations, Ayetoro soils had very friable to friable consistency in all the profiles, however, Odogbolu profiles were either moderately friable or moderately firm in all the profiles. The soils of Ayetoro were gravelly with the present of plinthites. The sand and silt content of Ayetoro pedon 1 increased down the profiles, but there was no pattern of distribution in pedon 2. The silt content of Ayetoro soils ranged from 35.00 g/kg to 32.00 g/kg in the surface horizons, but the subsurface horizons had silt content that ranged in values from 70.00 g/kg to 45.70 g/kg. The sand content of the two profiles ranged from 515.80 g/kg to 583.6 g/kg, while the subsurface horizons had the sand ranged from 533.60 g/kg to 681.5 g/kg. Chemical Properties of the soils of the study areas Abeokuta formation Table 2 presents the chemical properties of the studied soils. The soils of Abeokuta formation and Basement complex had neutral pH range with mean value of 6.32 and 6.74, and the coefficient variation of 8.16% and 6.73% respectively. However, the soils of Oshosun formation were slightly acidic with a mean pH of 5.53 and %CV of 9.01. The pH (H 2 O) of the cultivated soils of Abeokuta ranged from 6.15 to 7.15 in the surface horizons, while the subsurface horizons had pH that ranged from 6.15 to 6.70. Whereas, the uncultivated soils had pH that ranged from 5.95 to 6.70 in the surface horizons the subsurface horizons had pH that ranged from 5.25 to 6.65. The Ca content in the cultivated land of Abeokuta formation decreased down the horizons, but the uncultivated land had no pattern of Ca distribution. In the cultivated land of Abeokuta formation, the Ca content of the soils ranged from 2.70 to 3.60 cmol/kg in the surface horizons but ranged from 3.60 to 5.50 cmol/kg in the subsurface horizons. However, the uncultivated soils had Ca content that ranged from3.30 to 4.30 cmol/kg in the surface horizons, while the Ca content in the subsurface horizons ranged from 3.30 to 3.50 cmol/kg. The Magnesium (Mg) and total exchangeable acidity (TEA) in the surface soils of the cultivated soils of Abeokuta formation ranged from 3.80 to 4.50 cmol/kg and from 0.10 to 0.20 cmol/kg respectively. Similarly, the subsurface horizons had Mg and TEA content that ranged from 3.70 to 8.00 cmol/kg and from 0.20 to 0.70 cmol/kg respectively. The Mg and TEA in the uncultivated soils ranged from 4.40 to 6.20 cmol/kg and from 0.10 to 0.50 cmol/kg respectively in the surface horizons, while the subsurface horizons ranged from 3.60 to 4.90 cmol/kg and from 0.30 to 0.70 cmol/kg respectively. (Table 2) The organic carbon (OC) and the available P in the soils of Abeokuta formation were generally low, the Organic Carbon and available P in the surface of the cultivated land ranged from 0.32 to 0.78% and from 1.42 to 71.92 mg/kg respectively (Table 5). The subsurface horizons of the cultivated land had %OC and available P that ranged from 0.22 to 0.36% and < 0.001 to 8.12 mg/kg respectively. Oshosun formation The pH of this formation was in the acidic range in the all the locations studied. The pH and Ca content in this formation ranged from 5.85 to 5.20 and 3.00 to 7.60 mg/kg in the surface soils of the cultivated lands respectively. While, the subsurface soils ranged from 4.80 to 6.20 and 3.10 to 9.70 mg/kg. Whereas, the pH and Ca in the uncultivated soils varied from 5.25 to 5.95 and 3.60 to 4.50 mg/kg in the surface horizons, those of the subsurface horizons varied from 4.75 to 6.05 and 2.60 to 6.60 mg/kg respectively. More so, the Mg and TEA of the soils of the cultivated lands varied from 6.70 to 11.40 cmol/kg and from 0.10 to 1.7 cmol/kg in the surface horizons, while the subsurface horizons varied from 3.00 to 11.00 cmol/kg to 6.40 cmol/kg respectively. The uncultivated lands had Mg and TEA content that ranged from 5.60 to 11.40 cmol/kg and from 0.10 to 1.60 cmol/kg respectively in the surface horizons but ranged from 4.10 to 9.50 cmol/kg and from 0.10 to 1.60 cmol/kg in the subsurface horizons respectively. The Organic Carbon and Available P in the cultivated lands of this formation ranged from 5.40 to 8.40 g/kg and from 7.97 to 18.23 mg/kg in the surface horizons, while the subsurface soils ranged from 1.00 to 1.8 g/kg and from 1.14 to 9.54 mg/kg respectively. However, the uncultivated lands had Organic Carbon and available P that ranged from 8.10 to 11.80 g/kg and from 0.85 to 8.54 mg/kg in the surface horizons respectively, while the subsurface horizons ranged from 0.8 to 3.4 g/kg and from 0.28 to 10.40 mg/kg respectively. Phosphorus fractions across the geological formations Abeokuta formation The distribution pattern of the P forms in this formation (Table 3) had Ca-P, WS-P and Labile-P increasing with increased depth, while, Al-P and Fe-P decreased with increased in depth in the cultivated land of Ayetoro. The Ca-P and Al-P content in Ayetoro ranged from 6.67 to 16.22 mg/kg and 4.46 to 11.16 mg-kg respectively in the cultivated land (pedon 1). The Ca-P content in the uncultivated land increased with increasing and it’s ranged from 6.67 to 16.22 mg/kg, while the Al-P ranged from 4.46 and 5.58 mg/kg. The Fe-P and WS-P content in Ayetoro decreased with increasing depth ranging from 24.41 to 29.40 mg/kg and 7.13 to 8.23 mg/kg in the cultivated land (pedon 1) respectively, while the uncultivated land ranged from 25.52 to 32.17 mg/kg and 7.68 to 24.13 mg/kg respectively. The Labile-P content in the cultivated (pedon 1) of Ayetoro ranged from 27.42 to 28.51 mg/kg with increased in soil depth, while the uncultivated land had the Labile-P content ranging from 16.01 to 49.35 mg/kg with increased in soil depth. Considering the Ca-P and Al-P in the soils of Odogbolu, the Ca-P and Al-P profile distribution in this location were irregular while the Al-P decreased with increasing soil depth in the cultivated. The Ca-P and Al-P in the cultivated soil (pedon 1) of Odogbolu ranged from 6.79 to 65.71 mg/kg and 6.14 to 20.09 mg/kg respectively. The Fe-P and WS-P profile distribution in the cultivated soils (pedon 1) were irregular, and they ranged from 33.28 to 54.36 mg/kg and 4.39 to 17.55 mg/kg respectively. Similarly, the Labile-P profile distribution was irregular and ranged from 28.59 to 92.12 mg/kg. Oshosun formation The pattern of the profile distribution of the P forms in this formation was irregular across the locations. The Ca-P and Al-P in the cultivated land (pedon 1) of Ibese ranged from 2.14 to 5.25 mg/kg and 7.23 to 10.60 mg-kg respectively. Similarly, the Fe-P and WS-P content in this location ranged from 17.75 to 62.13 mg/kg and 3.29 to 16.45 mg/kg, the labile-P content ranged from16.01 to 44.94 mg/kg respectively. However, the uncultivated land (pedon 2) of Ibese had Ca-P and Al-P contents ranging from 4.75 to 8.75 mg/kg and 8.37 to 9.49 mg/kg respectively, while Fe-P and WS-P ranged from 5.54 to 88.75 mg/kg and 3.33 to 28.84 mg/kg respectively. More so, the Labile-P content ranged from 38.84 to 81.70 mg/kg (Table 3). Similar to Ibese soils, the Ijebu-Ife had Ca-P and Al-P content that ranged from 4.53 to 7.01 mg/kg and 1.67 to 16.18 mg/kg in the cultivated soils (pedon 1) respectively. The Fe-P and WS-P in this location ranged from ranged from 29.40 to 56.02 mg/kg and 4.99 to 12.06 mg/kg, while, the Labile-P ranged from 12.58 to 29.61 mg/kg respectively. However, the uncultivated land had Ca-P and Al-P that ranged from 6.72 to 12.34 mg/kg and 3.35 to 11.16 mg/kg, the Fe-P and WS-P ranged from 25.52 to 79.88 mg/kg and 4.94 to 12.20 mg/kg respectively. The Labile-P content ranged from 13.72 to 55.93 mg/kg (Table 3). Interactions Effect of Geology and Land use on Phosphorus Forms Interactions between geological formation and land use (cultivated land and uncultivated land) significantly affected the Al-P, Fe-P, Labile-P and Water Soluble-P content of the soils, but, there was no significant different (p > 0.05) in the Ca-P contents across the formations. (Table 4). Considering the effect of geology and land use in the distribution of Al-P, the result showed that in the cultivated soils, the values of Al-P in Oshosun formation was significantly lower. Interactions effects of Geology and Depth on Phosphorus Forms Table 5 presents the interactions between the geology and soil depths. It was observed that Al-P and Water Soluble-P were significantly affected, while Ca-P, Fe-P and Labile-P were not affected by the interaction of these factors at 5% level of probability (Table 5). Statistically, the mean values of Al-P content in the surface ( 0.05). However, the values of Al-P content in the soils of Abeokuta formation and Oshosun formation were not statistically different (p > 0.05). Looking at the Al-P content down the profiles, the Al-P content in the soils of the Basement complex increased with increasing soil depth, while, the Al-P contents in the soils of Abeokuta formation and Oshosun formation decreased with increasing soil depth (Table 5). The interaction between the geological formation and soil depth significantly affected (p < 0.05) the Water Soluble-P of the surface soils. The value of Water Soluble-P in the surface soils of Abeokuta formation was statistically higher than those of the Basement complex and Oshosun formation. Furthermore, the mean value of the Water-Soluble content in the surface soils of the Basement complex was not statistically different (p > 0.05), but, there was significant different (p < 0.05) between the Water Soluble-P content of the surface soils of the Abeokuta formation and those of the Basement complex and Oshosun formation. The sub-surface Water Soluble content of the Basement complex was significantly different (p < 0.05) from those of Abeokuta formation and Oshosun formation, while, the mean values of the Water Soluble-P contents of the sub-surface soils of Abeokuta formation and Oshosun formation were not statistically different (p < 0.05). Considering the distribution of Water Soluble-P down the horizons, the Water-Soluble content in the sub-surface soils of the Basement complex and Oshosun formation increased down the horizons, whereas, the Water Soluble-P in the sub-surface of Abeokuta decreased down the horizons (Table 5). Interaction effects of Geology, Land use and Depth on Phosphorus Forms The interactions between the geological materials, land use and depth of the three formations on the phosphorus forms affected only the Labile-P significantly ((p < 0.05) (Table 6a & 6b). The Labile-P contents of the surface soils of the cultivated land of Abeokuta formation were significantly higher in the formations and significantly different (p 0.05) between the Basement complex and Oshosun formation, however, the subsurface soils of Abeokuta formation and Oshosun formation were significantly different (p < 0.05) from those of the Basement complex subsurface soils which had the highest Labile-P content. Oshosun formation had the least mean value of Labile-P (Table 6a & 6b). Comparatively, the Labile-P contents according to the soil depths in the geological formations showed that, Basement complex soils had the highest Labile-P content that increased with soil depth in the cultivated soils, whereas, the Labile-P content in the soils of Abeokuta formation and Oshosun formation decreased with soil depths in the cultivated lands. However, the Labile-P content in the uncultivated soils of the Basement complex decreased with soil depth, while the Labile content in the uncultivated soils of Abeokuta formation increased with soil depths. Conversely, the mean value of the Labile-P content in the surface and sub-surface soil of the uncultivated soils of Oshosun formation was constant down the horizons. Conversely, the mean value of the Labile-P content in the surface and sub-surface soil of the uncultivated soils of Oshosun formation was constant down the horizons. DISCUSSION Oshosun formation and Abeokuta formations had deep soils, this is due to sedimentary origin. The organic carbon contents of Abeokuta formation were low, this could be as result of the rapid rate of decomposition as aided by the shallow soil depths (Don et al., 2011 ). However, the organic carbon in the soils of Oshosun formation were high. The soil pH of the geological formations was moderately acidic. The soils had high magnesium but moderately low calcium content. The available phosphorus was also low. Generally, the soils of these geological formations are highly weathered and of inherently low fertility. The distribution of the P forms in the geological formations had Fe-P as the most abundant P forms and Ca-P as the least abundance. This is because hydroxides and oxyhydroxides of Fe are the predominant, whereas Calcium is the lowest in the the geological formations. Mustapha et al., ( 2007 ) reported that Fe-P was more abundant in the soils of Bauchi Local Government Area. The P forms, Al-P, Fe-P, Labile-P and Water Soluble-P were not affected significantly by the the geological formations, but, Ca-P varied significantly in the geological formations. This could be as the result of the parent materials of the formations (Daly et al., 2015 ). Labile P content in the soils was affected significantly by the interactions between geology and land use and depth. This could be as the result of applied fertilizer on the cultivated lands (Maranguit et al., 2017 ). The distribution of phosphorus fractions was influenced by soil properties such as pH, clay content and exchangeable as reported Achile et al., ( 2024 ) in the Basement Complex formation of Ogun State. The report also stated that Avail-P, Ca, Ca-P, Mg, k and pH were significant (p < 0.001) but negatively correlated with the Aluminum P (Al-P) content of the soils. CONCLUSION This study was design to investigate the distribution of phosphorus fractions in soils developed from major geological formations. The P forms distribution in the geology was as follows; Iron-P (40.94 mg/kg) > Labile-P (35.17 mg/kg) > Water soluble-P (9.98 mg/kg) > Calcium-P (9.34 mg/kg) > Aluminium-P (8.39 mg/kg) and this P distribution varied across the geological formations. The study also indicated that Fe-P was the most abundance and Al-P as the least. The abundance of Fe-P fraction will definitely decrease the Avail-P content in the soils. It is therefore recommended that further studies be carried to understand the sorption characteristics of the soils of the geological formations. Declarations Ethics approval and consent to participate Not applicable. Consent for publication Not application. Competing interests The authors declare no competing interests. Clinical Trial number Not applicable Funding This research work was personally funded and no organization shared in the funding. Author Contribution Achile Blessed-Amos Kadiri carried out the experimental works, performed data analysis and interpretation, and manuscript drafting.Basil Ejike Charles assisted in the field work, laboratory analysis and review of the manuscript.Iduh Jonathan Joseph Otene assisted proof-reading of the manuscript and formatting of the tables. Data Availability All the datasets for this study available from the corresponding author on reasonable request via email of the author. References Achile BK, Basil EC, Muhammed B, Otene IJJ, Adeyi HA, Omatule LA. (2024). Impacts of Land Use and Soil Depth on Phosphorus Forms in Soils of Basement Complex Geology, Ogun State, Nigeria. Journal of Agriculture, Forestry & Environment, 2024, 8(1): 131–145 , https://jafe.net.ng/ Bouyoucos CJ. (1962). Hydrometer method improved for making particle size analysis of soils. Soil Science Society American Proceedings . 26: 464–465. Brady NC, Weil RR. (2016). The nature and properties of soils (15th ed.). Pearson. Cross AF, Schlesinger WH. A literature review and evaluation of the Hedley fractionation. Geoderma. 1995;64:197–214. Daly K, Styles D, Lalor S, Wall DP. Phosphorus sorption, supply potential and availability in soils with contrasting parent material and soil chemical properties. Eur J Soil Sci. 2015;66(4):792–801. Don A, Schumacher J, Freibauer A. Impact of tropical land-use change on soil organic carbon stocks–a meta‐analysis. Glob Change Biol. 2011;17(4):1658–70. FAO. Guideline for soil description. Fourth Edition. World Food and Agricultural Organization. Rome; 2006. Italy 109pp. Hedley MJ, Stewart JWB, Chauhan BS. Changes in soil phosphorus fractions. Soil Sci Soc Am J. 1982;46:970–6. Hinsinger P. Bioavailability of soil inorganic phosphorus. Plant Soil. 2001;237:173–95. Liu W, Zhang Y, Jiang S, Deng Y, Christie P, Murray PJ, Zhang J. Arbuscular mycorrhizal fungi in soil and roots respond differently to phosphorus inputs in an intensively managed calcareous agricultural soil. Sci Rep. 2016;6(1):24902. Manojlovic D, Todorovic M, Jovicic J, Krsmanovic VD, Pfendt PA, Golubovic R. Preservation of water quality in accumulation Lake Rovni: the estimate of the emission of phosphorus from inundation area. Desalination. 2007;213(1–3):104–9. Maranguit D, Guillaume T, Kuzyakov Y. (2017). Land-use change affects phosphorus. fractions in highly weathered tropical soils. Catena , 149, 385–393. Mclean EO. (1965). Aluminum: In methods of soil analysis (ed. C.A. Black) agronomy No.9 part 2. American Society of Agronomy , Madison. Wisconisin pp978-998. Moazed H, Hoseini Y, Naseri AA, Abbasi F. Determining phosphorus adsorption isotherm in soil and its relation to soil characteristics. J Food Agric Environ. 2010;8(2):1153–7. Mustapha S, Yerima SI, Voncir N, Ahmed BI. Plinthaquults in Bauchi Local Government Area, Bauchi State, Nigeria. Int J Soil Sci. 2007;2(3):197–203. Sanchez PA. Properties and management of soils in the tropics. 2nd ed. Cambridge University Press; 2019. Nelson DW, Sommers LE, Page AL. Methods of soil analysis. Part. 1982;2:539–79. Tables Tables 1 to 6 are available in the Supplementary Files section. Additional Declarations No competing interests reported. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9215421","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":629790595,"identity":"e3ef896a-b5c0-435b-9f50-a50d4a1563af","order_by":0,"name":"Achile Blessed-Amos Kadiri","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABA0lEQVRIiWNgGAWjYBACCQYGgwMMBkCSmbmBgbHBBijG2HiASC2MIC1pIC0NBLWAGQYMYC2HwRy8WiTbD288XFFgJ2/Oztj4gHHHebu17YeBttTYROPSIs2TVnDwjEGy4c5mxmYDxjO3k7edSQRqOZaW24BDixxDjsHBBgPmBIPDjG0SjG23k80OALUAXYhbC/8bkJZ6kJb2H4xt55LNzj/Er0VaAmzLYbAtDIxtB+zMbhCwRXLGswKgluOGGw4zNksknklOMLsBtCUBj18kzidv/tjwp1re4Pzhgx8+7rCzNzuf/vDBhxobnFpQQQIDQ2IDlEE8sCdF8SgYBaNgFIwMAAD3v2aw2QuXUwAAAABJRU5ErkJggg==","orcid":"","institution":"Federal University of Agriculture","correspondingAuthor":true,"prefix":"","firstName":"Achile","middleName":"Blessed-Amos","lastName":"Kadiri","suffix":""},{"id":629790597,"identity":"a917ade4-4e87-45c3-a97b-ac6d32216b0a","order_by":1,"name":"Ejike Charles Basil","email":"","orcid":"","institution":"Federal University of Agriculture","correspondingAuthor":false,"prefix":"","firstName":"Ejike","middleName":"Charles","lastName":"Basil","suffix":""},{"id":629790603,"identity":"43006c5a-54ad-44c9-8136-98c5bec7acb6","order_by":2,"name":"Iduh Jonathan Joseph Otene","email":"","orcid":"","institution":"Prince Abubakar Audu University, Anyigba","correspondingAuthor":false,"prefix":"","firstName":"Iduh","middleName":"Jonathan Joseph","lastName":"Otene","suffix":""}],"badges":[],"createdAt":"2026-03-24 18:53:31","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9215421/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9215421/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":108007745,"identity":"81467afc-d6fb-4bcd-844c-c419a34bf498","added_by":"auto","created_at":"2026-04-28 13:01:40","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":186842,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9215421/v1/bd267e78-c283-42c0-a6f4-ebcaf57d2530.pdf"},{"id":108001177,"identity":"aeb19b61-f0f9-4dba-bb46-11b0220b9194","added_by":"auto","created_at":"2026-04-28 11:58:03","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":73890,"visible":true,"origin":"","legend":"","description":"","filename":"Tables.docx","url":"https://assets-eu.researchsquare.com/files/rs-9215421/v1/c9fdaf35b770e31e14b70ed2.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eDistribution of Phosphorus Fractions in Soils Developed From Two Geological Formations in Ogun State, Nigeria\u003c/p\u003e","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003ePhosphorus (P) is one of the most essential macronutrients required for plant growth, playing a fundamental role in energy transfer, photosynthesis, nucleic acid synthesis, and overall metabolic processes in plants. Despite its importance, phosphorus is often a limiting nutrient in many tropical soils due to its low solubility and strong fixation reactions, which reduce its availability to plants (Brady \u0026amp; Weil, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). In highly weathered soils of the humid tropics, phosphorus is predominantly bound to iron (Fe) and aluminum (Al) oxides and hydroxides, forming stable complexes that are not readily accessible for plant uptake (Hinsinger, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2001\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe concept of phosphorus fractionation has been widely used to understand the distribution and transformation of P in soils. Phosphorus exists in multiple pools, including labile, moderately labile, and non-labile fractions, each differing in their availability to plants and susceptibility to environmental changes. Sequential extraction procedures, such as the widely used Hedley fractionation method, provide insights into these P pools and their relative contributions to soil fertility (Hedley et al., \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e1982\u003c/span\u003e). The distribution of these fractions is influenced by several soil-forming factors, including parent material, climate, topography, biological activity, and time.\u003c/p\u003e \u003cp\u003eAmong these factors, parent material, as expressed through geological formation, exerts a strong control on soil mineralogy and chemical composition, thereby influencing phosphorus dynamics. Soils derived from different geological formations often exhibit significant variations in clay mineral types, Fe and Al oxide contents, and organic matter levels, all of which affect phosphorus retention and transformation processes (Sanchez, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). In tropical regions, highly weathered soils such as Ultisols and Oxisols typically have high P sorption capacities due to the dominance of sesquioxides, resulting in reduced P availability.\u003c/p\u003e \u003cp\u003eSoil depth is another important factor affecting phosphorus distribution. Surface soils generally contain higher concentrations of organic matter and biologically active phosphorus fractions due to litter deposition and microbial activity, whereas subsoils tend to be dominated by more stable and occluded forms of phosphorus (Cross \u0026amp; Schlesinger, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e1995\u003c/span\u003e). Additionally, land use practices such as cultivation, fallowing, and forest cover significantly influence phosphorus cycling by altering soil structure, organic matter content, and microbial processes. Continuous cultivation often leads to depletion of labile P fractions, while natural vegetation systems enhance P recycling and retention.\u003c/p\u003e \u003cp\u003eIn southwestern Nigeria, particularly in Ogun State, soils are formed from diverse geological formations, including basement complex rocks and sedimentary materials, which contribute to spatial variability in soil properties. However, there is limited information on how these geological formations influence the distribution of phosphorus fractions under varying soil depths and land use systems. Understanding these interactions is critical for developing efficient and site-specific phosphorus management strategies aimed at improving soil fertility and crop productivity in the region.\u003c/p\u003e \u003cp\u003eTherefore, this study aims to evaluate the distribution of phosphorus fractions in soils developed from major geological formations in Ogun State, Nigeria.\u003c/p\u003e"},{"header":"MATERIALS AND METHODS","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy Area\u003c/h2\u003e \u003cp\u003eThis study was carried out in Ogun State, Nigeria, on the soils of Abeokuta geological formation and Oshosun geological formation. Ogun State of Nigeria is located between Latitude 6.2 \u003csup\u003e0\u003c/sup\u003eN and 7.8\u003csup\u003e0\u003c/sup\u003e N and Longitude 3.0\u003csup\u003e0\u003c/sup\u003e E, and 5.0\u003csup\u003e0\u003c/sup\u003e E, and has a total land mass of 16,409.2 km\u003csup\u003e2\u003c/sup\u003e. The State shares interstate boundaries with Oyo State to the north, Lagos and Atlantic Ocean to the south and Ondo State to the east and an international border with the Republic of Benin to the West. The northern part of the state lies within the derived savanna ecology, while the central part falls within the rain forest belt and the Southern part of the state falls into mangrove swamp. The climate of Ogun state is of typical tropical pattern with the rainy season starting about March and end in November, followed by dry season. The mean annual rainfall varies from 1280 mm in the Southern parts of the State to 1050 mm in the northern areas.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eField Work\u003c/h3\u003e\n\u003cp\u003eTwo locations were selected in each of the two geological formations (Abeokuta and Oshosun formations). In the Abeokuta formation, the study was carried out in Odogbolu and Ayetoro village. Meanwhile, in Oshosun formation, Ibese and Ijebu-Ife Village was the study area. In Odogbolu village, two soil profile were sunk, first was on a cultivated land (6.83165\u003csup\u003e0\u003c/sup\u003e N, 3.79448\u003csup\u003e0\u003c/sup\u003e E) and the second on an uncultivated land (6.83161\u003csup\u003e0\u003c/sup\u003e N, 3.79443\u003csup\u003e0\u003c/sup\u003e E). Similarly, in Ayetoro, first soil profile pit was located on a cultivated land (7.25722\u003csup\u003e0\u003c/sup\u003eN, 3.05519\u003csup\u003e0\u003c/sup\u003eE) while, the second soil profile was an uncultivated land (7.25701\u003csup\u003e0\u003c/sup\u003eN, 3.05526\u003csup\u003e0\u003c/sup\u003eE).\u003c/p\u003e \u003cp\u003eAlso, in Ibese village, a soil profile pit was sunk on two land use types; cultivated (7.05162\u003csup\u003e0\u003c/sup\u003eN, 3.04562\u003csup\u003e0\u003c/sup\u003eE) and uncultivated (7.05128\u003csup\u003e0\u003c/sup\u003eN, 3.04378\u003csup\u003e0\u003c/sup\u003eE). In the same manner, two soil profile pits were sunk on cultivated land (6.77644\u003csup\u003e0\u003c/sup\u003eN, 4.03095\u003csup\u003e0\u003c/sup\u003eE) and uncultivated land (6.77666\u003csup\u003e0\u003c/sup\u003eN, 4.03027\u003csup\u003e0\u003c/sup\u003eE) respectively. The profile pits were described according to the FAO (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2006\u003c/span\u003e) guideline on soil profile description, a total of 27 soil samples were collected according to the pedogenic horizons of the profiles in a well labeled sample bag. All the samples collected were air dried and sieved using 2 mm sieve before taking to the Laboratory for the forms of phosphorus studies.\u003c/p\u003e\n\u003ch3\u003eLABORATORY ANALYSIS\u003c/h3\u003e\n\u003cp\u003eSoil pH was determined electrometrically in 1:2 (soil: water ratio) suspension (Mclean, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e1965\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eParticle size analysis was determined using the hydrometer method as described by Bouyocous (1962). Total soil organic carbon was determined using acid dichromate wet-oxidation procedure of Walkley and Black method as described by Nelson and Sommers (1982). The available P was extracted using Bray-1 extractant at a soil: extractant ratio of 1:5, while the concentration of the available P in the extract was determined by vanado-molybdate blue method of Murphy and Riley (1962) using spectrophotometer at 882 nm wavelength. Finally, the phosphorus forms in the soil were determined by sequential fractionation method of Chang and Jackson (1957) as modified by Manojlovic et al. (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2007\u003c/span\u003e).\u003c/p\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eSTATISTICAL ANALYSIS\u003c/h2\u003e \u003cp\u003eData obtained were subjected to Analysis of Variance (ANOVA) of GENSTAT discovering software and means were separated using Least Significant Difference at 5% level of probability.\u003c/p\u003e \u003c/div\u003e"},{"header":"RESULTS","content":"\u003cdiv id=\"Sec8\"\u003e\n \u003ch2\u003eMorphological and physical Properties of Soils of the study areas\u003c/h2\u003e\n \u003cdiv id=\"Sec9\"\u003e\n \u003ch2\u003eOshosun Formation\u003c/h2\u003e\n \u003cp\u003eThe soils of Oshosun formation were very deep with depths greater than 150 cm at Ibese and Ijebu-Ife which were the two locations studied on this geological formation (Table\u0026nbsp;1). The colour varied between Yellowish red (5YR) and Red (2.5YR) range.\u003c/p\u003e\n \u003cp\u003eThe surface horizons had colours that ranged from very dark red (10YR) to very dusky red (10R). While, the profiles dug at Ibese had very dusky red epipedon, those of Ijebu-Ife had colours variation between Dark reddish brown (5YR3/4) and very dark brown (10YR2/2) in the epipedon. In terms of land use, uncultivated soil at Oshosun formation, had a dark brown (7.5YR3/4) epipedon while the cultivated soil was dark reddish brown (5YR3/4).\u003c/p\u003e\n \u003cp\u003eThe sub-surface colours, especially at depths below 30 cm were dark red (10R3/6) in all the profiles irrespective of the location (Table\u0026nbsp;1).\u003c/p\u003e\n \u003cp\u003eThe texture of all the surface soils of Oshosun formation were loamy sand (LS), while the sub-surface horizons had sandy clay loam (SCL) texture. In term of soil textural characteristics, the soil of Oshosun formation were uniform across the locations. Furthermore, the soils had structure that ranged from granular, crumb to fine sub-angular block (fsbk) on the surface but predominantly coarse-angular block (Cak) structure in the subsurface. The structures of the subsurface horizons were more uniform across the location and varied directly with the clay content of the soil.\u003c/p\u003e\n \u003cp\u003eIn terms of the soils ability to resist deformation under an externally applied force (consistency), all the soils sampled at Ijebu-Ife profiles had loose (L) consistency, while, those of Ibese were loose in the surface but were moderately firm at the subsurface horizons.\u003c/p\u003e\n \u003cp\u003eThe pattern of distribution of the sand particle fraction was similar in the two profiles dug at Ibese. The profiles had sand content that decreased with increasing soil depth. Conversely, the clay content of the soils increased with increasing soil depth with the subsurface argilluviation. However, the distribution pattern of silt content in Ibese was irregular within the profiles. The sand content in the surface soils (\u0026lt; 30 cm) of Ibese ranged from 715.00 g/kg to 725.00 g/kg, while the subsurface (\u0026gt; 30 cm) had sand content that ranged from 533.60 g/kg to 703.60 g/kg. The clay content in this region ranged between 270.0 g/kg and 274.30 g/kg at the surface, while, the sub-surface (\u0026gt; 30 cm), clay content ranged between 285.40 g/kg and 452.2 g/kg within the profiles. The silt contents in the soils of Ibese ranged from 0.6 g/kg to 15.00 g/kg in the surface, while the subsurface horizons had silt contents that ranged from 35.00 g/kg to 15.00 g/kg.\u003c/p\u003e\n \u003cp\u003eSimilar to Ibese particle size distribution pattern, the Ijebu-Ife had particle size distribution that was similar in the two profiles. The sand contents in the two profiles decreased with increasing soil depth, while, the clay contents increased with increasing soil depth. The sand contents in the surface soils ranged from 635.00 g/kg to 685.00 g/kg, while, the sub-surface soils had sand content that ranged from 473.60 g/kg to 635.00 g/kg within the profile. The clay contents in the surface and subsurface soils ranged from 302.20 g/kg to 321.40 g/kg and from 331.4 g/kg to 522.2 g/kg respectively. The silt content in Ijebu-Ife had an irregular pattern of distribution within the two profiles. The surface soils had silt content that ranged from 35.00 g/kg to 12.8 g/kg, while the subsurface soils had silt contents that ranged between 42.00 g/kg and 28.00 g/kg.\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003ch3\u003eAbeokuta Formation\u003c/h3\u003e\n\u003cp\u003eThe soils of Ayetoro in Abeokuta formation were generally shallow with maximum depth \u0026lt; 70 cm and are generally gravelly in all the profiles. On the other hand, Odogbolu soils, also in Abeokuta formation were deep with the soil depth \u0026gt; 100 cm in all the profiles. The soils of Ayetoro had colours that varied from dark brown (7.5YR3/4) at the surface (epipedon) to yellowish red (5YR4/6) at the subsurface, while, Odogbolu soil had very dark greyish brown (10YR3/2) colour at the surface horizons and red (2.5YR4/6) at the subsurface horizons. The subsurface soil colour in Ayetoro profile 2 and Odogbolu profiles were generally yellowish red (5YR4/6) to red (Table\u0026nbsp;1).\u003c/p\u003e\n\u003cp\u003eGenerally, the textures of the soils of this formation were Loamy sand on the surface and sandy clay loam at the subsurface. The structure of the soils varied among the profiles, Ayetoro pedon 1 had coarse sub-angular blocky down the profile, while, pedon 2 had crumbly structure at the surface and granular on the subsurface. Odogbolu profiles had fine sub-angular blocky structure in the surface horizons and fine sub-angular blocky to medium fine blocky at the subsurface horizons.\u003c/p\u003e\n\u003cp\u003eThe consistency of the soils in this formation varied in all the locations, Ayetoro soils had very friable to friable consistency in all the profiles, however, Odogbolu profiles were either moderately friable or moderately firm in all the profiles.\u003c/p\u003e\n\u003cp\u003eThe soils of Ayetoro were gravelly with the present of plinthites. The sand and silt content of Ayetoro pedon 1 increased down the profiles, but there was no pattern of distribution in pedon 2. The silt content of Ayetoro soils ranged from 35.00 g/kg to 32.00 g/kg in the surface horizons, but the subsurface horizons had silt content that ranged in values from 70.00 g/kg to 45.70 g/kg.\u003c/p\u003e\n\u003cp\u003eThe sand content of the two profiles ranged from 515.80 g/kg to 583.6 g/kg, while the subsurface horizons had the sand ranged from 533.60 g/kg to 681.5 g/kg.\u003c/p\u003e\n\u003cdiv id=\"Sec11\"\u003e\n \u003ch2\u003eChemical Properties of the soils of the study areas\u003c/h2\u003e\n \u003cdiv id=\"Sec12\"\u003e\n \u003ch2\u003eAbeokuta formation\u003c/h2\u003e\n \u003cp\u003eTable\u0026nbsp;2 presents the chemical properties of the studied soils. The soils of Abeokuta formation and Basement complex had neutral pH range with mean value of 6.32 and 6.74, and the coefficient variation of 8.16% and 6.73% respectively. However, the soils of Oshosun formation were slightly acidic with a mean pH of 5.53 and %CV of 9.01. The pH (H\u003csub\u003e2\u003c/sub\u003eO) of the cultivated soils of Abeokuta ranged from 6.15 to 7.15 in the surface horizons, while the subsurface horizons had pH that ranged from 6.15 to 6.70. Whereas, the uncultivated soils had pH that ranged from 5.95 to 6.70 in the surface horizons the subsurface horizons had pH that ranged from 5.25 to 6.65.\u003c/p\u003e\n \u003cp\u003eThe Ca content in the cultivated land of Abeokuta formation decreased down the horizons, but the uncultivated land had no pattern of Ca distribution. In the cultivated land of Abeokuta formation, the Ca content of the soils ranged from 2.70 to 3.60 cmol/kg in the surface horizons but ranged from 3.60 to 5.50 cmol/kg in the subsurface horizons. However, the uncultivated soils had Ca content that ranged from3.30 to 4.30 cmol/kg in the surface horizons, while the Ca content in the subsurface horizons ranged from 3.30 to 3.50 cmol/kg. The Magnesium (Mg) and total exchangeable acidity (TEA) in the surface soils of the cultivated soils of Abeokuta formation ranged from 3.80 to 4.50 cmol/kg and from 0.10 to 0.20 cmol/kg respectively. Similarly, the subsurface horizons had Mg and TEA content that ranged from 3.70 to 8.00 cmol/kg and from 0.20 to 0.70 cmol/kg respectively. The Mg and TEA in the uncultivated soils ranged from 4.40 to 6.20 cmol/kg and from 0.10 to 0.50 cmol/kg respectively in the surface horizons, while the subsurface horizons ranged from 3.60 to 4.90 cmol/kg and from 0.30 to 0.70 cmol/kg respectively. (Table\u0026nbsp;2)\u003c/p\u003e\n \u003cp\u003eThe organic carbon (OC) and the available P in the soils of Abeokuta formation were generally low, the Organic Carbon and available P in the surface of the cultivated land ranged from 0.32 to 0.78% and from 1.42 to 71.92 mg/kg respectively (Table\u0026nbsp;5). The subsurface horizons of the cultivated land had %OC and available P that ranged from 0.22 to 0.36% and \u0026lt; 0.001 to 8.12 mg/kg respectively.\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec13\"\u003e\n \u003ch2\u003eOshosun formation\u003c/h2\u003e\n \u003cp\u003eThe pH of this formation was in the acidic range in the all the locations studied. The pH and Ca content in this formation ranged from 5.85 to 5.20 and 3.00 to 7.60 mg/kg in the surface soils of the cultivated lands respectively. While, the subsurface soils ranged from 4.80 to 6.20 and 3.10 to 9.70 mg/kg. Whereas, the pH and Ca in the uncultivated soils varied from 5.25 to 5.95 and 3.60 to 4.50 mg/kg in the surface horizons, those of the subsurface horizons varied from 4.75 to 6.05 and 2.60 to 6.60 mg/kg respectively. More so, the Mg and TEA of the soils of the cultivated lands varied from 6.70 to 11.40 cmol/kg and from 0.10 to 1.7 cmol/kg in the surface horizons, while the subsurface horizons varied from 3.00 to 11.00 cmol/kg to 6.40 cmol/kg respectively. The uncultivated lands had Mg and TEA content that ranged from 5.60 to 11.40 cmol/kg and from 0.10 to 1.60 cmol/kg respectively in the surface horizons but ranged from 4.10 to 9.50 cmol/kg and from 0.10 to 1.60 cmol/kg in the subsurface horizons respectively. The Organic Carbon and Available P in the cultivated lands of this formation ranged from 5.40 to 8.40 g/kg and from 7.97 to 18.23 mg/kg in the surface horizons, while the subsurface soils ranged from 1.00 to 1.8 g/kg and from 1.14 to 9.54 mg/kg respectively. However, the uncultivated lands had Organic Carbon and available P that ranged from 8.10 to 11.80 g/kg and from 0.85 to 8.54 mg/kg in the surface horizons respectively, while the subsurface horizons ranged from 0.8 to 3.4 g/kg and from 0.28 to 10.40 mg/kg respectively.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec14\"\u003e\n \u003ch2\u003ePhosphorus fractions across the geological formations\u003c/h2\u003e\n \u003cdiv id=\"Sec15\"\u003e\n \u003ch2\u003eAbeokuta formation\u003c/h2\u003e\n \u003cp\u003eThe distribution pattern of the P forms in this formation (Table\u0026nbsp;3) had Ca-P, WS-P and Labile-P increasing with increased depth, while, Al-P and Fe-P decreased with increased in depth in the cultivated land of Ayetoro. The Ca-P and Al-P content in Ayetoro ranged from 6.67 to 16.22 mg/kg and 4.46 to 11.16 mg-kg respectively in the cultivated land (pedon 1). The Ca-P content in the uncultivated land increased with increasing and it’s ranged from 6.67 to 16.22 mg/kg, while the Al-P ranged from 4.46 and 5.58 mg/kg. The Fe-P and WS-P content in Ayetoro decreased with increasing depth ranging from 24.41 to 29.40 mg/kg and 7.13 to 8.23 mg/kg in the cultivated land (pedon 1) respectively, while the uncultivated land ranged from 25.52 to 32.17 mg/kg and 7.68 to 24.13 mg/kg respectively. The Labile-P content in the cultivated (pedon 1) of Ayetoro ranged from 27.42 to 28.51 mg/kg with increased in soil depth, while the uncultivated land had the Labile-P content ranging from 16.01 to 49.35 mg/kg with increased in soil depth.\u003c/p\u003e\n \u003cp\u003eConsidering the Ca-P and Al-P in the soils of Odogbolu, the Ca-P and Al-P profile distribution in this location were irregular while the Al-P decreased with increasing soil depth in the cultivated. The Ca-P and Al-P in the cultivated soil (pedon 1) of Odogbolu ranged from 6.79 to 65.71 mg/kg and 6.14 to 20.09 mg/kg respectively. The Fe-P and WS-P profile distribution in the cultivated soils (pedon 1) were irregular, and they ranged from 33.28 to 54.36 mg/kg and 4.39 to 17.55 mg/kg respectively. Similarly, the Labile-P profile distribution was irregular and ranged from 28.59 to 92.12 mg/kg.\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec16\"\u003e\n \u003ch2\u003eOshosun formation\u003c/h2\u003e\n \u003cp\u003eThe pattern of the profile distribution of the P forms in this formation was irregular across the locations. The Ca-P and Al-P in the cultivated land (pedon 1) of Ibese ranged from 2.14 to 5.25 mg/kg and 7.23 to 10.60 mg-kg respectively. Similarly, the Fe-P and WS-P content in this location ranged from 17.75 to 62.13 mg/kg and 3.29 to 16.45 mg/kg, the labile-P content ranged from16.01 to 44.94 mg/kg respectively. However, the uncultivated land (pedon 2) of Ibese had Ca-P and Al-P contents ranging from 4.75 to 8.75 mg/kg and 8.37 to 9.49 mg/kg respectively, while Fe-P and WS-P ranged from 5.54 to 88.75 mg/kg and 3.33 to 28.84 mg/kg respectively. More so, the Labile-P content ranged from 38.84 to 81.70 mg/kg (Table\u0026nbsp;3). Similar to Ibese soils, the Ijebu-Ife had Ca-P and Al-P content that ranged from 4.53 to 7.01 mg/kg and 1.67 to 16.18 mg/kg in the cultivated soils (pedon 1) respectively. The Fe-P and WS-P in this location ranged from ranged from 29.40 to 56.02 mg/kg and 4.99 to 12.06 mg/kg, while, the Labile-P ranged from 12.58 to 29.61 mg/kg respectively. However, the uncultivated land had Ca-P and Al-P that ranged from 6.72 to 12.34 mg/kg and 3.35 to 11.16 mg/kg, the Fe-P and WS-P ranged from 25.52 to 79.88 mg/kg and 4.94 to 12.20 mg/kg respectively. The Labile-P content ranged from 13.72 to 55.93 mg/kg (Table\u0026nbsp;3).\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec17\"\u003e\n \u003ch2\u003eInteractions Effect of Geology and Land use on Phosphorus Forms\u003c/h2\u003e\n \u003cp\u003eInteractions between geological formation and land use (cultivated land and uncultivated land) significantly affected the Al-P, Fe-P, Labile-P and Water Soluble-P content of the soils, but, there was no significant different (p \u0026gt; 0.05) in the Ca-P contents across the formations. (Table\u0026nbsp;4). Considering the effect of geology and land use in the distribution of Al-P, the result showed that in the cultivated soils, the values of Al-P in Oshosun formation was significantly lower.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec18\"\u003e\n \u003ch2\u003eInteractions effects of Geology and Depth on Phosphorus Forms\u003c/h2\u003e\n \u003cp\u003eTable\u0026nbsp;5 presents the interactions between the geology and soil depths. It was observed that Al-P and Water Soluble-P were significantly affected, while Ca-P, Fe-P and Labile-P were not affected by the interaction of these factors at 5% level of probability (Table\u0026nbsp;5).\u003c/p\u003e\n \u003cp\u003eStatistically, the mean values of Al-P content in the surface (\u0026lt; 30 cm) soils of the geological formations were not statistically different (p \u0026gt; 0.05). However, the values of Al-P content in the soils of Abeokuta formation and Oshosun formation were not statistically different (p \u0026gt; 0.05). Looking at the Al-P content down the profiles, the Al-P content in the soils of the Basement complex increased with increasing soil depth, while, the Al-P contents in the soils of Abeokuta formation and Oshosun formation decreased with increasing soil depth (Table\u0026nbsp;5).\u003c/p\u003e\n \u003cp\u003eThe interaction between the geological formation and soil depth significantly affected (p \u0026lt; 0.05) the Water Soluble-P of the surface soils. The value of Water Soluble-P in the surface soils of Abeokuta formation was statistically higher than those of the Basement complex and Oshosun formation. Furthermore, the mean value of the Water-Soluble content in the surface soils of the Basement complex was not statistically different (p \u0026gt; 0.05), but, there was significant different (p \u0026lt; 0.05) between the Water Soluble-P content of the surface soils of the Abeokuta formation and those of the Basement complex and Oshosun formation. The sub-surface Water Soluble content of the Basement complex was significantly different (p \u0026lt; 0.05) from those of Abeokuta formation and Oshosun formation, while, the mean values of the Water Soluble-P contents of the sub-surface soils of Abeokuta formation and Oshosun formation were not statistically different (p \u0026lt; 0.05).\u003c/p\u003e\n \u003cp\u003eConsidering the distribution of Water Soluble-P down the horizons, the Water-Soluble content in the sub-surface soils of the Basement complex and Oshosun formation increased down the horizons, whereas, the Water Soluble-P in the sub-surface of Abeokuta decreased down the horizons (Table\u0026nbsp;5).\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec19\"\u003e\n \u003ch2\u003eInteraction effects of Geology, Land use and Depth on Phosphorus Forms\u003c/h2\u003e\n \u003cp\u003eThe interactions between the geological materials, land use and depth of the three formations on the phosphorus forms affected only the Labile-P significantly ((p \u0026lt; 0.05) (Table\u0026nbsp;6a \u0026amp; 6b). The Labile-P contents of the surface soils of the cultivated land of Abeokuta formation were significantly higher in the formations and significantly different (p \u0026lt; 0.05) from Oshosun formation. There was no significant different (p \u0026gt; 0.05) between the Basement complex and Oshosun formation, however, the subsurface soils of Abeokuta formation and Oshosun formation were significantly different (p \u0026lt; 0.05) from those of the Basement complex subsurface soils which had the highest Labile-P content. Oshosun formation had the least mean value of Labile-P (Table\u0026nbsp;6a \u0026amp; 6b).\u003c/p\u003e\n \u003cp\u003eComparatively, the Labile-P contents according to the soil depths in the geological formations showed that, Basement complex soils had the highest Labile-P content that increased with soil depth in the cultivated soils, whereas, the Labile-P content in the soils of Abeokuta formation and Oshosun formation decreased with soil depths in the cultivated lands. However, the Labile-P content in the uncultivated soils of the Basement complex decreased with soil depth, while the Labile content in the uncultivated soils of Abeokuta formation increased with soil depths. Conversely, the mean value of the Labile-P content in the surface and sub-surface soil of the uncultivated soils of Oshosun formation was constant down the horizons. Conversely, the mean value of the Labile-P content in the surface and sub-surface soil of the uncultivated soils of Oshosun formation was constant down the horizons.\u003c/p\u003e\n\u003c/div\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eOshosun formation and Abeokuta formations had deep soils, this is due to sedimentary origin. The organic carbon contents of Abeokuta formation were low, this could be as result of the rapid rate of decomposition as aided by the shallow soil depths (Don et al., \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2011\u003c/span\u003e). However, the organic carbon in the soils of Oshosun formation were high. The soil pH of the geological formations was moderately acidic. The soils had high magnesium but moderately low calcium content. The available phosphorus was also low. Generally, the soils of these geological formations are highly weathered and of inherently low fertility.\u003c/p\u003e \u003cp\u003eThe distribution of the P forms in the geological formations had Fe-P as the most abundant P forms and Ca-P as the least abundance. This is because hydroxides and oxyhydroxides of Fe are the predominant, whereas Calcium is the lowest in the the geological formations. Mustapha et al., (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2007\u003c/span\u003e) reported that Fe-P was more abundant in the soils of Bauchi Local Government Area.\u003c/p\u003e \u003cp\u003eThe P forms, Al-P, Fe-P, Labile-P and Water Soluble-P were not affected significantly by the the geological formations, but, Ca-P varied significantly in the geological formations. This could be as the result of the parent materials of the formations (Daly et al., \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2015\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eLabile P content in the soils was affected significantly by the interactions between geology and land use and depth. This could be as the result of applied fertilizer on the cultivated lands (Maranguit et al., \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2017\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe distribution of phosphorus fractions was influenced by soil properties such as pH, clay content and exchangeable as reported Achile et al., (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2024\u003c/span\u003e) in the Basement Complex formation of Ogun State. The report also stated that Avail-P, Ca, Ca-P, Mg, k and pH were significant (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) but negatively correlated with the Aluminum P (Al-P) content of the soils.\u003c/p\u003e"},{"header":"CONCLUSION","content":"\u003cp\u003eThis study was design to investigate the distribution of phosphorus fractions in soils developed from major geological formations. The P forms distribution in the geology was as follows; Iron-P (40.94 mg/kg) \u0026gt; Labile-P (35.17 mg/kg) \u0026gt; Water soluble-P (9.98 mg/kg) \u0026gt; Calcium-P (9.34 mg/kg) \u0026gt; Aluminium-P (8.39 mg/kg) and this P distribution varied across the geological formations. The study also indicated that Fe-P was the most abundance and Al-P as the least. The abundance of Fe-P fraction will definitely decrease the Avail-P content in the soils. It is therefore recommended that further studies be carried to understand the sorption characteristics of the soils of the geological formations.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e \u003cp\u003eNot applicable.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eConsent for publication\u003c/strong\u003e \u003cp\u003eNot application.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eCompeting interests\u003c/strong\u003e \u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e \u003c/p\u003e\u003cp\u003e \u003ch2\u003eClinical Trial number\u003c/h2\u003e \u003cp\u003eNot applicable\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eFunding\u003c/h2\u003e \u003cp\u003eThis research work was personally funded and no organization shared in the funding.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eAchile Blessed-Amos Kadiri carried out the experimental works, performed data analysis and interpretation, and manuscript drafting.Basil Ejike Charles assisted in the field work, laboratory analysis and review of the manuscript.Iduh Jonathan Joseph Otene assisted proof-reading of the manuscript and formatting of the tables.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eAll the datasets for this study available from the corresponding author on reasonable request via email of the author.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAchile BK, Basil EC, Muhammed B, Otene IJJ, Adeyi HA, Omatule LA. (2024). Impacts of Land Use and Soil Depth on Phosphorus Forms in Soils of Basement Complex Geology, Ogun State, Nigeria. \u003cem\u003eJournal of Agriculture, Forestry \u0026amp; Environment, 2024, 8(1): 131\u0026ndash;145\u003c/em\u003e, \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://jafe.net.ng/\u003c/span\u003e\u003cspan address=\"https://jafe.net.ng/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBouyoucos CJ. (1962). Hydrometer method improved for making particle size analysis of soils. \u003cem\u003eSoil Science Society American Proceedings\u003c/em\u003e. 26: 464\u0026ndash;465.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBrady NC, Weil RR. (2016). The nature and properties of soils (15th ed.). Pearson.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCross AF, Schlesinger WH. A literature review and evaluation of the Hedley fractionation. Geoderma. 1995;64:197\u0026ndash;214.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDaly K, Styles D, Lalor S, Wall DP. Phosphorus sorption, supply potential and availability in soils with contrasting parent material and soil chemical properties. Eur J Soil Sci. 2015;66(4):792\u0026ndash;801.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDon A, Schumacher J, Freibauer A. Impact of tropical land-use change on soil organic carbon stocks\u0026ndash;a meta‐analysis. Glob Change Biol. 2011;17(4):1658\u0026ndash;70.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFAO. Guideline for soil description. Fourth Edition. World Food and Agricultural Organization. Rome; 2006. Italy 109pp.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHedley MJ, Stewart JWB, Chauhan BS. Changes in soil phosphorus fractions. Soil Sci Soc Am J. 1982;46:970\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHinsinger P. Bioavailability of soil inorganic phosphorus. Plant Soil. 2001;237:173\u0026ndash;95.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu W, Zhang Y, Jiang S, Deng Y, Christie P, Murray PJ, Zhang J. Arbuscular mycorrhizal fungi in soil and roots respond differently to phosphorus inputs in an intensively managed calcareous agricultural soil. Sci Rep. 2016;6(1):24902.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eManojlovic D, Todorovic M, Jovicic J, Krsmanovic VD, Pfendt PA, Golubovic R. Preservation of water quality in accumulation Lake Rovni: the estimate of the emission of phosphorus from inundation area. Desalination. 2007;213(1\u0026ndash;3):104\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMaranguit D, Guillaume T, Kuzyakov Y. (2017). Land-use change affects phosphorus.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003efractions in highly weathered tropical soils. \u003cem\u003eCatena\u003c/em\u003e, 149, 385\u0026ndash;393.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMclean EO. (1965). Aluminum: In methods of soil analysis (ed. C.A. Black) agronomy No.9 part 2. \u003cem\u003eAmerican Society of Agronomy\u003c/em\u003e, Madison. Wisconisin pp978-998.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMoazed H, Hoseini Y, Naseri AA, Abbasi F. Determining phosphorus adsorption isotherm in soil and its relation to soil characteristics. J Food Agric Environ. 2010;8(2):1153\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMustapha S, Yerima SI, Voncir N, Ahmed BI. Plinthaquults in Bauchi Local Government Area, Bauchi State, Nigeria. Int J Soil Sci. 2007;2(3):197\u0026ndash;203.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSanchez PA. Properties and management of soils in the tropics. 2nd ed. Cambridge University Press; 2019.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNelson DW, Sommers LE, Page AL. Methods of soil analysis. Part. 1982;2:539\u0026ndash;79.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTables 1 to 6 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":"discover-soil","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"Learn more about [Discover Soil](https://link.springer.com/journal/44378)","snPcode":"44378","submissionUrl":"https://submission.nature.com/new-submission/44378/3","title":"Discover Soil","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Discover Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Phosphorus forms, geology, soil depth and land use","lastPublishedDoi":"10.21203/rs.3.rs-9215421/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9215421/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThis study was carried to investigate the phosphorus distribution pattern in the soils developed from major geological formations in Ogun State Nigeria. Four locations were selected from the two geological formations that was used in this study and consequent of the land use types (cultivated and uncultivated). Soil profile were sunk in each of the four locations, making a total of four soil profile pits and a total of 27 soil samples collected according to pedogenic horizons were used in this study. Data obtained were subjected to Analysis of Variance (ANOVA) of GENSTAT discovering software and means were separated using Least Significant Difference at 5% level of probability. Results showed that the soils of the three geological formations were similar in texture (Loamy sand at the surface and Sandy clay loam at the sub-surface) while the soil pH (4.75\u0026ndash;7.15), calcium (2.60\u0026ndash;9.70 cmol kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), magnesium (3.60\u0026ndash;11.40 cmol kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) and organic content (0.40\u0026ndash;18.00 g/kg) varied across formations. The soils of Oshosun and Abeokuta Formations were deeper (\u0026gt;\u0026thinsp;180 cm) with soil colour that ranged from dark brown (epipedon) to yellowish red (endopedon). Al-P and water-soluble-P were significantly affected by geology and soil depth. However, the interactions of geology, land use and soil depths were seen to have been significant effect on Labile-P. Also, this study showed that Al-P, Fe-P and Labile-P was significantly affected by geology and Land use. The P forms distribution in the geology was as follows; Iron-P (40.94 mg/kg) \u0026gt; Labile-P (35.17 mg/kg) \u0026gt; Water soluble-P (9.98 mg/kg) \u0026gt; Calcium-P (9.34 mg/kg) \u0026gt; Aluminium-P (8.39 mg/kg). The study concluded that P distribution varied across the geological formations and had Fe-P as the most abundance and Al-P as the least.\u003c/p\u003e","manuscriptTitle":"Distribution of Phosphorus Fractions in Soils Developed From Two Geological Formations in Ogun State, Nigeria","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-28 11:57:59","doi":"10.21203/rs.3.rs-9215421/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorInvitedReview","content":"","date":"2026-04-29T08:52:51+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"301923941860627650595851408576607704996","date":"2026-04-25T08:06:07+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"9380017147339812599141837329632741078","date":"2026-04-23T04:56:26+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"286108939786561277130509744657430891906","date":"2026-04-21T20:17:32+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-04-20T07:49:04+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-03-30T11:52:48+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-03-30T11:52:27+00:00","index":"","fulltext":""},{"type":"submitted","content":"Discover Soil","date":"2026-03-24T18:45:10+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"discover-soil","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"Learn more about [Discover Soil](https://link.springer.com/journal/44378)","snPcode":"44378","submissionUrl":"https://submission.nature.com/new-submission/44378/3","title":"Discover Soil","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Discover Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"c0977cfc-96aa-4f39-9f7d-e9fdf0670d11","owner":[],"postedDate":"April 28th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-04-28T11:57:59+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-28 11:57:59","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9215421","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9215421","identity":"rs-9215421","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}