Distribution of phosphorus fractions and their relationships with physiochemical properties in the Agricultural soils of the Yamuna River region

Abstract Purpose To expand the research on soil phosphorus. Little is known about the concentrations of phosphorus fractions in the phosphorus-deficient area of the Yamuna River bank in Prayagraj. To overcome this gap, we suggest the exploitation of soil phosphorus fractions from soil samples in the study area. Methods We analysed 24 soil samples from four different depths at six different sites in agricultural fields around the Yamuna River. The samples were analysed, and different phosphorus fractions were sequentially extracted. UV spectrometry was subsequently used to analyse the individual P fractions. Results We found that P-deficient soils were neutral in pH and low in salinity. Among the P fractions, calcium-P was the most predominant, followed by Fe-P, S-P, Occl-P, Red-P, and Al-P. Overall, the available P, organic P, and total P decreased with increasing depth, whereas calcium P was significantly positively correlated with organic carbon (r = 0.55*) and available nitrogen (r = 0.55*) and significantly negatively correlated with clay (r = -0.32*), pH (r = -0.22*), and EC (r = -0.23*). However, the occurrence of P is a major contributing factor to the availability of P in soils. Conclusion Our regression equations showed that soil pH was the main soil property influencing the different P fractions. Applying organic P fertilizers can improve the quantity of P in these soils, and if enhanced analytical techniques are applied to soil samples, it is possible to gain more detailed insights into the dynamics of phosphorus fractions.