The Effects of Dissolved Organic Matter Derived from Agricultural Waste Materials on Phosphorus Sorption in Sandy Soils

Abstract

The effect of organic matter (OM) on soil phosphorus (P) sorption is controversial, as there is still no clear answer whether organic matter inhibits or increases P sorption. Despite the great need for renewable sources of available P and OM in agricultural soils, little is known about the interaction between P and dissolved organic matter (DOM) in natural soil systems. The aim of this research was to uncover if and how soil saturation with DOM derived from different types of abundant agricultural wastes (cattle manure, horse manure, biogas digestate, compost) affects the phosphate sorption. We examined the P sorption process in control and DOM-saturated sandy soils. The results indicated that OM introduced with agricultural waste did not always reduce P sorption, but certainly had an effect on impairing P fixation, and thus, may result in potentially greater P mobility in the soil, including P availability. Among these waste materials, DOM from horse manure had the most positive effect on P mobilization; thus, horse manure—if available—is recommended for spreading on soils with low P mobility.

Deciphering competitive interactions: Phosphate and organic matter binding on goethite through experimental and theoretical insights

“…This significantly affects soil fertility and the fate of P in natural environments such as transfer from soil to freshwater systems, where P accelerates eutrophication (Ahmed et al, 2023;Andersen et al, 2015;Roy et al, 2017;Tisdale and Tisdale, 1993; Y. T. . These aspects are significantly influenced by the diverse interactions of P with soil constituents involving free metal ions (Gros et al, 2019;Urrutia et al, 2013), soil minerals (Ahmed et al, 2019;Ganta et al, 2021;Kruse et al, 2015;Kubicki et al, 2012;Liu et al, 2022), and soil organic matter (Ahmed et al, 2018a;Debicka et al, 2023;Gros et al, 2017). Among these constituents, mineral surfaces such as Fe-and Al-(oxyhydr)oxides, calcium phosphates, silicates, and carbonates exhibit a strong affinity for binding phosphates (Bellier et al, 2006;Liu et al, 2012;Minamisawa et al, 2022;Okano et al, 2013;Tunesi et al, 1999).…”