Effects of plant residues and environmental factors on phosphorus availability in soils

Abstract

Abstract Phosphorus availability is a major nutritional problem in several northern Idaho soils. Traditionally, fertilizers containing P have been applied to improve availability in soils; however, organic materials added to soils have the ability to provide large quantities of labile P via mineralization processes and to reduce sorption of P. Using this concept, plant residues applied to soils would increase P availability for future plant needs. This research evaluated the effect of plant residue, incorporated into a Northern Idaho soil, on P availability under controlled laboratory conditions. Alfalfa (Medicago sativa), pea (Pisum sativum) and wheat (Triticum aestivum) plant residues were incorporated into soil collected from the Ap horizon of a Latahco silt loam (fine‐silty, mixed, frigid Argiaquic Xeric Argialboll) at rates of 0, 1, 5 and 10% (w/w). The soils were incubated at soil water potentials of ‐0.05, ‐0.15 and ‐0.40 MPa, and temperatures of 10, 20 and 30°C over a 20 week period. Soils were sa...