Evaluating phosphorus availability in soils receiving organic amendment application using the Diffusive Gradients in Thin-films (DGT) technique

David Kane - Cranfield University


Phosphorus is a resource in finite supply. Use of organic amendments as a source of P in agriculture can be a sustainable alternative to inorganic P, provided it can meet crop requirements.The Diffusive Gradients in Thin-films (DGT) technique is based on natural diffusion of P via a hydrogel and sorption to a ferrihydrite binding layer; which should accurately represent soil P (CDGT) in a plant available form.

The aim of this research was to evaluate changes in soil P availability, following the addition of organic amendments, cattle farmyard manure, green waste compost, cattle slurry and superphosphate using Olsen P and DGT. This study bridges the gap in knowledge about transfer of P between organic amendments to soil and its influence on plants showing a good relationship between soil P available by diffusive supply following treatment additions, and its influence on root and shoot dry matter yield and total P uptake.