Solid-phase phosphorus buffer for sustained, low-leaching phosphorus fertilization of field-grown plants

Abstract

A method of providing a continuous, buffered, low-leaching phosphorus fertilization of field plants in soil has been developed. The method is broadly applicable to field soils, but is particularly well-suited to soil that has inherently low phosphorus (P) retention ability, including sandy soils, peats, and mucks. The invention describes the use of phosphorus (P) fixed to alumina (Al) as a fertilizer and phosphorus buffer in field soils. The Al—P. when incorporated into soil in a concentration between 0.25 and 20% by weight/volume, will release P from the Al using a dynamic solid phase solution phase exchange equilibrium driven by plant uptake of P, thus providing P for plant growth, while also minimizing P leaching from the soil. The Al—P buffer/fertilizer can be applied and incorporated into field soils prior to planting of crops, grass, or other plants requiring P for growth, or may be incorporated into exposed soil between growing plants to buffer against P leaching and runoff. Importantly, once incorporated into the soil, modified Al can be recharged with P in situ to provide a continuous and persistent P buffer and fertilizer.