Influence of biochars prepared from poultry manure on phosphorus availability and recovery in a calcareous soil

Abstract

This study was conducted to investigate the effects of poultry manure (PM) and its derived biochars on change in phosphorous (P) availability and apparent recovery in a calcareous soil. Treatments consisted of four rates of P (0, 30, 60 and 90 µgg-1) and five organic substances (control, poultry manure and its derived biochars at 200, 300 and 400°C). The organic substances were incorporated with 400 g of soil at 2% level (w/w) and were incubated for 150 days. Soil P availability determined at 8 different stages of incubation time period. Phosphorous availability was less in soil samples untreated with organic substances and also decreased over time. Phosphorus recovery from inorganic P fertilizer was more than organic sources at the early stages of incubation time, but decreased over time sharply.. Phosphorus availability and recovery increased over time in organic substances treated soil samples. Application of inorganic P with organic substances decreased apparent P recovery. Negative interaction was observed between organic substances and high rates of inorganic P fertilizer on P availability. It was concluded that biochar produced at 300°C had the highest effect on adjusting P availability in the soil.