Long-term Fertilizer Application Alters the Balance and Vertical Distribution of Phosphorus in a Calcarosol

摘要

The information on the distribution of P fertiliser in soil profile would be beneficial for better P management in farming systems. The aim of this study is to investigate how the long-term application of fertiliser P affects the vertical distribution of P in the soil and P balance. Soil samples were collected from a long-term permanent P fertiliser trial and were sequentially extracted for P fractions. There was a net negative P balance over the 66 years in the niI-P and low P (3 kg P·ha-1) treatments. In contrast, applying 12 kg P·ha-1 to each wheat crop led to a highly positive P balance of 106 kg P·ha-1 in this soil, resulting in P accumulation in the top 10 cm. Nil and low P application rates resulted in lower soil Pi content at 520 cm depth. The transformation of the residual P fertiliser into all Pi fractions suggests that the applied P had transferred into different P forms which are either readily available or sparingly available to subsequent crops.