Abstract
Prediction of accumulation of available phosphorus (P) in paddy soils is crucial for the best management of P fertilizers. Based on the long-term double-rice rotation systems, a predictive model for accumulation rates of Olsen P in paddy soils with chemical fertilization was developed. In paddy soils with more than 40 kg applied P ha−1, the accumulation of Olsen P in the soils could occur. With the target rice yield of 10 tons ha−1 per year, the increases in Olsen P in paddy soils were estimated by the model as 0.7, 2.2, and 3.8 mg kg−1 when P application rates are 40, 60, and 80 kg P ha−1, respectively. The accumulation rate of Olsen P was relatively high in paddy soils. The predictive model can be used to predict accurately the concentrations of Olsen P in paddy soils based on initial Olsen P, P application rate, and crop yield and to optimize P fertilization for rice crop production and environmental protection.
Acknowledgments
We thank the National Natural Science Foundation of China (30971868) and the State Key Laboratory of Soil and Sustainable Agriculture, China (081000032), for supporting for this work.