Phosphorus Efficacy in Four Chinese Long‐Term Experiments with Different Soil Properties and Climate Characteristics

Abstract

Four long‐term experiments in China were used to study the efficacy of phosphorus (P) fertilizers in soils. The results showed that the increased yield by P fertilization varied with different crops: early rice > late rice. We suggest applying the P fertilizer heavily on winter wheat and early rice. The P agronomic efficiency was about 27 kg rice grain kg−1 and 30.8–55.7 kg wheat grain kg−1. The P recovery efficiency by plants was >80% in three of four sites, and the fertilizer‐use efficiency was 34% on average. The current applications of about 40 kg P ha−1 year−1 for rice–rice rotation could maintain yields of 8–11 t ha−1 year−1, and 65.5 kg P ha−1 year−1 applied for wheat–maize rotation could maintain yields of 5.3–6.2 t ha−1 for wheat and 4.2–6.0 t ha−1 for maize, although no P was added to maize. However, sustaining higher yields will require soil P‐supplying capacity and farm‐specific management targets and strategies.