Effect of phosphorus fertilizer application and phosphorus use efficiency of early, middle and late rice in Hubei Province

Multipoint field experiments of rice were conducted to study the effect of phosphorus (P) fertilizer application on rice yield, to investigate the P use efficiency, and to compare early, middle and late rice in their responses to the P application in 18 counties of Hubei Province during 20062009. The results show that the average yields of the NPK (with phosphorus) treatment of early, middle and late rice are 706, 774 and 565 kg/ha higher than those of the NK (without phosphorus) treatment, respectively. It is concluded that the P application increases grain yield significantly, with the yield increase rate of 13.3% for early rice, 11.3% for middle rice and 9.4% for late rice. The responses of early, middle and late rice to the P application are different. At present production conditions, P2O5 agronomic efficiencies (PAE) of early, middle and late rice are 13.3, 13.3 and 11.6 kg/kg, partial factor productivities of applied P2O5 (PFPP) are 116.4, 148.0 and 157.5 kg/kg, P2O5 recovery efficiencies (PRE) are 14.2%, 13.7% and 11.3%, and P2O5 physiological efficiencies (PPE) are 85.2, 110.4 and 65.4 kg/kg in Hubei Province, respectively. The average soil P dependent rates (SPDR) of early, middle and late rice are between 87% and 89%, which mean that P absorption of rice is primarily from soil but not from fertilizer, and the highest SPDR was observed in late rice.