Effect of applying N combined with K fertilizer on rice yield and fertilizer use efficiencies in area along Huaihe rive

In this paper,a field experiment was carried out to study the impact of N combined with K fertilizer on rice yield and fertilizer use efficiencies(FUE).The results showed that,applying N fertilizer significantly improved rice yield,and increased yield by 20.3%～29.0%,but applying K fertilizer insignificantly improved rice yield;Suitable N and K application rate could improve FUE.The N fertilizer effective equation have been obtained by mathematic simulation,and suitable N application rate was ensured preliminary,that was at range of 225～250 kg·hm-2.