Effects of N, P and K fertilization on wheat yield and fertilizer use efficiency in Weibei rainfed hihgland

The purpose of this research was to study the fertilization effect on wheat, and to investigate the effect of fertilizer application rate and fertility level on the yield, profit, fertilizer contribution rate (FCR) and agronomy efficiency (AE) under present conditions based on the 180 3414 field experiments in Weibei rainfed highland during 2006 to 2009. The results indicate that the yields of wheat are improved about 986, 679 and 405 kg/ha and the yield increase rates are 30.0%, 18.9% and 9.5% respectively by applying nitrogen (N), phosphorus (P2O5) and potassium (K2O) fertilizers. The average profits are increased about 1098, 810 and 392 Yuan/ha, which correspond to 21.5%, 14.8% and 8.8% of FCR, and 6.4, 7.1 and 7.1 kg/kg of AE respectively. The increased yields, profits and contribution rates of fertilizers are N＞P2O5＞K2O, and the AEs are P2O5＝K2O＞N. The N2P2K2 is the best treatment according to the yield, profit, FCR and AE. Compared with the CK, the yield and profit under the balanced fertilization are increased by 73.0% and 1923 Yuan/ha respectively, and the FCR is 40.0% and AE is 5.8 kg/kg. The yield is not significantly decreased under the excessive fertilization. In medium and low fertility soils, the fertilization has high fertilizer use efficiency and high profit. The use efficiency of N decreases significantly, the use efficiency of P2O5 remains the same basically and the use efficiency of K2O increases rapidly compared with those in 1980s. The most effective way of increasing the yield and profit of wheat in rainfed areas is to combine rational fertilization, farming and cultivation.