Study of Potassium Nutrition of Wheat and Fertilizer Use Efficiency under Long-term Fertilization Conditions in Dryland of Loess Region

[Objective] The purpose of the experiment was to provide scientific basis for rational fertilization and grain yield increase in dryland of Loess Region.[Method] Based on the long-term located experiment,the effects of different fertilization on wheat yield,potassium nutrition in each growth stage and fertilizer use efficiency were studied.[Result] N application could increase wheat yield by 75.3% while P application could decrease wheat yield by 24.7%.The combination of NM,PM,NPM application could increase the wheat yield by 75.9%～92.9%. The potassium uptake of wheat mainly concentrated on the earlier stage,after the booting stage wheat potassium uptake mainly manifested minus,organic fertilizer application,especially,the combination of organic fertilizer and mineral fertilizer could obviously increase the potassium uptake of wheat.N application and the combination of NP could obviously increase potassium uptake and uptake rate of wheat.Compared with CK,wheat potassium uptake and uptake rate increased obviously with organic fertilizer application.The fertilizer use efficiency(FUE) was high when only N fertilizer was applied,which was 76.73%.While the FUE was only 14.20% when only P fertilizer was applied.The combination of N and P could increase the absorbed amounts of N,P and K significantly,and organic fertilizer application could also increase the absorbed amounts of N,P and K significantly while the FUE was low.[Conclusion] Applying manure(or manure and chemical mixed) not only could promote the absorption of N,P and K in wheat,but also could increase wheat yield significantly.