Simulation of yield and deep soil water effects of winter wheat field under different fertilization levels in Baoji dry-land of the Loess Plateau

【Objective】 The experiment was to provide scientific basis for sustainable development of local wheat production,which was fit for the fertilization levels adaptive to precipitation condition of the semi-humid area of Loess Plateau as well as beneficial to soil water sustainable utilization.【Method】 Based on model validation,the WinEPIC model was used to simulate yield and deep soil water effects of continuous winter wheat under 5 fertilization treatments in Baoji semi-humid area of the Loess Plateau.【Result】 Grain yield of the continuous winter wheat under no fertilization,low fertilization,medium fertilization and high fertilization treatment decreased significantly with fluctuation,average yield was 1.588,2.306,3.327,3.981 and 4.764 t/hm2 respectively;Simulated monthly available soil water content of all 5 fertilization treatments declined with annual and seasonal fluctuations,average annual soil desiccated rate was 11.4,11.6,14.9,14.9 and 18.2 mm/a respectively;soil desiccation and stable desiccated soil layers of all 5 fertilization treatments occurred after 5-16 years of continuous cropping simulation.Distribution depth of dried soil layers was 2-3 m of no fertilization and low fertilization treatment,2-4 m of medium and high fertilization treatments,2-5 m of superhigh fertilization treatment respectively.【Conclusion】 As fertilization and crop yield increased,dried soil layers were thickened and crops water consumption was increased.The suitable fertilization level of Baoji dry-land was N 120-150 kg/hm2,P 60-75 kg/hm2.