Simulation of yield and soil desiccation effects of continuous spring maize under different level fertilization treatments in Jinzhong semiarid areas of the Loess Plateau

Based on model validation,the WinEPIC model was used to simulate yield and soil desiccation effects of continuous spring maize under different level fertilization treatments in Jinzhong semiarid areas of the Loess Plateau.The simulated results show as following:(1) Crop yield of continuous spring maize under no fertilization,low fertilization,medium fertilization and high fertilization treatment decreased significantly with fluctuation,and the average yield was 1.484 t/hm2,1.768 t/hm2,2.129 t/hm2 and 2.337 t/hm2 respectively;(2) Simulated monthly available soil water content of all 4 fertilization treatments declined with annual and seasonal fluctuations,and the average annual decreasing rate was 5.6 mm,8.4 mm,8.4 mm and 11.4 mm separately,and strong soil desiccation and differences of available soil water content among fertilization treatments occurred during the 5 beginning years of the simulation,and differences of soil water content among no fertilization,low fertilization and medium fertilization,as well as high fertilization treatments were very significant;(3) Soil moisture decreased and desiccated soil layers thickened gradually at the beginning of simulation,and stable desiccated soil layers occurred during middle and end of simulation.Distribution depth of desiccated soil layers was 1～2 m of no fertilization treatment,1～3 m of both low and medium fertilization treatments,and 1～4 m of high fertilization treatments,and indicated that desiccated soil layers thickened with the increasing of fertilization and crop yield;(4) Soil water carrying capacity of dryland spring maize field at Jinzhong is 1.868～2.154 t/hm2,and its fertilization application amount is N 45～60 kg/hm2 and P 15～55 kg/hm2.