ZHANG Shoudu, LI Yanfeng, LI Jiusheng

Abstract: The high rainfall during the growing season of maize brought some difficulties for field experiment aiming at attaining optimal fertilization scheduling in northeast sub-humid area. In this study, DNDC model was used to optimize fertilizing schedule for maize in sub-humid Northeast China, and a 2-year field experiment including maize growth and yield data measured under mulched drip irrigation in Northeastern China was used to serve the model calibration and verification. The sensitivity analysis of the modelparameters was carried out. Furthermore, the validated model was used to optimize fertilizing frequency and fertilizing ratio of maize under different fertigation scenarios. The simulated results showed that atmospheric CO2 concentration, crop water requirement, rainfall, and the Grain C:N had a greater effect on yield and nitrogen uptake of maize. The DNDC model performed well in predicting yield and nitrogen uptake of maize, whereas the dynamics of corn growth was not adequately preserved. Besides, for a higher initial nitrogen content level with about 60 mg/kg, the nitrogen amount of 150~200 kg N/hm2 and the ratio of 1:3 during heading stage and filling stage were recommended for obtaining higher crop yield and less nitrogen leaching in sub-humid region of northeast China.

Keywords: mulched drip irrigation; nitrogen uptake; maize yield; fertilizing system; DNDC model

(Journal of China Institute of Water Resources and Hydropower Research, Vol. 16, No. 2, 2018)