Nitrogen Use Efficiency in a Wheat-Corn Cropping System From Long-Term Application of Manure and Chemical Fertilizers Application.

Nitrogen Use Efficiency in a Wheat-Corn Cropping System From Long-Term Application of Manure and Chemical Fertilizers Application

Yinghua Duan, Minggang Xu, Xueyun Yang, Shaomin Huang, Bairen Wang and Suduan Gao

Sustaining optimal yields, improving soil productivity, and minimizing adverse environmental impact of fertilization are essential to ensure food security with the shrinking cropland and limited resources. To develop effective nitrogen management practices, we investigated the long-term (1991−2005) effect of various fertilization regimes on yield and nitrogen use efficiency (NUE) in wheat-corn system at four sites (Changping, Zhengzhou, Yangling and Qiyang) in China. The treatments included unfertilized control, chemical fertilization (N, NP, NK, NPK), manure application (70% N supply) with NPK (NPKM) and at 1.5× rate (1.5NPKM), and NPK with corn-stover returned (NPKS). The treatment effects on wheat yield and NUE were examined and compared to that on corn. Compared with NPK, NPKM treatment improved the wheat grain yield at Qiyang (acid soil) only (by 33%) although increased straw biomass at all four sites, which is different from corn for which improvement on yield occurred at all sites. The overall NUE of wheat-corn system was increasing at a rate of 0.86−2.71 % yr ^{−1 in the manure treatments at three sites (Changping, Yangling and Qiyang), while a decreasing trend in treatments without manure or P at all four sites. Manure and P applications were the most effective way to improve grain production and NUE of the wheat-corn system. Wheat was more responsive to P fertilizer and corn was more to manure application. Thus an effective nutrient management strategy would be ensuring P fertilization for wheat season and manure application for corn season to improve overall NUE for the wheat-corn production systems in China. The results may be applicable to other wheat-corn rotation systems.}