Sustainability of wheat-corn rotation system under various long-term fertilizations in the Huang-Huai-Hai plain of China.

Wheat (Triticum aestivum L.)-corn (Zea mays L.) rotation system is important for food security in the Huang-Huai-Hai plain of China. Rotation system productivity, sustainable yield index (SYI), and the contribution of each individual nutrient during an 18-year fertilization experiment in Zhengzhou, Henan, China, were recorded. The results showed that applications of NPK fertilizer or combined manure (NPK, NPKS, NPKM, and NPK1.5M) lead to obtain higher grain yields and maintain better sustainability for wheat, corn and rotation system, respectively. Nevertheless, sustainable yield index (SYI) value and order of rotation system is NPKS(0.68) > NPK1.5M(0.64) > NP(0.60) > NPK(0.59) = PK(0.59) > NPKM(0.58) > CK(0.54) > NK(0.40) > N(0.32), respectively.