长期不同施肥模式对我国玉米产量可持续性的影响

采用产量可持续性指数(SYI)对我国22个长期试验点5种施肥模式下的玉米产量可持续性进行了研究。结果表明：玉米SYI受施肥、经纬度和气象因子的影响，据此将玉米产量稳定性划分为3类，不施肥和单施氮肥(N)，玉米产量低，产量持续性差，SYI小于0.45，极显著地受到温度、降雨量等气象因子的影响；氮磷肥(NP)配施玉米产量较高，SYI在0.45～0.55，受气象因子的影响较小；氮磷钾肥配施与氮磷钾和有机肥配施(NPK和NPKM)，玉米产量高，持续性好，SYI大于0.55，气象因子对其无显著影响。不施肥、单施N和NP肥的玉米SYI与纬度或气象因素间呈显著相关性，而施用NPK和NPKM的SYI相对稳定。

Effects of Different Long-term Fertilizations on Sustainability of Maize Yield in China

The SYI was analyzed that of maize under different fertilization treatments, the five models from more than 22 long term fertilizer sites throughout China. The results showed that the SYI was affected by the longitude, altitude and weather. As a general rule, We divide SYI value in three portions by the degree of the weather' affect. Control and N treatments, the variation of SYI was affected by effective accumulated temperature and the sunshine hours significantly, is lowest among those treatments, obtained a worse sustainable yield and the SYI was lower than 0.45, the yields were lowed. A common sustainable yield was between 0.45 and 0.55 in NP treatment. The variation of the SYI was also affected by effective accumulated temperature and the sunshine hours significantly. A good sustainable yield was obtained when the SYI value was greater than 0.55 for NPK and NPKM treatments, and do not affect by the altitude or weather significantly, the yields were high. The significant relationship between the SYI value and the altitude or weather was observed in maize crops with no fertilizer, N or NP, while that of NPK and NPKM was relatively stable.