长期施肥和不同生态条件下我国作物产量可持续性特征

Sustainability of crop yields in China under long-term fertilization and different ecological conditions

采用产量可持续性指数(SYI)法,研究了我国不同生态条件下20个长期试验点8个肥料处理的水稻、玉米和小麦产量的可持续性.结果表明:作物SYI值因施肥、作物种类和水热因子不同而呈显著差异.长期不施肥(CK)条件下,水稻、玉米和小麦的SYI值较低,分别为0.55、0.44和0.43;施肥尤其是NPK化肥配施有机肥可显著提高作物产量的可持续性,水稻、玉米和小麦的SYI值分别为0.66、0.58和0.57;单施N肥或NK肥的玉米和小麦的SYI值在0.36～0.47.SYI值大于0.55表明可持续性较好,小于0.45表明可持续性差.经纬度和气象因子对作物SYI也有不同程度的影响,3种作物不施肥时,水稻SYI变异较小,与各因子间没有显著相关性,玉米SYI变异最大且与各因子间存在显著的相关关系,小麦介于两者之间.因此,NPK配施有机肥有利于作物高产稳产,是维持系统可持续性的最优施肥模式.

By using sustainable yield index （SYI）,this paper analyzed the sustainability of maize,rice,and wheat yields at 20 long-term fertilization experiment sites in China under different fertilization system and ecological conditions. The SYI value of test crops varied significantly with fertilization system,crop kind,effective accumulated temperature,and sunshine hour. Irrespective of fertilization,the SYI value of rice was generally higher than that of maize and wheat. Under long-term no fertilization,the SYI values of rice,wheat,and maize were lower,being 0.55,0.44,and 0.43,respectively. Fertilization,especially a combined application of NPK and manure,promoted the sustainability of crop yields,with the SYI values of rice,wheat,and maize being 0.66,0.58,and 0.57,respectively. Under the application of N and NK,the SYI values ranged in 0.36-0.47. SYI value 0.55 represented the better sustainability of crop yields,while SYI0.45 represented a worse one. Longitude,altitude,and weather factors also affected the SYI values,especially that of maize. Under no fertilization,maize had the largest variation of SYI value,followed by wheat,and rice. Our results indicated that a combined application of chemical fertilizers with manure benefited high and stable yielding,being the optimal fertilization mode for maintaining the sustainability of grain yield.