长期施肥下中国主要粮食作物产量的变化

 【目的】阐明长期不同施肥下中国主要粮食作物产量变化态势及其差异，为评价和建立长期施肥模式、促进粮食持续生产提供依据。【方法】对中国主要长期试验不施肥（CK）、施化肥（NPK）、化肥配施有机肥（NPKM）3个处理的玉米、小麦、水稻等粮食作物产量700多组数据进行整理和统计分析。【结果】长期不施肥的玉米和小麦产量总体上表现为极显著（P＜0.05）下降趋势，年下降量分别为110.9和33.4 kg?hm-2，而水稻产量基本保持稳定。施用化肥，玉米、小麦和水稻的产量均呈极显著（P＜0.01）下降趋势，年平均下降量分别为90.9、48.5和25.3 kg?hm-2。化肥配施有机肥，3种作物的产量随时间没有显著变化，均比较稳定，与NPK比较，玉米、小麦和水稻产量变异系数分别降低了8%、4%和3%。3种作物比较，小麦和玉米产量年际间变异较大，而水稻产量相对稳定。施肥的作物产量与不施肥的作物产量（反映土壤基础地力）呈极显著（P＜0.01）正相关，基础地力产量每增加一个单位，施肥产量增加量NPKM处理比NPK处理小0.12～0.31 kg?hm-2?a-1，表明长期施用化肥作物产量对基础地力的依赖程度高于化肥配施有机肥（NPKM）。【结论】中国农田长期不施肥或施用化肥的作物产量变化趋势为玉米和小麦下降，水稻基本稳定;化肥配施有机肥具有明显的增产和稳产效果，是农业生产可持续性的施肥模式。

Grain Yield Trends of Different Food Crops Under Long-Term Fertilization in China

【Objective】 The study was conducted to reveal the difference and dynamic of grain yield in China under long-term fertilization, and to provide scientific references for evaluating and establishing long-term fertilization mode. 【Method】 Grain yield trends of rice, wheat and maize crops in different treatments (unfertilized control, fertilizer NPK, and fertilizer NPK plus manure, i.e., NPKM) under long-term fertilization were investigated and 700 sets of data were included. 【Result】 It was discovered that grain yield of unfertilized maize and wheat showed a very significant (P＜0.01) declining trend, the decline rates (per year) were -110.9 kg?hm-2 and -33.4 kg?hm-2, respectively, while rice yield was stable. Yield trends of the all three crops in NPK treatment decreased significantly (P＜0.05) with year, the yield decline rates of maize, wheat and rice were -90.9 kg?hm-2, -48.5 kg?hm-2 and -25.3 kg?hm-2, respectively. Grain yields of 3 crops were stable under NPKM fertilization. The coefficients of variation (CV%) of maize, wheat and rice decreased by 8%, 4% and 3% in NPKM treatment, respectively, compared with those of NPK treatment. The yields of wheat and maize varied greatly with year, while that of rice was stable relatively. A significantly positive correlation between the fertilized and unfertilized crop yields was found. When the yields of unfertilized crops increased by one unit, the magnitude of yields increased in NPKM treatments decreased by 0.12-0.31 kg?hm-2?a-1 compared with those in NPK treatments. The crop yields under long-term NPK fertilization was more dependent on soil basic fertility than that of NPKM fertilization. 【Conclusion】 The yield declining trends were observed in wheat and maize crops with no fertilizer or chemical fertilizers alone, while that of rice was relatively stable. Chemical fertilizer in combination with manure is a more effective fertilization to improve and maintain the grain yield, and it is strongly recommended for sustainable agriculture.