摘要： 通过多年在全市郊县布点试验结果,明确了NPK化肥在天津市主要类型土壤和主要粮食作物上的增产效果,NP化肥效果显著,且效果近似,其有效施用面积可占全市耕地80—90%,K肥只在15%耕地上有效果.NPK的增产效果与土壤中速效养分有显著的负相关性,从而确定出施用化肥有效土壤的速效养分临界值.并根据多元回归分析的计算结果,兼顾产量和经济效益两方面,选择出主要粮食作物在不同产量水平下的最佳施肥方案,供推广应用.

关键词: 氮磷钾, 合理用量, 天津

Abstract: The fixed-spot test progressed in the suburbs of Tianjin for four years.The results indicate that the effects on increasing yield of N P K fertilizers in the main types of soil and main crops are significant N and P fertilizers can be effectively applied in 80-90%cultivated area of the all suburbs while K fer-tilizer in 15%area.The effects on increasing yield of N P K have a signifi-cant negative correlation to the quantity of the quick effective nutrients in the soil,thus we can decide the critical value of the quick effective nutrients in the soil where chemical fertilizer is effectively applied.According to the result of poly-regression analysis and given attention to both yield and economical gains.In order to popularize,we may choose the best applying fertilizer plans for different yield level of main crops.

Key words: Nitrogenous fertiilizer, Phosphatic fertilizer, Potassium fertilizer, Ratinoal dose Tianjing