长期施肥对塿土硝态氮分布、累积和移动的影响

利用 18年长期定位试验研究了冬小麦 夏玉米轮作制度下 ,有机 无机肥配合施用对土剖面NO3-N的分布累积和阶段性移动的影响。结果表明 ,土壤剖面中NO3-N的总量与氮肥施用量直接相关 ,而作物对化肥氮的利用率与施肥量呈相反趋势。低氮处理 (75kg/hm2)及其与有机肥配合施用 ,NO3-N主要累积在 0～100cm土层内 ;高氮处理 (120kg/km2)及其与有机肥配合施用 ,NO3-N在剖面出现 2个累积峰 ,且在400cm土层处NO3-N的含量接近或超过 10mg/kg。适宜的氮肥用量、施用有机肥及合理的有机 无机肥料配比是减少NO3-N在土壤剖面中的累积和淋失的有效措施

A long-term experiment oneffect of organic manure and chemicalfertilizer on distribution

A 18 years' fertilizer experiment was conducted in cumulic cinnamon soil to study the distribution,accumulation and movement of NO3-N in 4 m depth profile with application of organic manure combined chemical fertilizer in the winter wheat corn crop system per year The results showed that NO3-N was mainly accumulated in 0 to 100cm depth soil profiles for most treatments, and total amount of NO3-N in the soil profiles was related to the N rate There were two peaks of NO3-N accumulation in the high N (120 kg/hm2) and low N (26 kg/hm2) treatments with or without organic manure, and the content of NO3-N at the depth of 4 m layer was over 10 mg/kg Suitable fertilizers rate, application of organic manure, and organic manure combined chemical fertilizer with a proper ratio is the effective ways to control accumulation of NO3-N in soil profiles and leaching loss