有机肥料氮替代部分无机氮对水稻产量的影响及替代率研究

通过田间试验，研究了不同氮用量下有机肥料氮替代部分无机氮对水稻产量、氮肥利用率和土壤矿质态氮的影响，试图探索出有机肥料氮替代无机氮的最适替代率，并对有机肥与化肥配施的经济效益进行评价。结果表明:1）有机肥与化肥配施处理（8381~9810 kg/hm2）能获得与单施化肥处理（8381~10124 kg/hm2）更高或持平的产量；2）与单施化肥相比，氮用量在N 240 kg/hm2内，有机肥料氮替代无机肥料氮的最适替代率为10%~20%（相当于施用1500~3000 kg/hm2商品有机肥），此时水稻产量、氮肥利用率和经济效益都达到最佳水平；3）与单施化肥相比，氮用量在N 240 kg/hm2以内并且有机肥料氮占氮总量的10%~20%时可以获得较为平稳的氮素供应过程，改善了土壤供氮能力。上述结果可为研制有机无机复合肥提供理论基础。

Effects of partial mineral nitrogen substitution by organic fertilizer nitrogen on the yields of rice grains and its proper substitution rate

pplication of mixed mineral and organic fertilizers can ensure sustainable agriculture development. Field experiments were carried out to study the effect of partial mineral nitrogen (N) substitution by organic N on the yields of rice grains, N use efficiency and soil mineral N. The results obtained were listed as follows: 1) Application of mixed mineral and organic fertilizers resulted in a higher yield of rice (8381–10124 kg/ha) compared to single application of mineral fertilizer (8381–9810 kg/ha); 2) Substitution of 10-20 percentage of inorganic N, corresponding an application of 1500–3000 kg/ha of common compost organic fertilizer, was recommended when the nitrogen application rate was lower than 240 kg/ha because the rice grain yield, N use efficiency and economic benefits were highest under such condition；3) Compared with inorganic fertilizer treatment, application of mixed mineral and organic fertilizers maintained a steady supply of nitrogen, consequently improved the capability of soil nitrogen supply.