长期施肥对氮素利用以及土壤剖面氮素分布、积累的影响

Effects of Long-Term Fertilizer on N Use Efficiency and Distribution Accumulation of NO-N in Soil Profile

依托28年长期定位试验,采集不同施肥处理土壤剖面样品,测定土壤硝态氮含量,结合产量计算氮素利用效率。结果表明,长期施肥显著增加玉米子粒产量、地上部总吸氮量及氮收获指数。化肥+有机肥(NPKM)处理产量最高,较单施化肥(NPK)处理提高8.7%。各处理硝态氮含量随着土层的加深均呈先降低后升高的趋势,硝态氮主要积累在0~100cm土体,NPK、NPKM处理硝态氮积累量占比高于55%。因此,有机肥替代部分化肥可显著提高子粒产量,增加氮素利用效率,减少氮素淋溶。

Based on the 28-year long-term fertilizer experiment,soil nitrate nitrogen content was analyzed under different fertilizer treatments,and nitrogen use efficiency was calculated based on the yield.The results showed that long-term fertilization significantly increased grain yield,total N uptake and N harvest index.NPKM treatment had the highest yield which was 8.7%higher than NPK.In all treatments nitrate nitrogen content decreased first and then increased with the deepening of soil layer.Nitrate nitrogen mainly accumulated in 0-100 cm soil layer,and the proportion of nitrate nitrogen accumulation was higher than 55%under NPK and NPKM treatments.Therefore,organic fertilizer N replaced part of chemical fertilizer N can significantly improve maize grain yield,increase N use efficiency,reduce N leaching.