东北黑土水稻主产区氮肥减施潜力研究

东北平原是中国重要的商品粮生产基地,水稻是该地区的主要粮食作物之一,虽然该地区黑土质量和肥力均较高,但农田施肥过量的现象仍较为普遍。因此,为了阐明黑土区水稻施肥空间格局、差异特征及减施潜力,本文选择东北平原黑土水稻种植区为研究对象,在黑龙江、吉林、辽宁三省水稻施肥和产量进行了大规模调研分析基础上,结合土壤本底供氮能力培养试验,开展相关研究。结果表明：区域内由南至北施氮强度和经济产量均逐渐下降,施氮强度下降幅度大于产量下降,氮肥偏生产力逐渐增加。通过与理论适宜施氮量对比发现,辽宁稻区理论减氮潜力达16.7%~24.7%,吉林中、西部稻区潜力达8.7%~17.8%,黑龙江稻区还有2.0%~11.4%理论减氮空间。三省典型水稻土土壤累积矿化量没有明显差异。因此,地上部生物量变化所引起的氮携出量的变化是引起东北黑土区黑龙江、吉林和辽宁水稻施氮量差异的主要影响因素。

Nitrogen fertilizer reduction potential in the main rice producing region of black soil in Northeast China

The Northeast China Plain is an important commercial grain production base of the country, with rice being one of the region's principal food crops. Despite the exceptional quality and fertility of the region's black soil, excessive fertilizer application is nonetheless widespread. As a result, large-scale surveys and soil incubation experiments were conducted in Heilongjiang, Jilin and Liaoning provinces to clarify the spatial pattern, differential characteristics and the reduction potential of rice fertilization in the black soil area. The findings revealed that both netrogen (N) application intensity and economic yield dropped progressively from south to north in the region, with the decrease in N application intensity being greater than that in yield. As a result, N fertilizer partial productivity steadily increased from south to north. Compared to the theoretically suitable N application rate, the theoretical N reduction potential of rice area in Liaoning, central and western Jilin and Heilongjiang were determined to be 16.7%~24.7%, 8.7%~17.8%, and 2.0%~11.4%, respectively. In the three provinces, there is no significant difference in the quantity of accumulative soil mineralization of typical rice soils. Therefore, variances in N application to rice in Heilongjiang, Jilin, and Liaoning are mostly influenced by changes in the N quantity carried by aboveground biomass.