保证水稻最高分蘖期吸收适量的氮素,对于高产稳产十分重要。为了确定最适宜的施氮量,必须正确的推断包括干土效果在内的土壤氮素矿化量及其利用率,干土效果就是水田土壤因干燥程度不同而地力发挥的程度。地力氮素矿化量的年际变化很大。主要受干土效果影响,为了准确估量干土效果,作者建议采取水整地土样,测定“定温培养氮素”含量。为使采土时间 To ensure that the highest tillering stage of rice absorbs the appropriate amount of nitrogen, which is very important for high and stable yield. In order to determine the optimum amount of nitrogen fertilizer, we must correctly infer the soil nitrogen mineralization including dry soil effect and its utilization efficiency. The effect of dry soil is that the paddy soil exerts its earth-ground force due to different degrees of dryness. Soil nitrogen mineralization varies greatly from year to year. Mainly affected by the effects of dry soil, in order to accurately estimate the effect of dry soil, the authors propose to take soil preparation soil samples, determination of “fixed temperature nitrogen content.” To make mining time