一、挖掘土壤潜在肥力的现实意义随着科学种田水平的提高,提高土壤供肥能力日益显其重要。在低产水平下,增施肥料可以取得显著增产效果,但到了一定生产水平,如果没有相应提高土壤的供肥能力,肥料的持续增产效果便会受到限制。这在美国已有所觉察,他们统计,50年代一磅化肥可增产玉米15—25磅,而现在只有5磅。因为作物吸收养分不仅来自肥料,而且来自土壤,后者还是占主要方面。如水稻所需的氮素,土壤供给的占60—80%,而肥料供给的只占20—40%。如果土壤供给的那部分养分不能达到基本要求,那么增施大量肥料也就难以充分发挥其作用。因此,要持续增产就必须提高土壤的供肥能力。然而土壤供肥能力决定于土壤中养分含量和土 First, the practical significance of mining potential fertility of soil With the improvement of scientific farming, increasing soil fertility is increasingly important. Under the low-yielding condition, increasing fertilizers can achieve significant increase in yield, but to a certain level of production, if there is no corresponding increase in soil fertility, the continuous increase of fertilizers will be limited. This is something that has been detected in the United States. According to their statistics, a pound of fertilizer in the 1950s could increase 15-25 pounds of corn, and now it is only 5 pounds. Because the crop absorbs nutrients not only from fertilizers, but also from soils, the latter still predominate. For example, nitrogen needed by rice accounts for 60-80% of the total supply of the soil and only 20-40% of the supply of fertilizers. If the soil can not meet the basic requirements of the part of the nutrients, then the application of large amounts of fertilizer will be difficult to fully play its role. Therefore, to continue to increase production must increase soil fertility. However, soil fertility depends on soil nutrient content and soil