连年不变的在同一块土地上种植水稻,由于土壤肥力灭退,杂草繁生,会使产量激减。在同一土地上连种数年水稻,土壤会变得贫瘠,缺乏营养底物质;这不仅是由于随着产品的吸收而攝出,同时也因为土壤中的有益微生物降低了生活力。稻田经常浸水的结果,土壤中已充满水份,土壤细粒膨胀,降低对空气的渗透能力,徙而进入土壤中的空气自亦减少,在这种情况下,由于 Year after year in the same piece of land on paddy rice planted, due to regression of soil fertility, weeds flourishing, production will be reduced. In the same land for several years paddy, the soil becomes barren and lacks nutrients; not only because of the product’s absorption, but also because of the reduced viability of beneficial microorganisms in the soil. As a result of the frequent soaking of paddy soils, the soil is already full of moisture, the soil fines are expanded, reducing the ability to penetrate the air, and the air that migrates into the soil is also reduced. In this case,