低洼田地下水位高，排水条件差，土壤水分处于饱和状态，在俺灌条件下容易造成缺氧，使稻浪不能正常呼吸，吸收能力下降，导致僵苗；水多带来的另一个不良因素是土壤处于还原状态，高价铁和锰还原成亚铁、亚锰，这两种离子积累多了，对水稻有害。同时在缺氧条件下，有机质易生 Low groundwater table, low drainage conditions, the soil moisture is saturated, under irrigation conditions are likely to cause hypoxia, so that rice can not breathe properly, the absorption capacity decreased, leading to stiff seedlings; water brings another adverse factors Soil is in a state of reduction, high-priced iron and manganese reduced to ferrous and manganic, these two kinds of ions accumulated more harmful to rice. At the same time in hypoxic conditions, organic matter prone