一、地力关 植棉地块有机质必须在1％左右,速效磷5～10ppm,速效钾80～120ppm,碱解氮50～70ppm,以上各种养分含量稍微低于下限,也可以通过中后期追肥来弥补肥力不足的问题,养分合量低 First, the fertility of cotton land block organic matter must be about 1%, available phosphorus 5 ~ 10ppm, 80 ~ 120ppm available potassium, alkali hydrolysis of nitrogen 50 ~ 70ppm, above a variety of nutrient content slightly below the lower limit, but also through the late dressing To make up for the problem of lack of fertility, low amount of nutrients