一、砂姜黑土发展棉花生产的潜力砂姜黑土是黄淮海平原南部古老耕作土壤之一。表层呈黑色,上层有砂姜,有机质低于1%,全氮0.07%左右,速效磷3～5ppm,普遍缺氮少磷,土壤物理性状差。该土带约4760万亩,安徽省面积最大,计有2100万亩,占淮北耕地面积的52%。七十年代以 One, sand Jiang black soil potential for the development of cotton production Shajiang black soil is one of the ancient tillage soil in the southern Huang-Huai-Hai Plain. The surface is black, the upper layer of ginger, organic matter less than 1%, total nitrogen 0.07%, available phosphorus 3 ~ 5ppm, generally lack of nitrogen and phosphorus, poor physical properties of the soil. The earth belt about 4760 acres, the largest area in Anhui Province, with 21 million mu, accounting for 52% of the area of ​​arable land in Huaibei. Seventies