苏丹草为禾本科植物,条状叶脉,叶茂嫩绿,夺取苏丹草高产需要追施大量的氮肥。前几年,除施足基肥外,均使用尿素作追肥,最高的亩产达1.15万公斤以上,一般的也不低于0.75万公斤。每年刈割八至九遍,每割一次则松土、追肥一次,由于频繁的松土施肥,劳动强度较大。去年以来,越来越多的渔业专业户已改用碳铵作追肥,每松土追肥一次可连割三遍不返黄,虽减轻了劳动强度,结果使单产不断下降,有人误认为草种变劣是主要原因。据调查,有个渔场的专业户种苏丹草,1986年每亩共追施尿素75公斤,亩产1.1万公斤,1987年每亩共追施碳铵225公斤,亩产仅0.6万公斤。他说:“实在碳铵的肥效期比尿素长,不知何故减产, Sudan grass for grasses, strip-shaped veins, leafy green, capture high sudan grass need to pursue a large amount of nitrogen fertilizer. A few years ago, in addition to Shizujifei, are using urea for top-dressing, the highest per mu reached 11,500 kilograms or more, generally not less than 7,500 kilograms. Cutting eight to nine times a year, each cutting is loosening, top dressing time, due to frequent soil fertilization, greater labor intensity. Since last year, more and more fishery households have switched to ammonium bicarbonate for top-dressing. Each top-dressing can be cut and cut three times without returning to yellow. Although labor intensity has been reduced, yields have been declining. Some people mistakenly believe that grasses have changed Poor is the main reason. According to the survey, there was a Sudanese grass family, a specialized household for fisheries. In 1986, a total of 75 kilograms of urea was chased each kilogram of mu of urea and 11,000 kilograms of mu were produced per acre. In 1987, a total of 225 kilograms of ammonium bicarbonate was chased up and only 6,000 kilograms per mu was produced. He said: "In fact, the effect of ammonium bicarbonate fertilizer longer than urea, somehow cut,