石膏含有硫、钙两种元素,是一种间接肥料。它能改良土壤,促使微生物活动,提高土壤及肥料中营养元素的功效,对农作物有较好的增产效果。睢宁县双沟公社在盐碱地上试验,每亩施用石膏500斤,大麦苗数比未施的多34％。铜山县张集花碱土试验站在重盐碱土上试验,每亩施用石膏400斤,棉花出苗率由30％增加到90％以上。句容县在稻田施用大量绿肥时,每亩加施石膏3—5斤,可以防止秧苗发僵现象。石膏的作用大致可分两个方面:一是硫、钙本身的作用; Gypsum contains sulfur and calcium two kinds of elements, is an indirect fertilizer. It can improve the soil, promote microbial activity, improve the effectiveness of nutrients in the soil and fertilizers, the crop has a better yield. Suining County Shuanggou commune in saline on the ground test, 500 kg per acre gypsum, barley seedling 34% more than before. Tongshan County, Zhang Ji Hua alkaline soil test station in heavy saline soil test, application of 400 kg per acre gypsum, cotton germination rate increased from 30% to 90%. Jurong County in the paddy application of a large number of green manure, 3-5 kg ​​per acre of cast gypsum, seedlings can prevent stiff phenomenon. The role of gypsum can be roughly divided into two aspects: First, the role of sulfur, calcium itself;