开原县金沟子公社良种场二队过去很重视使用化肥,并累积了一些好经验。1975～1976两年在二队进行土壤普查时,发现耕地土壤绝大部分属于平地棕黄土类型,有效氮、磷含量很低。如淤黄土的速效养分含量是:水解氮50ppm(每亩约合15斤),速效磷15ppm(每亩约合4.5斤),速效氮、磷含量比例是:1:0.3。根据 Kaiyuan County Golden Grove commune breeding farm team in the past, the emphasis on the use of chemical fertilizers, and accumulated some good experience. During the two-year soil survey carried out by the two teams from 1975 to 1976, it was found that most of the cultivated land belonged to the plain brown loess type, and the available nitrogen and phosphorus contents were very low. Such as silt loach nutrient content is: hydrolyzed nitrogen 50ppm (about 15 pounds per acre), available phosphorus 15ppm (about 4.5 kg per acre), available nitrogen, phosphorus content ratio is: 1: 0.3. according to