据我市土肥站1996年在天长市开展的以耕地钾素为主体的养分调查、该市土壤缺钾面积为48％，其中严重缺钾面积在16％。与1982年土壤普查相比较，土壤速效钾含量下降。一、耕地土场钾素下降原因1、有机肥用量减少。近年来，我市有近1／4的耕地面积白田下种。据肥情资料统计，1985 According to the survey conducted by Tianjin Fertilizer Station in Tianchang City in 1996, the main nutrient content of crop potassium was 48% of the potassium in the soil, of which 16% was seriously deficient in potassium. Compared with the 1982 census of soil, the content of available potassium in the soil decreased. First, arable land farm potassium decline causes 1, reduce the use of organic fertilizer. In recent years, the city has nearly 1/4 of cultivated land under the white fields. According to statistics of fertility information, 1985