淡灰钙土由于成土母质的影响,土壤贫瘠,有机质含量多在0.5%左右,碳酸钙含量常高于10%,微碱性(pH值多在8以上),土壤有效锌甚低(平均水平0.31ppm).七十年代末,不少地区相继出现玉米白苗花叶病.为了探讨其原因和寻求解决途径,自1980年起,在土壤微量元素含量普查的同时,先后与暖泉农场、中宁县等有关单位协 Because of the influence of soil parent material, light gray soil is poor in soil, organic matter content is mostly about 0.5%, calcium carbonate content is often higher than 10%, slightly alkaline (pH is more than 8), and soil available zinc is very low Level of 0.31ppm) .Seventies, many areas have appeared white seedling Mosaic in order to explore its causes and ways to seek solutions, since 1980, in the soil trace element content survey at the same time, has with the spring farm , Zhongning County and other relevant units Association