The reasons of declining were mainly caused by supplying of chemical fertil i zer.
英
美
对施肥较多,且施肥历史较长的营养元素,在进行测土推荐施肥时,不仅要考虑大田的平均养分含量,还应考虑土壤的养分的空间变异状况;
目录
查词历史
英 汉