The present invention provides a granulated agricultural composition in which the stability of an organophosphorus compound as an active ingredient is improved. The present invention relates to a granulated agricultural composition comprising an organophosphorus compound and clacined clay, relates to a process for producing the above granulated agricultural composition comprising an organophosphorus compound as an active ingredient, which comprises compounding calcined clay to improve stability of the active ingredient, and relates to a method for improving stability of an active ingredient comprised in a granulated agricultural composition, comprising compounding calcined clay, wherein the active ingredient is an organophosphorus compound.本發明提供為有效成分之有機磷系化合物之穩定性提高的粒狀農藥組成物。本發明係關於包含有機磷系化合物及經煅燒之黏土的粒狀農藥組成物，且本發明係關於前述粒狀農藥組成物之製造方法，其係製造含有有機磷系化合物當做有效成分之粒狀農藥組成物，其中，摻合經煅燒之黏土並使前述有效成分之穩定性提高。又，本發明係關於一種使前述有效成分之穩定性提高之方法，其係於含有有機磷系化合物當做有效成分之粒狀農藥組成物中摻合經煅燒之黏土。
