| 1. | Collecting a large number of atmosphere , soil and irrigation water , using the method of monomial and composite pollution exponent , the general situation of grain early warning is studied and a grain early warning system is built 本文从粮食生产过程中的大气、土壤及农田灌溉水出发,运用单项污染指数与综合污染指数相结合的评价方法进行粮食生产的预警研究,构建了粮食本底安全预警系统。 |