Based on the formula,yield trends of winter wheat and cli-mate wheat yields in Qianxian county for nearly 30 years are calculated,and so do thosein experimental area in Wudian and Shanhe Townships since its establishment.

• 依此算出了乾县近30年来逐年的冬小麦产量趋势项与气候产量,及乾县吴店乡、三合村全乡、全村的试区成立以来的冬小麦产量趋势项与气候产量,并找出了影响试区冬小麦产量的主要气候因子:光、热、水。