In the wheat/maize rotation fields of the two years, the input of N,P and K for the winter wheat account for 67.27% and 67.41% , 86.43%and 84.72%, 54.43%and 75.88%of total inputs respectively so that much less fertilizer were used for maize.

• 曲周还存在“重冬轻夏”的不合理现象，在1998年和1999年小麦/玉米轮作分别有67.；27%25和67