为贯彻北京市 2 6项节水措施 ,北京市水稻种植面积已由 1999年的 1.9万ｈｍ2 锐减至 2 0 0 1年的 0 .72万ｈｍ2 。 3年后 ,水稻将退出北京市农作物的行列。据市农业局粮经办工作人员介绍这种种植结构调整的必要性时指出 :虽然北京地区水稻单产高于小麦(水稻 4 0 0ｋｇ左右 ,小 In order to implement 26 water saving measures in Beijing, the rice acreage in Beijing has dropped sharply from 19,000 hm2 in 1999 to 0.72 million hm2 in 2001. Three years later, rice will withdraw from the ranks of Beijing’s crops. According to the Bureau of Grain Economics of the Municipal Bureau of Agriculture introduced the necessity of this planting structure adjustment, although the rice yield in Beijing is higher than that of wheat (about 400 kg of rice, small