经５年的定位试验，结果表明：稻田年内水旱轮作（二水一早的麦＝玉米－稻）的晚稻产量比连作（一旱二水的麦－稻－稻）晚稻产量显著增加，增产幅度为６．５４％～１５．８７％，平均为１０．７５％，其增产的原因主要是稻田年内水旱轮作不仅可促进晚稻分蘖早、分蘖快、数量多，从而使有效穗明显增加；而且还促进叶面积的扩展并使叶片叶绿素含量增加，延缓后期衰老，使干物质积累明显增加，从而使每穗粒数明显增加，并能维持与连作晚稻相同的结实率和千粒重 After 5 years of location test, the results showed that the yield of late rice in paddy field during the rotation and drought (early summer wheat = maize-rice) was significantly higher than that of continuous cropping (arid-dry wheat-rice-rice) Which is 6.54% ~ 15.87% with an average of 10.75%. The main reason for its increase is that the rotation and rotation of paddy fields during the year can not only promote early tillering and fast tillering of tillers, but also increase the number of effective tillers. Moreover, It also promoted the expansion of leaf area and increased chlorophyll content in leaves, postponed senescence and significantly increased the accumulation of dry matter, resulting in a significant increase in grain number per spike and maintaining the same seed setting rate and 1000-grain weight