一、前言 从1956年至57年的生产实践证明:水稻改制、增加复种对于增产水稻已产生显著的效果,是提高粮食单位面积产量的重要措施。但是在改制过程中。由于缺乏经验,从全面和长远安排出发不够,也产生了一些问题,如:挤掉了一部分原有的优良换茬制(稻——泥豆——冬作),有些地区未能按照土壤特性分配作物(早稻种到不发早稻的低湖田 I. Preface From 1956 to 57 years of production practice has proved that: rice restructuring, increased cropping for the production of rice has had a significant effect, is an important measure to improve grain yield per unit area. But in the restructuring process. Due to lack of experience, inadequate departure from full-scale and long-term arrangements has also brought some problems such as squeezing away some of the finest old crop systems (paddy-muddy beans - winter cropping) and failure to follow the soil characteristics Allocate crops (early rice to low lake without early rice