前言 几年来,我省实行“三变”和扩大复种面积,已取得很大的增产效果。全省复种指数,由1950年的141%增加到1956年的189.5%;双季稻面积,由1950年的400万亩增加到1956年的860万亩。但有些地区由于没有根据当地具体条件,因地制宜地进行改制,也存在一些问题,个别地区虽然增加了复种面积,却未能达到增产增收的目的。为此,必须积极展开轮作和复种的调查研究工作。通过调查总结, Foreword In recent years, our province has implemented “three changes” and expanded the area of ​​multiple cropping. It has made a great yield-increasing effect. The province’s multiple cropping index increased from 141% in 1950 to 189.5% in 1956; the area of ​​double-crop rice increased from 4 million mu in 1950 to 8.6 million mu in 1956. However, in some areas, some problems have not been achieved due to the lack of specific conditions in the region and the restructuring according to local conditions. Although the area of ​​multiple-cropping has been increased in some areas, it has not achieved the goal of increasing output and increasing income. To this end, we must actively carry out investigations and studies on rotation and multiple cropping. Through investigation and conclusion,