<正> 湘、鄂、赣三省五十年代初的稻田耕作制度是以一年一熟制为主,一季稻占稻田面积的85%以上,冬季多为冬炕或冬泡,只有部分种冬作物。六十年代中期始,推广一季稻改双季稻,复种指数不断提高,双季稻面积逐年扩大,与此配套的紫云英绿肥也很快发展起来。七十年代“绿肥—双季稻”已成为稻田复种制度的主体,到1977年,三省双季稻面积达到最高峰,占水田总面积的60%以上,“绿肥—双季稻”又占双季稻面积的70%以上。这种改革措施对三省粮食增产,尤其是水稻增产,起了重要作用。
The South China is a major producing area of double cropping ofrice.Owing to the continuous cropping of green manure-double croppi-ng of rice carried out in a large area,soil physical-chemical properthad gone bad,secondary gley was aggravated,yields of green manureand double cropping of rice remained stagnant,insect pest and plantdiseases were serious,weeds were spread,as a result the economic eff-ect was lowered.For these reasons,the experiment was conducted in1978～1982 to change the unitary system of cont...
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