宁夏回族自治区引黄灌区是我国西北主要水稻产区之一。种稻已有千年以上历史。灌区由于蒸发量大、降雨量小,土层中含有盐碱,因而形成了一套严格的轮作制度,通常是在旱种一二年后土壤盐分增加才种稻压盐,或在盐碱较重的低洼田连年种稻。该区日照对数多、病虫害轻,光温条件均适于水稻生长。解放前,耕作粗放,水稻产量很低,亩产200多 The Yellow River Irrigation Area in Ningxia Hui Autonomous Region is one of the major paddy producing areas in Northwest China. Rice has been more than a thousand years of history. Irrigation due to large evaporation, rainfall is small, soil contains saline, which formed a set of rigorous rotation system, usually one or two years after the dry soil salt to increase salt was only rice, or salt in the more Heavy low-lying fields year after year kinds of rice. The area sunshine logarithm, light pests and diseases, light and temperature conditions are suitable for rice growth. Before liberation, extensive farming, rice yield is very low, more than 200 acres