受市场经济和需求双重拉力，农民不得不在有限的耕地上连续种植大豆，致使黑龙江省大豆重迎茬种植面积进一步扩大。研究调查表明大豆迎茬种植减产１０％，重茬种植减产２０％，同时大豆的商品品质明显下降。为了控制大豆重迎茬减产，国家科技部将之列为国家“九五”科技攻... Driven by the dual demands of the market economy and peasants, the farmers had to plant soybean continuously on limited cultivated land, resulting in further expansion of soybean planting area in Heilongjiang Province. Research survey shows that the yield of soybean is reduced by 10% at planting of stubble crop and that of stubble planting is reduced by 20%, meanwhile, the quality of soybean’s products declines obviously. In order to control the reduction of soybean output, the Ministry of Science and Technology will list it as the national “Nine Five” technology attack ...