我国的传统农业,是靠耕作、倒茬和施有机肥维持地力的,在世界农业发展史上占有重要地位。但是,我省土壤肥力普遍较低,土壤有机质一般仅0.6%左右,有效氮20ppm左右,速效磷不足10ppm。在低肥力的条件下,小麦生产要获得高产量、高效益,就得变封闭型 The traditional agriculture of our country is maintained by the means of farming, stubble and organic manure and occupies an important position in the history of world agricultural development. However, soil fertility in our province is generally low, soil organic matter is generally only about 0.6%, about 20ppm available nitrogen, available phosphorus less than 10ppm. In low-fertility conditions, wheat production to obtain high yield, high efficiency, you have to change closed