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渭北旱原以往群众采用豆科培育地力,首蓿、豌豆、大豆、扁豆面积几乎与禾谷类作物相当,素有“豆麦平”之说。但近年由于许多原因,特别是依赖氮素化肥,豆科作物逐年减缩,致使土地养用失调,单产不能提高。本文就豆科植物固氮养地问题进行讨论。一、豆科植物面积与固氮水平 1.种植面积本区现有豆科作物大豆、豌豆(主要夏杂)和首蓿等,据1957年与1981年其所占耕地比例如表1。由表1可知,全区1981年豆科植物和大豆
In the past, people in the Weibei dry land used legumes to cultivate fertility. The area of first crop, pea, soybean and lentil was almost the same as that of cereal crops, which is known as “bean flour flat”. However, in recent years, due to many reasons, especially dependent on nitrogenous fertilizers and leguminous crops, the annual reduction has led to the mismanagement of the land and the increase in yield. This article discusses the issue of nitrogen fixation of leguminous crops. First, the leguminous plant area and nitrogen fixation level 1 planting area The existing leguminous crops in this area soybeans, peas (mainly summer hybrid) and the first crop, according to 1957 and 1981, the share of arable land in Table 1. Table 1 shows that the region 1981 legumes and soybeans