渭北旱原常用一年生豆科作物和绿肥培肥麦田。豆科根茬能否增加土壤氮素,历来就有争论,迄今尚未解决。为了摸清底细,我们先后多次进行了有关试验。方法和设计 (一)秋播一年生豆科作物 1963—64年,盆栽设四个处理:即土培豌豆和毛苕,石英沙培豌豆和毛苕。1964—65年,盆栽设土培豌豆和毛苕、土培山黧豆和鸡头豆。以上八个处理,均以小麦作对照,重复三次,每盆分别种供试作物10株。收后改种玉米1株。土培的土壤取自大田复种玉米茬地。沙培的给予适量的草木灰灰分元素。 Weibei drylands often annual bean crops and green manure fertilize wheat fields. Leguminous stubble can increase soil nitrogen, has always been controversial so far has not been resolved. In order to find out clearly, we have carried out the relevant test several times. Methods and Design (I) Autumn sowing annual leguminous crops 1963-64 years, potted plants set up four treatments: that is, soil culture peas and Mao Zhi, quartz sand Peas and Mao Zhi. In 1964-65, potted peas and mullet, potatoes, peas and beans. The above eight treatments were wheat as a control, repeated three times, each pot was planted 10 plants for trial. After the harvest of a corn plant. Soil cultivated soil from the field of multiple crop corn stubble. Sapi to give the right amount of ash ash elements.