黄土高原旱地春谷吸肥与土壤供肥规律研究

１９９０～１９９２年在山西榆次市对黄土高原旱地春谷吸肥与土壤耕层供肥规律进行了研究。结果表明，土壤耕层氮磷供给能力动态变化遵循倒Ｌｏｇｉｓｔ１０生长曲线方程变化，钾的供给能力动态变化遵循一次方程变化；谷子不同生育时期吸收氮磷钾动态变化遵循Ｌｏｇｉｓｔ１０生长曲线方程变化；谷子一生随着生育进程对氮磷钾的吸收量逐渐增加，土壤氮磷钾供给量则随着谷子吸收量的增加而减少，即供给能力趋于减弱，氮的吸收高峰与土壤供给高峰基本一致，磷的吸收高峰在土壤供给高峰之后，钾的吸收高峰在土壤第一供给高峰期，孕穗至抽穗阶段是谷子吸收氮磷钾的高峰期；从谷子一生来看，吸收氮磷量小于土壤供给量，钾的吸收量大于土壤供给量。通过分析并对榆次市黄土高原区旱地春谷施肥问题提出新见解，即亩产要达到２００ｋｇ以上应重视施用钾肥。

Studies on the Laws of the Nutrition Absorption of Spring Millet and the Fertilizer Supplies of Soil in the Dryland Area of Loess Plateau

During the 3-years experiment(1990-1992),the laws of nutrition absorption of spring millet and the fertilizer supplies of the soil in dryland of loess plateau were studied at Yuci,Shanxi.The results indicated that the movements of N and P2O5 the soil supplied show as negative logistlo growth trends and that of K2O shows a liner one;with the growing of millet plants,the absorption of N,P,K changes as a logistic trend;the absorption of N,P and K increased with the growing of millet plants,but the supplies decreased;the absorbing peak of N is similar to the supply peak,but itwas some later for P2O5,tha absorption peak of K2O is at the first supply peak;from booting to earing is the very period that spring millet absorbs fertilizers quickly;in the whole life of millet the absorptions of N and P is at the lower level than the level of nutrition supplied,and absorption of K is higher Based on the experimental results, a proposal on the using of fertilizers on millet in this region are made as follow.To keep the millet yield at the level of 200kg per mu,potassium fertilizer should be used.