作物根茬对土壤培肥作用的研究——Ⅱ.作物根茬对土壤腐殖质组成的影响

STUDY ON THE EFFECT OF CROP ROOT SYSTEMS ON SOIL FERTILITY Ⅱ. EFFECT OF CROP ROOT SYSTEMS ON THE COMPOSITION OF SOIL HUMUS

本文对黑钙土、黑土中各种作物根茬留茬与否对土壤腐殖质、土壤重组有机质的组成、结合形态及某些光学性质进行了测定。结果表明,各种作物根茬留在土壤中是以非腐解态有机物发生作用的,对于改善土壤腐殖质的组成发生了良好的作用。说明作物根茬留在土壤中不仅对调节土壤有机质的平衡具有重要意义,而且发挥着很好的培肥作用。试验结果同分析土壤酶活性一样初步证明玉米根茬比大豆根茬有更好的培肥作用。

There are few studies on the effect of crop root systems on the composition, particularly on the heavy fraction of soil humus.The contents, the composition of heavy fraction, the combined forms of humus and the optical density of humic acid were determined in the paper. The results indicated that undecomposed crop root could improve the composition of soil humus. It means that crop roots benefit soil fertility not only from adjusting the balance of soil organic materials but also from improving the quality of soil humus. It has been proved preliminarily that the corn roots play a more important role in fertilizing soil than soybean root does.