【摘要】 <正> 紫色土在四川盆地分布最广,占全省总面积的28%,占耕地总面积的68.7%,是该省粮食生产基地,粮食产量约占全省总量的70%。这种土壤除种植粮食作物外,还适宜种植蔗、棉、油、桑和水果。紫色土生产潜力极大,但也存在不少问题。从三十年代以来,许多土壤学者对紫色土进行过一系列研究,一致认为紫色土肥力与母质特性关系密切。本文以底土或岩石风化碎屑(即母质,C)为基本材料,同时用表土(A)和岩石(R)作辅助样品,研究了紫色土肥力与母质特性的关系。更多还原

【Abstract】 Six main purplish parent materials of soil in Sichuan basin have been studied by chemical, physical, differential thermal, X-ray and micromorphological analysis and pot culture. Results obtained are as follows:1. The difference in SiO₂/R₂O₃ ratio of the clay minerals among the soils derived on purple parent material, parent material and rock is insignificant. There are irregular lithorelicts in both soil and its parent material. Microaggregates are poorly developed in the soil. All these indicate the feature of purple soil characterized by the profile of A-C pattern and being young skeleton soil.2. The SiO₂/R₂O₃ ratio of clay minerals in different purple soils ranges from 2.09 to 3.06. The day minerals of parent materials are predominantly montmorillonite and hydromicas. Total content of Fe and Zn is closely correlated with organic matter content in rocks, the correlation coefficients （r） are 0.925 and 0.962.3. The pot culture of rice also shows that in addition to the effect of N,P,K content, the rice yield is also closely related to the percentage of <0.05 mm particles and the content of available Fe in the parent materials, the correlation coefficients （r） are—0.907 and 0.948.更多还原