Abstract
We investigated the physical and chemical properties of soil, and the patterns of crop root growth from a serial experiments on successive no-tillage farming for seven years in this paper.
1) The soil hardness of no-tillage plot (NT) was higher than that of conventional tillage plot (CT) in 5-20cm layer, the hardness of NT was almost equivalent to that of CT in 25-35cm layer and the hardness of NT was lower than that of CT in layer below 35cm. The soil hardening has already progressed since the second year of no-tillage farming.
2) There was no difference between CT and NT in three phase of soil. The significant differences in both water content and bulk density for soil layers were observed in common with the two plots.
3) The pH of NT was slightly lower than that of CT.
4) In the analysis on various chemical properties of soil after six years of no-tillage farming, no clear difference between CT and NT was observed except for a few chemical components.
5) Most of the crop root in NT concentrated on 0-10cm soil layer.
