Abstract
The shaft tillage cultivation method is a no-tillage method for transplanting seedlings in an artificial macro-pore that facilitates placement of the crop roots much deeper than weeds. To test the effectiveness of this shaft tillage method on Chinese cabbage, column cultivation experiments were carried out. Then, water flow experiments were conducted to observe the process of root growth and water flow around an artificial macro-pore (8 mm diam., 20 cm long）under drip irrigation. Column experiments showed high density roots in the artificial macro-pore. The dry matter content of roots and leaves were found to be higher after use of the shaft tillage method as compared to the method without an artificial macro-pore. As determined in the water balance analysis of water flow experiments, most of the water uptake came from roots in the lower depth of the soil profile, suggesting important contributions of the high density roots to transpiration. Additionally, in the macro-pore experimental condition, we observed preferential water flow through the high density roots, indicating a shift to deeper sources of water for plant growth.
