熟畑化過程における雑草植生の変遷に関する研究 : 第7報熟畑から原野化に至る過程における雑草植生の変化

概要

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A completely ripened field on relatively old volcanic ash soil was not cropped for thirteen years' duration. The chemical properties of soil and weed vegetation in each year were investigated during that period. The chemical properties of soil in the uncultivated plot deteriorated earlier than that of the cultivated one (cultivation to the depth of 25cm once a year). In both test plots the weed vegetation changed in the order, a field type weed (weed vegetation of ripened field), mixture of field type and upland type (weed vegetation of unripened field) and upland type (wild field type weed vegetation). Change of the weed vegetation occurred after one year, after two to four years and after five years, respectively, in the uncultivated plot; and after three years. after four to seven years and after eight years,respectively, in the cultivated one. Border line values at which vegetation changed from ripened field type to unripened field type were pH (KCl) 5.00; base exchange acidity (y_1) 1.0; and saturation degree of calcium 50%. Those at which weed vegetation changed from unripened field type to wild field type were 4.40, 10.0 and 20%, respectively.
日本雑草学会の論文
1978-12-25