The Effectiveness of Herbicides in Upland Soil Types in Kyushu

Abstract

This experiments were carried out at 1966 in order to study the action of three herbicides in six upland soils in Kyushu with special respect to soil moisture content. The experimental results obtained were summarized as follows:
(1) Isahaya soil (andesite: 0.75% humus) and Oita soil (alluvial soil: 1.98%) is unstable compared with other soil types, in the emergence of weeds and phytotoxicity of herbicides on account of the difference of soil moisture content.
(2) Of volcanic ash soils (humus content: Ono 15.25%, Nishigoshi 12.10%, Kanoya 11.05% and Miyakonojo 4.65%, respectively), Miyakonojo soil is comparatively unstable in weed emergence and herbicidal activity. However, other soils are unlike.
(3) Soil properties principally affecting the behavior of herbicides in the soils are considered maximum water-holding capacity and humus content of soil.