Abstract
The improvement of soil structure to bring out the maximum ability of fumigans and the development of proper application mechanism which is based on the physico-chemical characteristics of soil fumigants are necessary to improve the safety in fumigating operations and the efficacy of pests control in the soil.
The purpose of this work is to consider the effect of clod size on the movement of chloropicrin gas in the soil.
The relationships between clod sizes and permeability coefficient, diffusion coefficient and diffusion patterns of chloropicrin in the soil were measured in the laboratory. It was cleared that the gas diffusion coefficients in the case of clods smaller than 10mm∅ were 1/7-1/700 times as that in atmosphere and 1/10-1/50 times as that in the clods of 15-20mm∅. The clod diameter smaller than 10mm seemed to be suitable for the soil fumigation.
