Abstract
The use of methyl bromide, which had been widely used all over the world, was banned in 2005 in Japan, so that it is very important to develop new tech-niques for soil sterilization. Using hot water for soil ster-ilization has become popular in Japan as an alternative for methyl bromide. Many studies have been done on bac-terial survival in soil when hot water was applied. Few studies focused on measurement temperature at multiple locations in the field. Even it is necessary to keep soil tem-perature between the surface and 30 cm deep with 45 ◦C for 5 h although hydraulic conductivity for hot water var-ied place to place at a field. Therefore, we investigated temperature distribution before and after using hot water for soil sterilization in a greenhouse by measuring soil sur-face temperature using thermography. We also focused on effect of water movement by repacked soil at field with hot water application. We found that a temperature mea-surement was expressed the representative temperature at the field by the sterilization with hot water applied. How-ever, a place, where we dag a hole for putting the sensors, was showed higher temperature than other places because of large amount of hot water application due to higher hydraulic conductivity and to destroyed hard pan layer. Therefore, we have to take care of refilling a hole after putting the sensors. Otherwise, over estimates of temper-ature occur due to applying large amount of hot water at such a place.
