2016 Volume 7 Issue 1 Pages 29-36
Decomposition of soil organic carbon as well as growth of crops are affected by soil physical condition such as soil moisture and soil temperature. Thus predicting soil moisture and temperature condition of arable lands under future climate change is important for both mitigation and adaptation of climate change in agriculture. In this study, we attempted to predict soil temperature condition in arbitrary arable lands in Japan. Soybean fields of Toyama city, middle part of Japan facing Japan Sea were chosen as the experimental site. There, monitoring of soil temperature and measurement of soil thermal properties which is a function of soil moisture, was conducted. For the future application to arbitrary locations, the thermal properties were also predicted with a mathematical model, by using soil physical properties such as the ratio of sand: silt :clay, soil particle density and dry bulk density in soil physical database. Then, numerical simulation of soil moisture and temperature was conducted with predicted soil hydraulic and thermal properties. The model with estimated thermal properties described the measured soil temperature fairly well especially when the soil condition was wet.