Soil temperature is an important factor influencing crop growth. Within limits, a higher soil temperature will promote crop growth, especially in cool climate regions. Compost application can increase soil temperature, however the mechanism of increasing soil temperature remains unclear. We conducted a pot experiment to examine the effects of compost application on soil temperature and evaporation in a bare Andisol. Pots with compost (16㎏ m?²) had a higher soil temperature and less evaporation than pots without compost. The decrease in evaporation and the increase in soil temperature by compost application were significantly correlated. We conclude that compost application increases soil temperature by decreasing evaporation from the soil surface.

• Shin Deguchi
• Hidenori Kawamoto
• Osamu Tanaka
• Akihide Fushimi
• Sunao Uozumi