抄録
No-tillage culture is useful to reduce energy consumption, but it is often associated with degradation of soil physical properties leading to yield loss. The effects of sorghum (Sorghum bicolor L.) as a summer cover crop on infiltration of soil were investigated by analysis of the relationship between precipitation and soil water content. When the sorghum grew well, reaching a height of about 180cm, soil infiltration was improved because soil water content was favorable, while total precipitation became about 50mm at an initial soil water content of 50%db. In contrast, when the sorghum showed insufficient growth with a height of about 40cm, soil infiltration was not improved. The effects of sorghum on soil infiltration are bigger and lasted longer than the effects of mechanical tilling. The improvement of soil infiltration by sorghum contributes to prevent yield decrease in subsequent buckwheat (Fagopyrum esculentum Moench) culture.
