Meteorological and Soil Characteristics in the Central Ethiopia
摘要
Crop production systems in the Central Ethiopia are mostly under rainfed condition. Although the mean amount of annual rainfall is still much for crop growth (400 to 800 mm), the crop production systems often suffer from severe drought stress resulting in unstable food security. This is in part due to erratic and fluctuated rainfall distribution patterns in the region. However, it is required to investigate soil infiltration characteristics, soil water holding capacity, and meteorological condition other than precipitation (ex. evaporation) in order to know how much rainfall can be utilized for crop growth. In the current study, changes in soil water content associated with irrigation or subsequent rainfall were monitored in both dry and rainy season in an experimental field established in the Central Ethiopia. Meteorological observation system was also established. In the dry season, the applied water did not reach down to 25 cm due to poor permeability associated with dry soil condition. In contrast, initial irrigation and subsequent rainfall increased soil water content and infiltrated into the depths in the rainy season. Even in the rainy season, evaporation affected on moistening of deeper soil depths associated with infiltration and redistribution. The meteorological observation revealed that intense solar radiation, high temperature, low relative humidity, and constant wind speed would accelerate evaporation from soil surface.