Korean Journal of Soil Science and Fertilizer ISSN:0367-6315(Print) 2288-2162(Online) 한국토양비료학회 학회지

In South Korea, the area of agricultural land has steadily decreased and the overall food self-sufficiency rates have consistently dropped with a decrease in farm population since 2000. This study aimed to evaluate water requirements of crops soybean, sorghum, and sesame using lysimeter. Using the lysimeter with different groundwater levels, 20 cm and 40 cm, and different types of soils, sandy loam and clay loam, the evapotranspiration for crops was measured to determine the water requirement and the water use efficiency. The results showed that the maximum evapotranspiration of soybean and sesame was at the blooming stage, and that of sorghum was at the panicle formation stage. In water use efficiency, the optimal soil texture (groundwater level) for soybean was clay loam (40 cm), for sorghum was sandy loam (20 cm), and for sesame was sandy loam (40 cm). The water requirement of soybean and sesame was lowest at sandy loam (40 cm), while sorghum had the lowest at sandy loam (20 cm). The 100-kernel weight of soybean was found to be higher under the groundwater level 40 cm than 20 cm regardless of soil types, and 1,000-kernel weight of sorghum and sesame was found to be the highest under the sandy loam (40 cm). In consideration of these results, sandy loam (40 cm) was more suitable for cultivating soybean and sesame, and so was sandy loam (20 cm) for sorghum. The results of this study are expected to provide useful data for the development of an irrigation system which is possible to set the groundwater level as desired.

Evapotranspiration of soybean and precipitation at sandy loam.