Irrigation Scheduling Model for Dry Crops

밭작물(作物)의 계획관개(計劃灌漑) 모형(模型) - 토양수분(土壤水分) 변화(變化)를 중심(中心)으로 -

This study was carried out to investigate the evapotranspiration and variations of soil moisture contents for soybeans. The relationship between actual evapotranspiration obtained by the water balance equation and estimated evapotranspiration obtained by the soil moisture model was analyzed. The results obtained were summarized as follows; 1. The total amount of actual evapotranspiration of soybeans during growing season was 405.7mm. The total amount of reference crop evapotranspiration of soybeans that was estimated by Pan evaporation and Hargreaves method were 547.8 mm and 586.8 mm, respectively. Crop coefficient during growing season were shown on Table 1. 2. Measured actual evapotranspiration of soybean during growing season was 405.7 mm and estimated actual evapotranspiration by pan evaporation and Hargreaves method were 424.7 mm, and 426.1mm, r3 respectively. 3. The variations of soil moisture content for soybeans were high at 10cm layer, as compared with those at 30cm and 50cm layers. Because discrepancy between the variations of soil moisture content predicted by model and observed by soil moisture meter was still great, it is required to study the consumptive types of soil moisture at each root depth.

콩의 생육시기별(生育時期別) 증발산량(蒸發散量)과 토양수분(土壤水分) 변화량(變化量)을 추정(推定)하기 위한 토양수분추정모형(土壤水分推定模型)을 설정(設定)하였으며 라이시미터 실험(實驗)을 통한 실측치(實測値)와 비교(比較)한 결과(結果)는 다음과 같다. 1. 라이시미터 실험(實驗)을 통(通)하여 측정(測定)한 실제증발산량(實際蒸發散量)은 405.7mm 이었으며 Pan 증발량법(蒸發量法)과 Hargreaves식(式)에 의한 잠재증발산량(潛在蒸發散量)은 각각(各各) 547.8mm, 586.8mm이었다. 작물(作物)의 생육기간중(生育期間中) 작물계수(作物係數) K는 Table 1 과 같다. 2. 라이시미터 실험을 통한 전생육기간(全生育期間)(133일(日)) 동안의 실제증발산량(實際蒸發散量)은 405.7 mm이었으며 Pan 증발훈법(蒸發暈法)과 Hargreaves식(式)에 의해 추정(推定)된 실제증발산량(實際蒸發散量)은 각각(各各) 424.7mm, 426.1mm였다. 3. 콩의 생육기간별(生育期間別)로 10cm, 30cm, 50cm 깊이에서 관측된 토양수분변화(土壤水分變化)는 10 cm (첫 20cm 토층)에서는 변화(變化)가 크게 나타났으나 30 cm와 50 cm에서는 변화(變化)가 거의 없었다. 모형으로 추정(推定)된 토양수분변화(土壤水分變化)와 관측된 토양수분변화(土壤水分變化)사이에는 아직도 큰 차이가 있으므로 뿌리의 깊이별 토양수분소비형태(土壤水分消費形態)에 대한 연구(硏究)가 요구된다.