Ecology, Environment and Conservation Paper

WATER REQUIREMENTS IN BEAN CROPS USING CROPWAT 8.0 IN OENONI VILLAGE KUPANG DISTRICT, INDONESIA

Lano M.L. and J.J.S. Dethan

Abstract

A study has been carried out to plan the provision of water in the cultivation of green beans based on Cropwat analysis. Climatology data was obtained from BMKG Kupang Class II Climatology Station which included rainfall, minimum temperature, maximum temperature, relative humidity, wind speed, and duration of sun exposure. The data needed is the result of observations for five (5) years, with the period 2014 to 2018 for the Regency of Kupang. Data processing in this study uses 4 main panels in the Cropwat 8.0 program, namely Climate / ETo (climate data) is input data in the form of monthly average maximum air temperature and minimum air temperature, the average month-long sun exposure, and monthly average humidity. The climate data input is used to estimate ETo and the magnitude of the value of solar radiation. Rainfall data to determine effective rainfall with the input of average monthly rainfall over the period 2014- 2018. Plant data are plant characteristics and the time of the start of the plant season. Data on plant characteristics referred to are Kc (Plant growth coefficient), length of day for each phase, root depth, plant height, and soil type. The results showed that crop evapotranspiration (ETc) using Cropwat 8.0 software was 270.8. with the highest actual crop evapotranspiration achieved in October of the third period of 4.44 mm and the lowest in October of the second decade of 2.6 mm. The highest irrigation water demand is in the second decade of September at 38.7 mm and the lowest in October the third period at 1.6 mm. These results are quite in accordance with the conditions in the field to plan the start of the growing season. However, daily irrigation operations need to be carried out based on observing actual conditions in the field to maintain groundwater levels in the appropriate range for plant growth.