analisis kekeringan pertanian berdasarkan neraca air harian di lahan tadah hujan

ANALYSIS OF AGRICULTURAL DROUGHT BASED ON DAILY WATER BALANCE AT RAIN FED FARM LAND Aini Nurjanah, Sumani, Komariah, Dwi Priyo Ariyanto ABSTRACT Agricultural drought related to soil moisture which is characterized by deficit of soil moisture. The condition leads to the limitedness for crop culture due to soil moisture availability is not enough for plant’s needs. Therefore, this research aims at finding when exactly the agricultural drought occurred using water balance approach. This research employed descriptive exploratory method which was done by surveying in the field and also supported by laboratory analysis. The component of daily local weather data, included air temperature, air relative humidity, soil temperature, soil moisture, and rainfall at two locations, each at Ampel and Teras District, Central Java, Indonesia from October 1st, 2015 to March 31st, 2016. Then laboratory analysis to determine soil water availability at pF 2.54 – 4.2 was conducted using hydraulic properties calculator. The results show that the meteorological drought at both locations ended earlier than the agricultural drought, which was at the third decadals (20th-30th) of October 2015. But the agricultural drought ended on decadal (Nov.2nd and Nov.5th, 2015) At Ampel and Teras district, respectively. During dry conditions,the rain-fed lands were left fallow until the end of agricultural drought, which enters rainy season. Start from this point, the lands can be planted with rice. Key word : Soil available water, meteorological drought, decadal, local weather data