Penilaian Opsi Budi Daya Padi Sawah Tadah Hujan Adaptif Kekeringan: Studi Kasus Kabupaten Subang

Abstract

Extreme climate events, particularly drought significantly affectproduction of rainfed lowland rice in Indonesia. This might affect food security. This study aims to assess alternative technologies or crop management strategies of rainfed lowland rice more adaptive to drought in Subang, West Java. Technology options and strategies are determined through surveis and crop simulation models of DSSAT (Decision Support System for Agrotechnology Transfer). Input data for the model consists of a 21-year daily climate data (1991-2011), soil physic and chemical properties, genetic data of IR 64 rice varieties and rice cultivation technologies. The cultivation technology options being tested included soil management (fertilization) and crop management (varieties and planting time). Simulations was carried out according to the time of planting from January to December with 15 days interval. The results of field survei confirmed that the main problem in rainfed rice at Subang District was drought. The simulation results showed that the main options to address drought was to set appropriate planting time with the use of proper cultivation technology (balanced fertilizers). In general, the appropriate time for rainfed lowland rice planting was rainy season (October-April) the yield can reach 6.0 ton/ha, while dry season (May-September can be lower than 1.0 ton/ha. The use of SST Nino 34 index to see the phenomenon of ENSO which affecting rice yield variance of rain. So that farmers can appropriate started of planting time based on seasonal climate forecast to solve the drought problem. The recommended amount of fertilizer for the rainfed lowland rice at Subang was 300 kg/ha of inorganic fertilizer and 5 tons/ha of organic fertilizer with planting space of 40 × 40 cm. The use of this technology resulted in yield of more than 5 ton/ha with B/C ratio of about 1.76.