BOBOT BIOMASSA DAN NILAI PANAS RUMPUT GAJAH (Pannisetum purpureum.cv.king grass) PADA BERBAGAI DOSIS PUPUK N,P,K DI LAHAN PASIR PANTAI

Abstract

Indonesia has about 49 species of plants that can be used as an alternative energy source, one of them is the elephant grass (Pennisetum purpureum Schumach). Elephant grass is known have a biggest biomass weight and high heat value so that it can be used as fuel for various industrial purposes including the generation of electricity. Elephant grass biomass production depends on culture technique aspects such as fertilizing and environmental conditions. Research in order to determine the effect of fertilizer N, P, K on elephant grass (Pennisetum purpureum.cv.king grass) against the weight of biomass and that heat value has been done on sandy coastal land of Bugel , Panjatan, Kulonprogo, May through September 2011. Five-level dose of fertilizer N, P, K, which consists of a mixture of urea, SP-36 and KCl were attempted in the elephant grass using RAKL experimental design with 3 blocks as replicates. Five-level dose of fertilizer has tried were 1). 0 kg / ha; 2) 115 kg urea, 90 kg SP-36, 115 kg KCl / ha; 3). 230 kg of urea, 180 kg SP-36, 230 kg KCl / ha; 4) 345 kg urea, 270 kg SP-36, 345 KCl / ha and 5). 460 kg of urea, 360 kg SP-36, 460 kg KCl / ha. The results showed that vegetative growth increased significantly with increasing doses of N, P, K fertilizer, but the harvest of fresh and dry biomass weight, did not differ between dose of fertilizers, as well as its heat value. Fresh weight obtained in this study ranged from 96.79 tons to 146.66 tons per hectare, while the weight of dry biomass ranged 36, 54 tons to 48.45 tons per hectare. Heat or caloric values obtained ranged from 221. 867 .226 kilo calories to 328 .943. 039 kilo calories. Keywords : elephant grass; biomass weight; heat value; N,P,K fertilizer; sandy coastal land