A preliminary report of integrating sheep farming in combination with adopting biogas technology in organic rice farming systems in upland areas in Indonesia

Abstract

This study aims to understand the preliminary results of integrating sheep farming in combination with adopting biogas technology in organic rice farming (ORF) systems in upland areas. The research was conducted in upland areas in Grabag Subdistrict Magelang Regency, Central Java Province (UPL1) and Kertasari Subdistrict, Tasikmalaya Regency, West Java Province (UPL2), Indonesia. At each upland area, a demo plot with a 17 m3 digester has been established, and 120 sheep were introduced. A combination of sheep and beef cattle manure was used as a biogas substrate. The soil sample of one and three-year conversion of ORF was collected, and macro and micro minerals were analyzed. The biogas quality was analyzed, including dry matter (DM), nitrogen (N), carbon (C) and nitrogen-ammonia (N-NH3). The greenhouse (GHG) emissions, including methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O), were measured. The results indicated that C-organic content at three-year conversions of ORF in UPL1 was much lower (P<0.05) than the one-year conversion. The average CH4, CO2, and N2O contents in UPL1 were 661, 477.3, and 0.16 mg/m2/day, respectively. The average CH4, CO2, and N2O contents in UPL2 were 3328, 3038 and 2.42 mg/m2/day, respectively. In UPL1, the proportion of CH4 was 52.5 %, CO2 was 47.4 %, and N2O was 0.01 % while the proportion of CH4 was 57.9 %, CO2 was 42.0 %, and N2O was 0.01 % in UPL2. To conclude, integrating sheep farming in combination with adopting biogas technology in the ORF system improves manure management and provides organic fertilizer, which subsequently reduces the use of artificial fertilizer and avoids GHG emissions.v