Keywords : mitigation ; GHG ; land productivity ; organic paddy
By: Jauhari Syamsiyah, Bambang Hendro
Wetland, especially organic rice paddy fields, have been assessed to increase greenhouse gas (GHG) emissions and contribute enormously to global warming. Therefore, we need a deep study on GHG emissions from rice paddy fields of organic systems in various management treatments are usually carried out by farmers. One effort that is required is to mitigate GHG emissions periodically through land characterization and measurement of the amount of GHG emissions, how to manage the land that can minimized GHG emissions, but still can improve land productivity.
Steps of GHG mitigation are characterization, experiment, measurement of GHG emissions and selection recommendations. Land characterization is deeply object to the condition of soil (organic matter, mineralogy, nutrient status, pH, texture, Eh, soil temperature), climatic conditions (rainfall, temperature), crop factor (species/variety), and factor of culture (land preparation, planting, fertilizing, irrigation, weeding, harvesting). Experimental demonstration plots with the treatment and management of which is commonly done by farmers.
Measurement of GHG emissions include CH4, CO2, and N2O are measured on each land unit experiment. Election recommendations are based on management that is able to maintain or improve fertility and land productivity, and reduce GHG emissions of CH4, CO2 and N2O or there are still within the limits allowed.
The results of the research shows that ; (1) treatment of varieties (Mira-1, Mentik Wangi and Merah Putih), manure doses (0 and 10 tons/ha), and Azolla inoculum doses (0 and 2 tons/ha) are not give significant effect to total emissions of CH4, CO2 and N2O, (2) emission level of CH4, CO2 and N2O in all treatments did not differ significantly, the average rate of CH4 emission is 32.81 kg CH4/ha/MT, CO2 is 23.08 kg CO2/ha/MT and N2O is 7.72 kg N2O/ha/MT, and (3) using of varieties of Mira-1, Mentik Wangi and Merah Putih, manure at dose 0 and 10 tons/ha, and Azolla inoculum at doses 0 and 2 tons/ha is not cause the difference in total GHG emissions of CH4, CO2 and N2O. Total CH4 emissions generated by all treatments are still well below the allowable emission.
Recommendations that can be sugested based on the results of the research were : (1) the management system of organic paddy in the surrounding land experiment conducted can be continued with the use of varieties of Mira-1, Mentik Wangi and Merah Putih, manure 10 tons/ha and Azolla inoculum 2 tons/ha, considering the results of this management techniques in this research that do not cause problems of GHG emissions of CH4, CO2 and N2O, and (2) land management of organic paddy experiment carried out in this research almost the same as the habit of farmers around the experimental area, thus management is usually done by farmers in terms of environment, GHG emissions are not significantly contribute. The management of organic paddy by farmers so far has been in a form of mitigation of GHG emissions of CH4, CO2 and N2O itself. .
Therefore, management can be sustainable for the production of paddy (rice) organic.