SYSTEM OF RICE INTENSIFICATION: AN ANALYSIS OF ADOPTION AND POTENTIAL ENVIRONMENTAL BENEFITS
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The world's population is increasing and there has been more concerns towards food security but is challenged by increasing food demand with declining water availability. South Asia faced acute shortage of food in 1960s because of declining productivity of rice. Since then, efforts have been made into increasing the rice productivity. System of Rice Intensification (SRI) has emerged as an alternative to traditional way of flooded rice cultivation and is showing great promise to address the problems of water scarcity coupled by doubling the yield. In an effort to evaluate the adoption and potential environmental benefits of SRI, a case study was conducted in Morang district of Eastern Nepal. Paper I investigates the determinants of SRI adoption. Data were obtained through household survey with structured questionnaire, key informant interviews, focus group discussion, and field observations. With SRI methods, the cost of chemical fertilizers was reduced by 48 percent, seed requirement was reduced by 90 percent, and the cost of pesticide was reduced by 99 percent. In addition, the farmers in the study area were found to achieve 118 percent increase in rice yield with SRI methods compared to non-SRI methods. The results of the binary logistic regression showed that age of the farmer, landholding, irrigated land, livestock, food sufficiency, training facilities and membership into the farmers’ association significantly influenced the adoption of SRI. Weed management, water management and lack of institutional support were found to be the major constraints for SRI adoption. Planners and policy makers should consider the farmers’ interest, capacity and limitation in order to promote an environmentally and economically sound approach to enhance the prospects of adopting SRI by farmers. Paper II investigates the effect of SRI on climate gases particularly CH4 and N2O. Closed chamber method was used to collect the gas samples in 2-day interval from 19 July til 14 August 2009. The soil temperature and the gravimetric moisture content were also measured for each sampling site at each day of sampling. Significant effect of SRI on the fluxes of CH4 and N2O was observed. The emission of CH4 from SRI soil exhibited 4 times less than that of non-SRI soil whereas N2O flux from SRI soil was 5 times less than non-SRI soils. It is well known that agriculture releases significant amount of CH4 and N2O into the atmosphere and that the global warming induced by the concentration of such GHGs is a matter for great environmental concern nowadays. SRI practices not only help to minimize CH4 emissions but also reduce N2O emissions. SRI practice was found to have double benefits: increase yield and have potential to reduce climate gas emission to the atmosphere.