Agricultural Intensification in South Asia and Its Contribution to Greenhouse Gas Emission: A Review

Abstract

This paper reviewed the agricultural intensification in South Asian region. The indications of intensification in terms of intensive use of chemical fertilizers (urea) and introduction of agro equipments like tractor were reviewed. From 1961 to 2005, Sri Lanka was in the top position to intensify agriculture. There has been a feedback loop between agricultural intensification and climate change. The observed positive outcome of agricultural intensification are mainly improved livelihood and secure food whereas enhanced emissions of greenhouse gases due to addition of nitrogen fertilizers (N inputs) was examined as one of the negative outcomes. Agricultural soil has been adding up major green house gases like methane (CH $_4$ ) and nitrous oxide (N $_2$ O) to the atmosphere through tillage, fertilizer application and irrigation. From the review, N $_2$ O emission from total arable land (in '000 ha) were analysed and estimated. The N $_2$ O emission rate was found to be highest in Bangladesh and Sri Lanka (3 kg of N $_2$ O-N ha $^{-1}$ ) followed by India and Pakistan (2 kg of N $_2$ O-N ha $^{-1}$ ), assuming that crop intensification will demand urea application in all arable land in future.