Climate change is an emerging issue these days. Scientists are storming brains to solve this issue, improving agricultural production system to meet the food security concerns globally. Among all climatic affects, seasonal droughts and uneven floods are major damaging the agricultural system with changing rainfall distribution. In Pakistan this might take away or alter monsoon with erratic and intensive rains, dry winter and prolonged dry spells. Three important Green House Gases (GHGs) CO2, CH4 and N2O are emitted by agricultural systems, which contribute significantly to global warming.
Rice is a staple food for more than half population of the world. Flooded rice cultivation with puddling and transplantation is considered major source of methane emitted by prolonged flooded conditions resulting in an anaerobic soil conditions. CH4 in flooded conditions is produced by microorganisms that respire CO2 just like human beings respire O2. It accounts 10 to 20 per cent of total annual CH4 global emissions. CH4 has Global Warming Potential (GWP) 25 times higher than CO2.
Direct seeding of rice (DSR) is establishment of rice crop from seeds sown in a field without transplantation of seedling from nursery. DSR is done by three methods dry direct seeding, wet direct seeding and water seeding. Dry-DSR is sowing of dry seeds into dry soils. It can reduce CH4 emission from 24 to 79 per cent with 40-44 per cent decline in GWP. Dry-DSR has some other benefits over flooded method. Labour shortage is an issue for transplanted rice as 25-50 person-days are required for transplantation of one hectare while in case of Dry-DSR it only demands 5 person-days. Water scarcity is increasing globally; scientists are predicting that there will be shortage of water in future because glaciers are melting at increasing rate by Climate Change. In this aspect Dry-DSR can save water up to 40 per cent. Puddling results in completely breakdown of soil aggregates, destruction of macro pores and formation of hard pan at shallow depth which favours Dry-DSR. Economically Dry-DSR is most beneficial method; reduce labour charges, water required and tillage operations. Its yield might be less than transplanted rice but net benefits are higher. Among bottle necks of Dry-DSR weeds are on top. These can be settling down by applying pre-emergence herbicides with integrated management practices. Micro-nutrients can be applied to overcome their deficiency. N2 is emitted in Dry-DSR almost 0.90 kg per hectare in the form of N2O as compared to 0.39 kg in transplanted rice. This issue can be resolved using control and slow released fertilizers.The direct seeded rice technique is helpful to overcome the problem of global warming in sense of climate change. By adopting this practice farmers can enhance their income by less input cost and can maintain soil productivity on sustainable basis. So, there is a need to create awareness among farmers about this technique.