The countries that have ratified the Kyoto Protocol are taking actions to reduce their emissions of greenhouse gases that cause global warming. In the Japanese country report for greenhouse gas inventory in fiscal 2005, the amount of greenhouse gas emissions from the agriculture sector was 0 g for carbon dioxide (CO
2), 13, 417 GgCO
2eq (CO
2 equivalent in terms of Global Warming Potential) for methane (CH
4) and 19, 812GgCO
2eq for nitrous oxides (N
2O), totaling 33, 229 GgCO
2eq. in Japan, the ratio of total greenhouse gases from the agriculture sector to that of all sectors (1, 259, 426 GgCO
2eq) is 2.6%, showing the contribution of the agriculture sector to be very low. However, the amounts from the agriculture sector relative to total CH
4 and total N
2O emissions are high, accounting for 69.7% of CH
4 and 57.2% of N
20. Efforts are therefore needed in the agriculture sector to reduce emissions of CH
4 and N
2O. One mitigation technique for CO
2 is improvement of farmland management such as conservation tillage by reduced plowing. For CH
4, reduction techniques include improvement of water management and fertilizer application in rice fields, and improved feeding and animal management of enteric fermentation in ruminants. As for N
2O, reduction techniques include the use of nitrification inhibitors with fertilizers, and matching nutrient release to crop demand during crop cultivation by using controlled-release fertilizers. Although the development of mitigation technologies is being promoted, in numerous cases, the effectiveness of these mitigation techniques cannot be confirmed. Unfortunately, available data is insufficient. Efforts are needed to obtain data and to develop new mitigation technologies.
View full abstract