The Effectiveness Analysis of Water-saving Irrigation and Conservation Tillage in Coping with Climate Change
|School||Chinese Academy of Agricultural Sciences|
|Keywords||Climate Change Mitigation Adaptation Water-Saving Irrigation Conservation Tillage Effectiveness Analysis|
Climate change has become a global environment issue, which has had and will go on havingimpacts on natural environment and human life. Agriculture is one of the most vulnerable sectorsaffected by climate change. The effects of climate change on agriculture in China do more harm thangood. An effective response to climate change should include both mitigation and adaptation. But thereis no systematic researches focus on the effects of emission reduction, adaptation and cost-effectivenessof measures coping with climate change in China. So based on the review of response measures inagriculture in China, water saving irrigaiton (WSI) and conservation tillage (CT) which recommendedby Chinese government have been chosed for sduty. And this research quantitatively studies the effectsof mitigation and datpation and cost-effectiveness of WSI and CT in coping with climate change, with aview to provide technical support to address climate change effectively.The main results are as follows:1. As to the mitigation, both WSI and CI have positive effects on greenhouse gas (GHG) emissionreduction. In2010, the CO2equivalent emission reduction of WSI is3.15～6.83Mt, that of CI is12.77~25.84Mt. The emission intensity of WSI significantly correlates with the amount ofirrigation water and pumping head, and emission intensity of irrigation can be reduced by theimprovement of water use efficiency and the increase of groundwater level. The GHG emission fluxfrom the process of CT may partially or even fully offset the emission reduction achieved by Soilcarbon sequestration. So great importance must be attached to the GHG emission flux of CT.2. As to the adaptation, the saved water achieved by WSI in2010is31.65～47.85Bm3, whichaccounting for8.58%~12.97%of water used for irrigation in the same year. If the saved water usefor expanding irrigated farm land. In theory, the possibly newly increased grain yield is about514.68~30.15Mt. The directly increased grain yield achieved by the impovement of the water useefficiency stands at24.39~31.02Mt. The implementation of CT can improve water use efficienfy,reduce soil erosion, improve or maintain soil fertility, increase food production. In2010, theincreased grain yield stands at1.72Mt.3. As to economic feasibility, when soncider the totoal benefit of mitigation and adaptaion, both WSIand CT have good economic feasibility. But the difference is that when compared to traditionalirrigation all the WSIs need additional cost input except canal ling irrigation, while when comparedto traditional tillage CT can save781.7RMB/ha. The total benefit achieved by mitigation andadaptaion of WSI is1068.22(micro-irrigation)~1783.68(canal ling irrigation) RMB/ha, that of CTis1562.47~2192.53RMB/ha.4. Based on the results of this research and the regional characteristics of China, this research makefollowing suggestions for the development of WSI:1) It is important to strengthen the regulationand control of the use of water resources, integrate and coordinate use of groundwater and surfacewater, and promote water-saving irrigation techniques actively;2) In the development of WSI, if forhigh emission reduction, the micro-irrigation is recommended when have sufficient capital, orotherwise canal ling irrigation; if for high effects of adaptaion, sprinkler is recommended when have sufficient capital, or otherwise canal ling irrigation. For the development of CT, suggestionsare made as follows:1) develop and promote different farm machineres to support differentcropping patterns of CT;2) research and develop different CT technical system to suitable forcultivations in different regions;3) explore and implement risk compensation mechanism tomobilize the enthusiasm of farmers;4) Monitor and make clear the GHG emissions flux from CTsystem;5) research and promote the integrated pest management techniques to supporte theimplement of CT technology.This research studied the effects and cost-benefit of mitigation and adaptaion of WSI and CT, butdue to the uncertainty of climate change research and assessment methods and the constraints of dataavailability, there are still some shortcomings and points need further study. More efforts and researchesneed to be carried out in order to provide technical support to cope with climate change effectively.