Michler Jeffrey D, Baylis Kathy, Arends-Kuenning Mary, Mazvimavi Kizito
Dept. of Agricultural and Resource Economics, University of Arizona, Tucson, USA.
Dept. of Agricultural and Consumer Economics, University of Illinois, Urbana, USA.
J Environ Econ Manage. 2019 Jan;93:148-169. doi: 10.1016/j.jeem.2018.11.008.
Agricultural productivity growth is vital for economic and food security outcomes which are threatened by climate change. In response, governments and development agencies are encouraging the adoption of 'climate-smart' agricultural technologies, such as conservation agriculture (CA). However, there is little rigorous evidence that demonstrates the effect of CA on production or climate resilience, and what evidence exists is hampered by selection bias. Using panel data from Zimbabwe, we test how CA performs during extreme rainfall events - both shortfalls and surpluses. We control for the endogenous adoption decision and find that use of CA in years of average rainfall results in no yield gains, and in some cases yield loses. However, CA is effective in mitigating the negative impacts of deviations in rainfall. We conclude that the lower yields during normal rainfall seasons may be a proximate factor in low uptake of CA. Policy should focus promotion of CA on these climate resilience benefits.
农业生产率增长对于受气候变化威胁的经济和粮食安全成果至关重要。作为回应，各国政府和发展机构正在鼓励采用“气候智能型”农业技术，如保护性农业（CA）。然而，几乎没有严格的证据表明保护性农业对生产或气候适应能力有何影响，而且现有的证据受到选择偏差的阻碍。利用来自津巴布韦的面板数据，我们测试了保护性农业在极端降雨事件（包括降雨不足和降雨过剩）期间的表现。我们控制了内生性采用决策，发现正常降雨年份使用保护性农业不会带来产量增加，在某些情况下还会导致产量损失。然而，保护性农业在减轻降雨偏差的负面影响方面是有效的。我们得出结论，正常降雨季节较低的产量可能是保护性农业采用率低的一个直接因素。政策应将保护性农业的推广重点放在这些气候适应能力益处上。
