2023+-03-21 ノースカロライナ州立大学(NCState)
米国コーンベルトの12州で2005年から2016年までのカバークロップの植え付け、作物保険データ、および気象測定を調べた研究では、より高いカバークロップ採用率は、春の過剰な湿度を土壌が処理するのを助けたため、防止植え失敗による作物保険損失が低下したことがわかりました。カバークロップ採用率1％増加は、防止植え関連保険金支払い額約4,000万ドル減少することにつながりました。
＜関連情報＞
- https://news.ncsu.edu/2023/03/cover-crops-help-mitigate-farmer-losses/
- https://onlinelibrary.wiley.com/doi/10.1111/ajae.12396
カバークロップの使用による植え付けロスの防止効果の把握 Understanding the effect of cover crop use on prevented planting losses
Sunjae Won, Roderick M. Rejesus, Barry K. Goodwin, Serkan Aglasan
American Journal of Agricultural Economics Published: 26 February 2023
DOI:https://doi.org/10.1111/ajae.12396
Abstract
Cover cropping has the potential to improve resilience of agriculture to climate-change-induced extreme weather events. However, rigorous quantitative evidence on the resilience effect of cover crops is still lacking. Using a novel data set that combines satellite-based cover crop information and county-level crop insurance data, we examine the impact of planting cover crops on prevented-planting-related losses that are typically caused by heavy rainfall events. The US federal crop insurance program offers “prevented planting” coverage, which pays indemnities if insured growers are unable to plant their crop due to adverse weather. Linear fixed effects models, instrument-based estimation methods, long-difference models, and a number of other robustness checks are utilized in the empirical analysis to achieve the study objective. Our findings suggest that counties with higher cover crop adoption rates tend to have lower levels of crop insurance losses due to prevented planting. The resulting reduction in prevented planting risk also becomes larger with longer term, multiyear cover crop use. These results support the notion that cover crops improve soil conditions such that the likelihood and magnitude of prevented planting losses decrease. We posit that the ability of cover crops to handle excess moisture (i.e., through better water absorption and improved water infiltration in the soil) is the main factor in its ability to reduce prevented planting losses in the US Midwest.
