Department of Land, Air, and Water Resources, University of California, Davis, United States.
Department of Land, Air, and Water Resources, University of California, Davis, United States.
J Environ Manage. 2020 May 1;261:110205. doi: 10.1016/j.jenvman.2020.110205. Epub 2020 Mar 2.
Winter cover crops could contribute to more sustainable agricultural production and increase resiliency to climate change; however, their adoption remains low in California. This paper seeks to understand barriers to winter cover crop adoption by monetizing their long-term economic and agronomic impacts on farm profitability in two of California's specialty crop systems: processing tomatoes and almonds. Our modeling effort provides a present, discounted valuation of the long-term use of winter cover crops through a cost-benefit analysis. A net present value model estimates the cumulative economic value of this practice. We then explore how the long-term trade-offs associated with winter cover crops can affect an operation's profits under a spectrum of hypothetical changes in California's agricultural landscape. Our analysis sheds light on the barriers to adoption by reporting benefit-cost ratios that indicate profitability across several scenarios; however, benefits and costs accrue differently over time and with long planning horizons. At the same time, a small portion of gained benefits are external to the grower. Findings from this study reveal that winter cover crops in California can be profitable in the long-term, but the extent of profit depends on the cropping system, extent of irrigation savings due to improved soil function, access to financial subsidies and climate change. Winter cover crops can return positive net benefits to growers who have flexible contractual obligations, can wait for the long-term return on investment and manage cover crops as closely as cash crops. This analysis contributes to the study of conservation agriculture practices by explaining possible reasons for low adoption through an economic valuation of the implications of soil management choices and policy counterfactuals.
冬季覆盖作物有助于实现更可持续的农业生产，并提高对气候变化的适应能力；然而，它们在加利福尼亚的采用率仍然很低。本文旨在通过量化冬季覆盖作物对加利福尼亚两个特色作物系统（加工番茄和杏仁）的农场盈利能力的长期经济和农艺影响，了解其采用的障碍。我们的建模工作通过成本效益分析对长期使用冬季覆盖作物进行了当前贴现估值。净现值模型估计了这种做法的累积经济价值。然后，我们探讨了随着时间的推移和加利福尼亚农业景观的假设变化，与冬季覆盖作物相关的长期权衡如何影响一个运营的利润。我们的分析通过报告效益成本比来揭示采用的障碍，这些效益成本比表明了在几种情况下的盈利能力；然而，效益和成本随时间和长期规划而不同地累积。同时，一部分获得的收益是外部的。本研究的结果表明，加利福尼亚的冬季覆盖作物在长期内可能是有利可图的，但利润的程度取决于种植系统、由于土壤功能改善而节省的灌溉程度、获得财政补贴和气候变化的情况。对于具有灵活合同义务、能够等待长期投资回报并像管理现金作物一样密切管理覆盖作物的种植者来说，冬季覆盖作物可以为他们带来正的净效益。这项分析通过对土壤管理选择和政策反事实的影响进行经济评估，解释了低采用率的可能原因，为保护农业实践的研究做出了贡献。
