Divergent impacts of crop diversity on caloric and economic yield stability
Divergent impacts of crop diversity on caloric and economic yield stability
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DOI：
10.1088/1748-9326/aca2be
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发表时间：
2022-12-01
影响因子：
6.7
通讯作者：
Mueller, Nathaniel D.
中科院分区：
文献类型：
--
作者：
Driscoll, Avery W.;Leuthold, Sam J.;Mueller, Nathaniel D.
粮食安全和农业经济都取决于作物产量的时间稳定性。为此，在世界各地种植系统多样性不断减少的情况下，增加作物多样性被认为是稳定农业产量的一种手段。虽然多样性在许多自然生态系统中赋予稳定性，但在农业系统中，作物多样性与产量稳定性之间的关系尚未在空间尺度上得到很好的解决。在这里，我们利用1981年至2020年的作物面积，产量和价格数据来评估美国各州作物多样性与经济和热量产量稳定性之间的关系。我们发现，在控制了气候不稳定性和灌溉面积的差异后，作物多样性与经济产量稳定性呈正相关，但与热量产量稳定性呈负相关。此外，我们发现，作物的倾向，增加经济产量的稳定性，但减少热量产量的稳定性往往是在最多样化的国家。我们认为，价格对高价值作物产量变化的反应是多样性和经济产量稳定性之间的正相关关系的基础。相反，低多样性状态的热量密集作物的空间集中有助于多样性和热量产量稳定性之间的负相关关系。我们的研究结果表明，作物多样性和产量稳定性之间的关系是不普遍的，而是依赖于空间尺度的问题和稳定性指标的利益。
Food security and the agricultural economy are both dependent on the temporal stability of crop yields. To this end, increasing crop diversity has been suggested as a means to stabilize agricultural yields amidst an ongoing decrease in cropping system diversity across the world. Although diversity confers stability in many natural ecosystems, in agricultural systems the relationship between crop diversity and yield stability is not yet well resolved across spatial scales. Here, we leveraged crop area, production, and price data from 1981 to 2020 to assess the relationship between crop diversity and the stability of both economic and caloric yields at the state level within the USA. We found that, after controlling for climatic instability and differences in irrigated area, crop diversity was positively associated with economic yield stability but negatively associated with caloric yield stability. Further, we found that crops with a propensity for increasing economic yield stability but reducing caloric yield stability were often found in the most diverse states. We propose that price responses to changes in production for high-value crops underly the positive relationship between diversity and economic yield stability. In contrast, spatial concentration of calorie-dense crops in low-diversity states contributes to the negative relationship between diversity and caloric yield stability. Our results suggest that the relationship between crop diversity and yield stability is not universal, but instead dependent on the spatial scale in question and the stability metric of interest.