This article analyzes the trade-off between yield and farmed area when a valuable species is affected by agricultural practices. Itrevisits, from an economic perspective, the ``land-sparing versus land-sharing'' debate elaborated in conservation biology using themethodology of the density-yield curve: The density of the species on farmland is a decreasing function of the yield. It is shown thatthe optimal yield is either increasing or decreasing with respect to the value of the species depending on the shape of the density-yieldcurve. Land-sparing and land-sharing are not necessarily antagonistic; for sufficiently elastic demand function, both the optimal yield andthe farmed area decrease with the value of the species. A general assessment of a second-best policy is performed, and several particularpolicies are considered, including a subsidy on biodiversity in farms, a tax or subsidy on farmland, and a tax or subsidy on a dirty input.In several cases, the first-best strategy and the second-best one induce contrasting effects on the yield.

中文翻译：

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土地节约与政策不完善的土地共享

当有价值的物种受到农业实践的影响时，本文分析了产量和养殖面积之间的权衡。它从经济角度重新审视保护生物学中使用密度-产量曲线方法阐述的“土地保护与土地共享”的争论：农田上物种的密度是产量的递减函数。结果表明，根据密度-产量曲线的形状，最佳产量相对于物种的值是增加还是减少。土地节约和土地共享不一定是对立的；对于足够弹性的需求函数，最优产量和养殖面积都随着物种价值的增加而减小。对次优策略进行一般评估，并考虑几个特定策略，