Current land use trends show an increasing preference for monocropping – mostly a consequence of policies and incentives aimed at enhancing the intensification of cereals. This shift has caused some to question whether legume–cereal rotations can remain economically viable options for farmers, particularly in the dry areas. In this paper, we present the results of an endogenous switching regression model which suggests, for the first time, that legume–cereal rotations have clear economic advantages over cereal monocropping. Rotations provide higher yields, gross margins, and consumption of wheat and faba beans. Most past economic analyses on rotation used data from experimental stations or small-sized farmer surveys covering only one season and variety. This study makes an important improvement by employing two-year data from a large sample of 1230 farm households and their 2643 fields cultivated with different varieties of wheat and faba beans in the wheat-based production system of Morocco. Assuming a biennial rotation – the fastest cycle possible in a rainfed dryland system, this paper is also the first to demonstrate that joint adoption of rotations and improved faba bean varieties leads to a two-year average gross margin that is US$537/ha (48%) higher than wheat monocropping. This is the highest economic benefit of all available cropping options. A striking result of the study is that, contrary to common expectations, adopters of rotation did not use lesser amounts of nitrogen fertilizer than those monocropping wheat, thereby undermining the ecological benefits of faba bean–wheat rotations. Given that current average applications are below marginal product-maximizing levels, higher marginal yields of nitrogen fertilizers after rotation help explain farmers’ current behavior. Our results suggest that: 1) promoting improved legume varieties may enhance adoption of rotation; and 2) an economic rationale should be used as the main driver of the rotation agenda in the dry areas.

中文翻译：

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与豆类单作相比，豆类轮作在干旱地区具有明显的经济优势

当前的土地使用趋势表明，人们越来越倾向于单作作物，这主要是旨在加强谷物集约化的政策和激励措施的结果。这种转变引起了一些人的质疑，豆类-谷物的轮换是否仍然是农民的经济上可行的选择，特别是在干旱地区。在本文中，我们介绍了内生转换回归模型的结果，该模型首次表明，豆类-谷物轮作比谷物单作具有明显的经济优势。轮换提供更高的单产，毛利率以及小麦和蚕豆的消费量。过去对轮换的大多数经济分析都使用了实验站的数据或仅覆盖一个季节和品种的小型农民调查数据。这项研究通过使用来自摩洛哥的小麦生产系统中的12个3030个农户及其2643个用不同种类的小麦和蚕豆栽培的田地的两年样本数据，进行了重要的改进。假设每两年轮换一次（在旱地旱地系统中可能是最快的循环），本文也是第一个证明轮换和改良蚕豆品种联合采用可导致两年平均毛利率为537美元/公顷（48）的论文。 ％）高于小麦单作。这是所有可用种植方式中最高的经济效益。该研究的一个惊人结果是，与人们的普遍预期相反，采用轮作的人使用的氮肥的施用量不比单作小麦少，因此损害了蚕豆-小麦轮作的生态效益。鉴于当前的平均施用量低于边际产品最大化水平，轮作后较高的氮肥边际产量有助于解释农民目前的行为。我们的结果表明：1）推广改良的豆科植物品种可以提高轮作的采用率；2）应将经济原理作为干旱地区轮换议程的主要驱动力。