Diversification of cropping systems has been proposed as a major mechanism to move towards sustainable cropping systems. To date, a diversification option that has received little attention is introduction of ley pastures into cropping systems, but the use of ley pastures is challenged by most future-oriented scenarios aiming to feed the world sustainably. In these scenarios, ruminant livestock feed only on permanent pastures, while cropping systems focus completely on production of crop-based human food. Diversification of cropping systems with ley pastures is thus compromised by knowledge gaps and future-oriented policy options. Here, we review ecosystem services provided by introducing ley pastures into cropping systems to increase sustainability of agriculture, discuss types of ley pastures and their management liable to promote these services, and raise future challenges related to introducing ley pastures into cropping systems. We conclude that (1) ley pastures provide a large set of input (soil conservation, nutrient provision and recycling, soil water retention, biological control of pests) and output (water purification, climate regulation, habitat provision for biodiversity conservation, forage production) ecosystem services of primary importance to cropping systems and society, respectively, as long as their spatial and temporal insertion within cropping systems is well-managed; otherwise, disservices may be produced. (2) To benefit from ecosystem services provided by ley pastures in cropping systems while limiting their disservices, it appears necessary to define a safe operating space for ley pastures in cropping systems. Moving towards this space requires changing plant breeding programs towards multiservice ley pastures, producing knowledge about emerging ways of introducing ley pastures into cropping systems (e.g., living mulch, green manure) and better quantifying the bundles of ecosystem services provided by ley pastures in cropping systems.

中文翻译：

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牧场在明天的种植系统中的作用。回顾

已经提出了种植系统的多样化作为迈向可持续种植系统的主要机制。迄今为止，很少有人关注将牧草引入作物种植系统的多样化选择，但是对于大多数以可持续发展为目标的面向未来的方案，使用牧草受到了挑战。在这些情况下，反刍动物只以永久性牧场为食，而种植系统则完全集中在以农作物为基础的人类食品的生产上。因此，知识差距和面向未来的政策选择损害了带有牧场的农作物系统的多样化。在这里，我们将介绍通过在牧场系统中引入ley牧场以提高农业的可持续性而提供的生态系统服务，并讨论ley牧场的类型及其易于推广这些服务的管理，并提出与将牧场引入农作物系统相关的未来挑战。我们得出的结论是：（1）牧草场提供了大量输入（土壤保护，养分供应和循环利用，土壤保水，害虫的生物防治）和输出（水净化，气候调节，为生物多样性保护提供栖息地，饲料生产）只要对它们在作物系统中的时空插入进行了良好的管理，就分别对作物系统和社会至关重要的生态系统服务；否则可能会造成伤害。（2）为了从种植系统中的草场提供的生态系统服务中受益，同时限制其危害，看来有必要为种植系统中的草场定义一个安全的工作空间。