At regional scale issues such as diffuse pollution, water scarcity and pollen transfer are closely related to the diversity and location of cropping systems because agriculture interacts with many other activities. Although sustainable land use solutions for territorial development and natural resource management are needed, very few agro-environmental studies account for both the coherence and the spatial variability of cropping systems. The originality of this article is to review methods that describe and locate cropping systems within large areas. We mainly based our analysis on four case studies using the concept of cropping systems on a regional scale, but differing in their objectives and extents. We found that describing and locating cropping systems in space meets not only decision-making stakes but also a scientific stake that allows multi-simulations over large areas when models require cropping system information. Simulation models are indeed necessary when the study aims at estimating cropping system externalities. Then, the involved process determines the extent, and the model determines the support unit, unless socio-economic considerations prevail. In this case, as well as when no model is involved, it is often considerations related to stakeholders that determine extent and support unit choices. On a regional scale, the cropping system must be described by only a few variables whose selection depends on the study objective and the involved processes. Collecting cropping system information for all support units is often simplified by identifying determining factors of cropping systems. However, obtaining deterministic relations between easily accessible factors and cropping system variables is not always possible, and sometime accessing modalities of determining factors for all support units is also difficult. We found that describing and locating cropping systems relied very much on expertise and detailed survey data. The development of land management practice monitoring would facilitate this description work.

中文翻译：

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在区域范围内描述和定位种植系统。回顾

在区域尺度上，由于农业与许多其他活动的相互作用，诸如弥漫性污染，水资源短缺和花粉转移等问题与农作系统的多样性和位置密切相关。尽管需要用于土地开发和自然资源管理的可持续土地利用解决方案，但很少有农业环境研究能够说明种植系统的连贯性和空间变异性。本文的独创性是回顾描述和定位大面积种植系统的方法。我们主要基于四个案例研究的分析，这些案例使用区域范围内的种植系统的概念，但目标和程度不同。我们发现，描述和定位空间中的种植系统不仅满足决策风险，而且还可以满足科学风险，当模型需要种植系统信息时，该科学利害关系可以在大面积上进行多次仿真。当研究旨在估计种植系统的外部性时，仿真模型的确是必要的。然后，除非考虑到社会经济因素，否则所涉及的过程将确定范围，而模型将确定支持单位。在这种情况下，以及不涉及任何模型时，通常需要与利益相关者相关的考虑因素来确定范围和支持单位的选择。在区域范围内，种植系统只能由几个变量来描述，这些变量的选择取决于研究目标和所涉及的过程。通常通过确定确定种植系统的因素来简化收集所有支持单位的种植系统信息的过程。然而，并非总是可能获得容易获得的因子与耕作系统变量之间的确定性关系，并且有时访问所有支持单位的确定因子的方式也很困难。我们发现，描述和定位种植系统非常依赖专业知识和详细的调查数据。土地管理实践监测的发展将有助于这项描述工作。我们发现，描述和定位种植系统非常依赖专业知识和详细的调查数据。土地管理实践监测的发展将有助于这项描述工作。我们发现，描述和定位种植系统非常依赖专业知识和详细的调查数据。土地管理实践监测的发展将有助于这项描述工作。