Building a Cropping System Typology from Plot Survey: Scaling-up from Crop Management Plan Information to Cropping System Scale.

Cropping system (CS) can be defined as a crop sequence and the corresponding crop management. It is identified as a relevant scale to deal with pests or nitrogen management for example. Indeed, it makes it possible to consider crops after-effects. However, information about current cultural practices remains widely gathered at the temporal scale of a crop. Thus, there is a need from public policy makers to better know what are the current CS and how they evolve in time. We established a method to create a CS typology from a crop-oriented survey, assuming that crop management of a given crop depends on the crop sequence in which it occurs.

We used a survey carried-out by the French ministry of agriculture every five years. The sampling results in 100 to 200 surveyed plots per region for each targeted crop. The crop management plan is collected, as well as additional information about five previous years, including crop sequence. We first performed for each single crop a classification of crop management plans. Then we performed a classification of crop sequences, all crops mixed up. Finally, we combined both classifications to build the CS typology.

This work illustrates that crop management plan is not independent from crop sequence. Thus, for a given crop, it is possible to identify the most frequent crop management plan according to the crop sequence. This also means that among all numerous possible combinations, only a few CS are dominant. For example, in the Bourgogne region, 23 CS gathered the half of the sample. Among thme, the most frequent one represent 16% of the sample. The typology we produced has been used as a baseline for design and assessment of scenarios for scaling-out legume-based CS.