Marianne Le Bail

SALADPLAN: a model of the decision-making process in lettuce and endive cropping

Market gardeners are facing new environmental, commercial and safety requirements and regulations that weigh heavily on their crop planting and management decisions. Producing high-quality products and simultaneously reducing the use of chemical products needs change in the multi-field planning of crops. In order to identify which cropping practice may be altered depending on each farm’s characteristics, we built a rule-based model that represents how market gardeners plan cropping cycles of lettuce and endive, here denoted as salad vegetables, on a farm scale. The model is adapted to the specificities of salad vegetable crops in the Mediterranean region, in particular the combination of several cycles per year and of open field and sheltered crops. The output variables are the developed areas allocated to the different salad types and the range of the harvest dates, which are two key factors for commercialisation. The model is based on identifying the successive decision steps of growers when building their farming systems; descriptive variables are the effective surface area and period for salad cultivation, the number of salad cycles per year, the developed surface area of each salad type and the dates of harvest. The decision-making rules leading to each descriptive variable are based on the agronomic characteristics of soil, climate and crops, farmers’ strategic objectives and organisation of farm resources. The cropping decisions were recorded in 38 farms in the large market-gardening region of Languedoc-Roussillon. In the sample, the number of salad types cultivated per farm varied from 1 to 8 and the harvesting period from 3 to 7 months. Our results demonstrate that the model can explain a substantial part of this variability, 26 and 28 farms among 38, respectively, being correctly classified by the model for the two variables. The original result of this work is to enhance the generality of a similar framework built earlier for arable cropping systems. From a practical point of view, this model can be used to determine the leeway available to the farmers for the introduction of technical change in salad cropping. It could therefore be used by agricultural advisors to plan salad crops either for individual farms or on the scale of a marketing structure.

Socio-technical lock-in hinders crop diversification in France

Crop diversification is considered as a major lever to increase the sustainability of arable farming systems, allowing reduced inputs (irrigation water, pesticides, fertilizers), increasing the heterogeneity of habitat mosaics, or reducing yield gap associated with too frequent returns of the same species. To free up paths of collective action, this article highlights obstacles to crop diversification, existing at various levels of the value chains. We used a threefold approach: (i) a cross-cutting analysis of impediments to the development of 11 diversifying crops (5 species of grain legumes, alfalfa, flax, hemp, linseed, mustard, sorghum), based on published documents and on 30 interviews of stakeholders in French value chains; (ii) a detailed study (55 semi-structured surveys, including 39 farmers) of three value chains: pea and linseed for animal feed, hemp for insulation and biomaterials; and (iii) a bibliometric analysis of the technical journals and websites (180 articles) to characterize the nature of information diffused to farmers. We highlight that the development of minor crops is hindered by a socio-technical lock-in in favor of the dominant species (wheat, rapeseed, maize, etc.). We show for the first time that this lock-in is characterized by strongly interconnected impediments, occurring at every link of the value chains, such as lack of availability of improved varieties and methods of plant protection, scarcity of quantified references on crop successions, complexity of the knowledge to be acquired by farmers, logistical constraints to harvest collection, and difficulties of coordination within the emerging value chains. On the basis of this lock-in analysis, that could concern other European countries, the article proposes levers aimed at encouraging actors to incorporate a greater diversity of crops into their productive systems: adaptation of standards and labelling, better coordination between stakeholders to fairly share added value within value chains, and combination of genetic, agronomic, technological, and organizational innovations.