Résumé
Identifying locally adapted and adopted efficient practices can be a step towards the agroecological transition of irrigated plains of the Southern Mediterranean region. However, these types of practices - often little known - are drowned within a wide range of practices. The objective of this study was, first, to elaborate a method to describe this diversity in a semi-arid irrigated landscape, at both the plot and farm scales; second, to show the main characteristics of these types of crop management; and third, to question their sustainability according to agroecological principles. To do so, this paper focused on Southern Mediterranean irrigated cropping systems as i) studies on management routes are scarce with regard to this region; ii) irrigated landscapes are known for their high level of natural, technical and financial constraints, often favoring more intensive farming practices regarding chemical inputs. A series of semi-directive interviews were conducted in order to assess farmers’ management of chili-pepper-based (Capsicum annuum) cropping systems, a widespread crop in the Merguellil plain, Central Tunisia. The "Typ-iti” method, combining multivariate analysis, clustering and association rules, was used to characterize the diversity of technical management routes (TMR) of these systems. The environmental sustainability was qualitatively accessed by classifying the clusters of TMRs obtained according to their potential impact on natural resources. Then, these management routes were qualitatively associated to some farm structural characteristics, to analyze their diversity at the farm level. These enabled to distinguish a gradient of farming practices and characteristics, respectively at both plot and farm scales relative to environmental impacts. The study showed that some agroecology-compatible TMRs coexisted with conventional TMRs for chili-pepper-based cropping systems. Our method characterized three main groups: i) a group of intensive TMRs regarding chemical input powered especially by tenant farmers, ii) an intermediary group iii) a moderate group powered by land owners. Throughout these main groups, seven types of TMRs were described. These were always comprised of both agroecology and non-agroecology-compatible technical operations. This coexistence of diversely impacting practices challenges agroecology in multiple ways. Fertilization management appeared as a major issue in the study zone, often resulting in high applied doses. These findings could allow actors in charge of agriculture to better focus their action. However, the study did not take into account the outputs of the studied systems, so that their productivity and environmental impacts have not yet been assessed in a quantitative manner. For future studies, the paragons obtained from our analysis are typical cases that could be studied for such a purpose.