Challenging agroecology through the characterization of farming practices’ diversity in Mediterranean irrigated areas

Highlights

• Chili-pepper farming practices are studied in a Southern Mediterranean irrigated area.

• A high level of diversity was found in technical operations and management routes.

• The latter included both (non)-environmental-friendly TOs.

• The area was characterized by a gradient of environmental-friendly managements routes.

• The coexistence of diversely impacting practices challenges agroecology.

Abstract

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.

Introduction

The Southern Mediterranean region is vulnerable to climatic hazards and at a high risk of severe degradation of both biodiversity and agricultural production, due to the combination of climate change and conventional farming practices (Migliorini et al., 2018; MedECC, 2020). New patterns of action would be required to address these issues simultaneously (Caron et al., 2014), with an acute need to implement new agricultural models combining biodiversity conservation, climate change adaptation and food production. Agroecology, which is the production of significant amounts of food, valorizing ecological processes and ecosystem services and integrating them as essential factors in the improvement of practices (Gliessman, 1990; Altieri, 2008. Wezel et al., 2014), with its three pillars i) efficiency increase, ii) substitution of inputs, iii) system redesign or diversification (Hill, 1998; Wezel et al., 2014; Duru et al., 2015; Ci and Ma, 2016), could be a pathway for a more sustainable agriculture in the Southern Mediterranean region (Horlings and Marsden, 2011). Agroecology suggests that actions to achieve this goal must be adapted to each agrosystem and take into account local conditions.

Although recent literature is appearing on the subject (for example, de Lattre-Gasquet et al., 2017; Ameur et al., 2020), little is still known on the potential of agroecological concepts to address these issues in this region of the world, in particular within irrigated areas. In North African irrigated areas, agriculture is strongly based on the use of external productive factors (especially chemical inputs). Efficiency increases and input substitutions could appear as a first step of action towards a more sustainable agriculture. This could start by a widespread adoption of local efficient and environmental-friendly farming practices. In this paper, it is hypothesized that strong social, economic and environmental constraints in irrigated areas (Jamin et al., 2011) might lead to a diversity of farming practices. Could more environmental-friendly farming practices arise from this local diversity? In what extent are these practices already present or how can they be developed in Mediterranean irrigated systems? In a first step to answer these questions, the objective of this study was to i) describe the possible diversity of farming practices in a typical North African irrigated area and ii) identify the existence of environmental-friendly management routes, and the types of farmers implementing them. The paper seeks to provide a complete and comprehensive description of existing farming practices at the plot and farm-scale, enhancing their diversity, and putting forward in particular potential agroecological practices, but does not undertake a quantitative evaluation of their agronomic or environmental impacts.

Access to irrigation is a recurrent demand of smallholder farmers in North Africa, due to expected productivity and income increases, compared to rainfed systems. Progress has been made in this matter, with the development of individual pumping systems giving access to the aquifers. The number of pumping wells has indeed increased drastically in North Africa, irrigating more than 1.75 million ha in Algeria, Morocco and Tunisia (Leduc et al., 2004; Kuper et al., 2017). The Merguellil plain in Central Tunisia is a typical example. In parallel, public policies sought to encourage water economy and have promoted the development of modern irrigated systems, resulting in a wide adoption of drip irrigation. Through fertigation, the latter also facilitates increased applications of nutrients, at a certain environmental cost due to pollutions (Philip and Gates Timothy, 2005; Poussin et al., 2008; Laib et al., 2018). However, it has been shown that modern irrigated systems could also enable a better management of nutrients and inputs (Benouniche et al., 2014; Al-Ghobari and Dewidar, 2018; Sandhu et al., 2019).

In addition, smallholder farmers, such as those in the Merguellil plain, can design environmental-friendly farming practices, more adapted to their local social, economic and environmental conditions, allowing them to achieve their production goals, depending on neither chemical inputs nor pesticides (Altieri, 2008). To achieve this, farmers often combine different strategies as part of a usual household management scheme (Pinto-Correia et al., 2017). Thus, the farmer makes choices through diverse ways of farming. So, it is fair to ask whether diversity is one of the main characteristics of these farming practices at the territorial scale.

In this paper, we elaborate a method to describe the diversity of local farming practices in the Merguellil plain – a location of multiple researches, characterized by its dynamic and diverse agricultural system (Azizi et al., 2017) – at both the plot and farm scales. This can be achieved by characterizing existing technical management routes (Renaud-Gentié et al., 2014; Salou et al., 2017), noted TMRs, and identifying a gradient between chemically-intensive and more environmental-friendly TMRs.

TMRs are the logical and ordered succession of technical operations (TOs) aiming to control the environment and obtain a given production (Sébillotte, 1974). So far, investigations that integrate all TMRs steps to describe existing cropping systems in small-scale household agriculture are scarce (Renaud-Gentié et al., 2014; Czyrnek-Delêtre et al., 2018), even the more in Mediterranean irrigated areas. Multiple studies characterizing farming systems and crop management practices exist (Bellon et al., 2001; Köbrich et al., 2003; Maton et al., 2005; Poussin et al., 2008; Blazy et al., 2009; Ibidhi et al., 2018). These studies used either statistical analysis or participatory and expert-based methods. These methods have limits as they i) only identify the most relevant character of each TMR; and ii) do not describe the logical links between TOs (Renaud-Gentié et al., 2014). For instance, only quantitative data on farming practices were used to describe the diversity of coffee-based agroforestry systems in Costa-Rica (Meylan et al., 2013). Another study, examining the variability of farm structure and farming practices, highlighted both low input and intensive systems, but was limited to the analysis of water and N use, pest and crop residue management (Caballero, 2001).

This paper, focused on chili-pepper (Capsicum annuum) as a cropping system model, proceeds in the following way. First, it develops the approach used to assess farmers’ practices. Then, it describes the technical operations, their interconnexions within TMRs, and their (non-)agroecological orientation and (non-)association to farm types. Finally, it discusses this diversity of farming practices in the light of co-existing irrigation, pollution and agroecology stakes, and how these conditions challenge the implementation of agroecological practices in Southern Mediterranean irrigated areas.