Agroecological transition: A viability model to assess soil restoration

Abstract

Since the 1950s, intensive and specialized agricultural systems using a few select species and relying heavily on agrochemical inputs have enabled a huge increase in food production. However, in parallel, drawbacks appeared including biodiversity loss, greenhouse gas emission, erosion, and water pollution. Today shifting farming systems to mitigate soil degradation trends is indispensable. Using viability theory, we propose a dynamic model of the sequence of agricultural productions and practices that can be implemented in the long term to restore soil quality while respecting a set of agronomic and economic constraints. The paths to soil restoration vary depending on agronomic and economic constraints, the time available for restoration, the initial soil conditions, and investment capacities. Economic valuation of the minimum cost of restoration shows that the agroecological transition may be costly and that farmers can have difficulty meeting the costs, thus raising the question of how the cost of agroecological transition is to be shared.

Relationship between biodiversity and agricultural production

“…On one hand, agricultural production has a negative impact on biodiversity: in particular, we suppose that agricultural production and chemical inputs affect the carrying capacity of the land to host biodiversity. Whatever technique is used for agricultural production, even when only small quantities of pesticides and fertilizers are used, still farming activity damages biodiversity, since the land is devoted to humans and not to biodiversity (Durand et al, ; Newbold, Hudson, Hill, Contu, & Lysenko, ). On the other hand, biodiversity also has an impact on agricultural production (or yield, since in our case they coincide).…”

“…Note that, even if already depends on inputs , we want to distinguish their effects on the environment. Farming activity impacts biodiversity both through production, independently of the inputs used due to exported biomass, and through agricultural practices (use of chemical inputs, fertilizers), since, independent of the amount of yield obtained, when chemical inputs are used, they have a negative impact on biodiversity Durand et al ().…”

“…Notice that the improved management of these regulating services has been a major proposal of agroecology (Kremen & Miles, ), and/or of ecological intensification (Bommarco, Kleijn, & Potts, ). As a consequence, biodiversity may provide important services for farming activity, as soil quality (Durand, Désilles, Saint‐Pierre, Angeon, & Ozier‐Lafontaine, ) and pollinators (Garibaldi, Aizena, Kleinc, Cunninghamd, & Hardere, ), biological control etc. (Millenium Ecosystem Assessment, ), while at the same time being negatively impacted by agriculture, as shown by several authors (Flohre et al, ; Geiger et al, ).…”

Bounded set of economic uncertainty and robust viability: An illustration from farming systems

“…To answer this question, we extend the model of Durand et al. () by integrating economic uncertainty based on a bounded set of fluctuations in sales price.…”

“…This paper introduces uncertainty into a viability model by calibrating stochastically the extent of a bounded‐set uncertainty related to sales prices as a driver of economic uncertainty. We investigate the implications of bounded sets of economic uncertainty for farmers' strategy by extending the initial model suggested in Durand, Désilles, Saint‐Pierre, Angeon, and Ozier‐Lafontaine (). This leads to a robust viability analysis in which the economic contingencies of prices capture different sources of uncertainty and allow for stochastic and nonprobabilistic conceptions.…”