Simulating incomes of radical organic farms with MERLIN: A grounded modeling approach for French microfarms

Microfarms are commercial soil-based market gardens with < 1.5 ha of organic vegetables per farmer seeking to make a living on that small acreage by combing high land-use intensity, low input and few mechanized practices with direct sells. Insights in their profitability are missing in literature. Our research objective was to build a simulation model of micro-farms' income and agricultural area based on farmers' expertise. An interactive development based on grounded modelling was implemented. This implied an inductive qualitative analysis and farmers' participation to collect data and to build and validate the model. With data collected on 20 micro-farms', a stochastic simulation model (MERLIN) was built, combining (i) two mixed models to predict yields and workload for 50 crops, and (ii) a crop-planning model. MERLIN generates cropping plans that match the complex and temporal commercial requirements for direct selling of vegetable boxes through community-supported agricultural schemes. The model was validated with various strategic choices, climate assumptions and annual workload. Our model was judged relevant and legitimate by agricultural practitioners because it was not prescriptive and corresponds to strategic preferences of organic farmers. Grounded modelling is promising to create generic knowledge adapted to radical organic farming systems, but some epistemological implications require further investigation, e.g. by taking benefit from the transdisciplinary framework developed in agroecological studies.