PhD Student University of Vermont, Vermont, United States
Abstract: Soil health is critical for sustaining agroecosystems while providing a range of additional ecosystem services that benefit human populations at various scales. Farmers hold intimate knowledge of soil conditions and sustained healthy ecosystems for a diversity of benefits, but the pressures of commodity production have resulted in an oversimplification of agroecosystem structures and functions as well as a narrowing of benefits. Smallholder coffee production in Mesoamerica presents a telling case: in recent decades, these systems have transitioned from diverse polycultures to either sun-grown, input-intensive operations or to intensified organic-certified systems with a single species of shade tree and a reliance on bio-inputs to compensate for losses in natural nutrient-cycling services. These changes have implications for soil health that are still understudied. Through a Participatory Action Research process with the CESMACH producers’ cooperative in Chiapas, Mexico, we identified concerns over declining soil health as a factor in diminishing coffee productivity and resilience of coffee systems. We also identified skepticism on the part of the producers regarding the efficacy of some of the organic practices promoted by the cooperative. Our research with CESMACH and with the ASOBAGRI cooperative in Guatemala is designed as a co-learning process that investigates the correlations between aboveground agroecosystem structure and practices with the physical, chemical, and biological attributes of the soil. We have established two 10 meter by 10 meter observation sites within each of 60 coffee plots, one where the producer perceives soils to be more fertile and another where they perceive soils to be less fertile. In March and April of the current year, we will test soil attributes with materials accessible to farmers and cooperative technical assistance staff. These tests produce useful and precise metrics related to key indicators of soil health: available phosphorus, active carbon, particulate organic matter, aggregate stability, bulk density, and soil macrofauna counts. We will also use qualitative methods including soil chromatography and visual evidence of nutrient deficiencies and soil erosion. These will be correlated to existing data (collected in October and November 2022) on agroecosystem attributes including shade cover, groundcover, and the presence of soil conservation measures; to fertilization practices; and to agroecosystem benefits in coffee productivity and bean quality. In June 2023, the results will be analyzed with producers, cooperative staff, and local students, grounding findings in local decision contexts and permitting a discussion regarding which indicators are amenable to local participation in soil health monitoring and intervention.
