Ecuador

The subject of research is the potato-pasture production system in San Gabriel, Carchi, Ecuador. This CONDESAN site is particularly interesting due to the human health and environmental problems related to pesticide use. In addition, productivity is under pressure due to tillage erosion. With a large number of organizations, ranging from the ministry of agriculture and livestock, farmer organizations, and non-governmental organizations, we applied the Tradeoff Analysis Model to analyze the tradeoffs between a range of sustainability indicators. This site was also the study site when originally developing the Tradeoff Analysis Model.

Carchi Province in northern Ecuador is typical of the northern humid páramo Andes. The agricultural system on the steep Andean hillsides is dominated by the production of potatoes and milk. The research focused on two watersheds corresponding to the San Gabriel and Chitan rivers encompassing a total area of 95 km2 ranging in altitude between 2,700 and 3,800m above sea level. Being located close to the equator there is virtually no change in average monthly temperature ranging from 9 to 12°C. Average rainfall varies between 950 to 1300 mm/yr with significant year-to-year variation. Volcanic ash soils with their typical thick, black A-horizon, high organic matter content and high infiltration capacity have developed in relatively young volcanic ash deposits.

Landscape around the village of San Gabriel. Potato can be grown whole year round in this area, which results in a colorful green-brown land use pattern.

Pesticide application on potato. The pesticides cause health problems, as well direct, as indirect via leaching to the groundwater.

Many topsoil is lost due to tillage erosion on the top and upper slope parts of the field. The yellowish less fertile subsoil becomes visible in the field, causing a yield decline.