Soil Conservation Methods for Vegetable Farmers in the Dominican Republic
The Dominican Republic, like many tropical islands, suffers from years of deforestation and improper land use that results in damage to the environment, excess pollution in streams and rivers, and extended dry periods that make land unsuitable for agricultural production. In the Jarabacoa region, home to the Yaque del Norte watershed, much of the deforestation occurs on slopes in excess of 30 to 70 percent, which exacerbates the problem of soil erosion. However, farmers depend on this land to provide food for their families, and their yearly harvests are often their sole source of income.
Through the USAID-funded Farmer-to-Farmer program, Partners of the Americas (a Washington, D.C.-based non-profit organization) is seeking to address soil conservation issues. The Farmer-to-Farmer program provides voluntary technical assistance to farmers, farm groups, agribusiness and other organizations in developing countries to promote sustainable improvements in food security, agricultural processing, production and marketing. In December 2014, Partners of the Americas sponsored Jeff Knowles, a 30-year retired veteran of the USDA’s Soil Conservation Service/Natural Resources Conservation Service, to travel to the Dominican Republic to evaluate the extent of land degradation and soil erosion within priority watersheds.
Knowles assessed three sub-watersheds (Jimenoa, Baiguate and El Dajao) and provided several locally adaptable recommendations to help reduce soil erosion. Below are some of his recommendations:
1. Prioritize the purchase of soil testing kits and promote community education on proper nutrient management: Nearly all farmers apply fertilizers at least once per crop cycle with little to no soil testing occurring. While soil testing laboratories exist in the Dominican Republic, the average farmer is not using this practice as a management tool and are unaware of the potential savings they may have from simply testing the soil and applying fertilizer based on needs of the soil and plant. In many cases the soil test will reveal less fertilizer is needed than what is typically applied.
2. Use contour and ridge farming methods: Over 60 percent of the cropland in Jimenoa is over 30 percent slope, and it is common to see crops planted on slopes in excess of 45 percent. The extent of deforestation and degradation in the Baiguate sub-watershed appears to be the most severe, with slopes of up to 70 percent being extensively farmed. In some regions, farmers use horses and oxen to plow the land on the contour that create ridges and furrows. These ridges and furrows placed on the contour help curb erosion and slow runoff. According to the USDA’s Universal Soil Loss Equation (USLE), ridges and furrows planted on the contour can reduce soil erosion by 75 percent over planting a crop up and down the hill. Farmers who have not adopted this practice should be assisted to do so.
3. Use local grasses or legumes for ground cover: Some local options are vetiver, perennial peanut, carpet grass and other low growing grasses for tajota fields.
4. Use filter strips or vegetative barriers: For vegetable or tajota crop production, the cropland should have 30 to 40 meters of crops followed by 3 to 5 meters of grass, and so on down the hill. Only 5 to 10 percent of the cropland needs to be devoted to the filter strips or vegetative barriers, and plant species capable of filtering and catching sediments should be used. In order to be effective, this practice needs to be in conjunction with contour and ridge farming methods.
Learn more about Partners of the Americas' work in the Dominican Republic here.