Soil Conservation Methods for Vegetable Farmers in the Dominican Republic

Steep deforested hillsides demonstrate the need for soil protection

According to the UN General Assembly, 2015 has been declared the International Year of the Soils (IYS). The purpose of IYS is to raise awareness on the importance of soil for food security, climate change adaptation and mitigation, sustainable development, and overall human life. 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 30-70%, which exacerbates the problem of soil erosion. However, farmers depend on this land to provide food for their families and many of the farmers rely on yearly harvests as their sole source of income.

In December 2014, Partners of the Americas sponsored Farmer-to-Farmer volunteer, 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 the priority watersheds. Jeff assessed the soil and environmental management of hillside farms in the Jarabacoa region and identified appropriate, economically feasible, and environmentally friendly methods and technologies for improved soil protection in the upper watershed.

Below are some of his locally adaptable recommendations to help reduce soil erosion:

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 DR, 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% of the cropland in Jimenoa is over 30% slope and it is common to see crops planted on slopes in excess of 45%. The extent of deforestation and degradation in the Baiguate sub-watershed appears to be the most severe, with slopes up to 70% 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% 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.
   
   

   

   Newly planted tajota approximately 4'' above the ground with limited ground cover below

4. Use filter strips or vegetative barriers: For vegetable or tajota crop production, the cropland should have 30-40 meters of crops followed by 3-5 meters of grass, and so on down the hill. Only 5-10% 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.

Example of 10-inch grass filter strip on 12% slope

It has been nine months since Partners' first Farmer-to-Farmer volunteer arrived to the DR under our new strategy to increase resilience to climate change. Jeff's above recommendations, along with the recommendations left by previous volunteers and those that will be left by volunteers to come, will be essential to ensuring effective and sustainable soil management and protection. Through the Farmer-to-Farmer program and Partners' Mission to Connect, Serve, and Change Lives, we look forward to assisting farmers maintain their food systems and protect their natural ecosystem.