The Sierra Nevada de Santa Marta, a UNESCO-declared Biosphere Reserve, is an isolated mountain complex encompassing approximately 17,000 km², set apart from the Andes chain that runs through Colombia. The Sierra Nevada has the world’s highest coastal peak (5,775 m above sea level) just 42 kilometres from the Caribbean coast. The Sierra Nevada is the source of 36 basins, making it the major regional ‘water factory’ supplying 1.5 million inhabitants as well as vast farming areas in the surrounding plains used mainly for the cultivation of banana and oil palm. The main problems to be solved in these basins are: i) Declining availability of water for irrigation, ii) Declining availability and quality of water for human consumption, iii) Increasing salinization of ground water and soils, iv) Increasing incidence of floods.
This is a feasibility study on the adoption of more efficient irrigation techniques by oil palm farmers in the Sevilla basin (713 km²), one of the key basins in the Sierra Nevada. The general objective is to identify the local environment at basin scale, the limiting factors and suitable field interventions in oil palm areas to improve the water use. A preparation and implementation phase was developed including an initial baseline assessment of the basin on climate, water availability, drought hazard, soil characteristics, land use, and topography. The agronomy (e.g. cultivars) and current field practices (e.g. nutrient management and irrigation practices) of the oil palm areas were characterized, and the crop water requirements determined. In addition, costs and benefits associated to the implementation of efficient irrigation technologies such as fertigation and water harvesting were assessed. Potential locations, risks and opportunities for water harvesting were evaluated with the idea to store water in the wet season to be able to use the resource in an efficient way in the dry season. A range of GIS and satellite-based datasets (e.g. CHIRPS, MODIS-ET, MODIS-NDVI, HiHydroSoil) were used to evaluate the environmental conditions, and local data and information was provided by local partners Cenipalma and Solidaridad to generate a comprehensive assessment at basin and field scale. The expectation is that fertigation and water harvesting techniques can be adopted in the Sevilla basin, but also in other basins in the Sierra Nevada de Santa Marta to reduce the environmental impact of oil palm production.