Coffee (Coffea arabica) planting in the interior mountainous region of Puerto Rico is usually performed on steep slopes after vegetation removal. The construction of individual terraces around the tree, such as the "Media Luna" planting method, prior to planting could reduce sediment and nutrient losses and could increase yields by improved on-site water and nutrient retention. Experiments were conducted to test the hypothesis that the "Media Luna" planting technique could reduce sediment, total phosphorus (TP), and total Kjeldahl nitrogen (TKN) in runoff during and after the establishment of a coffee plantation in Puerto Rico. The experiments were conducted on a commercial farm where the predominating soils were Mucara (Dystric Eutrudepts) in Phase 1, and Humatas (Typic Haplohumults) in Phase 2. In Phase 1 (recent plantings), sediment and nutrient runoff losses were similar in the conventional countour planting method and in the "Media Luna" treatments. Nutrient concentrations in runoff increased in events following fertilization. Recently loosened unconsolidated sediment material in the "Media Luna" treatment may be more susceptible to losses during the initial establishment phase. In phase 2 (mature plantings), sediment and nutrient losses were greater from soils planted with the conventional contour planting method than from those with the "Media Luna" treatment. The lower TP concentrations measured during Phase 2 suggests that the "Media Luna" technique could be a beneficial practice for coffee production in some areas of Puerto Rico.
Electrical analog model study of the alluvial aquifer in the Yabucoa Valley, Puerto Rico; Phase 2, the planning, construction, and use of the model