Impact of organic amendments on watermelon crop yield in Costa Rica Island

Abstract

The impact of organic amendments (mangrove leaves, beach bean, and carob leaves) on the productivity and quality of watermelon in sandy soils on Costa Rica Island, Ecuador. A completely randomized block design with four treatments and five replications was used. The amendments improved soil properties, increasing electrical conductivity (EC), and slightly reducing pH, which enhanced nutrient availability. The treatment with beach bean leaves showed the highest number of fruits per plant (1.9), and the highest average fruit weight (7.9 kg), followed by carob leaves. The Brix degrees, indicators of sweetness, were higher in these treatments (9.8 and 9.80, respectively), suggesting an improvement in fruit quality. Density, related to the concentration of soluble solids, also increased with the amendments. These results indicate that organic amendments improve water and nutrient retention in sandy soils, increasing watermelon productivity and quality. The study highlights the feasibility of these practices for optimizing agriculture in fragile soils, contributing to sustainability and food security in the region.

Keywords: Organic amendments, Watermelon, Sandy soil, Costa Rica Island.