Soil Quality Assessment for Coffee Production in Pakxong District, Champasak Province of Lao People’s Democratic Republic

Abstract

Soil properties and soil types suitable for coffee production have not been well researched in Lao People’s Democratic Republic. The objectives of this study were to determine the basic physical and chemical properties of the soils planted to coffee at different elevations and to identify the soil types that are suitable for coffee production. Nine coffee growing sites located in nine villages of Pakxong district, Champasak province were selected as representatives of major coffee growing areas in Laos including Lak 35, Lak 40, Nongbone, Lak 43, Kapheu, Nonglouang, Phoumaknao, Phou Oy and Phoumako. Trenches were created in these coffee plantations to study soil profiles and soil samples were analyzed physically and chemically in laboratory. Soils in all sites were classified in the great group of Acrisols. These soils were mostly highly acidic, and lime amendment was necessary to sustain coffee yield. Deficiencies of phosphorus and potassium occur in some sites but nitrogen was abundant in most soils. Soil physical and hydraulic properties favor the production of coffee and it can be grown successfully in all soils without severe limitations. Phoumaknao and Phoumako were identified as the most productive sites for coffee because of high organic mater, high cation exchange capacity and high soil nitrogen content. Fertilizer recommendations and lime requirement are site-specific and should be based on plant and soil analysis. Maintaining high organic matter should result in sustaining coffee productivity in these areas.