Abstract

To investigate the contribution of coffee agroecosystem to soil fertility, soil samples were collected at the depth of 0 to 20 and 20 to 40 cm from four different land usages: coffee agroecosystem, eucalyptus plantation, grazing and cultivated lands. The soil samples were analyzed for texture, active and exchangeable acidity, organic carbon, total nitrogen, available forms of nitrogen and phosphorus, CEC, exchangeable cations and micronutrients. The results indicated that land use systems significantly (P < 0.05) affected all soil quality indicators except sand content, available Fe and Mn. Except for the exchangeable Mg, available Cu and Zn soils at coffee agroecosystem were superior for all soil quality indicators than other land use systems. The highest values of exchangeable Mg, available Cu and Zn were observed at grazing lands while the lowest values were recorded at coffee agroecosystem. Hence, the existing coffee agroecosystem in the study area contributes a significant role to improve the fertility status of the soil. Therefore maintaining the existing coffee agroecosystem, reducing overgrazing and intensive cultivation and integrated use of inorganic and organic fertilizers are recommended to replenish the degraded soil quality parameters in the study area.

Key words: Coffee agroecosystem, land use systems, soil quality, Ethiopia.