EVALUATION OF COFFEE (Coffea arabica L.) PRODUCTION AND SELECTED SOIL PHYSICOCHEMICAL PROPERTIES UNDER CORDIA AFRICANA AND ERYTHRINA ABYSSINICA TREES IN ARSI GOLELCHA DISTRICT, ETHIOPIA

Abstract

Coffee plantation with shade trees is important to improve soil health, increase coffee production, sustain and restore agroecology and nature based agroforestry practices. The study was conducted on farmers’ fields in Golelcha District of East Arsi Zone, Ethiopia. The study was intended to evaluate the influence of coffee shade trees on growth performance, yield and quality of coffee (Coffea arabica L.), to characterize selected soil physicochemical ix properties under the canopy of coffee shade trees and to get best coffee shade trees and appropriate distance of coffee seedling plantation area in which away from shade tree trunks. Key informants and household interviews were used to get imperative information from three age categories, i.e. from old farmers, middle age farmers and young farmers. Randomized complete block design on three farmers’ fields as a replication in each PAs were used for data collection. A total of 48 circular samples were taken for both treatments’ parameters, under both coffee shade tree species at the distance of 1m, 3m, 6 m and 25m away from shade tree trunk including unshaded zone. The two widely grown indigenous coffee shade tree species in the area were Cordia africana and Erythrina abyssinica. Even though farmers’ preference focused on Cordia africana tree based on its utility, the best results were recorded under Erythrina abyssinica tree. The outcome had a significant value at (p<0.05) and highly significance value at (p<0.01) between and within the treatments. Analysis of regression was taken to evaluate difference between treatments’ parameters. Positive and negative relationship of soil and coffee parameters were tested by Pearson’s correlation coefficient. Statistically significant comparison differences were observed between shaded and unshaded as well as within shaded effect based on both parameters across PAs. Integration of shade in coffee farming system created creditable promising in producing organic coffee. Shade utility was also adopted as ecologically sustainable, economically viable and socially acceptable practice. The second distance layer (3m) away from shade tree trunks illustrated the highest mean value across PAs in most parameters. Almost all the given coffee and soil parameters’ value increased significantly under the tree canopy than in the open area in both PAs showing decreasing trend with increasing distance from the tree trunk. Average result of both PAs' coffee; the greater value of branch/coffee plant; 13%, and 19%, all fruits/ coffee plant; 5,060 and 9,740, thousand seed weight; 23% and 41%, clean coffee yield/ ha in qtl; 3.25% and 6.1%, screen size of coffee beans; 9.1% and 7.7%, shape and make of beans; 1.08 and 1.085, aromatic intensity; 0.47 and 0.035, aromatic quality; 0.38 and 0.33, acidity; 0.5 and 0.5 and body of coffee beans; 0.53 and 0.57 than open areas were detected under the canopies of Cordia africana and Erythrina abyssinica shade trees, respectively. Average result of both PAs' soil; the greater value of pH 44%, and 54%, OC; 60.5% and 92%, TN; 40% and 50.5%, CEC; 68.75% and 87%, ex. K; 13.5% and 14%, silt; 22.65% and 27.5% than open area were detected under the canopies of Cordia africana and Erythrina abyssinica, respectively. The best shade tree was Erythrina abyssinica and the recommended distance of coffee seedling plantation area away from shade tree trunk was 3m. Generally, the vital signal of the treatment’s means difference were indicated between shaded and unshaded rather than within shaded means variation at most treatments’ parameters.