Status of Soil Properties Under Canopy of Farmers’ Preferred Coffee Shade Tree Species, in Adola Rede District, Guji Zone, Southern Ethiopia

Aschalew Emire

doi:10.11648/j.ajaf.20180605.15

Abstract

The study was conducted at Adola Rede District, in Guji Zone, Southern Ethiopia. The aim of the study was to investigate farmers’ preference criteria of soil fertility improving shade tree species and to identify Status of soil properties under canopy of farmers’ preferred shade tree species. To address the objectives of this study, all necessary data were collected through key informant interview, questionnaire survey and soil sampling. A total of 20 key informants and 90 households were participated for household interview. Based on their selection criteria, sampled households have done preference ranking of shade tree species used for soil fertility enhancement. The results of this study showed that, farmers’ main selection criteria were based on decomposition rate of shade treelitter fall, soil moisture status under shade tree canopy, coffee yield increments and growth rate of coffee plants under shade tree canopy. Generally, the preference ranking of key informants and respondent households soil fertility improvingcoffee shade tree species were in the order of: Ficus sur>Cordia africana>Millettia ferruginea>Albizia gummifera> croton macrostachyus>Acacia abyssinica. From the identified soil fertility improving coffee shade treespecies, soil samples were taken from under canopy of Ficus sur with 1st rank and Cordia africana with 2nd rank farmers’ preferences. For soil analysis from under canopy of both coffee shade trees and from outside the tree canopy, a total of 48 soil samples were taken. The results of soil properties under canopy of both shade trees showed that SOC, total N, available P, exchangeable K, CEC and soil pH were significantly (P<0.05) higher than outside the tree canopy. The results of BD outside the tree canopy was significantly (P<0.05) higher than undercanopy of both coffee shade trees. However, soil textures under canopy of both coffee shade trees and outside the tree canopy was not significantly different. Based on the finding of this study, statusof soil fertility under canopy of Ficus sur was significantly (P<0.05) higher than Cordia africana. Thus, the soil laboratory analyzed results of soil physico-chemical properties are in agreement with farmers’ rank of coffee shade tree preferences. Therefore, the findings suggest that if knowledge of local farmers is recorded and effectively used with scientific findings, it can provide valuable information. Moreover, for soil fertility enhancement and increments of coffee production incorporation of the two shade trees incoffee farms of similar agro-ecological conditions is paramount.

Highlights

Trees can improve the nutrient balance of soil by reducing unproductive nutrient losses from erosion and leaching and by increasing nutrient inputs through nitrogen fixation and increased biological activities by providing biomass and suitable microclimate [1]
The study was conducted in Adola Rede District of Oromia Regional State, in Southern part of Ethiopia, located at 475 km south of Addis Ababa(Figure 1).It is situated between 5°44'10” - 6°12'38” North latitude and 38°45'10” 39°12'37” East longitude at an elevation of 1500-2000 meters above sea level
Tree Selection From identified shade tree species commonly used for shading coffee plants in coffee growers’ fields of the study District, farmers’ have done preference ranking of shade tree species used for soil fertility enhancement

Summary

Introduction

Trees can improve the nutrient balance of soil by reducing unproductive nutrient losses from erosion and leaching and by increasing nutrient inputs through nitrogen fixation and increased biological activities by providing biomass and suitable microclimate [1]. The presence of strips of different tree species within agricultural fields has been associated with increases in soil carbon, soil nitrogen, enzyme activity and as well as an increase presence of a soil structure features that inhibits erosion [2]. Shade tree species play an important role in erosion control because they protect the soil against raindrop impact; reduce runoff velocity by increasing surface roughness and water infiltration as well as providing a litter. Shade tree root systems hold soil in place and create large pore space for increased infiltration. The mixture of leaf litter from different species (such as crop and shade trees) as well affects the decomposer community structure, and the litter decay and associated nutrient fluxes to the soil [6]

Objectives

Methods

Findings

Discussion

Conclusion