EFFECTS OF ACACIA TORTILIS (FORSSK.) HAYNE ON SOME SELECTED SOIL PHYSICOCHEMICAL PROPERTIES AND MAIZE YIELD IN PARKLAND AGROFORESTRY, GURSUM DISTRICT, EAST HARARGHE, OROMIA REGION, ETHIOPIA

Abstract

The study was conducted to investigate the effects of Acacia tortilistree in farmland on some selected soil physicochemical properties, and maize grain yield in Gursumdistrict, Eastern Hararghe, Oromia, Ethiopia. For the experiment of soil physicochemical properties, two factors: distance from tree trunk with three levels (under canopy, edge of canopy and out of canopy) and soil depth with two levels (0-20cm and 20–40cm depth) with factorial arrangement in RCBD replicated six times were employed. For maize yield only one factor; distance from tree trunk with three levels ((under canopy, edge of canopy and out of canopy) for maize yield in RCBD replicated six times were used. The result showed that, for soil physical properties values of soil bulk density under canopies were significantly lower than out of canopy distance (p<0.05) and soil moisture content was significantly difference (p<0.05) higher under a canopy of trees than open fields. But for chemical properties except for Soil reaction andElectrical Conductivity all are the same properties likes, OrganicCarbon, Organic Carbon Stock, Total Nitrogen, Available Phosphorus, and Cation Exchange Capacity were significantly (p<0.05) higher under the tree canopies than in the open field and surface than subsurface soil .The result also revealed that the grain yield of maize was significantly (P<0.05) higher under a canopy of tree species as compared to the open field. The findings suggest that the enrichment of soil fertility and improvement, as well as increment in grain yield of maize by small holder farmers can be attained by incorporation of tree species in agricultural landscapes; this tree species provides various benefits and services to the rural community.