s:967:"%T Species interference and soil changes in contour hedgerows planted on inclines in acid soils in southeast Asia %A Garrity, D.P. %A Mercado, Jr.A. %A Solera, C. %X Contour hedgerow systems are widely viewed as an important element of conservation farming on the Oxisols and Ultisols that dominate the humid tropical uplands of Southeast Asia. However little is known concerning the nature of hedger-crop interference planted on uplands on acidic soils. This paper discusses recent results on above and below-ground interactions on Oxisola and Ultisols. Row-wise sampling of upland rice biomass and grain yield showed a characteristic dome-shaped response pattern often modeled satisfactorily by a quadratic response function. The suppression effect of hedgerow on crop was not overcome by the application of more nutrient as green leaf manure or inorganic fertilizer. Forage grasses interfered more with the alley crop than leguminous forages and shrubs ";