A long term effects of conservation agriculture technology on sustainability and profitability of soil and water management and crop productivity in the northern Ethiopian highlands

Background: Conservation Agriculture (CA) technology is one of the options to curb problems arise from high runoff rates, soil erosion, period drought, period water logging in vertisols and low crop productivity in Northern highlands of Ethiopia. Hence, a long-term tillage experiment has been carried out (2005 to 2010) on a Vertisol to quantify changes in runoff, soil loss and crop yield due to Conservation Agriculture (CA) in the sub-humid Dogua Tembien district of the Northern highlands of Ethiopia. Methods and Materials: The experimental layout was implemented in a randomized complete block design with 3 replications on permanent plots of 5 m by 19 m. The tillage treatments were (i) permanent raised bed (PB) in a furrow and bed system with 30% standing crop residue retention and no-tillage on top of the bed, (ii) reduced tillage (RT), with ploughing once at sowing with 30% standing crop residue retention and contour furrows made at 1.5m distance interval, and (iii) conventional tillage (CT) with a minimum of 3 tillage operations and removal of crop residues. All ploughing, as well as refreshing of the furrows of the permanent raised beds when sowing, was done using the local ard plough mahresha. Crops planted during the five years were wheat, grass pea, wheat, hanfets (wheat and barley sown together) and grass pea. Glyphosate was sprayed starting from the third year (2007) at 2 L/ha before planting to control pre-emergent weed in PB and TER. Runoff and soil loss were measured in plastic sheet lined collector trenches, which were located at the lower end of each plot. Crop stands were evaluated with local farmers and NDVI was measured on the spot at several phenological stages, using green seeker. Result and Discussion: Significantly different (p