TEKLU ERKOSSA1, KARL STAHR1, GETACHEW TABOR2
1University of Hohenheim, Soil Science and Land Evaluation, Germany
2Ethiopian Agricultural Research Organisation, Debre Zeit Agricultural Research Centre (DZARC), Ethiopia
The Ethiopian highlands are characterised by high human and livestock population pressure, land degradation as a result of soil erosion, soil fertility decline and organic matter depletion, low agricultural productivity and persistent poverty. In most of the farming systems, there is low external inputs that crop and livestock production depends mainly on the soil nutrient stock. A field experiment was thus launched at Debre Zeit on Andosols (1999-2001) to evaluate the effects of Farm Yard Manure (FYM) and inorganic fertilisers application on the productivity of horticultural crops. Two selected rates of FYM (2 and 6 Mg ha-1 on dry weight bases), were combined with three rates of Nitrogen (N) and Phosphorus (P) fertilisers (0,0), (61, 31) and (92,46) kg ha-1 to make six treatments. A randomised complete block design with three replications was employed. Four crops (Shallot, tomato, cabbage and potato respectively) were planted in a rotation on permanent plots. The treatments resulted in a significant effect on both biomass and economic yields of the crops, but shallot. Supplementing the recommended inorganic fertilisers by only 2 Mg ha-1 FYM resulted in a significant yield increase over the recommended rates. Also, it was found out that reducing the recommended fertilisers by one third did not significantly reduce yield, if supplemented by 2 Mg ha-1 FYM. This does not only reduce the production cost due to reduced fertiliser use but also improves the soil quality leading to sustainability.
Keywords: Farmyard manure, inorganic fertiliser, marketable yield, organic fertilisers and relative yield index