Progress of Soil Acidity Management Research in Ethiopia

Abstract

This review paper tries to put together soil acidity management research based evidences generated recently. In the context of agricultural problem soils, acid soils are soils in which acidity dominates the problems related to agricultural land use. Soil acidity problems are increasing in the highland areas of Ethiopia. Application of lime coupled with fertilizer improves the productivity of crops in acid affected soils. In Nedjo condition, lime level 5 t ha^-1 with 69 kg ha ^-1 phosphorus gave best yield (1346.2 kg ha ^-1) and (1635.5 kg ha ^-1) of finger millet and teff respectively. Similarly, yield of faba bean was obtained by applications of 16 .5 (t ha^-1) and 13(t ha^-1) of lime along with 30 kg ha^-1 P fertilizer at Bedi and Emdibir respectively.  Application of 16.5 t ha ^-1 lime with 30 P (kg ha^-1) gave 212% yield increment over the control that has no lime but 30 P (kg ha ^-1).  Integrated reclamation approach centring lime-fertilizer and soil nutrients interaction is vital to establish cost effective and sustainable nutrient management of this soil.  50% FYM + 50% NP + 50% lime treatment gave significant yield and yield component of teff at Nedjo testing site, this result showed that proper knowledge and enhanced use of integrated soil fertility management technologies such as combined use of organic and inorganic fertilizers in the presence of a soil- conditioner  lime are vital in improving and sustaining crop production. From an experiment conducted to evaluate the effectiveness of limes produced at different locations in Ethiopia no statistical yield difference was observed, and this implies that both lime produced at Senkele (Oromia region) and Dejen (Amhara region) can successfully answer their regional lime needs. When Senkele lime, Dejen lime and Ca(OH)2 from Ghion gas factory were compared with Awash calcite and Awash dolomite, these two Awash products were greatly preferred. The reason might be mainly from the material they are processed and as well the technology under which they were crushed. Research results revealed that in CASCAPE (Capacity building for scaling up of evidence–based best practices in agricultural production in Ethiopia) South, application of 1800 kg ha^-1 lime with recommended fertilizer rate gave the highest yield (1367 kg ha^-1) with a 150% yield advantage over the control. In Amhara, yield showed significant variation among treatments where both lime-applied treatments (2050 kg ha^-1 lime and 1925 kg ha^-1 lime) gave grain yields of 3648 kg ha^-1 and 3643   kg ha^-1, respectively. This was over 50% yield advantage over the control.

Keywords: soil acidity, nitosol, lime, pH, phosphorus, exchangeable acidity