Review on the Extent of Acid Soil in Ethiopia, Its Impact and Management Methods

doi:10.7176/jbah/9-15-03

Abstract

Soil degradation is a global threat. Developing countries are more severely affected by soil degradation than developed countries. Ethiopia, one of the developing countries in eastern Africa, is highly threatened by soil degradation problems. Soil acidity is one of the main factors that limit and prevent profitable and sustained agricultural productivity in many parts of the world . The objective of this paper is to review the extent of acid soil distributions in Ethiopia, its impact on crop production and management practices. About 40.9% of the total arable land of Ethiopia is affected by soil acidity, from these 27.7% moderately to weak acids with pH 5.8-6.7 and 13.2% covered by strong to moderate acidic soils with pH less than 5.5. According to Ethio SIS, (2014) about 43% of the Ethiopian arable land is affected by soil acidity of these about 28.1% of soils in Ethiopia are dominated by strong acid soils (pH 4.1-5.5). Most of investigators confirmed that the two fundamental factors that limit the fertility of acid soils are: nutrient deficiencies, e.g. phosphorus (P), calcium (Ca) and magnesium (Mg) and the presence of phytotoxicity substances, e.g. soluble aluminium (Al) and manganese (Mn). To overcome these problems, different acid soil management has been implemented in the country. Thus many studies have been conducted with regards to Acid soil management which influences soil physical and chemical properties and crop yield directly or indirectly. Therefore, the aim of this seminor paper is to review different literature on the extent of acid soil in Ethiopia, its impacts on some selected chemical soil properties and management methods. Different studies showed that some soil chemical properties such as pH, Ava_P, OC, CEC, Echangeable Acididy (EA), Excheanchable bases (Ca, Mg, Na and K) and crop yields were improved in different agro ecologies by effects of liming and ISFM. Soil acidity problems also can be overcome by growing crop genotypes which are adapted to acid soil condition. Thus, for sustainable agricultural systems within small-scale farming in developing countries like Ethiopia, use of integrated soil fertlity management, liming and crop varieties tolerant to Al toxicity are the mechanisms used for management of acid soils. Key note: Acidity, Lime, ISFM , Acid tolerant crop varieties DOI : 10.7176/JBAH/9-15-03 Publication date : August 31 st 2019

Highlights

Land degradation and low soil fertility are very common features of large parts of Sub-Saharan Africa (Vesterager et al, 2008)
According to Ethio SIS, (2014) about 43% of the Ethiopian arable land is affected by soil acidity of these about 28.1% of soils in Ethiopia are dominated by strong acid soils (Figure 1)
The objective of this paper is to review www.iiste.org the extent of acid soil distributions in Ethiopia, its impact on crop production and management practices

Summary

Introduction

Land degradation and low soil fertility are very common features of large parts of Sub-Saharan Africa (Vesterager et al, 2008). Soil degradation is caused by unsustainable land uses and management practices, and climate extremes (FAO, 2015). 50% of potentially arable land in Africa is currently under cultivation, of which 2000 million ha (23% of agricultural land) are already of low soil fertility, and the soil fertility of the remaining arable lands continues to decline due to mismanagement (FAO, 2003; UNEP, 2004). According to FAO (2015) estimation, about 83% of rural people in Sub-Saharan Africa depend on the land for their livelihoods, but 40% of Africa’s land resources are currently degraded. About 33% of soils are moderately to highly degrade due to erosion, nutrient depletion, acidification, salinisation, compaction and chemical pollution (FAO, 2015). Monocropping, nutrient mining, unbalanced nutrient application, removal of crop residues from the fields and inadequate resupplies of nutrients have contributed to decline in crop yields (Nyamangara, 2001)

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