Land and environmental degradation and desertification in africa. Soil degradation needs to be recognised, alongside climate change, as one of the. Degradation cont population pressure and human activities such as overcultivation which exhausts the soil, overgrazing which removes the vegetation cover that protects soil from erosion, deforestation which removes trees and vegetation which binds the soil to the land and poorly designed irrigation that turn cropland saline. South africa undertook a national land degradation neutrality ldn target setting process during 201718 in response to the united nations convention to combatting desertifications call for signatory countries to voluntarily commit to ldn as also requested under sustainability development goal 15. Impacts of climaterelated land degradation on poverty and livelihoods. Soil degradation is a widespread problem in africa resulting in decreased agricultural productivity while demand for food continues to increase. Severe degradation is already occurring, with rates of soil loss reaching at least ten times the natural rate of soil formation. Experiences from the south african land degradation. Degradation relating to poor rangeland management was the most common theme emerging from the nbi2000 and follow up lada2010 studies.
Degraded soil diminishes food production and leads to soil erosion, which in turn contributes to desertification. Regional and national soil maps and databases fao soils. Principal processes of land degradation include erosion by water and wind, chemical degradation comprising acidification, salinization, leaching etc. The most important onfarm effects ofland degrada tion are. The economics of land degradation in africa eld initiative. However, international organizations such as fao, isric world soil information, the joint research centre of the european commission and others have compiled and harmonized national soil information in regional datasets or made soil maps. Soil quality and soil productivity in africa introduction. Soil degradation and restoration in africa crc press book. There are currently 73 soil forms, defined by the nature of the topsoil organic, humic, vertic, melanic or orthic, and numerous diagnostic sub soil horizons. Different processes of land degradation also confound the available statistics on soil andor land degradation.
Land use, rangeland degradation and ecological changes in the. Jarvis1 department of agricultural and resource economics university of california, davis introduction livestock production has been an integral part of farming systems for hundreds of years in many. African dryland ecosystem changes controlled by soil water. Soil degradation includes erosion, salinization due to freshwater removal, soil loss following erosion after deforestation or overgrazing, compaction and crusting of soils, which can be caused by cattle trampling, and waterlogging with impaired water movement oldeman et al. There has been outright loss of natural habitat, over 18 per. The change in the characteristic and quality of soil which adversely affect its fertility is called as degradation. The need and the scope for government control of livestock numbers lovell s. Pdf the south african soil environment shoana leigh. This erosion is the dominant form of soil degradation troeh et al.
Our study explicitly assesses the links between land use and degradation in the kalahari across the southern portion of kgalagadi district, botswana fig. This section describes land degradation trends in kenya as an introduction to the following pairs of satellite images that show this degradation on the ground. In this report, land degradation is defined as a negative trend 4 in land condition, caused by direct or indirect humaninduced processes including anthropogenic. Soil degradation food and agriculture organization of the united. Land degradation is a concept in which the value of the biophysical environment is affected by one or more combination of human induced processes acting upon the land.
In other words, what explains soil degradation in ssa or why is there continued adoption and use of practices that degrade soils. The pressures and impacts on the environment which constitute environmental change highlights the increased generation of human pollution and waste. Pdf the state of soil degradation in subsaharan africa. The most notable phenomena contributing to this situation include. Chapter 6 land department of environmental affairs. The result is a loss of land productivity with impacts on livelihoods and the economy. The increase in population has also contributed when people need to crop, as a source of income, but do not take measures to protect the soil, due to low income. In africa, depletion of soil nutrients and poor water management are the major limiting factors, not the lack of improved crop varieties. Estimated impacts of soil degradation on the african water. More than four decades of research and development work in africa have not resulted in the 35 % annual increase in agricultural growth badiane and delgado, 1995 that is necessary for most african countries to ensure sustainability of agriculture and the promise of food security in the next decade. The state of soil segradation in subsaharan africa mdpi. The most updated national soil information can only be obtained from a countrys national soil service.
Regional assessment of soil changes in africa south of the sahara. Soil erosion and veld degradation are continually being depicted as acute problems, and overpopulation, overstocking and poor agricultural practices are viewed as the major causal. The three degradation terms, environmental degradation, land degradation, and soil degradation, are defined as any change or disturbance to. Soil quality and soil productivity in africa nrcs soils.
Read this article to learn about the meaning, factors responsible, prevention and control measures of land degradation. It literally refers to the impairment of natural quality of soil component of any ecosystem. Penny encyclopedia of life support systems eolss population growth and increasing per capita demands for forest products and therefore forest exploitation, and the conversion of forested land for the purpose. African farmers unsustainably exploit soils and water and why many do not adopt or adapt other, seemingly superior and already available technologies barrett et al. Land degradation is currently a major concern in south africa. Distribution, characteristics, degradation and management of. Innovative systems to reverse soil degradation and improve water management for enhanced food security. Soil erosion occurs when soil is removed through the action of wind and water at a greater rate than it is formed soil the soil covering the surface of the earth has taken millions of years to form and we must learn to respect it. Soil degradation is perceived as being significantly greater in the communal areas than in the commercial areas of south africa, especially on the grazing lands situated along the steep slopes of the escarpment in the eastern parts of south africa figure ia. Pdf there is insufficient data on the extent, severity and trend of land degradation in africa. Experi ences from african countries bashir jama, abednego kiwia and james mutegi, agra, nairobi.
Causes and impacts of land degradation and desertification. Pdf the primary cause of soil degradation in subsaharan africa ssa is expansion and intensification of agriculture in efforts to feed its growing. This is particularly worrisome since, according to the uns food and agriculture organization, some 83% of subsaharan african people depend on the land for their livelihood, and food production in africa will have to increase almost 100. The most widespread cause of degradation was water erosion, followed by wind erosion. Gibsona school of animal, plant and environmental sciences university of the witwatersrand, johannesburg, south africa submitted in partial fulfilment of the requirements for the degree of master of science in resource conservation biology supervisor. Soil degradation and restoration in africa 1st edition. Desertification has been defined as land degradation in arid, semiarid, and dry subhumid areas resulting from various factors, including climatic variations and human activities11. Pdf status and trends in land degradation in africa. The first three processes listed, erosion by water, wind and tillage, together dominate soil degradation on the vast majority of land area degraded. A high proportion 72 percent of degraded land was in drylands. Land degradation which is also seen as a decline in land quality caused by human. Estimated impacts of soil degradation on the african. Erosion and soil productivity in africa journal of soil and water.
However, awareness of the problem and attitudes towards it have changed little over the past century. Soil erosion has been found to be a pervasive problem on rangelands, particularly of concern in areas of communal land tenure shackleton, 1993. Specifically, it will simulate the impact of land degradation on soil water holding capacities, and the subsequent impacts on evapotranspiration rates, moisture. Land degradation is the major consequences of direct interference of human activities in the natural phenomenon. Environmental change, soil erosion and land degradation are key factors in reduced productivity. Overview and stocktaking of land degradation in general and in africa. In tanzania, land degradation has been ranked as the top environmental problem since more than 60 years assey et al. However, there are some well known cases of soil degradation in a number of countries in west africa, especially in the highly populated regions of the sahelian and savannah zones where continuous cultivation with inappropriate soil management practices have depleted the soils of nutrients. In addition to the cohost statement, the closing plenary featured the afss chairs conclusions by wanjira mathai, director, partnerships for womens entrepreneurship in renewables wpower, wangari maathai institute wmi and alexander muller, managing director tmg, thinktank for sustainability and study lead teebagrifood. Desertification affects around 45 percent of africas land, with 55 percent of this area at high or very high risk of further degradation unep 2015. African environmental issues minnesota state university. Soil management is, therefore, a major issue, especially that african soils hold a great potential for carbon sequestration.
In subsaharan africa, 70 percent of households are dependent on wood energy. Economics of land degradation in eastern africa econstor. Soil water emerges as the dominant driver of ecosystem changes in african drylands, in particular in arid and semiarid areas. The three degradation terms, environmental degradation, land degradation, and soil degradation, are defined as any change or disturbance to the environment, land, or soil perceived to be. Unchecked, this would result, by the year 2010, in an african landscape that had a greatly reduced potential for agricultural production. A main cause of soil degradation is lack of manufactured fertilizers being used, since african soil lacks organic sources of nutrients. It calls for enhanced agricultural productivity and sustainable landuse management through minimal water depletion and soil disturbing cultivation practices. To put the soil degradation results in perspective, the study will first demonstrate the sensitivity of water balance models to soil water holding capacities. The economics of land degradation benefits of action outweigh the costs a complementary report to the eld initiative the economics of land degradation in africa. The relatively young south african and active geology has given rise to soils of high nutrient status. Water and wind erosion, usually asso ciated with deforestation, overgrazing, and shifting cultivation, have left their mark on much of.
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