It is viewed as any change or disturbance to the land perceived to be deleterious or undesirable. Agricultural engineering a thesis submitted in the fulfilment for the award of the degree of doctor of philosophy of the university of nairobi 2006 university of nairobi library. Rain or wind blowing away topsoil and causing degradation. Soil quality indicator sheets a series of information sheets for physical, chemical and biological indicators is available to help conservationists and soil scientists with soil health assessment. 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. In the last two decades, various soil and water conservation interventions had been introduced in to different parts of ethiopia. Soil physical properties affecting soil erosion 233 introduction the total vegetated land area of the earth is about 11,500 hectare. The amount of silt, sand and clay in soil can be refer as soil texture. The formation of a soil is influenced by organisms, climate, topography, parent material, and time. Soil conservation is about solving the problems of land degradation, particularly accelerated soil erosion. According to the european soil framework directive 2006 soil compaction is besides water and wind erosion one of the main physical reasons and threats of. Indicators of physical soil degradation extent of organic layer, color of.
Physical, chemical, and biological properties of soil under. It thus covers the various forms of soil degradation, adverse human impacts on water resources, deforestation, and lowering of the productive capacity of rangelands. Largearea soil physical degradation assessment using gis. Physical, chemical, and biological properties of soil. The impact of chemical degradation of soil and agricultural land by hazardous heavy metals and metalloids originated from mine tailings after extraction and beneficiation of ores is a very serious danger and threat for the environment leading to its local and global contamination. Factors affecting, relationship to soil function, methods for improvement, and measurement options are discussed for each topic.
Land degradation indicators and management options. Meanwhile, soil erosion was becoming recognized as a serious problem in many countries and largescale soilconservation programs were launched in africa and, a few years later, in australia. Objective 2 to be able to discuss the environmental and socioeconomic consequences of soil degradation. Soil degradation, restoration and management in a global change context, volume four in the advances in chemical pollution, environmental management and protection series, explores a wide breadth of emerging and stateoftheart technologies and provides the best practices to manage soils affected by degradation. The erodible material is almost devoid of organic matter and lacks in mineral plant nutrients. Degradation leads to reduction in crop yield in the affected lands and a possible decline in cropping intensity. Soil crusting is a local phenomenon at the surface of the soil that results in a thin impermeable layer that, hamper seedling emergence, reduce infiltration and favor runoff and erosion. The loss of soil structure or change in permeability. Grain size distribution accordant world reference base for soil resources grain size distribution sand silt clay sample % of humusfree soil texture lane 2 86. 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. Causes and impacts of land degradation and desertification.
Impact of physical soil and water conservation structure. The term land degradation involves both soil and vegetation degradation. The most expedient physical assets of soil is soil texture because the necessary components i. Physical assets of soil also effect the usual division of species of woodland trees progression and production of biomass of woodland. Impact of physical soil and water conservation structure on. The most common form of soil physical degradation is soil compaction. Collapsing gully erosion was found to affect the soil physical and chemical properties by progressively reducing the sqi. Soil erosion and land degradation have been increasing in ethiopian highlands due to the existence of arable land 90 %, high human population 90% and. It would be very wrong to think of soils as just a collection of fine mineral particles. However, the performance of s oil and water conservation structures has not been well studied. The present rate of land degradation is estimated at 5 to 7 million hectares per year, suggesting that 0.
Soil physical properties affecting soil erosion in. Milan borisev, in biogeotechnologies for mine site rehabilitation, 2018. Whilst soil degradation is recognised as a major aspect of land degradation, other processes which affect the productive capacity of cropland, rangeland and forests, such as lowering of the water table and deforestation, are captured by the concept of land degradation. Soil degradation a major threat to humanity summary soil degradation needs to be recognised, alongside climate change, as one of the most pressing problems facing humanity. Soil compaction is a global problem associated with mechanized agriculture. Western europe 21, the extent and causes of chemical, physical, and biological soil degradation and soil loss vary greatly, but agriculture and. Abstract soil degradation is evident in the mountainous areas of ethiopia, is often represented as results of human pressure. To develop new technologies that will improve infield saving of water on every square meter of the. Ecological factors influencing physical soil degradation in the. Through a series of demonstrations and handson exercises, students are taught how to determine soil texture by feel and are given the opportunity to examine other soil physical properties such as soil. Biodegradation biotic degradation, biotic decomposition is the chemical degradation of contaminants by bacteria or other biological means and is often referred to as the natural method of degrading discharged chemicals chapter 8. Soil physical, chemical and biological properties are affected due to alteration in hydraulic conductivity, bulk density, osmoderegulation, poor. It depends on soil texture, aggregate stability, topography and rainfall characteristics. Degradation characteristics of soilqualityrelated physical.
The concept seems rather simple, but quantifying degradation has been very challenging and creates uncertainty associated with quantifying land degradation efforts bai et al. These soils generally have sandy loam surface horizons, with a high organic matter. Land degradation and rehabilitation in ethiopia society at large is also suffering from uncertain information about the rates of land use change and land degradation. Land degradation is, usually, the result of complex interrelationships between biophysical and socioeconomic issues which affect many people and their land, specially in the tropics and developing countries. Physical and chemical properties of soil quality indicating. Soil physical land degradation processes co meeting organizer. Solutions need to be developed and introduced which address both issues simultaneously. Physical soil degradation is one of the eight main risks and threats defined by the european thematic strategy for soil protection com2002179 final physical degradation comprises very different processes and morphometric forms, mainly through the deformation of the inner soil structure by compaction, caused by tracking with heavy agricultural machinery, through vertical sheer stress.
It has caused yield reductions of 2550 % in some regions of europe and north america and between 40 and 90 % in west african countries. The world is losing 10 ha of arable land each minute5 ha to soil erosion, 3 ha from salinity, and 2 ha by. Fundamental concepts scoop on soil educational cd may 2006 nrcs helping people help the land figure 1. Soil physical degradation due to drip irrigation in. Soil degradation ann verdoodt academic year 20112012 compilation of course notes by prof. Soil samples were taken during the trial 2005 and analysed in the laboratories of the federal institute for geosciences and natural resources bgr in hannover.
Causes of soil degradation and methods for soil conservation. Soil degradation, restoration and management in a global. It can be the loss of organic matter, decline in soil fertility, and structural condition, erosion, adverse changes in salinity, acidity or alkalinity, and the effects of toxic chemicals, pollutants or excessive flooding. Soil degradation nsw environment, energy and science. Physical degradation of soils, risks and threats springerlink. How to survive alone in the wilderness for 1 week eastern woodlands duration. Land degradation is a process in which the value of the biophysical environment is affected by a combination of humaninduced processes acting upon the land.
Soil conservation encyclopedia of life support systems. Accelerated soil erosion is a result of the ope ration of the physical. We briefly summarize the biochemical processes occurring during composting and the use and applications of compost in the environment. Chemical degradation an overview sciencedirect topics. Water erosion, chemical degradation, wind erosion, and physical degradation have been reported as main types of degradation.
Most soils in galicia nw spain have moderately good physical conditions. The paper suggests some rules of thumb for identifying the priority areas for government and donor intervention, including the need for targeted research on the productivity. Soil degradation is one of the crucial issues in mountainous areas of ethiopia which needs efforts to reduce it. Physical, chemical, and biological properties of soil under decaying wood in a tropical wet forest in puerto rico marcela zalamea 1, grizelle gonzalez 1, and deborah jean lodge 2 1 united states department of agriculture, forest service, international institute of tropical forestry. Its form depends on the material in question, but generalised examples of the symptoms of degradation of materials include discoloration, swelling, loss of strength, changes in the. Soil degradation needs to be recognised, alongside climate change, as one of the. This study takes the degradation of soil resources as its focus. Section v conservation practice physical effects resource concerns for soil quality degradation practice name practice code organic matter depletion compaction subsidence chemicals onfarm secondary containment facility 319 0 0 0 0 open channel 582 0 0 0 0 phosphorous removal system 782 0 0 0 0 pond 378 0 0 0 0 pond sealing or lining. Fanya juu soil conservation structure on selected soil. Chapter 2 types of land degradation food and agriculture. Soil loss from conventionally tilled land exceeds the rate of soil formation by 15 2 orders of magnitude medium confidence. This could be acidification, salinisation or chemical. The study was conducted in goromti watershed, in western ethiopia to evaluate the impact of fanya juu structures on some soil physical. Soil compaction decrease soil porosity and soil infiltration rate, can cause redistribution of water and nutrients, decrease root.
To characterize the spatial variability of soil physical properties within the same field. A soil is a threedimensional natural body in the same sense that a hill, valley, or mountain has three dimensions. Physical soil degradation is one of the eight main risks and threats defined by the european thematic strategy for soil protection com2002179 final physical degradation comprises very different processes and morphometric forms, mainly through the deformation of the inner soil structure by compaction, caused by tracking with heavy agricultural machinery. Land degradation is the temporary or permanent lowering of the productive capacity of land unep, 1992b. In this report, land degradation is defined as a negative trend 4 in land condition, caused by direct or indirect humaninduced processes. Soil physical properties in relation to soil degradation. Introduction the mountains and highlands of tanzania are facing several problems of land degradation. Analysis of physical properties of soil samples from test. Speight, in reaction mechanisms in environmental engineering, 2018. Soil degradation refers to negative changes in the physical, chemical, and biological properties of the soil, whereas vegetation degradation is the reduction in the number of species and the vegetational composition. Pdf soil degradation is a global problem caused by many factors.
Physical degradation involves changes to materials resulting from ambient conditions like sunlight, heat, humidity, exposure to chemicals or general wear and tear. In extreme cases, soil becomes unfit for cultivation. Examine the main causes of soil degradation globally and discuss to what extent they are human physical in nature. Physical soil degradation is one of the eight main risks and threats. Determine dry bulk density of soil first, independently extract soil core with known bulk volume and ovendry. Usually land degrad ation is described in terms of the loss. Land degradation is a major concern in ethiopia since it leads to declining agricultural productivity, poverty and food insecurity. Soil degradation is a nebulous term suggesting that the capacity of a soil to perform selected specified services, such as growing crops, has been diminished. Soils are the base of life, thus a sustainable soil. Soil sealing is prevalent in soils covered by infrastructure. Physical soil degradation induced by deforestation and slope. Chemical and physical characteristics of compost leachates.
The second category of soil degradation includes internal soil chemical deterioration salinization and acidification, soil pollution caused by excessive use of pesticides and manure, and soil pollution due to industrial and human waste accumulation and soil physical deterioration. Soil science institute of athensnational agricultural. Soil texture refers to the proportion of the soil separates that make up the mineral component of soil fine earth fraction aug 28, 2014 physical soil degradation is one of the eight main risks and threats defined by the european thematic strategy for soil protection com2002179 final physical degradation comprises very different processes and morphometric forms, mainly through the deformation of the inner soil structure by compaction, caused by tracking with heavy agricultural machinery, through vertical sheer stress. These areas can be easily identified by remote sensing. It can be improved through different soil and water conservation swc measures. Evidence and implications thesis submitted by dougal robert currie soil and land systems, school of earth and environmental sciences, the university of adelaide, adelaide, australia for the degree of doctor of philosophy december, 2006. Task 7 split into pairs and carry out some research to find out how the following factors are linked to soil degradation. Physical deterioration of soil involves the destruction of soil structure, dispersion of soil particles, sealing of pores, compression and increasing density, consolidation, compaction and reduced root penetration, low infiltration, waterlogging and runoff, and accelerated erosion. Soil erosion and land degradation have been increasing in ethiopian highlands due to the existence of arable land 90 %, high human population 90% and livestock density 60% which resulted in. Silting of drainage, canals, rivers and reservoirs results in increased floods and droughts. Soil degradation is the physical, chemical and biological decline in soil quality. Soil physical degradation due to drip irrigation in vineyards. Land degradation is, however, difficult to grasp in its totality.
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