Soil Degradation and Regeneration

Mr. Bijesh Mishra

bijesh.mishra@kysu.edu

Graduate Student

Environment Science and Bioremediation (ENV 595)

College of Agriculture, Food Science, and Sustainable Systems

Kentucky State University (KYSU)1

Outlines of the Slides:

• Soil Degradation: Definition.

• Soil Degradation is a Global Problem.

• Soil Degradation Process.

• Types of Soil Degradation.

• Impact of Soil Degradation.• Impact in Food Production.• Impact in people.

• Sustainable Soil Management: Principles.

• Management Steps to Increase Soil Quality.

• Use of Tools and Techniques to build Soil.

• References.

• Image Sources.2

Soil Degradation: • Definition: Soil degradation is defined as a change in the soil health status

resulting in a diminished capacity of the ecosystem to provide goods andservices for its beneficiaries. Degraded soils have a health status such, that theydo not provide the normal goods and services of the particular soil inits ecosystem. (FAO, 2015)

• Often Soil Degradation and Land Degradation can be used interchangeably.

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(Jnr, 2014)

Soil Degradation is a Global Problem:• It affects large number of people in more than 100 countries covering 33% of

overall world.

• Everyday, for more than twenty years, in arid and semi-arid region, 2,000 hectare irrigated land is being degraded by salt across 75 countries.

• Today, 62 million hectares (20%), an area equals to size of France, of worlds irrigate lands is affected by soil degradation which was 45 million in early 1990s.

• It has prompted a stream of national and international policy responders.

• Land degradation negatively affects a number of important problems of globally concern directly.

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In last 20-30 years, 24% of land has degraded, and trend continues.

are ADVERSLY AFFECTED!!! (UNU-INWEH, 2015)5

Soil Degradation is a Global Problem:

Good Ethiopian topsoil going down the Nile to Egypt.

Air view of destroyed village and badly eroded land in Northern Darfur.

Degraded valley of Mustang, Nepal(2750-6000 Meter MSL.)

The boundary between overgrazed sandy rangeland and threatened rain-fed agricultural zone is clearly visible.

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Soil Degradation Process• Soil Sealing:

• Covers soil surface making impermeable to water and air.

• Directly affects in areas where construction is heavily done. Egs. Urban Areas.

• Soil Erosion:• It is a natural process which is enhance by human activities and making it worse.

• The loss of one ton per hectare per year can be considered as irreversible within 50-100 years as soil formation rate is very slow.

• Top soil erosion reduces fertility and productivity increasing cost of production.

• Major cause are unsustainable agricultural practices, large scale farming, over-grazing, poor water and irrigation management.

• Salinization: • Found in arid region and abundant in Mediterranean region.

• Accumulation of salt on soil surface or nearby due to improper irrigation, evaporation of saline ground water, water extraction and industrial activities.

• Makes soil completely irresponsive and cause offsite effects as blown by wind.7

Soil Degradation Process (Contd.)

• Soil Contamination: • Can happen from diffusion and localized contamination.

• It can damage several water function (Buffering, filtration, transformation capacities), contaminate drinking water, ground water and surface water.

• Potentially harmful chemical are source of diffusion.

• Industrial plants (functional and non-functional) and past industrial accidents, improper municipal and industrial disposal are localized contamination sources.

• Soil Compaction:• The cumulative effect of use of heavy machinery in agricultural land over period of time.

• The layer below the cultivated layer becomes impervious to water.

• Cause surface runoff, water lodging leading to erosion, loss of top soil and nutrient loss.

• Alters the biochemical and microbial activities of soil.

• Can be solved by reworking in top soil but hard to solve problem in deep soil, thus persists longer period.

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Types of Soil Degradation.• Water Erosion.

• Wind Erosion.

• Chemical Deterioration:• Loss of nutrient or organic matter• Acidification.• Pollution.• Salinization.• Acid Sulphate Soil.• Eutrophication.

• Physical Deterioration:• Water Lodging.• Compacting, Sealing and Crusting.• Lowering of water table.• Subsidence of organic soils.• Mining and Urbanization.

• Degradation of Biological Activities. 9

Loss of top soilTerrain Deformation/Mass Movement.Flooding and Overblowing.

Causes of Soil Degradation:• Immediate Causes.

• Biophysical factors• Topography (determines soil erosion)• Climatic Conditions

• Temperature• Rainfall• Wind.

• Unsustainable Land management Practices• Deforestation.• Forest Degradation.• Soil Nutrient Mining.• Cultivation in Steep Slopes.

• Underlying Causes. (Self-perpetuating in nature and context specific.)• Population Density.• Poverty• Tenure• Market• Policies promoting use of land degradation practices. 10

Soil Degradation: Local Causes and Process

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Impacts of Soil Degradation:• Impact in Crop Production.

• The effect of soil degradation is not detected as serious global problem up to 2020. But, its localized effect is serious affecting food supply and production in poor and marginal areas with low income.

• Cumulative effect of soil degradation is a serious problem.

• Cost of degradation of erosion:• 5-10% production loss (light degradation)• 20% production loss (moderate degradation).• 75% Production( severe degradation).• Even 100% in severe condition.

• Effect of soil degradation in food production system combines with the land management techniques, use of fertilizers, irrigation and machinery uses.

• Degradation makes Soil irresponsive to inputs, reduce alternative use of land, failure of irrigation scheme, and reduce water use efficiency.

• In turn, it leads to other types of degradation.12

Impacts of Soil Degradation:

•Impact in People:• Famine (1970s and 1980s) in Ethiopia.

•Nearly one million (sixth of population) from Burkina Faso and half a million from Mali turned into Environmental Refugee during 1970s.

• Forced Migration: Those environmental refugee migrated in some other places during Sahel drought as the place was turning into desert. 13

Health Disorders

Forced Migration

Lowering in Income

CONFLICT!!!

Water Shortages

Yield Reduction

Dust Strom (ELD, 2015)14

Impacts of Soil Degradation (contd…)

Land reclamation, Soil Regeneration and Management Techniques.

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What Next?

Sustainable Soil Management: Principles

Five Basic Principles:

• Maintain Soil Livestock: They recycle nutrients and many other benefits!

• Organic matter (OM) is food for the soil microbes.

• Cover the soil (Mulching): You may loose nutrients due to erosion and temperature extremes.

• Minimum or No Tillage: It speeds the organic matter decomposition Also, Moldboard plough destroy the soil population beside speeding humus decomposition.

• Maintain Nitrogen in Soil: Higher nitrogen (N) in soil means higher decomposition of organic matters and vice versa. Also, Low N starves plant.

• OM degradation should be less than its addition to maintain the soil fertility. Soil Fertility should be in acceptable level before doing agriculture.

(Sullivan, 2001)16

Soil Degradation Conservation.

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• Assess Soil Health and Biological Activity on Farm.• Use USDA Soil Quality Test Kit.

• Early Warning Monitoring for Croplands.

• Direct Assessment of Soil Health. (Feel or Smell it!)

• Utilize tools and Techniques to Build Soil.• Crop Rotation: Alternating legumes and cereals in the field to restore the nutrients in soil and fight pests and

diseases.

• No Over-Irrigation.

• Organic Farming.

• No over grazing and over exploitation of resources.

• Integrated Nutrient Management: Maintaining optimum soil fertility and plant nutrient for desired productivity from all organic, inorganic, biological, and sustainable recyclable waste in integrated manner.

• Biotechnology: Bio-fertilizers, Bio-pesticides, Compost, Cover Crop, Green Manures, Animal Manure etc.

• Reduce use of synthetic or inorganic Fertilizers.

• Leave field fallow for a season.

• Continue to Monitor indicators of Success or Failure as you experience new practices and Amendments.

Management Steps to Improve Soil Quality:

(Sullivan, 2001)18

Utilization of Tools and Techniques to Build Soil:

1. Soil Conservation:

Terracing and Bunds: Terracing and

for bunds extreme hilly areas.

Both prevent massive landslides

and top soil removal.

Contour Farming: Ploughing and planting in perpendicular to

slope along the contour line. Contour farming Combined with

stripe cropping reduces soil loss by 75% compared to up-downhill

cultivation.

Shelterbelts and Windbreaks: Growing fast growing trees in

The bunds of field to block the winds.

Conservation Tillage: Minimum or No Disturbance to

soil layer.

Photo: Contour farming and Terrace farming with bunds toprevent landslide and top-soil erosion.

Photos: Shelter Belts to protect crops from wind. 19

Utilization of Tools and Techniques (Contd.)

• Ploughing and Tillage: Deep ploughing breaks soil crust in stratified soil.

• Dryland Farming • Water harvesting• Drought Tolerance Varieties.

• Integrating tree and Livestock with arable

farming with good cover (Mulching).

• Applying dune stabilization measures:

Planting grass, followed by bushy plants and trees.

• Improving Grazing system, pasture land and range.

• Use of techniques to control animal and plant diseases. 20

Utilization of Tools and Techniques (Contd.)

• Chemical Amendments: Helps to manage saline soil followed by leaching of soil.

• Application of organic matters, green manures and farm manures.

Crop Rotation between cereals, legumes. Sometime land can be left fallow.

• Site specific management Strategies with the participation of farmers, local stakeholders and technicians.

• Promotion of quantitative assessment of impacts of degradation on productivity at local and national level with the involvement of governmental and non-governmental bodies.

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Last but not the Least:

“RESPECT THE SOIL”

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References:• Food and Agriculture Organization (FAO). (January 28, 2015). Soil Degradation. Retrieved from http://www.fao.org/soils-

portal/soil-degradation-restoration/en/

• United Nations University (UNU-INWEH). (January 29, 2015). World Losing Farm Soil Daily to Salt-Induced Degradation. Retrieved from http://inweh.unu.edu/world-losing-farm-soil-daily-salt-induced-degradation/

• Theirfelder, C., Wall, P. C. (January 30, 2015). The Problem of Soil and Land Degradation. CIMMYT, Zimbabwe. Retrieved from http://www.nue.okstate.edu/SSA/ExtBulletins03.pdf

• Washington State University, University of Idaho, Oregon State University. (January 30, 2015). Trees against the Wind. A Pacific Northwest Extension Publication. Retrieved from http://cru.cahe.wsu.edu/CEPublications/pnw0005/pnw0005.pdf

• What are the methods of soil conservation? (18 Methods) (January 30, 2015) Retrieved from http://www.preservearticles.com/2012040429881/what-are-the-methods-of-soil-conservation-18-methods.html

• Global Soil Partnership. (January 30, 2015). Plan for Action for Pillar Five of the Global Soil Partnership. Retrieved From http://www.fao.org/fileadmin/user_upload/GSP/docs/ITPS_Pillars/annexV_pillar5.pdf

• Sullivan, P. ( 2001). Sustainable Soil Management. Retrieved from http://www.atra.org/atra-pub/pdf/soilmgmt.pdf

• United Nations University (UNU-INWEH). (Jan 29, 2015). Global Week Soil Infographics: The Economics of Land Degradation. Retrieved from http://inweh.unu.edu/wp-content/uploads/2013/12/ELD-UNU-INWEH.pdf

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Image Sources:• http://filipinofreethinkers.org/wp-content/uploads/2011/12/Open-pit-Mining-in-the-Philippines.jpg

• http://blogs.unimelb.edu.au/sciencecommunication/files/2014/09/pic-2-Copy.jpg

• http://tincaninafrica.com/wp-content/uploads/2012/07/DSC_27041.jpg

• http://postconflict.unep.ch/sudanreport/sudan_website/doccatcher/data/Photographs%20Figures%20and%20Captions%20by%20Chapter/Ch3/Chapter%20photos/3.2c%20Generally%20DSC%200185%208june.JPG

• http://postconflict.unep.ch/sudanreport/sudan_website/doccatcher/data/Photographs%20Figures%20and%20Captions%20by%20Chapter/Ch4/Chapter%20photos/4.2a%20Darfur%20C_0185%2015%20June.JPG

• http://3.bp.blogspot.com/-dGhSSr0hrKU/U9fJWBeJ81I/AAAAAAAAnCs/hWx30bcucww/s1600/1024px-Ackerboden.JPG

• http://2.bp.blogspot.com/_JoA0pNrXidk/TQUiRCEnKqI/AAAAAAAAAQI/isfo8Dprdek/s1600/Nepal+AC+Trek+Nov+2010+635.jpg

• http://spiralmonkey.com/nepal/nepal.0240.jpg

• http://inweh.unu.edu/wp-content/uploads/2014/10/Salt-induced-land-degradation-header1.jpg

• United Nations University (UNU-INWEH). (January 29, 2015). World Losing Farm Soil Daily to Salt-Induced Degradation. Retrieved from http://inweh.unu.edu/world-losing-farm-soil-daily-salt-induced-degradation/

• http://jamaica-gleaner.com/gleaner/20121020/news/images/OMEALLY3.jpg

• http://jamaica-gleaner.com/gleaner/20121020/news/news1.html] 24

Now the flour is open for queries!!!25