soil erosion and soil health


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  • Introduction to Soil Erosion Definition : Soil erosion is the detachment, transport & deposition of soil particle on land surface - termed as loss of soil.Measured as mass /unit area - tonne/ha or Kg/sq.m

    Soil loss is of interest primarily On -site effect of erosion such as loss of crop productivity Off site effect of erosion are siltation in ditches, streams , reservoirs Sediment generated by erosion processes are prime carrier of agricultural chemicals that pollutes stream or lakes

  • Soil Erosion ProblemSoil is the most precious gift of nature Prime resource -for food, fodder etc. -Soil mismanaged -less productivity. In India, more than 100 million hectares -soil degraded eroded unproductive About 17 tones/ha soil detached annually->20% of this is transported by river to sea -10% deposited in reservoir results 1 to 2% loss off storage capacity.Soil erosion deteriorates soil quality & reduces productivity of natural, agricultural & forest ecosystem Soil erosion deteriorates quality of water Increased sedimentation causes reduction of carrying capacity of water bodies

  • Factors Affecting Erosion

  • Human Causes

  • Natural Causes

  • Striking Factors

  • Degenerating Forces

  • Factors Affecting ErosionErosion is directly proportional to square root of length of slope

  • Mechanics of ErosionBegins with raindrops striking bare soil dislodging particles Intense rains seal surface When rainfall exceeds infiltration water is stored in small depressions Once depressions are filled, runoff beginsInitially water flows in a discontinuous sheet Eventually it concentrates into small channels or rills The runoff now has energy to break off particles and cut deeper The amount of erosion caused by sheet and rill erosion increases with slope and distance Rills may eventually form gullies

  • Soil Erosion ParametersSoil erosion function of: Erosivity ability to erode : depends on rainfall Erodibility Resistance offered to restrict erosion (property of soil)Topography property of land Management contributed by man Erodibility: Detachability & transportability Topography: Slope, length, relation to other land Management: Land use & crop management

  • Types of Soil ErosionGeological erosion, Natural erosion & Erosion from activities of human & animalsGeological erosion: -Soil forming and distribution-Long time process Human and animal: Tillage, removal of plants and Tillage, removal of plants and other vegetation- accelerated erosion Stream bank erosion Landslide, Volcanic eruption, flooding Water and wind: major factors of soil erosion

  • Soil Erosion Processes

  • Types of surface erosion

  • Splash ErosionSheet ErosionRill ErosionGully ErosionStream bank Erosion

  • Types of erosion

  • Principle of Soil and Moisture ConservationRidge to valley treatmentMaximum possible rain water should be conserved where it fallsAdequate vegetal cover during rainy seasonStorage/ disposal of excess water with safe velocityChecks/ barriers along the contour to control soil erosion & ground water rechargeIntegration of biological and mechanical measures

  • Soil Conservation

  • Agronomic Measures

  • Agronomic Measures

  • Contour cultivation

  • Vegetative BarrierFor Sloppy LandFor Gully Treatment

  • Strip cropping

  • Grass waterway

    To allow water to flowIn non-erosive velocityand helps in safe diposalof excess water

  • Aforestation

  • Cover Cropping

  • MulchingSugarcane trash mulchingMulching in mangoMulching in maize

  • Conservation Ditches

  • Agri-horti System ( Mango + G.Nut)

  • Agri-horti System

  • Agri-silviculture

    (A.mangium + sesame)

  • Silvi - Pastoral system(A.mangium + guinea grass)

    Horti-Pastoral System (Banana + Grass)

  • Horti - Pastoral system

  • Horti-silvi-pastoral system (Guava + sissoo + stylo)

  • Important principles for planning engineering measures

    Intercepting the rain before it reaches ground surface, dissipate the kinetic energy to reduce detachment of soil particle.

    Increasing time of concentration of run off and there by allowing more water to be absorbed and held by soil.

    Reduce the run off volume and run off velocity

    Protection against damage due to excess run off

    Trapping silt particle during its flow path.

  • InterventionsVegetative cover prevent rain drop to strike ground surface directly as well reduce its energy.Intercepting long slope into several short ones so as to restrict the run off velocity with in critical limit.Bunding breaks the slope length, terracing breaks the degree of slope which increase the time of concentration.Trenches, check dams, earthen cross bunds, gabion structure, etc. store part of run off there by reducing run off volume and velocity and protect against the damage caused due to excess run off and facilitate GW recharge. Gully control measures are constructed especially to prevent further increase in gully size (both horizontally and vertically) and to stabilize it to allow vegetation to grow.Finally utilization of excess water through check dams, diversion weirs, ponds, WHSs, wells for crop production.

  • Treatment options for different types of lands- Aat land (Up land)

    Distinct Features PurposeTechnological options for development Situated above Berna land having 8% -25% slope, unlevelled. Soil depth is up to 0.30 m and rain fed cereals, pulses and oilseeds along with rainy vegetables are usually cultivated. Soil erosion and nutrient loss possessions problems. Safe disposal of run-off water. Breaking the length of slope. Retain a part of run-off. Make the land suitable for tree plantation. Gully stabilization

    Option in varying slope Diversion drain/ Grass water way Terracing (Level/Inward/Outward) Continuous contour canal Trenching (CCT/ ST/WAT) Contour Bunding/ Graded Bunding / Stone Bunding Percolation Tank Gully control works (Semi Permanent) Gully Control works (Permanent) Sunken Gully Pit

  • Treatment option in varying slope

  • Grass waterways

  • Terracing

  • Grassed Waterways Diversion DrainContinuous contour canal

  • Continuous Contour Trenches

  • Staggered Trench

  • Water Absorption Trench (WAT)

  • Slope Contour Bunding

  • Contour Stone Bunding

  • Percolation Tank in upper reach

  • Sunken Gully Pit

  • Permanent GC Structures

  • Semi permanent Gully Control Structure

  • Treatment options for different types of lands- Berna (medium land)

    Distinct features PurposeTechnological options for development Situated above Bahal (low land) with mild slopeof 2% to 8% Under levelled and irrigation situation two crops are assured Paddy with short & medium duration are usually cultivated Erosion takes place due to over flow of runoff water from near by areas To break the slope length Conserve max. water for crop production. Drainage development. Silt detention.Field Bunding with outlets. Dev. of Drainage CourseDiversion Weir / Retention Weir.Check dams (Masonry/ Gabion /Low Cost Multiple Arch Type CD)Water Harvesting Structure(WHS) Run-off Management Structure

  • Field Bunding

  • Development of drainage course

  • Diversion Weir

  • Retention weir/ WallRetention Weir

    Retention Wall

  • Masonry check dam

  • Gabion Structure

  • Masonry Multiple Arch Type Check Dam

  • Water Harvesting Structure

  • Run off management Structure

  • Slope Contour bunding

  • Treatment options for different types of lands- Bahal (low land)

    Distinct features Technological options for development * Developed from stream bed where water flows regularly. Jholla land comes under this category.* Due to retention nature of soil moisture and continuous flow, two crops of paddy are usually taken * Drainage development* Stone packing of bunds* Farm Pond and Storage StructureProvision of spillways/Drop Str.Increase in water utilization efficiency through low cost technology


  • Drainage Development

  • Water Storage structures

  • Farm Pond in lower reaches

  • Provision of spillway/drop structure in lower reaches

    Drop StructureDrop Structure with silt trap

  • Stone Packing of Bunds

  • Increasing water utilization efficiency through low cost deviceMicro irrigation pressure pumpMicro irrigation bucketLow cost portable KB pumpRope washer pump

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