WATER CONSERVATION PRINCIPLES WATER CONSERVATION PRINCIPLES AND PRACTICESAND PRACTICES

Water Water conservationconservation

“ “The conservation The conservation treatment meant to treatment meant to reduce or prevent sheet reduce or prevent sheet erosion while achieving erosion while achieving the desired moisture the desired moisture conservation and/or runoff conservation and/or runoff disposal.”disposal.”

Important Important principlesprinciples

►Increasing the time of concentration Increasing the time of concentration and thereby allowing more runoff and thereby allowing more runoff water to be absorbed and held in the water to be absorbed and held in the soil profile.soil profile.

►Intercepting a long slope into several Intercepting a long slope into several short ones, so as to maintain less than short ones, so as to maintain less than a critical velocity for the runoff water; a critical velocity for the runoff water; andand

►Protection against damage owing to Protection against damage owing to excessive runoff.excessive runoff.

Practices for water conservationPractices for water conservation

Engineering measuresEngineering measures:: Hillside ditchesHillside ditches Bench terracesBench terraces Stone wallsStone walls

►Broad-based terracesBroad-based terraces

Engineering measuresEngineering measures

Hillside ditchesHillside ditches

A series of A series of shallow ditches shallow ditches built along the built along the contour lines contour lines of a hill side of a hill side slope at proper slope at proper intervalinterval

ObjectivesObjectives►To break up a long slope into To break up a long slope into

several short slopes, in order to several short slopes, in order to intercept runoff waterintercept runoff water

►The ditches may also serve as The ditches may also serve as farm paths to facilitate farm paths to facilitate transportation that the transportation that the operating cost may be reduced.operating cost may be reduced.

Bench terracesBench terraces►A series of A series of

level or nearly level or nearly level platform level platform built along built along the contours the contours at suitable at suitable intervals. intervals.

Objectives Objectives ►To intercept runoff and To intercept runoff and

control soil erosion.control soil erosion.►To make cropping To make cropping

operations possible and operations possible and safe on crop slope land.safe on crop slope land.

Stone wallsStone walls

► Using stones to Using stones to construct at a suitable construct at a suitable spacing on crop land spacing on crop land along contour linesalong contour lines

OBJECTIVESOBJECTIVES

►T makes good use of rocks and stones T makes good use of rocks and stones existing on slopes, thereby clearing the land existing on slopes, thereby clearing the land for cultivation.for cultivation.

► .to reduce soil and water losses and to trap .to reduce soil and water losses and to trap the soil washed down from above, thus the soil washed down from above, thus gradually building up bench terraces and gradually building up bench terraces and hillside ditches in later years.hillside ditches in later years.

►To minimize the gradient of a slope to To minimize the gradient of a slope to facilitate cultivation, mechanized operations facilitate cultivation, mechanized operations and soil conservation and soil conservation

Broad based Broad based terracesterraces

A series of A series of shallow, broad shallow, broad based terraces based terraces constructed on constructed on gently sloping gently sloping land at a suitable land at a suitable spacing along spacing along the contour the contour lines.lines.

ObjectivesObjectives►To break the length of a To break the length of a

slope to control soil erosionslope to control soil erosion►To conserve soil moisture To conserve soil moisture

so as to help crop growth.so as to help crop growth.

Grass planting on hill side Grass planting on hill side ditchesditches

► The establishment of The establishment of specific grasses on specific grasses on hillside ditches, including hillside ditches, including both bottom and side both bottom and side slopes of each ditch.slopes of each ditch.

ObjectivesObjectives►To stabilize the hillside ditch and To stabilize the hillside ditch and

thus reduce maintenance cost.thus reduce maintenance cost.►To save the labor costs of weeding.To save the labor costs of weeding.►To prevent soil erosion on the To prevent soil erosion on the

upper side slope of the ditch and to upper side slope of the ditch and to gradually reduce the slope as gradually reduce the slope as sliding soil is trapped by the grass. sliding soil is trapped by the grass.

Agronomic and vegetative Agronomic and vegetative measuresmeasures

►Contour planting Contour planting ►Grass planting on Grass planting on hillside ditches hillside ditches

►Planting grass on Planting grass on risers of terracesrisers of terraces

►Cover cropsCover crops

►Grass barriersGrass barriers►Mulching Green Mulching Green manuremanure

►windbreakswindbreaks►Weed removalWeed removal

Agronomic and vegetative Agronomic and vegetative measuresmeasures

Contour planting:Contour planting:

Plowing, furrowing and Plowing, furrowing and planting along the planting along the contour lines of a slope.contour lines of a slope.

ObjectivesObjectives►To increase water To increase water penetration into soil and penetration into soil and conserve soil moistureconserve soil moisture

►To control runoff and soil To control runoff and soil erosion.erosion.

Planting grass on Planting grass on risers.risers.

The planting of suitable grasses on the The planting of suitable grasses on the

risers of bench terraces.risers of bench terraces.

Objective.Objective. To prevent soil erosion from the To prevent soil erosion from the

risers and to maintain the stability risers and to maintain the stability of the terraces.of the terraces.

Cover cropsCover crops► Plants which are grown Plants which are grown to cover the surface of to cover the surface of the ground with dense the ground with dense foliage, to control soil foliage, to control soil erosion and improve the erosion and improve the soilsoil..

ObjectivesObjectives ►To protect the surface of the soil To protect the surface of the soil

from splashing of rain drops.from splashing of rain drops.►To built up soil organic matter To built up soil organic matter ►To suppress weed growth and To suppress weed growth and

surface management cost.surface management cost.►To minimize changes in micro-To minimize changes in micro-

climate and in soil temperature, climate and in soil temperature, thereby providing a better thereby providing a better environment for crop growth.environment for crop growth.

Green manure.Green manure.

►A green manure A green manure crop is grown crop is grown specially to specially to improve soil and improve soil and act as a fertilizer.It act as a fertilizer.It is plowed into soil is plowed into soil while still green,or while still green,or shortly after it shortly after it maturesmatures

ObjectivObjectiveeTo increase organic matter To increase organic matter

and nutrients in the soil,and and nutrients in the soil,and to improve the physical and to improve the physical and chemical characteristics of chemical characteristics of soil to increase the soil to increase the resistance of soil to erosion. resistance of soil to erosion.

Grass barriersGrass barriers► Contour Contour planting of planting of suitable suitable spaced strips spaced strips of grass on of grass on slope land.slope land.

ObjectivesObjectives►To arrest runoff so as to reduce soil To arrest runoff so as to reduce soil

and water losses and to hold soil and and water losses and to hold soil and prevent it from being washed downhill.prevent it from being washed downhill.

►To reduce the slope of a hillside To reduce the slope of a hillside cultural practices and mechanical cultural practices and mechanical operations.operations.

►To gradually convert the barriers into To gradually convert the barriers into bench terracesbench terraces

windbreaks.windbreaks.

. . Strips of trees or tall Strips of trees or tall grasses planted at grasses planted at appropriate intervals to appropriate intervals to prevent or reduce wind prevent or reduce wind erosion and crop losses erosion and crop losses caused by wind.caused by wind.

ObjectiveObjective

►To control wind erosionTo control wind erosion►To reduce physiological or To reduce physiological or

mechanical injuries to crops mechanical injuries to crops caused by strong winds.caused by strong winds.

►To reduce evapotranspirationTo reduce evapotranspiration►To reduce salt damages if the To reduce salt damages if the

locality is near the area.locality is near the area.

ObjectiveObjective ►To arrest runoff so as to reduce soil To arrest runoff so as to reduce soil

and water losses and to hold soil and and water losses and to hold soil and prevent it from being washed downhill.prevent it from being washed downhill.

►To reduce the slope of a hillside to To reduce the slope of a hillside to facilitate cultural practices and facilitate cultural practices and mechanical operations.mechanical operations.

►To gradually convert the barriers into To gradually convert the barriers into bench terraces.bench terraces.

DrainageDrainageDiversion Diversion

ditches:ditches:A ditch constructed A ditch constructed

approximately along approximately along the contour of a the contour of a slope for the slope for the purpose of purpose of intercepting surface intercepting surface and diverting it to a and diverting it to a suitable outlet.suitable outlet.

Objectives.Objectives.►To protect farmland and To protect farmland and buildings by diverting buildings by diverting runoff from hill slopes.runoff from hill slopes.

►To control gully erosion.To control gully erosion.

Drainage ditchesDrainage ditchesDrainage channels running Drainage channels running

along a slope, which are lined along a slope, which are lined with stone, brick, or concrete with stone, brick, or concrete etc.etc.

ObjectivesObjectives►To ease the flow of runoff To ease the flow of runoff

water and to protect the ditch water and to protect the ditch from erosion.from erosion.

►To gather water flow in hillside To gather water flow in hillside ditch and contour drainage ditch and contour drainage channels, and carry the flow to channels, and carry the flow to a safe place to be discharged.a safe place to be discharged.

Grassed water Grassed water ways.ways.

► Earth Earth waterways waterways planted with planted with grasses to grasses to control soil control soil erosion.erosion.

ObjectivesObjectives ►To provide safe outlet for runoff To provide safe outlet for runoff

water.water.►To prevent soil erosion and to To prevent soil erosion and to

stabilize waterways.stabilize waterways.►To facilitate the operations of farm To facilitate the operations of farm

machinery.machinery.►To maintain a stable field To maintain a stable field

environment.environment.