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WATER CONSERVATION PRINCIPLES AND PRACTICES. Water conservation. “ The conservation treatment meant to reduce or prevent sheet erosion while achieving the desired moisture conservation and/or runoff disposal.”. Important principles.
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Water conservation “The conservation treatment meant to reduce or prevent sheet erosion while achieving the desired moisture conservation and/or runoff disposal.”
Important principles • Increasing the time of concentration and thereby allowing more runoff water to be absorbed and held in the soil profile. • Intercepting a long slope into several short ones, so as to maintain less than a critical velocity for the runoff water; and • Protection against damage owing to excessive runoff.
Practices for water conservation Engineering measures: • Hillside ditches • Bench terraces • Stone walls • Broad-based terraces
Engineering measures Hillside ditches A series of shallow ditches built along the contour lines of a hill side slope at proper interval
Objectives • To break up a long slope into several short slopes, in order to intercept runoff water • The ditches may also serve as farm paths to facilitate transportation that the operating cost may be reduced.
Bench terraces • A series of level or nearly level platform built along the contours at suitable intervals.
Objectives • To intercept runoff and control soil erosion. • To make cropping operations possible and safe on crop slope land.
Stone walls • Using stones to construct at a suitable spacing on crop land along contour lines
OBJECTIVES • T makes good use of rocks and stones existing on slopes, thereby clearing the land for cultivation. • .to reduce soil and water losses and to trap the soil washed down from above, thus gradually building up bench terraces and hillside ditches in later years. • To minimize the gradient of a slope to facilitate cultivation, mechanized operations and soil conservation
Broad based terraces A series of shallow, broad based terraces constructed on gently sloping land at a suitable spacing along the contour lines.
Objectives • To break the length of a slope to control soil erosion • To conserve soil moisture so as to help crop growth.
Grass planting on hill side ditches • The establishment of specific grasses on hillside ditches, including both bottom and side slopes of each ditch.
Objectives • To stabilize the hillside ditch and thus reduce maintenance cost. • To save the labor costs of weeding. • To prevent soil erosion on the upper side slope of the ditch and to gradually reduce the slope as sliding soil is trapped by the grass.
Agronomic and vegetative measures • Contour planting • Grass planting on hillside ditches • Planting grass on risers of terraces • Cover crops
Grass barriers • Mulching Green manure • windbreaks • Weed removal
Agronomic and vegetative measures Contour planting: Plowing, furrowing and planting along the contour lines of a slope.
Objectives • To increase water penetration into soil and conserve soil moisture • To control runoff and soil erosion.
Planting grass on risers. The planting of suitable grasses on the risers of bench terraces. Objective. To prevent soil erosion from the risers and to maintain the stability of the terraces.
Cover crops • Plants which are grown to cover the surface of the ground with dense foliage, to control soil erosion and improve the soil.
Objectives • To protect the surface of the soil from splashing of rain drops. • To built up soil organic matter • To suppress weed growth and surface management cost. • To minimize changes in micro-climate and in soil temperature, thereby providing a better environment for crop growth.
Green manure. • A green manure crop is grown specially to improve soil and act as a fertilizer.It is plowed into soil while still green,or shortly after it matures
Objective To increase organic matter and nutrients in the soil,and to improve the physical and chemical characteristics of soil to increase the resistance of soil to erosion.
Grass barriers • Contour planting of suitable spaced strips of grass on slope land.
Objectives • To arrest runoff so as to reduce soil and water losses and to hold soil and prevent it from being washed downhill. • To reduce the slope of a hillside cultural practices and mechanical operations. • To gradually convert the barriers into bench terraces
windbreaks. . Strips of trees or tall grasses planted at appropriate intervals to prevent or reduce wind erosion and crop losses caused by wind.
Objective • To control wind erosion • To reduce physiological or mechanical injuries to crops caused by strong winds. • To reduce evapotranspiration • To reduce salt damages if the locality is near the area.
Objective • To arrest runoff so as to reduce soil and water losses and to hold soil and prevent it from being washed downhill. • To reduce the slope of a hillside to facilitate cultural practices and mechanical operations. • To gradually convert the barriers into bench terraces.
Drainage Diversion ditches: A ditch constructed approximately along the contour of a slope for the purpose of intercepting surface and diverting it to a suitable outlet.
Objectives. • To protect farmland and buildings by diverting runoff from hill slopes. • To control gully erosion.
Drainage ditches Drainage channels running along a slope, which are lined with stone, brick, or concrete etc.
Objectives • To ease the flow of runoff water and to protect the ditch from erosion. • To gather water flow in hillside ditch and contour drainage channels, and carry the flow to a safe place to be discharged.
Grassed water ways. • Earth waterways planted with grasses to control soil erosion.
Objectives • To provide safe outlet for runoff water. • To prevent soil erosion and to stabilize waterways. • To facilitate the operations of farm machinery. • To maintain a stable field environment.
