WATER CONSERVATION and WATER QUALITY

WATER CONSERVATION The HYDROLOGICAL CYCLE - Runs on solar energy The HYDROLOGICAL CYCLE - Runs on solar energy

WATER CONSERVATION –SOURCES of WATER WATER VAPOR – Evaporation & Transpiration WATER VAPOR – Evaporation & Transpiration –Evapotranspiration (ET) = total water vapor

WATER CONSERVATION –SOURCES of WATER PRECIPITATION – Condenses into Rain, Snow, Hail, etc. PRECIPITATION – Condenses into Rain, Snow, Hail, etc.

WATER CONSERVATION –SOURCES of WATER SURFACE WATER or RUNOFF (~25% precipitation) SURFACE WATER or RUNOFF (~25% precipitation)

WATER CONSERVATION –SOURCES of WATER GROUND WATER (75% precipitation) Water that infiltrates and percolates through soil to a SATURATED LAYER GROUND WATER (75% precipitation) Water that infiltrates and percolates through soil to a SATURATED LAYER –WATER TABLE –AQUIFER

WATER CONSERVATION Run-off vs. Infiltration/Percolation – – pBetweenSoilandWater pdfhttp:// pBetweenSoilandWater pdf

WATER CONSERVATION CONSERVATION by AGRICULTURE CONSERVATION by AGRICULTURE –80% of WATER used annually in US –EFFICIENT WATER USE depends on 3 BMP’s: CAPTURING RUNOFF CAPTURING RUNOFF INCREASING WATER INFILTRATION INCREASING WATER INFILTRATION RETAINING WATER in soil for BETTER CROP YIELDS RETAINING WATER in soil for BETTER CROP YIELDS

WATER CONSERVATION CAPTURING RUNOFF - Agriculture CAPTURING RUNOFF - Agriculture –TERRACING –FURROW DIKING –CONTOUR TILLAGE –STRIP CROPPING

WATER CONSERVATION CAPTURING RUNOFF - Landscape CAPTURING RUNOFF - Landscape –TERRACING –BERMS & SWALES

WATER CONSERVATION INCREASE WATER INFILTRATION INCREASE WATER INFILTRATION –SUBSOILING –AERATION

WATER CONSERVATION INCREASE WATER INFILTRATION INCREASE WATER INFILTRATION –MULCH –CONSERVATION TILLAGE

WATER CONSERVATION RETAIN WATER in soil for BETTER CROP YIELDS RETAIN WATER in soil for BETTER CROP YIELDS –REDUCE EVAPORATION by adding OM to HOLD onto WATER MULCHES / COVER CROPS MULCHES / COVER CROPS REDUCED TILLAGE / REDUCED TILLAGE / CONSERVATION TILLAGE CONSERVATION TILLAGE

WATER CONSERVATION RETAIN WATER in soil for BETTER CROP YIELDS RETAIN WATER in soil for BETTER CROP YIELDS –REDUCE TRANSPIRATION ANTI – TRANSPIRANTS ANTI – TRANSPIRANTS WIND BREAKS WIND BREAKS WEED CONTROL WEED CONTROL

WATER CONSERVATION RETAIN WATER in soil for BETTER CROP YIELDS RETAIN WATER in soil for BETTER CROP YIELDS –IMPROVING PLANT EFFICIENCY SOIL FERTILITY SOIL FERTILITY SELECT & BREED CROPS for LOW WATER USAGE and DROUGHT TOLERANCE SELECT & BREED CROPS for LOW WATER USAGE and DROUGHT TOLERANCE

WATER QUALITY A good QUALITY WATER SUPPLY in US is as IMPORTANT as the QUANTITY A good QUALITY WATER SUPPLY in US is as IMPORTANT as the QUANTITY POLLUTION POLLUTION –POINT SOURCE –NON-POINT SOURCE PESTICIDE & FERTILIZER POLLUTION PESTICIDE & FERTILIZER POLLUTION –RUNOFF & EROSION –LEACHING

WATER QUALITY MAINTAIN or IMPROVE WATER QUALITY by AVOIDING POLLUTION MAINTAIN or IMPROVE WATER QUALITY by AVOIDING POLLUTION –REDUCE RUNOFF –REDUCE EROSION –REDUCE FERTILIZER losses –REDUCE PESTICIDE use –APPLY and STORE MANURES properly –RETAIN and RESTORE WETLANDS - our natural water filters

SOIL WATER

How PLANTS use WATER is very important How PLANTS use WATER is very important –Plants are on ”LIQUID DIETS” and considered “HEAVY DRINKERS” Plant tissues can be 50-90% WATER Plant tissues can be 50-90% WATER –WATER is needed for many plant FUNCTIONS PHOTOSYNTHESIS PHOTOSYNTHESIS TRANSPIRATION TRANSPIRATION Conducting NUTRIENTS Conducting NUTRIENTS TURGIDITY of cells and tissues TURGIDITY of cells and tissues

SOIL WATER PHYSICAL FORCES of SOIL WATER PHYSICAL FORCES of SOIL WATER –GRAVITY – Pulls water DOWN through the soil profile

SOIL WATER OTHER FORCES - KEEP water in SOILS OTHER FORCES - KEEP water in SOILS –ADHESION – attraction between 2 dissimilar substances SOIL PARTICLES and H2O SOIL PARTICLES and H2O –COHESION – attraction between 2 alike substances H2O to H2O attraction H2O to H2O attraction

SOIL WATER –ADHESION and COHESION TOGETHER create a FILM of WATER around a soil particle TOGETHER create a FILM of WATER around a soil particle The CLOSER the WATER MOLECULE is to the SOIL PARTICLE, the MORE TIGHTLY it is HELD The CLOSER the WATER MOLECULE is to the SOIL PARTICLE, the MORE TIGHTLY it is HELD

SOIL WATER –CAPILLARY ACTION ABILITY of a LIQUID to MOVE UPWARD AGAINST the force of GRAVITY ABILITY of a LIQUID to MOVE UPWARD AGAINST the force of GRAVITY In SOILS we can have CAPILLARY MOVEMENT (or action) of WATER through SMALL PORES and CONNECTIONS In SOILS we can have CAPILLARY MOVEMENT (or action) of WATER through SMALL PORES and CONNECTIONS –The SMALLER the PORES the GREATER the MOVEMENT of WATER  UP and DOWN  SIDE to SIDE Any DISRUPTION in the CONTINUITY of CAPILLARY WATER will stop its FLOW Any DISRUPTION in the CONTINUITY of CAPILLARY WATER will stop its FLOW

SOIL WATER TYPES of SOIL WATER TYPES of SOIL WATER –SATURATION –GRAVITATIONAL WATER –FIELD CAPACITY Field Capacity = SATURATION – GRAVITATIONAL water Field Capacity = SATURATION – GRAVITATIONAL water –PERMANENT WILTING POINT Permanent Wilting Point = FIELD CAPACITY – AVAIL. WATER Permanent Wilting Point = FIELD CAPACITY – AVAIL. WATER –HYGROSCOPIC WATER WATER held so TIGHTLY by soil particle that it is UNAVAILABLE WATER held so TIGHTLY by soil particle that it is UNAVAILABLE

SOIL WATER WATER RETENTION WATER RETENTION –DIRECTLY influenced by SOIL TEXTURE COARSE TEXTURES soils COARSE TEXTURES soils –Holds the LEAST WATER MEDIUM TEXURED soils MEDIUM TEXURED soils –Holds the MOST PLANT AVAILABLE water FINE TEXTURED soils –Holds the MOST WATER of any soil type, but has LESS AVAILABLE WATER due to INCREASED HYGROSCOPIC water

SOIL WATER WATER MOVEMENT WATER MOVEMENT –INFILTRATION – Downward ENTRY of water into soils –PERCOLATION -Downward MOVEMENT of water THROUGH the soil profile –WATER MOVEMENT depends on PORE SIZE (texture) and CONTINUITY (structure)

SOIL WATER WATER MOVEMENT through blended and different HORIZONS WATER MOVEMENT through blended and different HORIZONS –Any sharp DIFFERENCE between the TEXTURES of TWO LAYERS of soil will RETARD DRAINAGE –A LAYER must be SATURATED before it will PENETRATE the next, called a WETTING FRONT

SOIL WATER HOW ROOTS GATHER WATER HOW ROOTS GATHER WATER –The THICKER the WATER FILM in PORES, the EASIER and LESS ENERGY it takes for PLANTS to get WATER

SOIL WATER –ROOTS grow BEST where the LARGEST AMOUNTS of O 2 and WATER exist As the UPPER ZONE is DEPLETED, ROOTS utilize WATER DEEPER and DEEPER As the UPPER ZONE is DEPLETED, ROOTS utilize WATER DEEPER and DEEPER As soil dries, ROOT GROWTH INCREASES over shoot growth to GROW DEEPER & DENSER As soil dries, ROOT GROWTH INCREASES over shoot growth to GROW DEEPER & DENSER –A – Dry land wheat –B – Irrigated wheat

SOIL WATER –EFFECTS of WATER SHORTAGE - DROUGHT Soil DRIES till NO AVAILABLE WATER Soil DRIES till NO AVAILABLE WATER TEMPORARY WILTING POINT TEMPORARY WILTING POINT PERMANENT WILTING POINT PERMANENT WILTING POINT Most plants AVOID WATER STRESS by …..??? Most plants AVOID WATER STRESS by …..???

SOIL WATER –EFFECTS of WATER EXCESS – POOR DRAINAGE EXCESS WATER displace O 2 in pores EXCESS WATER displace O 2 in pores Soil ANAEROBIC - Dissolved O 2 used by MICROBES and ROOTS Soil ANAEROBIC - Dissolved O 2 used by MICROBES and ROOTS ROOTS require O 2 for RESPIRATION ROOTS require O 2 for RESPIRATION Problems associated with waterlogged soils? Problems associated with waterlogged soils?

SOIL WATER MEASURING SOIL WATER MEASURING SOIL WATER –TENSIOMETER Liquid filled TUBE with a POROUS clay TIP on one end and a VACUUM GAUGE at top Liquid filled TUBE with a POROUS clay TIP on one end and a VACUUM GAUGE at top As soil dries it pulls water OUT of TIP and creates a VACUUM that is MEASURED by the gauge As soil dries it pulls water OUT of TIP and creates a VACUUM that is MEASURED by the gauge –ELECTRICAL RESISTANCE BLOCKS 2 ELECTRODES imbedded in BLOCKS of gypsum, and placed in soil 2 ELECTRODES imbedded in BLOCKS of gypsum, and placed in soil MEASURES ELECTRICAL CONDUCTIVITY of soil MEASURES ELECTRICAL CONDUCTIVITY of soil