WATER CONSERVATION and WATER QUALITY WATER CONSERVATION The

WATER CONSERVATION and WATER QUALITY

WATER CONSERVATION • The HYDROLOGICAL CYCLE - Runs on solar energy

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

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

WATER CONSERVATION – SOURCES of WATER • 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 – WATER TABLE – AQUIFER

WATER CONSERVATION • Run-off vs. Infiltration/Percolation – http: //www. soilsforsalmon. org/pdf/Relationshi p. Between. Soiland. Water 10 -14 -99. pdf

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

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

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

WATER CONSERVATION • INCREASE WATER INFILTRATION – SUBSOILING – AERATION

WATER CONSERVATION • INCREASE WATER INFILTRATION – MULCH – CONSERVATION TILLAGE

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

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

WATER CONSERVATION • RETAIN WATER in soil for BETTER CROP YIELDS – IMPROVING PLANT EFFICIENCY • SOIL FERTILITY • 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 • POLLUTION – POINT SOURCE – NON-POINT SOURCE • PESTICIDE & FERTILIZER POLLUTION – RUNOFF & EROSION – LEACHING

WATER QUALITY • 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

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

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

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

SOIL WATER – ADHESION and COHESION • 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

SOIL WATER – CAPILLARY ACTION • 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 – The SMALLER the PORES the GREATER the MOVEMENT of WATER v UP and DOWN v SIDE to SIDE • Any DISRUPTION in the CONTINUITY of CAPILLARY WATER will stop its FLOW

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

SOIL WATER • WATER RETENTION – DIRECTLY influenced by SOIL TEXTURE • COARSE TEXTURES soils – Holds the LEAST WATER • 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 – 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 – 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 – 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 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 • TEMPORARY WILTING POINT • PERMANENT WILTING POINT • Most plants AVOID WATER STRESS by …. . ? ? ?

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

SOIL WATER • MEASURING SOIL WATER – TENSIOMETER • Liquid filled TUBE with a POROUS clay TIP on one end a VACUUM GAUGE at top • 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 • MEASURES ELECTRICAL CONDUCTIVITY of soil