Water Transpiration or Water water everywhere and all

Water & Transpiration or Water, water everywhere and all the boards did shrink. Water, water everywhere and not a drop to drink.

Potential Evapotranspiration/ Las Cruces PET = evaporation + transpiration from a crop under non-stressed conditions • Adjusted to a ‘reference crop’ (grass) • Crop coefficient (k. C) = ETC / ETO • Function of T, RH, season, leaf area, shading, crop species, soil moisture

Las Cruces Potential Evapotranspiration Water (in/d)

Trees and Water… Turfgrass Actual Water Use / Farmington NM/ D. Smeal Warm Season Cool Season

Trees and Water… Turfgrass Actual Water Use/ Farmington NM /D. Smeal ET (in/d). 25 Cool Season Warm Season . 15 Late, Warm Season . 05 Apr Jul Oct 100 200 300 Julian Days

Trees and Water… How often should new trees be watered? Days without water (no. ) Time since transplanting (d)

Irrigation Scheduling-nonstressed Fancy formula: • PAW = AWC x MAD x RZ • Sooo, Plant Available Water = soil Available Water Content x Maximum Allowable Depletion x Root Zone depth

Pecan Water Use/ Sammis et al. . 75 Irrigation A B C . 50 in/d. 25 Budbreak

Water & Transpiration Irrigation & Water Management • Evapotranspiration: water loss through evaporation and transpiration – Yearly ET: – Yearly Ppt: – Deficit: ~ 200 cm ~ 20 cm ~ 180 cm • Daily ET (cm/d) Mar 0. 13 Apr May Jun Jul Aug Sep Oct 0. 25 0. 41 0. 61 0. 71 0. 61 0. 41 0. 20

Water & Transpiration Irrigation & Water Management • Goals of Irrigation: – Meet the needs of the plant – Minimize runoff • erosion • chemicals – Minimize evaporation – Manage leaching • salts • NO 3

Water & Transpiration Irrigation & Water Management • When to Irrigate? – Observe plants--too late! – Observe soil--’touchy-feeley’ – Measure soil or plant water stress • tensiometer • pressure bomb • leaf temperature – Estimate water use • evapotranspiration * neutron probe * electrical resistance

Water & Transpiration Irrigation & Water Management • Reducing Water Use in the Landscape – Goal: Reduce evaporation • water at night or early morning • water deep to develop deep rooted plants • apply 5 cm organic mulch to cool soil – Goal: Put the water where you want it • directional sprinklers • berms or swales

Water & Transpiration Irrigation & Water Management • Reducing Water Use in the Landscape – Goal: Use low water plants • xeriscaping • plant breeding • not ‘zeroscaping’ – Goal: Improve irrigation efficiency • drip irrigation • sub-irrigation

Things to Know • • • Colligative properties • Hydrologic cycle • Irrigation • Solvent • Solute • Field Capacity • Permanent Wilting Point • Water Use Efficiency Potential Evapotranspiration Turgor Wilting MAD RH AWC Water Potential Xeriscaping

Water & Transpiration Factors Influencing Transpiration/ Musk mallow leaves Base of Plant Top of Plant

Water & Transpiration Heat of Fusion/Frost protection in vineyard 495 L/min/ha 103 L/min/ha

Water & Transpiration Heat of Vaporization/ Peach bud bloom delay

Water & Transpiration Factors Influencing Transpiration/ Light, T, H 2 O Citrullus colocynthis Excised leaf Air T Intact leaf