Published on February 14, 2008
Slide1: Best Management Practices for Florida Turfgrasses – Fertility and Cultural http://turf.ufl.edu Slide2: http://turf.ufl.edu Benefits of Turfgrass: Benefits of Turfgrass Functional Benefits Soil Erosion Surface Runoff Abatement Dust Stabilization Heat Dissipation Noise Abatement Glare Reduction Air Pollution Control Aesthetic Benefits Quality of Life Mental Health Safe Play Area Community Pride Increased Property Values Compliments and ties together the rest of the landscape St. Augustinegrass(Stenotaphrum secundatum): St. Augustinegrass (Stenotaphrum secundatum) Advantages Good shade tolerance Good salt tolerance Tolerant to wide range of soil pH Establishes quickly from sod Dark green color Slide5: Disadvantages Poor cold tolerance Poor drought tolerance Poor wear tolerance Forms excessive thatch Susceptible to chinch bugs St. Augustinegrass (Stenotaphrum secundatum) Slide6: St. Augustinegrass Cultivars Floratam no longer chinch bug resistant poor cold and shade tolerance Floratine finer texture, denser growth tolerates some shade Classic claimed to have excellent shade and cold tolerance – is this true? Palmetto not as drought or shade tolerant as claimed to be Slide7: St. Augustinegrass Dwarf Cultivars Delmar good shade and cold tolerance does well in full sun Amerishade good shade tolerance less frequent mowing required (2 weeks in summer) tends to suffer freeze damage outgrows injury slowly because of slow growth habit Bahiagrass(Paspalum notatum): Bahiagrass (Paspalum notatum) Advantages Good drought tolerance Low fertility requirements Low maintenance Tolerant of sandy, infertile soils Establishes from seed Bahiagrass(Paspalum notatum): Bahiagrass (Paspalum notatum) Disadvantages Produces abundance of seedheads Open growth habit encourages weed competition Susceptible to mole crickets Coarse stems are difficult to mow Not wear tolerant Components of best management practices: Components of best management practices Right plant, right place Fertility practices Irrigation practices Mowing practices Pesticide spraying Turfgrass Growth: Turfgrass Growth We want to encourage turfgrass growth to keep turf dense and vigorous BUT, too much growth means more mowing Our management practices should aim for a balance of steady, not excessive growth and good tolerance to stresses How we fertilize has a big influence on this What Does Turfgrass Growth Have to do With Preventing Pollution?: What Does Turfgrass Growth Have to do With Preventing Pollution? Healthy turfgrass that is vigorous will grow and provide a good ground cover that can reduce leaching and protect groundwater It will take up the majority of the fertilizer applied to it, as long as the fertilizer is properly applied Fertilization: Fertilization Goals of fertility programs: To minimize environmental impacts To produce healthy, stress-tolerant turfgrass Turfgrass Fertility Considerations: Turfgrass Fertility Considerations Fertilizer storage Soil testing How to properly apply fertilizer Fertilizer source (quick-release vs. slow-release) Application amount Application timing Fall fertility Fertilizer Storage: Fertilizer Storage Store fertilizer in areas protected from rainfall Load fertilizer away from wells or waterbodies Store nitrates away from flammable substances such as solvents, fuels, or pesticides Keep fertilizer and pesticides in a locked area Know Your Soil: Know Your Soil Soil testing should provide the basis for determining a fertility program This includes pH testing as well as extractable levels of macro and micronutrients Do not soil test for N, as it is very mobile Proper Fertilizer Application: Proper Fertilizer Application Be careful not to apply fertilizer particles onto sidewalks, roadways, or other impervious surfaces where they might wind up in the storm drain Proper Fertilizer Application: Proper Fertilizer Application Leave a “Ring of Responsibility” around waterways to reduce potential for surface water pollution when fertilizing Proper Fertilizer Application: Proper Fertilizer Application Use a deflector shield when fertilizing near water bodies- this will allow for a 3’ ring – without a shield, leave a 10’ ring Proper Fertilizer Application: Proper Fertilizer Application Irrigate fertilizer in with only enough water to move granules off of leaves (~1/4” water) Elements Required for Turfgrass Growth: Elements Required for Turfgrass Growth Macronutrients: Nitrogen Phosphorus Potassium Calcium Magnesium Sulfur From Environment: Carbon Hydrogen Oxygen Micronutrients: Iron Manganese Boron Copper Molybdenum Zinc Nickel The Fertilizer Bag: The Fertilizer Bag Numbers refer to percent nitrogen, phosphorus, potassium in the bag Example: 15-0-15 has 15% N, (or 7.5 lbs. in a 50 lb. bag) 0% P, 15% K as K2O5 Nutrient sources also listed Nitrogen: Nitrogen Balance turf nitrogen needs with: time of year nitrogen source grass species too little or too much nitrogen can both have harmful effects on the turf Nitrogen: Nitrogen Before determining fertilization program, you should take into account the following: Customer’s level of desired lawn quality Customer’s ability to maintain lawn Turf species Nitrogen Fertilizer Sources: Nitrogen Fertilizer Sources Urea Water soluble quick release High N content (46%) Subject to volatilization, or loss of N to the air if not watered into the soil Irrigate in with ¼” water- too much water can cause leaching Applied as liquid or granules Nitrogen Fertilizer Sources: Nitrogen Fertilizer Sources Ammonium nitrate and ammonium sulfate Water soluble quick release AN (33.5% N) AS (21% N) High salt index and burn potential Ammonium sulfate acidifying May be used in liquid or granular form Nitrogen Fertilizer Source: Nitrogen Fertilizer Source Sulfur coated urea N release controlled by coating thickness Best responses occur with use during hot, rainy summer weather Spreaders can damage coating, producing uneven responses Nitrogen Fertilizer Source: Nitrogen Fertilizer Source Resin or polymer-coated urea Release controlled by diffusion Faster release in high temperatures If We Apply Too Much Nitrogen: If We Apply Too Much Nitrogen Excess shoot to root growth Thin cell walls Lush growth may make turfgrass more susceptible to insects, disease Turf that less easily tolerates environmental stresses Potential for scalping (removal of too much shoot tissue at one time) due to greater growth rates If We Don’t Apply Enough Nitrogen: If We Don’t Apply Enough Nitrogen Lawns unable to out-compete weeds Less shoot tissue Less root tissue = less ability to forage soil for nutrients & water Chlorotic yellow shoot tissue Leaching Potential: Leaching Potential Quick release sources that are properly applied will not leach anymore than slow release sources The potential for leaching due to misapplication is greater with soluble sources Application Amount: Application Amount Depends on percentage slow-release N No more than ½ lb. N 1000 ft2 if quick-release Up to 1 lb. N 1000 ft2 if slow-release Better to apply smaller amounts more frequently for optimal physiological functioning of turf Application Timing: Application Timing Warm-season turfgrass growth based on temperature AND daylength May be able to reduce N applications during summer growth (use iron to stay green without the growth) Also varies due to location in state, soil types, and turfgrass species Fall Fertilization Issues: Fall Fertilization Issues How should we fertilize in the fall? Fall K can be beneficial Varies with grass species and location in the state What about route-based businesses and winter fertilization? Current UF/IFAS Fertility Recommendations(lbs. N 1000 ft-2 yr-1): Current UF/IFAS Fertility Recommendations (lbs. N 1000 ft-2 yr-1) St. Augustinegrass: North FL: 2-4 Central FL: 2-5 South FL: 4-6 Current UF/IFAS Fertility Recommendations(lbs. N 1000 ft-2 yr-1): Current UF/IFAS Fertility Recommendations (lbs. N 1000 ft-2 yr-1) Bahiagrass: North FL: 2-3 Central FL: 2-4 South FL: 2-4 Current UF/IFAS Fertility Recommendations(lbs. N 1000 ft-2 yr-1): Current UF/IFAS Fertility Recommendations (lbs. N 1000 ft-2 yr-1) Centipedegrass: North FL: 1-2 Central FL: 2-3 South FL: 2-3 How Much Phosphorus Do We Need in Florida?: How Much Phosphorus Do We Need in Florida? P fertilization should be based on soil test results If a soil test indicates P is adequate in soil, use a fertilizer with no more than 2% P P may be required in greater amounts during establishment of lawns Potassium Provides Increased Tolerance to Many Stresses: Potassium Provides Increased Tolerance to Many Stresses Helps turf maintain water balance Functions in cellular activities such as photosynthesis Can enhance cold tolerance and spring green-up Other Considerations for Fertility: Irrigation: Other Considerations for Fertility: Irrigation Even if fertilizer is applied at proper rates, too much water following fertilizing can result in leaching or runoff Irrigate fertilizer in with ¼” of water Don’t fertilize during a heavy rainfall Fertility Under Drought Conditions: Fertility Under Drought Conditions Grass growth is reduced during drought You don’t want to try and push growth on drought-stressed grass, so fertilizer needs are reduced Best to postpone fertilization or reduce amount applied Slow-release N is better, as it will provide more regulated growth It’s raining out- should we leave the sprinklers on?: It’s raining out- should we leave the sprinklers on? An efficient watering program must include: How frequently to water how much to water time of day to water How Often to Water: How Often to Water The most efficient way is to apply water when turf begins to show signs of stress: bluish gray color footprints remain leaf blades folded in half How Much to Water: How Much to Water An efficient watering only wets the turfgrass root zone, does not saturate the soil, and does not allow water to run off. Apply 1/2” to 3/4” when turf shows symptoms of wilt and do not apply any more until water stress symptoms are again noticeable. Slide46: Short, frequent irrigations Longer, less frequent irrigations Time of Day To Water: Time of Day To Water Wet grass = disease opportunity Dew point should not be extended – grass must dry out Best time to water is just before or at sunrise Irrigation System Efficiency: Irrigation System Efficiency One of the most important things to do during a drought is to check the efficiency of your irrigation system Slide49: Mowing Don’t mow grass when wet Keep mower blades sharp! Mowing: Mowing Mow at highest recommended height for species Don’t remove more than 1/3 of the leaf blade at any one time Leave clippings on the ground Increase mowing height under any environmental stress (shade, drought, etc.) Slide51: Influence of mowing height on rooting depth Mowing Under Drought Conditions: Mowing Under Drought Conditions Grass growth is reduced during drought, but you should still mow at the same frequency- you will just have less shoot tissue to mow off Mow at the highest recommended height for your grass. This will help to encourage a deeper root system and place less stress on the grass Keep your mower blades at their sharpest to further reduce stress on the grass How Do I Manage Turf in the Shade?: How Do I Manage Turf in the Shade? Remove shade sources (trimming trees) Reduce traffic in shaded areas Increase mowing height if possible – more shoot tissue for photosynthesis will help turf perform better Reduce irrigation in shaded areas Reduce fertilization – trying to promote shoot growth with high fertility will further stress the grass Shade Tolerant Turf : Shade Tolerant Turf St. Augustinegrass = zoysiagrass Centipedegrass Bahiagrass Bermudagrass = Seashore paspalum St. Augustinegrass Shade Tolerance: St. Augustinegrass Shade Tolerance Seville, Delmar, Bitterblue Palmetto Floratam Slide57: This slide set was developed by Laurie E. Trenholm, Ph.D., Urban Turfgrass Specialist at the University of Florida. Thanks to the following for their review: Pamela Mattis Celeste White Erica Santella Jennifer Leggett Mike Thomas
Bermuda sod layed over sand? ... http://www.dep.state.fl.us/central/Home/MeetingsTraining/FLGreen/TurfBMP81704.ppt Check this PP presentaion out.