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Watering Theory

Discussion in 'Pesticide & Herbicide Application' started by RAlmaroad, May 28, 2007.

  1. RAlmaroad

    RAlmaroad LawnSite Silver Member
    from SC
    Messages: 2,253

    On MY South Carolina lawn, I water on MWF and SAT. Sandy soil is like rain on a tin roof--inthat it drains so fast that the roots do not get a chance to absorb any moisture. I know that watering this often leaches the soil of fertilize. But the difference is a dead lawn or adding extra fertilizer to compensate for the leaching. As Ric stated, adding SOM to increase the water retention is a great way slow down the leaching. I have truck loads of SOM delivered and I sprinkle it over the lawn in the winter and the spring green-up works upwards to the light. Clay soils are like rain on pavement--it puddles and runs off. However, eventually it will settle into the soil after many weeks.
    Around Myrtle Beach, SC there are in excess of 100 golf courses. I see their rotors wetting the greens at night (3:00AM or so). I've been told that watering at night increases fungus (?) but it does allow the water to penetrate the turf and not be evaporated quickly as during the early morning. I'm still debating that one.
    So in the end, watering often and long may be a practice for those with shallow wells. Watering deep and less often in sandy soils knowing that the water is not going to be there in a few hours tells me that the turf roots did not get a chance to take in moisture versus, watering deep and often to allow the roots to take in moisture and leaching available nutrients is a dilemma. To have a beautiful lawn is costly on the coast....so I pay a few dollars for a little extra fertilize about every 6 weeks on Centipede grass which likes poor soil anyway. On the St. Augustine, I fertilize lightly with 15-0-15 every 4 weeks in the summer until August.

    Now for the biggest problem--Those no grass hurricane ditches????????No water, No SOM, pure sand, too much sun....Bermuda grass or even crab grass???
  2. Ric

    Ric LawnSite Fanatic
    Messages: 11,969


    I agree that on Coastal sandy we have a harder time than those on good hard pan developing good turf. Golf Courses are a totally different story in the fact they have the Big Budget and mow very short. The very fact that Golf Courses Mow so short creates many problems. Someone on here was very upset when I posted my price per Thousand price, But they have no Idea of my cost Per thousand cost on Calcareous Sandy Soil either.

    My Irrigation recommendation for Sandy soil is every 5 days. I like to water deep and hope the roots grow down to make more use of the water. But the true way to determine water need is by watching the Leaves to see when they need water. As the plant drys out the Leaf closes, By watching the leaf close you soon see when it is perfect time to water again.
  3. txgrassguy

    txgrassguy LawnSite Gold Member
    Messages: 3,083

    I am not aware of what area you are located in.
    Here in Central Texas, and the Austin area that Hess operates in we are subject to both voluntary and mandatory watering restrictions.
    What I have found to be the best way to encourage acceptable turf growth on predominately clay based soils is to aggressively aerify twice per year.
    Followed up with a heavy top dressing of sand then proper fertilization according to a decent soil/tissue test.
    Typically, due to water availability (which thankfully hasn't been a problem THIS year) and the restrictions based upon what environmental recharge zone our properties are in, irrigation is limited to approximately twice per work week.
  4. Firm believer in watering deeply but infrequently!

    wait until the turfgrass is beginning to show stress, then water until the soil is wet to the depth of grass plant's roots, but don't apply more water per hour than the soil can absorb
  5. Runner

    Runner LawnSite Fanatic
    Messages: 13,497

    ^And yet another speaks who is DEFINITELY not to be undermined nor underestimated....^(Thanks, Tim) ...Again,...one of those who has probably forGOT more than I even know! :)
    I'm sorry, but coming on this site and asking questions about turf (and related subjects), and being answered by these guys is equated to going on a site like web MD and being answered personally by a physician. This is not to take away from those with doctorate degrees, but it is the truth.
  6. RAlmaroad

    RAlmaroad LawnSite Silver Member
    from SC
    Messages: 2,253

    The truth has been told! Clay soils thatis. Don't you just love this soil--TN and VA. I think we could plant toothpick and grow trees.
    Since you know golf courses. What is the theory of water at night vs. early morning? Any truth to fungus development when watering at night?

  7. Ric

    Ric LawnSite Fanatic
    Messages: 11,969


    Great to see you posting again. I am Look forward to getting into some interesting discussions again.


    In most cases Golf Course have so many zones to run each night they must start early. It is more of a practical thing than wise Agronomy move.
  8. JoeinJasper

    JoeinJasper LawnSite Member
    Messages: 173

    The 'latest' research that I have seen is to water during the 'dew hours' when the leaves are already wet. What are your practical observations and experiences? While this does make sense, I would be interested in your opinions.
  9. txgrassguy

    txgrassguy LawnSite Gold Member
    Messages: 3,083

    Joe, when I ran a golf course in NE Pa several years past - I would "whip" the greens in front of a mower, and water just the greens during the day.
    The outlying turf was not subject to the intensive maintenance program the greens were subject too so I was able to avoid problems with this strategy.
    The idea of watering during the "dew" hours stems from the observation/hypothesis if you "wash" the guttated fluids which comprises the exudates from C3 turf, you are diluting these exudates to the point that they will not support/enable the ever present pathogens due to the high carbon content associated with these exudates.
    Several factors have to be aligned for a program like this to bear fruition.
    Namely the areas irrigated absolutely have to be free from permeability issues, typically have to located in areas of air movement beyond 4 cubic yards per second ( basically a wisp of a breeze) and have to be free of excessive soluble nitrogen applications which will supplant the guttated fluids as an energy source for the pathogens.
    What I have found to be the most "safe" as far as turf conditions verse labor has been to lightly water, aka "syringe" the greens 3 to 4 days out of the week, regardless if they are C3 or C4 turfgrass, then irrigate up to 1/2", whip then mow.
    I have found an amazing correlation of maintenance practices of most varietal types of Agrostis spp putting greens and the newer Ultra-dwarf Cynodon spp.
  10. muddstopper

    muddstopper LawnSite Silver Member
    Messages: 2,341

    I am just going to throw this out there and see if someone wants to better explain it.

    According to some agronomists, raising Mg saturation levels in sandy soil will help maintain moisture in the soil. Israel did several studies in the 90's that suggested that magnesium has the ability to actually attract moisture, even pulling moisture from the air. I dont have a copy of that study, wish I did. Anyways, it would seem that manageing fertility levels would also help to manage water use. Comments please.

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