Watering practices and nutritional leaching test?

Discussion in 'Organic Lawn Care' started by JDUtah, Jun 19, 2008.

  1. JDUtah

    JDUtah LawnSite Silver Member
    from UT
    Messages: 2,636

    Today I was not out in the field as I am waiting for the back to calm down (I know I am WAY to young for back problems but they are there). Anyways, I did some reading out of a textbook from a botany class I took a couple years back and also some reading of a great article about “Mineral Nutrient Depletion in US Farm and Range Soils”. http://www.americanlongevity.net/misc/mineraldepletion.php and it got me thinking. I’m lying in bed and the brain isn’t shutting off. I doubt it will until I get this idea recorded, so for now I am using this post as a journal of an idea that I would love to perform a test on sometime.

    The idea is related to watering practices for turf and what they really do, not only in root growth promotion, but in soil fertility.

    To start there is the common idea that to encourage grass roots to grow deeply you need to water deep but infrequently. The roots do not necessarily look for the water but they can grow in the right environment. So the idea is when you have control over the environment, try to create the right environment to occur as deep in the soil as the grass roots can tolerate, thus they will be less affected by drought situations should they arise.

    This is where the reading comes in. In both the article and the textbook reading it talks about the minerals in the soil leaching. The textbook reads, “In desert areas, for example, there is little weathering by rain, and soils are poorly developed. In areas of moderate rainfall, however, well-developed soils are common. In some areas of high rainfall, the excessive flow of water through the soil may leach out important minerals. Similar leaching out of important minerals may occur when garden sprinklers are left on all night.”

    The article reads similar, “Soil erosion is particularly devastating on older, more highly weathered soils in the southeast U.S. since the supply of tiny nutrient-rich primary minerals is already limited. Erosion removes the soil organic matter where much of the soil's nutrient reserve exists. Soils that are low in organic matter, or have lost much of it through erosion exhausts the soil's native nitrogen supply quickly compared to soils unaffected by erosion or low organic matter. Erosion of soil organic matter not only causes nitrogen loss, but also loss of other nutrients, including sulfur and boron.”

    The questions begin here. Does deep watering encourage deep roots strictly because of water availability or are the roots more prone to develop lower because the nutrients are leached deeper into the soil? If the leaching of nutrients is a factor, those southeastern states (which the article claims has more mineral leaching problems) would generally find deeper roots than comparable moisture environments with nutrient soil ready available on the surface. That would explain why out here I do not seem to find grass roots much deeper than 4-6 inches even with deep and infrequent watering practices, but I hear of people in Florida who find roots down to 2 feet? (Of course grass variety plays a factor but i think the queston is worth ignoring that debate for now…)

    Perhaps the watering is also affecting the depth of soil fertility which in turn affects root growth depth? How can one test this?

    Basic concepts of test… partition a plot into 3 zones of equal fertility and soil structure. Keep all variables the same except the watering variable. I would recommend not adding any form of fertilizer during the test period. On one zone, water the traditional 10 minutes every day, on the other water the new idea of 45 minutes 2-3 times a week (that’s the recent buzz time out here). On the third plot, test until you find the appropriate watering time that will allow 6”? of soil to be moist when tested 1 hour? after watering. Then only water that plot after the top 1”? of soil has completely dried out.

    Periodically test how deep the moisture is in each area. Continue this watering schedule for 2-3 years and at the end of the test measure soil fertility on each plot at different depths. (1-3”, 4-7” 12-15”?) Also determine root depth on each plot. Compare data.

    You can even set drought conditions and test actual plant ressilience.

    I think it would be an interesting test; my theory is that the third plot would have the least amount of nutrient leaching (comparable to plot 2) with more tolerable root depth than plot 1.

    Anyways I do need to sleep and this is enough recorded to refer to and expand on later. Any input or ideas to refine the theory and test idea? Happy dreams.
  2. Smallaxe

    Smallaxe LawnSite Fanatic
    Messages: 10,082

    Watering 'deeply and infrequently' is a relative phrase. Relative to soils, temps, wind etc.,etc.
    Soils that I have seen, typically dry from the surface - down. Roots run out of water at the surface, but the roots deeper in the soil continue to grow. People are to afraid to let the grass dryout for 2 days, let alone to the point of actual 'infrequency'.

    If you consider your lawn and the root depth of 4", for example, then any water the saturates and percolates below that 4" is 'leaching' nutrients away.

    See a good Chiroprator, as opposed to seeing a quack, and get the back to heal correctly. If you are too young for back problems you do not want to spend your life in surgery. My biggest problem was actually posture while working in that the muscles were not working together as they were designed to. Be careful of your choice however. Many Chiropractors are unclear of the concept and do stupid useless things like 'clickers'.
  3. treegal1

    treegal1 LawnSite Gold Member
    Messages: 3,911

    acupuncture and a good seat. mom used to say sit up your going to hurt your back.
  4. DeepGreenLawn

    DeepGreenLawn LawnSite Silver Member
    Messages: 2,372

    I have a thought...

    When you spray your teas, you are to use dechlorinated water correct? Why is it not mentioned and practiced to use dechlorinated water when watering your organic soil. Is it not still killing the good guys? Or does it get filtered on the way down?
  5. k911lowe

    k911lowe LawnSite Senior Member
    Messages: 526

    my moms point also.the only trouble with acupuncture is you have to keep going.its not covered by insurance and gets to be quit expensive.back problems are cause by who knows?you need to see a specialist to take care of it.sometimes a shot in you're spine will take care of it.took care of mine,had to go for 3 of them.its the same thing they give pregnant women sometime for pain.i think its called an epidural..
  6. Smallaxe

    Smallaxe LawnSite Fanatic
    Messages: 10,082

    I don't have any lawns with chlorinated water so I don't really know about that. It does evaporate quickly, degrades in sunshine and isn't that concetrated in the drinking water. Your stomach runs on bacteria and enzymes as well.
  7. Kiril

    Kiril LawnSite Fanatic
    Messages: 18,335

    One quick item to point out for your test. You will not get any results you can rely on unless you can ensure the irrigation system is operating at the same efficiency on all 3 plots.
  8. JDUtah

    JDUtah LawnSite Silver Member
    from UT
    Messages: 2,636

    What do you mean Kiril? The point of the test is to see what different irrigation techniques do to the soul. Oh, nevermind, you mean make sure each has the same constant X water per area per amount of time? Thanks
  9. Kiril

    Kiril LawnSite Fanatic
    Messages: 18,335

    IMHO, you can just skip the test and get Mr. Lincoln to set your schedules, or use soil moisture sensors and/or ET values to control your irrigation. :)

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