What about Soil Microbes?

Discussion in 'Organic Lawn Care' started by Smallaxe, Mar 15, 2009.

  1. Smallaxe

    Smallaxe LawnSite Fanatic
    Posts: 10,080

    We hope we are feeding the beneficial microbes, when we spread molasses/sugar on the lawn. When we spread high volume water soluable N onto a soil; are we infact feeding the disease microbes?
    (As in the case of, 'Brown Patch', for exa.)

    We know that many other bacteria/fungi use N in their metabolism as well.
    Could it be that high N allows certain disease fungi to become 'so well fed and strong', that they are able to eat more than just dead tissue, but are able to overcome the defenses of living tissue as well? Especially when the living tissue was previously weakened?

    Of course all bacteria/fungi love water. :)
     
  2. bicmudpuppy

    bicmudpuppy LawnSite Silver Member
    Posts: 2,781

    By "brown patch", are you referring to anything in the lawn that resembles a disease "patch"? Or one of the species of rhizoctonia? Yes, some varieties of rhizoctonia benefit from excessive N, but many of the more common pathogens in the lawn thrive under low N conditions. Dollar spot, many mildews and rusts are in this list. I've never seen rhizoctonia on turf with a HOC above 1". I understands it happens, but I have never seen it. Dollar Spot on the other hand runs wild in 2-3" grass before it migrates to shorter turf. My best treatment for Dollar Spot is .25-.5#N/m. A sulfur or lime treatment will have the same results. Sulfur or Lime (make a 1/2pt change in surface PH) will control many active pathogens in turf. The key is to KNOW your enemy. Healthy turf is the goal and healthy turf is more disease resistant and therefore easier to maintain.
     
  3. NattyLawn

    NattyLawn LawnSite Bronze Member
    Posts: 1,643

    To become an issue you need the plant, the disease, a food substrate for the disease and cultural conditions for the disease to thrive. I think by adding molasses, you're feeding the good guys (and adding them) as well as the bad guys. You're keeping the balance. Throw high N into the mix and when you have the conditions listed above, disease can thrive.
     
  4. Smallaxe

    Smallaxe LawnSite Fanatic
    Posts: 10,080

    That is an intersting thought. Many diseases in the human body are given freedom to rule or be stopped - based on pH of the body.

    I also agree that the 'tested pH' could be differentiated from the surface pH allowing the disease to flourish.

    Remember, this is a benficial bacteria/fungi vs. the disease versions, of the same critter.

    Here, in Wisco, we have a propensity toward an acid soil. The disease fungi will get their boost from the - cool, moist weather - of an average spring.
    In your opinion: Is it reasonable to assume that - alkalizing the surface - would help the situation here.

    I am not asking that you go out on a limb and - make a claim - Only that you offer what you understand your knowledge to mean. :) thanks for your input.
     
  5. Smallaxe

    Smallaxe LawnSite Fanatic
    Posts: 10,080

    Adding molasses will also tie up the N for a period while the population grows. As the population grows it feeds the plant , the N, through its dead bodies.

    So we've cut off the excessive N and turned it into more of a gradual feed of N to both the the grass plant and the fungal plant.

    Does that make sense to you or do you have an alternative POV?
     
  6. ICT Bill

    ICT Bill LawnSite Platinum Member
    Posts: 4,115

    Using this practice you will eventually have a site that looks like you have killed the grass, everything turns brown.

    What has happened is a huge bacterial bloom, they eat almost every nutrient available in the soil, after a couple of weeks you will have the greenest lawn you have ever seen but it will scare the hell out of you at first

    Our tea will do the same if you grow it out for a short period, 12 hours or less, and apply to turf. That is why it should be added at the end of a brew or brewed for at least 24 hours so it can calm down

    We have had 2 brown turf phone calls both brewed for a short period, both said the whole neighborhood wanted to know what they had used a week or 2 later, it is the greenest thing you have ever seen
     
  7. Smallaxe

    Smallaxe LawnSite Fanatic
    Posts: 10,080

    I don't know that I would put down that much molasses or tea, but I see what you are saying.
    Thanks for running through that line of thinking with me. :)
     
  8. bicmudpuppy

    bicmudpuppy LawnSite Silver Member
    Posts: 2,781

    This type of control goes back to my youth working for an old man who definitely forgot more than I will EVER know about growing quality turf. Our absolute worst nightmare for disease was Pythium blight, and the cures that worked were short term and expensive. We would do a light lime dusting with drop spreaders at the very first sign of disease. This is on bentgrass greens in KY, The Ohio River Valley (90%+ Humidity year round). Greens in an area where neither the water or soil are naturally basic need lime anyway. We held off on heavy lime applications until fall when the weather "turned". Any lime we used in the summer was subtracted as having already been applied. A light dose of fertilizer has the same affect. The goal is to change that micro climate of the thatch layer where the detrimental pathogen is working and traveling.
     
  9. bicmudpuppy

    bicmudpuppy LawnSite Silver Member
    Posts: 2,781

    Bill, I've got ONE green that shows signs of EXACTLY what you have described above. I was afraid it might be winter damage. This is an area where I was expecting some winter damage. The other 20 greens look really good. They have all been treated the same by ME. The green in question was shoveled clear right after our Christmas snow while I was gone for 4 days. The following morning after they cleared the snow, we had a 6 degree low. Would that type of "hit" have affected the bacillus in a negative sense and the molasses treatments I have put down now have caused what I am seeing? Not asking for a guaranteed diagnosis via virtual reality, but just an opinion? It has seemed to get worse over the last few days. Anything I could look for that would tip me off? Can the bacillus steal enough N in that short of a period to actually cause dessication? or am I looking for a very positive turf response in a matter of days? I have applied 3 applications of molasses about 1 week apart. The rate was just over 2 gal/A the first two times, and 1 gal/A with the last app. I am due to repeat the app again tomorrow. I may put it off a few days. Thanks for the input.
     
  10. DUSTYCEDAR

    DUSTYCEDAR LawnSite Fanatic
    from PA
    Posts: 5,137

    do you have a pic of the green?
     

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