Soil Conditions Matter???

Discussion in 'Organic Lawn Care' started by Smallaxe, Jan 31, 2013.

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  1. Skipster

    Skipster LawnSite Bronze Member
    Messages: 1,086

    You don't think that there may be differences in disease incidence between different turf species or different management practices? You should learn more about plant culture, then rethink this statement.

    BTW, the scientific literature has documented quite thoroughly the different affinities of the Pythium spp and the impact of management practices, such as mowing height.

    I'm not saying they were intentionally misleading. But, I think their research is incomplete. Did you actually read the paper?

    My quick calculations (I just eyeballed it) came out to about 5.5#N/M, but the math shakes out to 4.6#N/M. In the early 1990s, most golf course superintendents were using about 2.0 to 2.5#N/M/yr on creeping bentgrass, so the rate the paper used was closer to 2X. Today, many supts are using 1.75 to 2.0#N/M/yr, which gets us closer to 2.6X. Not bad for eyeballing it, I think.

    Either way, it makes sense that the untreated control would have more Pythium than the compost plots, since its N was delivered as soluble N, while the N in the treated plots came from the compost.

    This is where knowledge and understanding really come in (and where you show us that you don't have it). Pythium activity is increased by available mineral N. When you compare a plot fertilized completely with soluble mineral N to a plot fertilized with insoluble immobilized N, you have the same total N application, but a completely different environment for disease growth.

    A more complete and more accurate comparison would have been to use the same amount of soluble N in all plots. But, this did not happen.

    If you're going to use research, you have read it, understand it, and have the ability to think critically about it.

    You should read the paper.
  2. phasthound

    phasthound LawnSite Fanatic
    Messages: 5,165

    I already gave you my answer to your question.
    Please explain why you think allowing the top inch to dry out will overcome the platy structure of clay. And why you think that will do so without any other procedures.

    There is no "bashing" in this post so I would appreciate it if you would discuss your own question without allowing other opinions to get under your skin.

    The drawback of the OBE strategy in the gov'tt school system is that the outcomes are ensured without an understanding as to how those outcomes(conclusions) were reached... The notion of "let's think this through" is completely foriegn ,,, isn't it???

    Just stay on tract, you are only disrupting your own discussion with comments like that.
  3. turfmd101

    turfmd101 LawnSite Bronze Member
    Messages: 1,376

    Soil is so importante, it's the only thing separating us from the rock we live on.

    I don't think smallaxe implied, drying out the surface without any mechanical requirement for success is most possible. Just most healthy. I deal with Florida central soil. Not much soil or clay compacts. But I can imagine your situation for I have 2 sons who have played baseball 7 years each. I would imagine you guys have to use spike mower tires or spiked weighted rollers. I'll bet the surface would get hard pan.
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  4. phasthound

    phasthound LawnSite Fanatic
    Messages: 5,165

    I'm confused as to what he may or may not be implying. Just looking for some clarity.
  5. Smallaxe

    Smallaxe LawnSite Fanatic
    Messages: 10,082

    I have my ground set up with reasonably thick turf but with blank zones or barespots,,, some about the size of a tennis ball... these barespots have grass clippings covering the clay loam topsoil... not greasy clay, but it is a loam with adequate OM and sand mix to create structure...
    That's the starting point...

    Now if I kept the surface of the soil moist, all growing season with irrigation,,, that means I could go onto the turf at anytime and scratch away the brown clippings on the barespot and the ground would be moist... even though the grass is dry, those barespots would be holding moisture right under the grass clippings... this isn't sand so I should take a look into the root zone and see how much moisture there is in the top 3" or 4" of topsoil...

    I find that when the surface is wet, there is very little air in the root zone... the structure is fairly homogenous and could easily be considered greasy as a result...(remember this: grab a handful of dirt, squeeze it into a ball, then poke it with your finger and it should bust up into crumbles)???
    Well that wouldn't happen with a clay loam that doesn't really get adequate air...

    Remember the article from "Clay Platelets" thread had listed the Wet/Dry cycle as being one way that structure is formed, along with freeze/thaw cycle...
    For that reason alone I have no problem letting the grass soils dry for a week or so, before turning on the irrigation again... afterall, if my turf is going to "stress out" in a week then I have bigger problems...
  6. Smallaxe

    Smallaxe LawnSite Fanatic
    Messages: 10,082

    The other thing about allowing the surface to dry out is to promote the health and well-being of the aerobic microbesin the soil... we know if the soil is dry the anaerobic microbes are NOT going to thrive and brief periods of dormancy in the aerobic microbes will not hurt a thing...
    Pathogenic microbes such as lawn diseases are much more likely to thrive if the aerobic microbes are continuously stifled in their growth...

    So,,, for those 2 reasons I believe that allowing the soil surface to dry out once in a while, or often, is superior as a "cultural practice" to always keeping the soil damp...
    The conclusion for me is that when the phrase "Proper Irrigation" is used,,, it is refering to allowing the surface to dry...

    I gave 2 reasons as to why I believe what I believe... what reasons are for the other side??? :)
  7. Kiril

    Kiril LawnSite Fanatic
    Messages: 18,335

    Hmmm, putting words in my mouth again.

    By all means, please provide some credible cites, in particular, with respect to compost suppression of the disease at different mowing heights.

    Also skip .... with respect to pythium, proper water and soil water management are more important than cutting height .... but of course you already knew that. And of course we won't mention the importance of nitrogen application timing or the fact that lush growth is more susceptible.

    Actually skip, that is exactly what you said. FYI, the point in all this was to show you hadn't read the papers you claimed to have read, you know, given your remarkably ignorant statement.

    Says you. I asked for data, not more declarations of supposed "truth" from you. By data, I mean credible data, not made up skipster data for irrelevant points.

    And you claim to have read this paper? Where did they state the type of N used?

    From material and methods:

    All greens were
    mowed three times a week at a 5-mm cutting height. In 1991 and 1992, total
    amounts of nitrogen applied were 178 and 215 kg/ha, respectively. In 1993, a total
    of 225 kg of nitrogen per ha was applied. No pesticides were applied at any time
    during the 3-year experimental period.

    This isn't the first time you have been caught intentionally misrepresenting cited literature.

    Further, perhaps you can explain how N rates or type of N make a difference with respect to the objective of the study?

    The purpose of this study was to investigate the mech-
    anisms by which a variety of composted amendments suppress
    P. graminicola-incited damping-off and root rot of creeping
    bentgrass and to determine the role of compost microbial
    populations and activity in disease suppression.

    What was it you were saying about understanding? BTW, I am still waiting for that name of conventional fungicide they supposedly tested against and used at 10% the label rate. Why don't you provide a quote from the paper.

    Amusing given what you just said. So we have more misrepresentation of the literature. BTW skip, how about providing some peer reviewed literature to substantiate that last statement.

    And more misrepresentation. You are really struggling here skip.

    Hmmm, yes indeed skip ..... all of which you have NOT accomplished here. You keep saying something about reading the study when you clearly have not, and are intentionally misrepresenting the study and accusing the authors of manipulating the study to produce a desired result. Reprehensible doesn't even begin to adequately define your behavior here.
  8. Kiril

    Kiril LawnSite Fanatic
    Messages: 18,335

    There are good reasons for allowing the surface to dry between irrigation events, none of which you have mentioned. The stuff you have mentioned are mostly inaccurate assumptions and opinions with little to no basis in fact. Further, "proper" irrigation has nothing to do with soil moisture at the surface.
  9. Smallaxe

    Smallaxe LawnSite Fanatic
    Messages: 10,082

    Here is a good example of what I've been talking about... response meaning:
    I was wrong on 2 things, but no explanation why... one of my mistakes was agreeing with the MO extension office... :laugh:

    and now we are to believe that moisture in the soil has nothing to do with "proper irrigation"... perpetual wet surface is Improper irrigation and anyone that allows it to continue is NOT a turf manager... that's my definition,,, at least in part... OH MY,,, I bet that's wrong too... what a joke...

    Don't tell me that OBE isn't relevant to the remarks in this thread... is anyone going to comment further if their discussion points don't meet with kiril's approval??? snide remarks from the plumber that are without rational patterns of understanding,,, is exactly what OBE is all about... what information did kiril actually put forth??? none... derision is not information... :)
  10. Smallaxe

    Smallaxe LawnSite Fanatic
    Messages: 10,082

    We're up to post 100 and what headway was made in the conversation about soil structure... I'm to stupid to talk to so I guess it doesn't matter... :)
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