Plant Growth Promoting Rhizobacteria (PGPR), its Effect on Turfgrass

Discussion in 'Organic Lawn Care' started by ICT Bill, Nov 13, 2008.

  1. ICT Bill

    ICT Bill LawnSite Platinum Member
    Posts: 4,116

    A study from 2006, of interest. This is not our product but one very similiar, they do not use mycorrhizae in their mix and I am not sure they are still around. We are expecting the same type result from our plots with the University of Rhode Island. Anecdotally our plots are doing very well, we have to wait for the statistics.

    The product PGPR (Plant Growth Promoting Rhizobacteria) was compared with a synthetic and an organic fertilizer for its effect on turfgrass quality, growth response, and nutrient uptake. The trial was conducted on a USGA specification sand based putting green located at Olds College, Olds,
    Alberta.
    The PGPR product produced better turfgrass quality than the untreated control on seven of the eight rating dates, although it was only statistically different on the final rating date (table 1). Generally, the PGPR was equal to the fertilized treatments in spite of the fact that there was no nutrient value to the product.
    The plots treated with PGPR had a better growth response, as measured by clipping yields, than the untreated control on each rating date and was significantly better on three rating dates (table 2). The PGPR produced clipping yields that were statistically similar to three of the four fertility treatments, Milorganite at 0.6 and 1.0 kg N/100m2 and the Contec at 0.6 kg n/100m2.

    When compared with the untreated control plant nutrient values were significantly higher for nitrogen, phosphorus, potassium, copper and magnesium when the PGPR product was applied (table 3 and 4).
    Calcium was considerably higher for the PGPR treatment, but it was not statistically different. The plant nutrient value for potassium in the PGPR treatment was equal to the high rate of Contec which had 0.5 kg K/100m2 added to the plots. These results would indicate that the PGPR promoted nutrient availability and uptake.

    Full paper is here http://ptrc.oldscollege.ca/pdf/PlantGrowthRhizo.pdf
     
  2. DUSTYCEDAR

    DUSTYCEDAR LawnSite Fanatic
    from PA
    Posts: 5,137

    thanks for keeping us up to date
     
  3. ICT Bill

    ICT Bill LawnSite Platinum Member
    Posts: 4,116

    what was most interesting about it was the NPK was the same or higher in the soil test

    WAIT A MINUTE...... there was no NPK applied???? just beneficials

    YEP nutrient miners, phosphorous miners, good guys that make nutrients available
     
  4. growingdeeprootsorganicly

    growingdeeprootsorganicly LawnSite Senior Member
    Posts: 766

    bill,

    wow! that was a great report....thanks for the link!

    .... if i wanted to have one of these really scientific unbiased ''UNIVERSITY'' studies for me what is the going $rate$ these days?
     
  5. ICT Bill

    ICT Bill LawnSite Platinum Member
    Posts: 4,116

    Great question, I am glad you are so interested in giving back to the community
    I would say ask your local University, great thing, you could give back to the community by supporting the University and they could test your theories

    It is a win win situation

    this is exactly what we need more of

    thank you for the question, actuallly a stunning report, microbes did better than fertilizers !
    Imagine, you may have data to begin supporting your theories
     
  6. Smallaxe

    Smallaxe LawnSite Fanatic
    Posts: 10,081

    " ...The PGPR produced clipping yields that were statistically similar to three of the four fertility treatments, Milorganite at 0.6 and 1.0 kg N/100m2 and the Contec at 0.6 kg n/100m2. ..."

    How does 0.6 kg of N/100m2 come out in lbs/k?

    " ...what was most interesting about it was the NPK was the same or higher in the soil test ..."

    That is why putting in the ammendments and structuring the soil is done B4 the soil test. Soil test are only a snapshot in time and will only show what's available now , rather than the potential of the soil.

    Soil tests are a diagnostic tools, that leads to, only treating the symptoms. Treat the disease first and see if the sympoms go away.

    Thanks for the confirmation. :)
     
  7. JDUtah

    JDUtah LawnSite Silver Member
    from UT
    Posts: 2,636

  8. Smallaxe

    Smallaxe LawnSite Fanatic
    Posts: 10,081

    Thanks JD, ... :)
     
  9. ICT Bill

    ICT Bill LawnSite Platinum Member
    Posts: 4,116

    I agree that a soil test is a snap shot only, I am not quite sure what you are saying about ammending first

    These were isolated plots, one got one ammendent and the other was treated completely different with another ammendment. These are 6 different plots all treated as an isolated plot with seperate treatments
     
  10. Smallaxe

    Smallaxe LawnSite Fanatic
    Posts: 10,081

    The reason for study is to apply what is learned to the real systems of our businesses and our techniques of cost effective quality service to our customers.

    What was learned from this study? and how would one apply the results to his/her business?

    We discovered that pgpr made available nutrients that are in the soil. The no-input Control Plot did not show increase nutrient usage in 'all' of the tested elements, but this is the same soil. [for all practical purposes]

    The question is: Would a soil test from the pgpr plot be different from the control plot by the end of their season??

    Actually, there are a couple of interesting questions that come to mind regarding the interaction of soil, nutrient, bacteria, soil testing, and plants just from this one study; however the answer to the main question is - - 'It doesn't matter'.

    The reason a soil test doesn't matter, is because - it does no good to know what nutrients are "in" the soil, but rather what can you do to increase the "availablity" of the nutrients.

    First ammend the soil, (with compost is a good start) to increase availability, and if you are still scratching your head, wondering what is going on - then spend your time and money on a soil test.

    So even though the idea of this study confirming the necessity or not of soil testing, was NOT your intention in presenting it - it actually had that effect.
    Keep an eye on the big picture and it is much simpler to avoid confusion on the details.
     

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