Please critique

Discussion in 'Pesticide & Herbicide Application' started by mac43rn, Jan 23, 2003.

  1. mac43rn

    mac43rn LawnSite Member
    Posts: 237

    Here is my tweeked program.

    Soil Test:

    pH - 6.6

    P- 20 ppm (medium)
    K - 66 ppm (low)
    Ca - 1328 (medium)
    Mg - 223 ppm (very high)

    Calculated Cation Exchange 7.6 meq/100g

    Calculated Cation Saturation

    %K 2.1
    %Ca 69
    %Mg 22.5
    % H 6.0

    K:Mg Ratio 0.09


    History of Lawn. Lawn is a little of 1 and 1/2 years. Lots of clay soil and really want to get some organic material into the mix. I have found a place locally that sells Sustane 5-2-4 with iron. I am going to aerate 3-4 times this year and get the perfect lawn.

    1. April 15 - sustane 5-2-4 (20lbs/1000)
    0-0-7 .10 Dimension (3lbs/1000)

    2. June 1 Proscape 5-5-20 .15 dimension (5lbs/1000)

    3. July 1 0-0-7 Mach II (grub) (3.6lbs/1000)
    Sustane 5-2-4 (10lbs/1000)

    4. Sept 1 Sustane 5-2-4 20lbs/1000
    with aeration
    5. October 15 Proscape 19-2-9 4lbs/1000
    with aeration
    6. Winterizer 13-25-12 5lbs/1000

    Again, my goal is to have a nice looking lawn and I do beleive I need som organic materail.

    Okay, have at it!!

    Thanks
     
  2. SWD

    SWD LawnSite Senior Member
    Posts: 989

    Interesting approach - however I have just a few questions:
    What type of turfgrass is the lawn?
    What type/how many trees are there?
    What use is the turfgrass going to see - kids/dogs etc?
    Is the turfgrass going to be irrigated with a system or natural?
     
  3. f350

    f350 Banned
    from mi
    Posts: 424

    for the money i would go with the higher end sustane. the one with nutralene, i think it's 18-?-?... man i looked at yesterday and i cant remember..
     
  4. mac43rn

    mac43rn LawnSite Member
    Posts: 237

    three way blend tall fescue on clay soil

    lawn is irrigated

    Have three trees in the lawn, pear, honey locust and river birch. Birch is in a landscaping bed so will be away from nutrients.

    dog will be in the lawn on occasion. 8 month old baby, will not see the lawn this year.

    thanks for the reply. keep them coming. I will call about the 18-1-8. I really like the 5-2-4 because I could get a large amount of potash, as I really need it.

    thanks
     
  5. f350

    f350 Banned
    from mi
    Posts: 424

    use gypsum for the dog urine or water the spots right away.
     
  6. lawnstudent

    lawnstudent LawnSite Senior Member
    Posts: 472

    First, lets talk about aeration. You plan on two aerations in fall; one aeration in September and a second in October. These aerations are in consecutive months. Because of their close proximtiy to each other, the second aeration will offer only a marginal gain. Second, aerations should be performed when roots are actively growing for maximum effect. October, especially late October is not the optimum time to aerate. I would recomend you areate this coming spring (April or May) and next September.

    Can you topdress after you aerate? Topdress with a good, composted organic matter like mushroom compost. Drag the turf after topdressing to encourage the compost into your aeration holes. Organic matter is going to be the best cure for a heavy clay soil.

    Next, I would reduce the fert app rate in April to no more than 0.75 lb N per 1000 sq ft. You are going to get a lot of vegatative growth in spring because of the rain and high N in spring promotes disease. Increase the N rate of your June app to 0.75 to compensate for the reduced rate in April. Also, I would skip the July fert application. Promoting vegetative growth in the heat of summer really stresses a C3 grass. Your lawn is already stressed from trying to grow on a heavy clay base without the N push in July. I would also skip the October fert application. This is a horrible time of year to promote a flush of new growth. Grass must harden-off before winter comes just like trees and shrubs. You do not want to force new growth just before the cold arrives. An October feeding high in N is a real big risk. You could have significant winter kill the following spring. Finally, the late fall app is a very good idea. This app must be timed to a period when the grass shoots are dormant but your roots are still growing. This app will give you a good early green up and a better root system. Its just hard to time this app. Too early and you promote top growth and the potential for winter kill. Too late and your roots don't benefit.

    Phosphorus - you don't need the 1.25 lb you are applying in fall nor the 2.58 lb your program supplies through the entire year. Phophorus run off is a real big environmental concern. Your soil analysis indicated you are OK with P. P does not leach from the soil like N or K. P is very stable in the soil. Your pH level is ideal and does not restrict your turf's access to P. Only put enough P down to maintain your currrent soil's level of P. Stick to a 312 or 313 ratio for overall N-P-K. This should maintain an adequet level of P. You do want to buld potassium levels, since your soil analysis indicates a low K value. Never apply more than 1.5 lb K per 1000 sq ft per app on K.

    Hope this helps.

    jim
     
  7. lawnstudent

    lawnstudent LawnSite Senior Member
    Posts: 472

    mac43rn,

    your calculated cation exchange of 7.6 mEg/ 100 g of soil should also be a concern. This is a low cation exchange value. It is more typical of a sandy soil than a clay soil, though there are some clay soils such as Kaolinite that can have a low CEC range of 3-15 mEg/100 g. Such a low CEC means that your soil has little nutirent holding capacity and you should fertilize with smaller amount of nutirents but more often. For example, cut the app rate in half and multiple the number of apps times two. This way fewer nutirents are leached out of your soil and are available to your turf.

    The best way to increase your CEC is adding organic matter. OM can have a CEC as high as 200. This is another reason you should consider topdressing with OM after you aerate. And don't think that one topdressing will turn the trick. You need to do this often to make a significant impact on the CEC of your soil. It is so much more difficult to do this once a lawn is established than incorporating OM into a site before the lawn is planted. Good luck.

    jim
     
  8. lawnstudent

    lawnstudent LawnSite Senior Member
    Posts: 472

    mac43rn,

    The next problem that I see from your soil analysis is the calculated cation saturation figures. They are listed below.

    Calculated Cation Saturation

    %K 2.1
    %Ca 69
    %Mg 22.5
    % H 6.0

    K:Mg Ratio 0.09


    You have good soil fertility in that nearly 94% of your Cation exchange sites are filled with Macro nutrients, but those sites are dominated by Calcium (69%) and Magnesium (22.5%). In fact, the ratio of Potassium (K) to Magnesium (Mg) is only 0.09!!!

    Calcium and Magnesium are Macro nutrients for turf, but they are only secondary Macro nutrients. Potassium (K) is a very important Primary Macro nutrient for turf and its very low at your Cation Exchange sites because of the amount of Calcium and Magnesium in your soil. What this means is that your turf is starved for potassium. You must correct this situation. Fertilizing with high amounts of Potassium will help some, but you must exchange Calcium and Magnesium at the Cation exchange sites with Potassium for a long term solution. This is the part I need help with. Maybe some of the more seasoned Lawnsite members can help with the process to correct your Cation Saturation problem. The best solution I could offer you right now is to increase the frequency of your fert apps and reduce the rates of those apps. Make sure you use a fert with high amounts of Potassium. A ratio of 3-1-3 I think would be best. Don't apply more than 0.5 lb of N and K on any single app. And apply your fert every three weeks (except in the heat of summer. Either refrain from fert apps this summer or only apply Potassium, provided your grass is irregated).

    jim
     
  9. lawnstudent

    lawnstudent LawnSite Senior Member
    Posts: 472

    mac43rn,

    I pulled down my Soil Science book to verify a few things. When many differnt cations are present in a soil, the cations with the strongest bonds will bond to the clay micelle before the weaker cations have a chance. It just happens that Calcium's bond is stronger than Magnesium which is stronger than Potassium. It is not by chance that this matches the % order of your cation saturation calculations.

    The only way documented in my soil science book for Potassium to overcome the stronger bond of Calcium is through a process called "mass action". Mass action says that Potassium ions must be present in larger numbers than Calcium ions to displace the Calcium at your cation exchange sites (micelle). Therefore, you need to apply Potassium in sufficent quanity to overcome the naturally occurring Calcium ions in your soil. With less than 50 lbs of Potassium per acre in your soil, you need to add 6 lbs of Potassium per 1,000 sq. ft. this year. Do this in multiple apps and make sure than no one app exceeds more than 1.5 lbs of Potassium per 1000 sq. ft. You may want to have another soil test performed next year to monitor your progress and adjust the program accordingly. That is my final thought on your program. I hope this helps. Does anyone else have any thoughts on this subject? Good luck and healthy grass!

    jim
     
  10. Ric

    Ric LawnSite Fanatic
    Posts: 11,957

    lawnstudent and mac43rn

    I am not going to write a novel or claim to know your answer. I am only going to ask questions. Those questions will help you.

    1. What happens to clay when Bulk Density goes up? What happens to the CEC?

    2. What are the three particles that make up the rizosphere? And how does your partial size distribution look?

    3. What role does sand play with clay. How can sand increase CEC when sands have low CEC?

    4. What is the difference between organic matter and Organic Material?

    5. Is Sutane an amendment or a fertilizer?

    6. Are you using the right top dressing?
     

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