slow release or ????

Discussion in 'Pesticide & Herbicide Application' started by onemancrew, May 8, 2003.

  1. onemancrew

    onemancrew LawnSite Member
    from tn. #7
    Posts: 95

    Have any of you guys heard of companies being able to coat fertilize with anything and be considered slow release when really their not?? The reseason I ask is I heard this through a fert. salesman, about Howard Johnson's fert. I'm very pleased with my results but I am having some growth spurts, or so I think so. But, on the other hand the conditions here have been great to grow grass. Rain at least 2-3 days a week with temps from 70-80 every day. What do you guys think?? Has anyone heard of this on slow release ferts.??? Thanks in advance.
  2. Slow release / SCU ferts have available nitrogen when you apply it.

    Like you stated you have ideal conditions grass will grow fast in theses times no matter what.
  3. onemancrew

    onemancrew LawnSite Member
    from tn. #7
    Posts: 95

    I don't think this is a scu fert.???
  4. Doesn't SCU mean slow release? I always thought so.

    40% SCU.......
  5. Hamons

    Hamons LawnSite Senior Member
    Posts: 706

    SCU means sulphur coated urea. It is a slow release type of fertilizer but there are many other types including the newer plastic polymer coated products. (IBDU, Ureaform products) and the slow release forms.

    The slowly soluble and slow release types are synthesized from urea. There are in fact three percentages (classes) of nitrogen solubility classes. These include the terms:

    (1) CWSN - cold water soluble nitrogen, (2) HWIN - hold water soluble nitrogen, and (3) CWIN - cold water insoluble nitrogen.

    At a temperature of 77F, it is the CWSN fraction which turfgrasses can absorb. This includes uptake of unreacted urea, and small size chains of methylene urea. Long chains of methylene ureas must be changed by soil bacteria before the turf can use them. Since this microbial activity is temperature dependent, the degree of solubilization is increased as the temperature increases. Thus more of the fertilizer is available during the warmer parts of the year. Therefore, fertilizers applied in the cooler fall and winter (of products like urea formaldehyde) may show limited response until the soil warms up which favors breakdown of the CWIN position of the fertilizer. You can still apply UF in the winter to save time, but it will just be available later.

    You have to know whats in the fertilizer you are putting down. This has been the biggest thing I have been learning lately. I am new to fertilizer side of things -- but have attacked it with a passion.

    I used to think it didn't matter what was in the bag as long it had the numbers I wanted. But thanks to a few people who know their stuff -- I have begun to research and understand that different products will have completely different results for the turf.
  6. SCU is/was the most common, there is also UMAXX, and some others I can't remember....

    ALl types of releasing agent.

    Also keep in mind cold temps help the grass store food.

    And the higher the last number is, it tell the first to what to do.
  7. hammons,

    Is 77 degrees air or soil temp, and if soil temp, at what depth?

    fert rep might be talking about umaxx, and I think its only slow release for a very short time
  8. Green Pastures

    Green Pastures LawnSite Silver Member
    Posts: 2,457

    The slow release fertilizers I always get from Lesco are usually 50% slow release. Meaning there is 50% available right now and 50% is SCU for slow release.

    I've never seen a fert that is 100% slow release. Not saying it does not exist, just saying.........well read what I said.
  9. Can't you buy straight scu? Then isn't that 100% slow release?

    I think some of scu is still quick release, ex,
    lesco 48-1-3 (make believe ex) / 50% scu
    I don't think label will state 24 units as some sort of slow or controlled release nitrogen and 24 units as urea. Some of the 50% scu is quickly avaiable , varies depending on many conditions!!
  10. Hamons

    Hamons LawnSite Senior Member
    Posts: 706

    My understanding ist that 77 degess is the water temperature used when classifying the fertilizer. When UF products are tested to determine solubility, 1 to 1.4 grams of fertilizer are added to 250 ml of 77o of water. The fertilizer that does not dissolve in the cold water is subsequently transferred to 110o water. Water Insoluble Nitrogen (WIN) is a term which denotes the percentage of N that is insoluble in both cold and hot water.

    It may seem like you really don't need to know this -- and I guess you don't if you are willing to rely on the Local Lesco to design your fertilizer applications for you. However, I prefer to understand what I"m putting in on the lawn so that I can provide absolutely the best program possible for my lawns.

    One strange thing I have found out about fertilizer sales people is they are always trying to sell the cheapest products available -- rather than the highest quality. When I was brand new -- I'm still pretty new -- into the land of fertilizers I talked to a Lesco Rep about helping me set-up a program and he had putting down 3.5#/ n from straight urea spread over four apps and two apps of a premeergent combo product. Total; N for the season was over 4.5# and my total cost per thousand was less than $5.00 -- for the whole season. But --- man it was junk. His theory was just load up on the customers and sell them junk and keep the grass green. Of course he didn't tell me how it would all be dead in two years because of disease, and ruined soil.

    Of course --- I'm still learning and I'm sure I always will be........


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