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View Full Version : soil/turf samples...how accurate?


bobbygedd
08-11-2005, 06:22 PM
i took a sod sample to the extension office for testing. the result stated that: there was brown patch disease present, but they couldn't confirm that this was the cause of death. they also said they believe the nitrogen was excessive. :nono: i applied .80 lbs per k in april. i applied .80 lbs per k again in may. that was it. i would not consider that excessive. it's not neccesarily "light" but certainly not excessive. they also said the grass type was perenial rye. for the past 4 yrs i have reseeded this lawn each fall with a rye/fescue/bluegrass mix. what are your thoughts on this? have you ever had a bogus test result? the final outcome on cause of death, in thier opinion was, due to clay soil, this lawn will have the same reaction after long periods of heat. it will die, every year if we have a heat wave such as the one we are having the last 3-4 weeks. the bottom line is, the lawn "cooked".

Drew Gemma
08-11-2005, 06:26 PM
those test are helpfull but there are so many natural contaminates that can throw it off. some yards have multiple zones of different soils and turf grass types. rain and what is in it throws off the whole test. also an abudnace of clippings will throw off the numbers. just a few things I learned in soils class when I was in school. you really need optimal conditions to do soil samples to get the best results.

lawnguyland
08-11-2005, 07:43 PM
I did about 15 soil tests that I mailed to a lab in Indiana for analysis last year. I think that they were pretty close to being accurate, at least in a general sense.
I took core samples with a soil sampler (T shaped, coring) from soil 2-5"deep in multiple spots for each property and combined all the soil from those cores for a single sample from each property. Anyhoo, the results came back and there was a noticable trend in that pH was close to my test results (using cornell and Kelway testers) for all of the samples. Also, on LI, the soil is slightly acidic and the reults agreed with that.
The soils here are also phophorous rich and potassium poor and this was indicated by the reults as well. The lime and nutrient recommendations were seemingly accurate as well. The tests were cheap too! Not for my clients though.
I find this info very useful and if proper samples are taken (not from surface, random, multiple) I believe you can get relatively accurate results.

PS, also a soils class nerd speaking!

paponte
08-11-2005, 09:40 PM
We have found soil tests to be not only accurate, but a necessity for maintaining our clients lawns. Sort of like going to the doctor, thay have to do tests before they can treat. :)

bobbygedd
08-11-2005, 09:42 PM
We have found soil tests to be not only accurate, but a necessity for maintaining our clients lawns. Sort of like going to the doctor, thay have to do tests before they can treat. :)
well, as i said, there were many discrepencies on my test. why?

Mower For Less
08-12-2005, 01:53 AM
well, as i said, there were many discrepencies on my test. why?

Maybe to borrow some computer terminology, Garbage In, Garbage Out.

Kevin

RedEarthLab
08-12-2005, 08:59 PM
I have been testing soil samples for six years now and have seen good and bad outcomes from my recommendations (mostly good). The thing is, there are numerous influences that can affect the results. Sometimes the history of where the sample came from plays more of a role in determining the diagnosis then the test results. For example, all nutrients may be at optimum levels but the sample came from a high traffic area, or not properly watered, etc... How the sample was collected can be more important then the testing. For diagnosing a problem, don't mix soil from good and bad areas, but compare the two results with each other. Also, you need to make sure the proper test are done on the sample, pH, and NPK don't always answer the question. If you have any other questions about testing soil let me know.