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Joined: Wed Mar 23, 2011 11:52 am
Location: NJ

Is my soil test kit accurate?

Hello. I have a small 15x20 vegetable garden for the past 5 years or so and found certain plants just do not grow well. Tomatoes, cuccumbers, some chiles and lettuce grow excellent. But bell peppers, other chiles, zucchini, strawberries (some others) do not do so well. So I picked up a Ferry Morse soil test kit from Lowes. I tilled the garden and proceeded with the test.

The pH test came out "Neutral 7.0", Potash was "Low" but not "Very Low". However, I didn't even get a reading for Nitrogen or Phosphorous? during the growing season I use (I think) Miracle Grow vegetable fertilizer. The one you attach to a garden hose. I'm not sure if the test is accurate where I need to add something to the soil to bring the nitrogen and phosphorous up.

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Greener Thumb
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Joined: Tue Apr 14, 2009 2:13 pm
Location: wnc - zones 6/7 line

the miracle grow won't ever leave much helpful nitrogenous residue in your soil, so that much probably makes sense. highly water-soluble stuff. other fertilizer options (a good well-composted compost/manure, perhaps) may make more lasting contributions.

Senior Member
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Joined: Sat Mar 27, 2010 8:43 am
Location: Jefferson Co., Arkansas

I doubt that soil test is accurate. I especially question the accuracy of the nitrogen test. I would expect a reading for phosphorus as well. It is probably high enough that you don't even need to add phosphorus.

I recommend a soil test through your cooperative extension service. It does take a few weeks, but it is worth it. I don't know about the cost, but it should be only a few dollars. In my state, it is free for the basic test which includes pH, phosphorus, potassium and other micronutrients.

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Joined: Wed Mar 23, 2011 11:52 am
Location: NJ

Thanks. My main concern is if the test kit was correct or not. It seems odd that the water in the vials for those 2 tests didn't even change color, yet certain plants grow great???

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Super Green Thumb
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Joined: Mon Mar 23, 2009 1:59 pm
Location: TN. 50 years of gardening experience.

I use litmus paper I got from the local wine making store. Check your water with the litmus paper then add water to soil and drain out water and check it again with litmus paper.

I never worry much about the soil I basically want potatoes and plants that like acid to be acid and things that like do not like acid not to be acid.

Add plenty of organic material in the soil if you have it. Add wood ash for potash and lime. Add lime to tomatoes. Add nitrogen to corn and things that like nitrogen.

Put legume enolucant on beans and peas for nitrogen fixation.

Cool Member
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Joined: Fri Feb 25, 2011 2:38 am
Location: Cheese mines of Wisconsin

I used one of those test kits before and got virtually the same results. I think the kits sit on the shelf for so long they don't work anymore. :(

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