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Teting for Ph
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Posted by kbhale (My Page) on Fri, Nov 6, 09 at 3:07
| I want to test my soil Ph. I have a good Ph Meter. How is the best way to test the soil? Looking for the process of testing. |
Follow-Up Postings:
RE: Teting for Ph
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| Take a soil sample and send it to a good, reliable soil testing lab. Very few of the "pH meters" that you can purchase for less that several hundred dollars are reliable enough to trust. The reading you get will also depend on the pH of the water that makes the solution you test. |
RE: Teting for Ph
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| Did the meter not come with instructions? Did you search under the manufacturer's name for directions? Various meters will have different approaches. FWIW, home testing of soil pH is one of the more reliable tests one can conduct - the results, if done correctly, are likely to be much more accurate than any nutrient testing. Be sure to test in different areas - pH can vary rather widely depending on specific conditions. |
RE: Teting for Ph
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- Posted by ericwi Dane County WI (My Page) on
Fri, Nov 6, 09 at 15:01
| It helps to know the natural history of the soil you are working with. Is your area part of the inland sea that covered most of North America? Are there limestone beds underground, and/or limestone outcrops in your area? Are you anywhere near a major volcano, that might have erupted in the past 1000 years? If you have hard water, & that water is being used on the garden, then the garden will very likely have a pH higher than 7. I use both a pH meter, and also two dye indicators, to confirm the pH of our soil, where the blueberry shrubs are located. Blueberries will not grow in soil with a pH much above 6, and they do best with soil pH around 4.5, so I have some experience with testing pH. The pH meter I use was manufactured by Hanna Instruments. It has a glass bulb on the sensing end, a battery power supply, and an LCD digital display. It is not temperature compensated. I have to calibrate the meter before testing, & for this I use our tap water, with a pH of 7.6, and white vinegar, 5% acidity, with a pH around 3.5. A small soil sample, about one teaspoon, is mixed with enough distilled water to make a slurry, and this is filtered through a paper filter. The solution is then tested for pH. I also test with bromothymol blue, to confirm that the meter is working. This dye is used over the range of 7.6(blue) to 6.0(yellow). Bromocresol purple can be used to confirm pH in the range of 6.8 to 5.2. You can pick up an "aquarium pH test kit" at a local pet store for under ten dollars. These kits use bromothymol blue to indicate pH. In general, over the past 15 years of growing blueberries, the health and appearance of the shrubs corresponds very well with the pH test results that I am seeing, when I test the soil. If the pH is over 6.5, the shrubs have yellow leaves, and look sickly. When the leaves are deep green, the pH is always below 6.5. Our native soil, in the lawn & garden, tests around 7.6, and this seems to be OK for growing vegetables in the garden, and also raspberries and currants. Our grass is green & healthy. As you may know, most of Wisconsin was underwater for much of the earth's history, and we have limestone deposits left over from this era. Our tap water is hard, and leaves lime deposits in any cooking pot used to heat water. |
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