With pH testing I hear you. top, slopes, and bottom of slopes, near concrete, foundations, etc. etc. will all have different pH values in the soil. When you get a soil test done you need to mix uniformly the samples from multiple sampling sites together and then send it in to the lab. If you test the same mixture sent to the lab you will have a better idea of your own testing as compared to the lab. If you mix a sample selection a second time you'll likely have yet again a different result, same as if you single sample but from a slightly different location. This I think is the best take away is not to be too worried that you don't get the same results as a lab because of the above you need to blend an average out over your entire property grow area. Or pay for lots of individual spot tests. This also means when treating your soil with amendments you will be over amending in some areas and under amending in others. But the average should be good enough provided the sample used for the tests was averaged well enough.
I first got my result then curious I searched for soil in my area and the answers they gave was we all have heavy gumbo soil that is alkaline. While I am not as worried about the exact figure of 7.5 pH, I am confident I am in the right ballpark as my alkaline test results match the alkaline results of the overal general area that were done by government scientists.
I use something like this rather than the Garland style one,
PH-200 HM Digital Professional Grade Handheld pH Meter (uswatersystems.com). I use it in brewing and other applications, and it is also lab calibrated to multiple distilled water samples with acidification powders to known pH values before I tested.
For the soil composition testing I have this procedure you all may want to give a go just for the fun of it:
Soil of course is a mixture comprised of major soil particles, organic matter, water, air and living organisms, all of which are important to the overall health of the soil and the plants that grow in it. The three primary soil particles are sand, silt, and clay. The relative percentages of these components present make up the soil’s texture. Texture is important to overall soil and plant health as it relates to soil porosity, which refers to the pore spaces where air and water reside.
The ideal soil texture is a mix of sand, silt, and clay particles, known as a loam. In most cases the particles will not be balanced, and the soil will need to be altered by adding organic amendments. To evaluate soil texture, use a simple jar test to determine the percentages of sand silt, and clay. Once the percentages are calculated, the soil textural triangle can be used to determine the soil type.
What you will need to test:
1. Straight edged, clear jar
2. Permanent marker
3. Ruler
5. Watch or stop watch
6. 1 tablespoon of powdered dishwashing detergent
7. Mesh sieve or old colander
How you set up the test (1 minute, 2 hours, 48 hours):
1. Using a mesh sieve or old colander, sift the soil to remove any debris, rocks, and large organic matter (leaves, sticks, roots, etc.).
2. Fill the jar ⅓ full of the soil to be tested
3. Fill the remainder of the jar with clean water, but leave some space at the top.
4. Add 1 tablespoon of powdered dishwashing detergent
5. Cap the jar and shake vigorously until the soil turns into a uniform slurry.
6. Set on a level surface and time for one minute.
7. Place a mark the outside of the jar, showing the coarse sand layer settled at the bottom of the jar.
8. Leave the jar in a level spot for 2 hours.
9. Mark the top of the next settled layer with the permanent marker. This is the silt layer.
10. Leave the jar on a level spot for 48 hours.
11. Mark the top of the next settled layer with the permanent marker. This is the clay layer that has settled on top of the silt layer.
12. Using a ruler, measure and record the height of each layer, and the total height of all three layers. Use the soil texture analysis worksheet below to record results.
How to draw three lines on the graph and determine your exact soil type:
Example Graph Result:
- Use the soil texture triangle to estimate the soil type for the site.
- The clay percentages are listed on the left side of the triangle. Lines corresponding to clay percentages extend from the percentages reading left to right (see red line).
- The silt percentage is on the right side, with lines extending downwardly, diagonally right to left (see green line).
- The sand percentage is on the right side, with lines extending upwardly, diagonally right to left (see blue line).
- Track the lines with the percentages measured and find the spot on the triangle where all three lines intersect. The region where these lines intersect indicates the soil type present. The example shown represents a loam soil texture.
Worksheet and New Graph:
Soil Texture Analysis “The Jar Test” Worksheet
Soil texture triangle to estimate the soil type for the site
Measurements:
Height of sand layer ________inches / cm
Height of silt layer ________inches / cm
Height of clay layer ________inches / cm
TOTAL HEIGHT OF LAYERS ________inches / cm
% SAND=(sand height)/(total height) x 100 =___________ % SAND
% SILT=(silt height)/(total height) x 100 =____________ % SILT
% CLAY=(clay height)/(total height) x 100 =____________ % SILT
Edit: At the 1 minute mark my soil has no delineated layers at all of sand, so you have an idea where my soil's results are headed!
PeterD