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pH is an important parameter known to influence agricultural soil properties affecting plants growth. Considering its profound influence in commercial and recreational activities, a lot of agriculturists and other professionals involved in soil-related practices are showing keen interest in conducting precise pH measurements of soil samples.

The pH testing of soil involves the measurement of its acidity or alkalinity strength on a scale of 0-14. The lower range between 0-6 indicates acidic nature and the higher range between 8-14 indicates alkaline nature. And the value 7 stands for neutrality, ie. the substance is neither acidic nor alkaline.

More than this, the pH of soil influences the availability of nutrients in the soil. Plus, it can also speak a lot about the soil life and particular type of plants that can grow on it.

Generally, the soil pH varies somewhere between the values 4.0 to 8.0. The ideal range where optimal availability of nutrients and minerals is found is 6.0- 7.0. This is the range where iron, copper, phosphorous, zinc, and manganese are readily available in the soil. Further, the capability of the soil to supply optimal growth nutrition to plants relies on the following factors:

  • Presence of essential elements in soil: The nutrient composition of soil depends on its elemental nature and the concentration of organic constituents in it. These nutrients in the soil can either be present in soluble form or insoluble form as organic materials.
  • Nutrients supply to plants: Soluble elements present in simple form can be easily released from the soil for absorption by plants. However, the complex organic compounds need to be broken into simpler elements through the decomposition process to make them available for release to plants.
  • The pH of the soil: pH value of soil can affect its nutrients availability in a number of ways. For instance, on a pH scale above 6.5 nutrients such as zinc, iron, and manganese tend to become less available while phosphorous, molybdenum tend to rise. Besides, the acidic nature of soil increase solubility for minerals such as aluminum, copper, zinc, manganese, and cobalt for absorption by plants. Nevertheless, an extreme increase of these elements in the soil can result in the toxicity of plants. Contrary to this, high alkalinity in the soil leads to higher bicarbonate ions which in turn hinder the absorption of other elements thereby leading to poor plants growth.

Now that you know the importance of pH, let’s discover different procedures for performing an agricultural soil pH Test of your Sample.

pH Testing Methods for Soil Sample

Soil Testing Equipment Required

In this section, we’ll be discussing two different pH testing methods.

Both of these procedures will require some soil testing lab equipment.

For method A you‘ll need

  • A standard pH meter.
  • An automatic Temperature Compensation probe.
  • A pH electrode.
  • A stirrer with a stir bar.
  • A beaker.
  • Deionized water along with buffers.

For method B you’ll need

If testing is conducted for personal gardening requirements, then you’ll just need

  • A handheld pH tester with ATC and buffers for calibration.

You can easily avail of this equipment from any of the reliable pH Soil Testing Suppliers.

How to Perform Soil Sampling

Take a spoonful of soil sample in a clean, moisture-free plastic bag or container. If there are any stones or lumps in the soil make sure to remove them. Likewise, take one or two more samples. Apart from this, you do not need any preparation.

Testing Method A

  1. Take 20 gm of soil sample.
  2. Next, take 20ml of deionized water in a beaker (100 ml) and add a soil sample to it.
  3. Mix it using a stirrer for over 30 minutes.
  4. Cover the beaker and let it rest for around an hour.
  5. For precise measurement, soil and buffer should be made to attain room temperature. Any deviation in temperature can cause an error.
  6. Use two-point calibration with pH 7 and pH 10 buffer solution. Slope electrodes 92% -102%.
  7. Afterward, clean electrodes and ATC with deionized water and then dry off it thoroughly.
  8. Insert probes in a soil sample and record pH measurement.

Testing Method B

  1. Take a jar and fill it with a soil sample up to 3/4th.
  2. Add distilled water to the jar to cover the soil.
  3. Cover soil and shake it robustly to two-three times.
  4. Next, leave the mixture to stand still for 10 minutes. This will ensure the proper dissolution of salts in the soil.
  5. Scale pH tester to pH 7 and pH 10 buffer solution.
  6. Place pH tester in the wet soil solution.
  7. Measure pH and record the observations.

Analyzing Results of Ph Soil Testing Sample

The test results with a minor difference of < ±0.5 pH between different test samples mean you have used the right technique and your outcomes are way accurate.

Here is what different results mean for your soil:

  • pH 3.0 to 5.0–  very acid soil.
  • pH 5.1 to 6.0 – acidic soil.
  • pH 6.1 to 7.0 – moderately acidic. Suitable for growing a wide range of plants.
  • pH 7.1 to 8.0

How to Correct Soil

  • Add compost. Recommended for both alkaline and acidic soil.
  • Add alkaline substances such as ground limestone to acidic soil.
  • Add acidic substances such as pine needles or peat moss to alkaline soil.

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