How to check soil pH: instructions for measuring soil pH in a few simple steps. What are the right tools to determine soil pH and where to buy them. Advice on post-measurement interventions: how to lower or raise the soil pH.
ThepHindicates the acidity or basicity of a substance which, in the case ofsoil, is an element fromto verifyas some plants fail to receive nutrients from agroundwith too high or too low pH. An alkaline soil can cause yellowing of the leaves because it would inhibit the absorption of mineral substances such as iron. At neutral pH, most of the micronutrients for plants are easily assimilated by the root system.
The pH of the soils
Based on the pH, a soil is saidstrongly acidic, acidic, neutral, calcareous (or basic) or strongly calcareous. In relation to the value obtained from the pH measurement you will have:
- Strongly acidic soils, pH = 4
- Acid soils, pH = 5
- Moderately acidic soils, pH = 6
- Soil with neutral pH, pH = 7
- Calcareous soil, pH = 8 (basic or alkaline soils)
- Strongly calcareous soil, pH = 9 (strongly basic or alkaline soils)
Let's clarify immediately: to say that a soil is calcareous, alkaline or basic, means the same thing and, in terms of pH, it must indicate a pH higher than 7. Acid soils are characterized by a pH value lower than 7.
Soil and plant pH
As stated, it is importantmeasure the pH of the soilbecause an excess of acidity in the soil could inhibit the absorption of nutrients by the root system of plants, similarly, even a pH that is too basic could damage a crop.
Why does pH affect soil fertility?
The pH of the soil does not directly affect soil fertility but affects the bioavailability of nutrients through the cation exchange capacity and conditioning the property of the soil to retain cations, making them unavailable for absorption.
The root system of plants is able to absorb the nutrients from the soil that are dissolved in water (rain or irrigation). A part of the nutrients of the soil cannot dissolve in water because it is retained by the clays due to the absorbing power. The more acidic a soil is, the less nutrients it can dissolve in water. Most of the plants we grow prefer slightly basic or slightly acid soils, that is, with pH between 6.5 and 7.2 but plants that prefer alkaline or acidic soil are also common.
How to check the pH of the soil
Measuring the pH of the soil is a simple operation that can be done with more or less accuracy depending on the equipment used. Litmus paper is the cheapest way to measure soil pH.
Measure the soil pH with litmus paper
What you need: Soil sample to analyze, deionized water (can be bought anywhere, even from Leory Melin or online), transparent container, stirring rod, sieve / filter, litmus paper.
Where to buy litmus papers?
On Amazon, a kit of 400 strips (litmus papers) are offered at a price of 5.23 euros with free shipping. The strips are pH reactive and change color according to the detected value. This kit allows you to measure soil pH from 1 to 14 without decimals.
Here is the procedure:
- In a container, mix a glass of soil with 2 and a half glasses of deionized water. Mix well and for a long time, at least for 5 minutes.
- Filter with a very narrow mesh sieve or with a filter paper like the one used for coffee;
- Immerse the litmus paper in the well-filtered liquid, wait a few minutes and observe the color obtained.
Depending on the color assumed by the paper, the reaction of thegroundand its pH.
Where to buy filter papers?
a pack of 100 pieces of universal filter papers is offered on Amazon at a price of 11 € with free shipping.