Soil pH - what should every farmer know about soil pH?

There are many factors that have a huge impact on the quality of the soil and consequently on the quality of the crop. One of the most important is the pH of the soil, the value of which determines the availability of all nutrients for plants.

Soil reaction and pH value

Table 1 shows the soil reactions with the assigned pH value.

The optimal pH for most plants ranges from 5.5-7.5 (slightly acid - neutral). Soils with a pH below 5.0 (excessive acidity) show a lot of active aluminum and manganese. These elements prevent the roots of plants from fully developing. The root system is reduced, as a result of which plants grow less, have a limited ability to take up water and nutrients from the soil. Such plants are observed to be much smaller and exhibit numerous discoloration on leaves and stems. Every crop needs a proper pH to thrive.

Suitable pH range for crops

In Table 2 we present the appropriate pH range for each crop.

Only rye and potatoes are tolerant to low pH, while the rest of the crops need an optimal pH. Therefore, before sowing, it is worth checking the pH of the soil in our fields, so that the plants have the full opportunity to develop, and we can be sure that the development process is going well.

We can check the soil reaction in several ways:

The first one is to collect a soil sample and deliver it to the regional chemical and agricultural station, where it will be checked for the content of components using wet chemistry. The second is the purchase of a device or product for this purpose - there are currently a lot of them on the market. These include :

• Electronic instruments which are designed to determine the soil reaction (pH measurement scale: 3.5-9), soil temperature (measurement scale: from -9°C to +50°C), insolation (solar measurement scale: LOW- / HIGH+ ), as well as showing soil moisture (humidity measurement scale: DRY+ / WET+).
• A soil acid meter, into which we place a small amount of soil and pour it with a few drops of a special liquid included in the kit.
• A universal litmus test that can be purchased at any pharmacy or chemistry store. To make this measurement, we need to take some soil, put it in a container or glass, then pour distilled water and stir. When the solution is mixed, dip the paper and stick it to the wall of the container. We should get the result after about a minute. The color of the paper can be compared with the scale we received with the set, then we will determine the pH of the soil.

pH of soil for vegetables

Vegetables and other crops grow and yield much better at a certain soil pH. It should be remembered that before we want to sow or plant our first vegetables, we must properly prepare the soil.

Vegetables that develop at an inappropriate pH very often starve and are unable to extract nutrients from the ground. Despite the fact that the substrate was previously well fertilized and watered, the vegetables still grow poorly, and sometimes even die.

Most vegetables require a slightly acidic or neutral soil (pH 6-7). However, it should be remembered that the reaction alone is not enough. Soil fertilizers are also important, as they have a significant impact on development.

Requirements of individual vegetables for soil pH

The detailed pH requirements of vegetables are presented in the table below:

Once we have examined the substrate and know exactly what its reaction and nutrient content are, we can proceed to an action that will lower or increase the pH of the soil for vegetables.

If there is a problem with too high pH, we have to dig the soil and mix it with acidifying fertilizer, bird manure or acid peat.

When the pH is too low, the soil should be limed, excavated and mixed with e.g. fertilizer chalk, magnesium-oxygen lime or with commercially available fertilizers for soil deacidification. Granulated lime mixed with stubble is also a great solution. However, we must remember that the effects will only be visible after a few months due to the fact that lime moves very slowly in the soil.

It should be remembered that after liming, it is forbidden to sow and plant plants.

Types of lowering and increasing soil pH fertilizers

When it comes to changing the pH of the soil for arable crops, there are two options for using fertilizers for:

• Lowering the soil pH - these include ammonium phosphate, slurry, manure, ammonium nitrate, urea.
• Increasing soil pH - dolomite (calcium-magnesium carbonate lime), potassium nitrate, sodium nitrate.

In summary, soil requirements are high, but if we keep all aspects in mind, we can expect a healthy and good yield. However, we should remember that even with all agricultural activities we cannot forget about the most important factor, namely weather conditions.