An important indicator
of soil fertility is its acidity. Quantitatively, it is expressed in terms of pH - a hydrogen indicator (a measure of the activity of hydrogen ions). Soil with an acidity in the pH range from 6.1 to 7.0 is neutral, it is more favorable for many plants, since in such conditions useful mineral substances are available. Good conditions for plants are created by soil in which the acidity is close to neutral (pH values less than 6, but more than 5.5). On alkaline lands (pH greater than 7.1), the ability to feed plants with elements such as iron, potassium, copper, phosphorus, zinc, magnesium, boron is greatly reduced. In an alkaline environment, molybdenum enters the plants in excessive volumes, and this inhibits their development. Both alkalinity and acidity negatively affect soil quality. It degrades filtration and breathability. Soils with pH less than 5.5 become acidified. If the pH is 5.5, but greater than 5.1, then the soil is slightly acidic; the soil will be sour at a pH in the range of 5.0 - 4.6; strongly acidic - at a pH of 4.5 - 4.1, and very strongly acidic - a pH of less than 4.0. The development of the root system and the plant as a whole slows down, the crop reduces acidic soil. What to do, because the acidic environment is destructive for beneficial soil microorganisms, earthworms. Soil nitrogen does not accumulate on the rhizomes of legumes in acidic soil. The structure of acidic soil is disturbed. It sharply restrains access to plants of soil trace elements: phosphorus, potassium, magnesium and calcium - but at the same time it increases the intake of radionuclides, ions of aluminum, manganese, iron, heavy metals, and acid soil.
Soil acidity can be determined independently, without resorting to the service of an agrochemical laboratory. To accurately determine the pH of the soil, use a set of litmus paper. Have a simple experience. Pour the sifted soil into the milk bottle with divisions to the level of the second strip, add water to the fifth division and pour 1/2 teaspoon of chalk powder. And then pull on the neck of the rubber nipple, previously tightly rolled it up. Wrap the bottle with newspaper and shake for five minutes. The reaction of the chalk with soil acids will release carbon dioxide, creating pressure. If the acidity of the soil is weak, then the twisted nipple will correct slightly, and with strong acidity it will inflate. There are visual methods that are less accurate. Weeds on acidic soils talk about its acidity level. Indicative plants such as creeping wheatgrass, dandelion, white clover, bird highlander, sour acid, odorless chamomile, and creeping buttercup suggest that the soil is slightly acidic. Tricolor violet, plowed clover, plantain, wild sorrel, wild mint grow on mildly acidic. Strongly acidic soils are covered with horsetail, cotton grass, cat's paw, and small sorrel. If in the spring the land does not dry for a long time, and then dries out very quickly and becomes covered with crust, this indicates that the soil is acidic.
Reduces liming acidity. For this, fluffy lime is applied, which is introduced in spring and autumn before plowing. You can replace lime with crushed chalk, wood ash, marl. Before liming, find out in the directories about permissible and sufficient doses of the application of a substance so that during liming from acidic soils they do not turn into alkaline. It should be noted that liming is not carried out:
- simultaneously with the introduction of manure (lime will destroy the nitrogen in it);
- simultaneously with phosphorite flour (phosphorus will turn into insoluble);
- before planting carrots, tomatoes, pumpkins, cucumbers, beans, celery, parsley, potatoes (strong scab on tubers).
The application of mineral fertilizers is necessary for the fertility of crops and where acidic soil. What to do to increase productivity? We will name the most effective and permissible fertilizers for acid soil. Of the nitrogen-containing, these are nitrates: sodium and calcium. Do not use ammonium nitrate and urea - they acidify the soil. Of phosphoric, use precipitate. From potash - potassium sulfate, wood ash (it must be stored in a dry room).