Alkaline soil: signs, which compounds of elements give such a reaction and what to do

Alkaline soils are defined as rich in s alts and having high soil pH values. Consider the composition, what compounds and elements make up alkaline soils, their reaction, the causes of salinization, the main features by which they can be identified, the vegetation of alkaline soils. What methods can be used to lower the high pH of this type of land so that it becomes suitable for growing plants.

What is this?

The so-called soils that have an alkaline reaction. If it is 7-8; then the soil is slightly alkaline, if pH 8-8.5 is medium alkaline, and pH 8.5 or more is strongly alkaline.

Alkalinity is determined by the high content of s alt compounds that are deposited in the soil layer. Due to the increased concentration of the elements calcium, magnesium and sodium, alkaline soils are generally unfavorable for the development of many plant species.

Causes of soil salinization

Saline soils are divided into 2 types: solonchaks and solonetzes. In the first s alt are distributed throughout the profile. In the second, they are not in the upper layer, but the lower one is saturated with s alts, due to which the soil properties are reduced, because there is a lot of sodium in the absorbing complex. The element creates adverse properties for plants.

Salinization of the earth occurs due to the arid climate, in which the evaporation of moisture from the surface exceeds the volume of water entering inside during the washing process. Together with groundwater, s alts rise, after the evaporation of water they remain in the fertile layer.In winter, s alts are washed out to a certain depth, in summer they rise up.

Soils are considered very slightly saline if they contain 0.2-0.25 g of s alts per 100 g, slightly saline - 0.25-0.50. If they contain 0.5-0.7 g, then these are moderately saline soils, if 0.7-1 - already solonchaks.

Key Features

Usually alkaline soils are low fertile, they have poor physical properties, not rich in chemical. compound. They are difficult to work with, wet, sticky and viscous, do not pass water well.

Alkaline soils can be determined by taking a small earthen clod and sprinkling it with vinegar. If foam appears on the soil, it begins to hiss, then these signs of an acid-alkali reaction indicate that the soil is alkaline. You can also determine the acidity by litmus paper - if the soil solution turns it blue, then the earth is alkaline.

What can grow in alkaline soils?

Despite the unfavorable growing conditions for plants, some types of plants can grow on alkaline soil. The variety depends on the amount of s alts contained in the ground.

Which do not tolerate saturation with s alts

Cannot grow on s alty soils from wild clover plants, from fruit plants - pome and stone fruits, viburnum, strawberries and roses, citrus and avocados. Of the flowers, you can not grow hydrangeas, azaleas, conifers, blueberries and lingonberries on them. Cultivated species will not produce large yields even in well-cultivated and fertilized land if it has a lot of s alts.

Medium resistant to salinity

Sunflower, flax, corn, fescue and ryegrass, motley sweet clover and alfalfa can tolerate alkaline soils, that is, pastures and industrial crops can grow in such areas with not the most favorable conditions.

Solanaceous, cucumbers, onions, root crops, cabbage, legumes and pumpkins carry alkali from vegetables. They can be sown in not very saline soil. As well as table and wine grapes, pomegranate, figs. Of the ornamental crops, juniper and thuja grow on such soils.

Resistant plants

From vegetables - beets, asparagus and spinach, kale. From fruit and berry bushes - date palm and oleander or a houseplant. Of the perennial plants, high fescue, beskilnitsa, horned bird's foot, and pigtail can withstand alkali.

Methods for lowering high pH

Gypsum, iron sulfate, sulfur are added to alkaline soils. It is necessary to apply organic matter and mineral fertilizers, since the nutritional value of such soils is low. It is necessary to use acidifying fertilizers, from organic matter - sawdust and manure, sow green manure, which will increase the level of humus.How much fertilizer to apply depends on the level of alkalinity. So, for example, 2-10 tons of gypsum should be applied per hectare.

The same should be done with s alt licks, but, first of all, reclamation measures should be carried out on this territory, then gypsum should be applied. Calcium, which it contains, displaces sodium, as a result, gradually saline soils become more structural, water is better absorbed into them, so s alt is removed not only from the upper, but also from the lower horizons.

Phosphogypsum can be used for alkalization. In it, in addition to calcium sulfate, there are impurities of fluorine and sulfuric acid. The dosage of gypsum on solonetzes - on average, 0.5 kg / m2, on not very saline soils - 0.2 kg / m2 of gypsum or phosphogypsum.

To improve saline and alkaline soils, it is necessary to carry out deep plowing, with the introduction of ameliorative additives. Irrigation is also needed, especially in dry regions.

Slightly alkaline land on private plots can be improved by surface digging, with the addition of large amounts of organic fertilizers in combination with the cultivation of green manure. It will take years of improvement to see results.

Alkaline soils do not have good characteristics, the more alkalinity and salinity, the less suitable they are for growing cultivated plants. In areas with slightly alkaline soil, many cultivated species can be grown; in areas that are too saline, even an average crop cannot be obtained. Alkaline soils need to be improved with gypsum, fertilizers and agrotechnical measures.

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