Malodi

Formed on weakly drained plains, depressions, drainless hollows. They are found in the field of permafrost distribution on the terraces of the Lena and Vilyuya rivers. Distributed quite widely on the forest-steppe plains of Western Siberia, the Far East (where they are called whites). The water regime is almost flushing. Soil solutions are significantly desalinated due to precipitation. Meadow vegetation, forest communities — birch, aspen pegs — are also often found.

Malt is characterized by a sharply differentiated soil profile , in which there are always signs of gleying in the form of bluish, rusty and buffy spots and ferromanganese nodules .

• In the upper part there is usually a sod horizon ( A _d ) or forest litter ( A ₀ ), sometimes with signs of peat when surface swamps. The thickness of the sod horizon is 4-8 cm.
• A ₁ - humus eluvial , dark gray or gray in color, structureless or with a weakly lumpy lamellar structure, 10-20 cm thick, abruptly passes into the A ₂ horizon.
• A ₂ is an eluvial or solodized horizon of a whitish color, with a tiled or lamellar structure of various degrees of severity, with numerous iron-manganese rust spots and nodules, with a thickness of 5-25 cm.
• A ₂ B - transitional eluvial-illuvial horizon, heterogeneously colored (dark brown with numerous whitish spots and streaks), tiled-finely lumpy structure, compacted, thickness - 5-15 cm, transition to the underlying horizon is noticeable.
• B - illuvial horizon of dirty brown color with bluish or grayish-brown films along the boundaries of structural units, dense, blocky or prismatic structure, with a thickness of 40 cm or more.
• BC or B _to - transitional horizon to the parent rock, characterized by spotting and abundant neoplasms (carbonates, gypsum , readily soluble salts).
• C is the mother breed .

According to the results of studying the gross chemical composition, the upper part of the malt profile is depleted in compounds of Fe , Al , Mg , Ca , K , Na and is relatively enriched in silica , which is one of the characteristic signs of malt and solodized soils. SiO _{2 is} formed due to the decomposition of the aluminosilicate part of the soil and the activity of diatoms and other microorganisms. Chemical processes for the formation of free silica can occur both during the destruction of solonetzes , and with periodic exposure to non-saline soils of weak solutions of Na ⁺ salts. In the latter case, the solonetzic process begins first, then, due to the overmoistening of the malt, the hydrolysis products are washed out and settle in the underlying horizon.

The profile is also differentiated by granulometric composition: the solodized horizon is depleted in silt particles, and the illuvial one is enriched in them.

The humus content in the humus horizon of malt ranges from 2-3 to 10%, sharply decreasing in the malt horizon. Fulvic acids predominate in the composition of humus. The absorption capacity is always less in the dense and mild horizons (10-15 mEq / 100 g) than in the illuvial (30-40 mEq / 100 g). In addition to calcium and magnesium, sometimes in significant quantities, sodium is present in the composition of PPC . In horizons A ₁ and A _2, in the PPC there are hydrogen and aluminum, which cause an acid reaction in the upper part of the soil ( pH 3.5-6.5). The illuvial horizon has a neutral or slightly alkaline reaction.

According to the 1977 " Classification and Diagnostics of Soils of the USSR ", the type of malt is divided into 3 subtypes according to the degree of hydromorphism:

• meadow-steppe (sod-gley) malods - develop in small depressions, in the conditions of periodic-leaching type of water regime, with a depth of groundwater at a level of 6-7 m from the surface. Typically weak development of the sod process.
• meadow (sod-gley) (groundwater at a depth of 1.5-3 m)
• meadow-marsh (groundwater at a depth of 1-1.5 m)

In the type of malt, genera are distinguished:

• ordinary
• non-carbonate - carbonates are not available in the entire profile
• saline - contain at least 0.3% water-soluble salts at a depth of 30-80 cm

Separation into types is carried out by:

• depth of salinity (horizon power A ₁ + A ₂ )
  • small (<10 cm)
  • medium (10-20 cm)
  • deep (> 20 cm)
• humus horizon power
  • turf (<5 cm)
  • small sod (5-10 cm)
  • mid-sod (10-20 cm)
  • deep sod (> 20 cm)
• humus content
  • light (<3%)
  • gray (3-6%)
  • dark (> 6%)

Malods have low natural fertility , as they are poor in nutrients and have an unfavorable water regime due to the low water permeability of horizons A ₂ and B. In addition, many malods are characterized by an acid reaction in the upper horizons, and therefore require liming . Dustiness and structurelessness of the humus-eluvial horizon lead to the formation of a surface crust that impedes aeration, and thus exacerbates waterlogging.

The most important agricultural technique that contributes to increasing the fertility of malt is deep cultivation and the application of organic and mineral fertilizers . In most cases, it is more expedient to leave the malt in its natural state, and use phytocenoses on them as hayfields and pastures .