The formation conditions, composition, and properties of soils are important characteristics that must be taken into account in agriculture. Brown soils rich in humus are considered fertile. Such soils have a loose structure and contain a variety of nutrients. Brown soil easily absorbs and retains moisture well, and is easy to cultivate.
Formation conditions
The main places for the formation of brown soils are foothills and mountainous areas, which are characterized by a moderately warm climate with hot, dry summers and wet, warm winters. Most often found in the flat areas of the Eastern Caucasus and the North-West.Soils are formed under conditions of significant moisture in the autumn-winter-spring period.
Soil humus is formed due to the vegetation cover of dry forests (hornbeam, beech, maple, xerophytic oaks, tree-like juniper, walnut). The main source of organic matter in the soil is the grass cover that develops under the sparse tree crowns.
Genesis
The main process of soil formation is turf, associated primarily with the vital activity of herbaceous vegetation. Simultaneously with the sod process, internal claying of the soil occurs (formation of clayey materials).
It is thanks to herbaceous plant crops and the non-flushing type of water regime that humus accumulates. The earth acquires a lumpy-grained structure, exhibiting water-physical and chemical qualities favorable for the development of plants. The top layer of soil accumulates nitrogen and ash substances necessary for the full growth of crops.
Profile structure and classification
Brown soils are heterogeneous. In the soil profile, several horizons can be conventionally distinguished due to color classification:
- The humus horizon (thickness - 30-50 cm) is dark brown in color, has low density, and high biogenicity. It is characterized by a granular-lumpy structure containing plant roots;
- The transitional humus/metamorphic horizon (thickness – 15-20 cm) is distinguished by its brown color and nutty-lumpy structure. Many vertical long roots grow through the layer;
- The carbonate horizon of light brown or pale-brown shades has a massive or small blocky structure.
Naturally, there is no clear division into horizons in nature - the transitions are smooth and not clearly defined.
Composition and properties
Due to the high humus content (4-7%), brown soils are characterized by high fertility. Soil properties: loose structure, rich in mineral elements, good moisture holding capacity and water permeability. To prevent compaction of the humus horizon, the method of deep loosening of the soil is used. At the same time, the depth of soil wetting increases, water and air permeability improves.
When cultivating brown soils, maintaining and increasing their fertility is of great importance. Therefore, attention is paid to the prevention of water and wind erosion. Preventive measures: strip distribution of crops, round slopes are fenced with trees and shrubs, and terraced design of slopes is also practiced. Periodic sowing of perennial grasses and green manure is recommended.
