Variety of soil-forming rocks, forms of relief, vegetation has caused a significant mosaic structure of the soil cover. Twelve types, 25 major subtypes and a large number of genera and soil types have been identified in the republic. The largest area is occupied by podzolic, gray forest, chernozem and alluvial soils.

Podzolic soils were formed on sandy fluvioglacial and ancient alluvial deposits under coniferous and coniferous-broadleaved forests with moss and moss-grassy cover. There are 2 subtypes: podzolic - the humus content in the upper part of the profile is 0.3-0.5%, the reaction is strongly acidic; sod-podzolic - the humus content is 1.5-3%, nitrogen, phosphorus, potassium is small, the reaction is acidic. They are distinguished by limited agricultural development, their share in the total area of ​​agricultural land is about 6%.

Gray forest soils formed in broadleaf forests are prevalent mainly in the enclosed spaces, composed of moraine and eluvial-deluvial loams. In the south-eastern part of the republic, maternal deposits are eluvial-deluvial formations of sedimentary rocks of the Paleogene age, consisting mainly of marls and flasks, which determines the presence of a considerable amount of crushed stone in the soil profile. According to the granulometric composition, the gray forest soils are mainly clayey and heavy loamy. They are divided into 3 subtypes: light gray, gray, dark gray. The humus horizon is light gray 12-19 cm, in gray - 15-25, dark gray - 30-40 cm. The humus content in light gray 2-3%, gray - 3-4, in dark gray - 4- 6%. Reaction of light gray acid, gray - acidic and slightly acidic, dark gray - slightly acid. All subtypes are characterized by low erosion resistance. Gray forest soils constitute 37% of the arable land of the republic.

Chernozems are associated with lower, near-bottom sections of the slopes of erosion-denudation and secondary moraine plains where the eluvial-deluvial and deluvial loams are soil-forming rocks. In the early periods of economic development, meadow and shrub steppes were widespread here. There are 3 subtypes: leached, podzolized, typical chernozems (on the deposits of chalk and marl in the southeastern part of the republic). Chernozems have mainly heavy loamy and clayey granulometric composition. According to the thickness of the humus horizon, there are powerful (80-120 cm), medium (40-80) and low-power (up to 40 cm), high humus content (more than 9%), medium (6-9) and low humus 4-6%). Medium-and medium-humus ones predominate. The reaction is weakly acidic, close to neutral. At present, the black earth soils are completely plowed up and constitute 35% of the total area of ​​the country's agricultural lands.

A group of alluvial soils occupy the flood plains of rivers. Alluvial turf (on an elevated riverine floodplain), alluvial meadow (on the central floodplain, around drying lakes-old men), alluvial marshy silty-humus-gley and alluvial marshy silty-peat soils (on sites of pricked swamping) are widespread. They constitute 11% of the total area of ​​agricultural land.

Agro-soil areas

There are five types of agro-soil areas in Mordovia.

The first agro-soil region is sod-podzolic and gray forest soils of light mechanical composition of sandy water-glacial plains and above-floodplain terraces. It is characterized by a wide distribution of the poorest soils, fertile soils, capable of flushing and formation of clefts even with insignificant slopes. Eroded lands occupy about 10% of the territory. The main tasks of agriculture are the full increase of soil fertility through the introduction of high doses of organic and mineral fertilizers, the expansion of crops of perennial grasses and siderates. Agriculture should specialize in the production of potatoes, meat, milk.

The second agro-soil region - leached and podzolized chernozems of heavy texture and gray forest soils in the riverine area - occupies the Moksha-Vad interfluve. Soils have high potential fertility and are suitable for cultivation of all agricultural crops. The share of eroded lands is from 5 to 15% of the area of ​​farms. The main task of agriculture is to preserve and increase soil fertility on the basis of a high crop culture. Agriculture has a grain maple-meat and dairy direction.

The third agro-soil region is gray forest soils of heavy mechanical composition on interfluve spaces and chernozems on the lower slopes of the secondary morainic plain. The predominantly gray forest soils in the soil cover structure are characterized by a relatively high potential fertility, but they are characterized by poor structure. The share of eroded lands varies from 20 to 30% of the territory of farms. In the system of measures to increase the effective fertility of the soils of the region, it is necessary to provide for a complex of erosion control measures, the creation of a powerful (25-30 cm) cultivated arable layer with obligatory liming and application of organic and mineral fertilizers. Agriculture specializes in milk and vegetables.

The fourth agro-soil region is leached chernozems of heavy mechanical composition with gray forest soils on the enclosed areas of the secondary moraine plains. It is characterized by the most fertile soils, suitable for cultivation of all agricultural crops. The share of eroded lands varies from 20 to 30% of the territory of farms. The task of agricultural technology is to preserve soil fertility and combat flat and linear erosion. Agriculture has a grain-and-meat-meat and dairy direction.

The fifth agro-soil region is gray forest soils on the remnant-watershed massifs with narrow bands of chernozems on the fore-part of the slopes. Characterized by crushed stone, strong erosion and low fertility. The share of eroded land to 50% of the territory of farms. The main tasks of agriculture are soil enrichment with organic substances, widespread introduction of erosion control technology. The direction of agriculture is cereal dairy.





Mechanical composition of soils