Zheltozems and red soils: soil characteristics and humus content, use

If we compare zheltozems and krasnozems, it turns out that these soils have a lot in common (characteristics of absorptive capacity, the process of soil formation). These lands are typical for the subtropics and are characterized by a poor content of humus. However, they can be used to grow crops if fertilized and irrigated regularly.

Soil formation conditions

Zholtozems and red soils are infertile soils common in the subtropics. Formed in a humid and warm subtropical climate. Their composition is affected by systematic washing and leaching.Such soils are characterized by medium structurization, high moisture capacity and low humus content.

As a result of intensive washing, almost all primary minerals are decomposed and secondary rocks are formed. Soluble substances move down, while insoluble substances remain and affect the color of the soil.

The type of soil is formed in a climate in which the average annual temperature is 13-15 degrees. Winters in the subtropics are mild and summers are moderately hot. On the territory of distribution of such lands, 1000-3000 mm of precipitation falls annually, mainly in the autumn-winter period. Plant vegetation lasts, depending on the geographical location, from 200 to 365 days.

Soil color is inherited from soil-forming rocks. The thickness of such a soil layer is -40–100 cm.Distributed in the subtropics in the south of North and South America, northern Africa, Southeast and Central Asia, South Australia, locally in southern Europe.

Characteristics of red and yellow soils

Despite the similar climatic conditions of soil formation, these two types of soil have many differences. The main features depend on the relief, parent rock, vegetation.

Composition and properties

Comparative characteristics (table):

KrasnozemsMechanical composition Clay, loamy, heavy loamyStructureLumpy-prismatic, weakly structuredLumpy-granularMoisture capacityHighMediumWater PermeabilityLowMedium Humus content Humus horizon Reaction Color Yellow due to free highly hydrated iron compoundsRed or orange due to the predominance of iron oxidesCondition With excess moisture - sticky, in the dry period - denseHigh silica, low iron and other minerals High iron and aluminum, low calcium, magnesium, potassium, sodium

Criteria	Zholtozems
3.5-5 %	4-8 %
5-10 cm	5 to 20 cm
Slightly acidic pH 5-6	Acid or slightly acidic pH 4-5
	Mineral composition

Structure and genesis

Schematically, the structure of zheltozems and red soils looks like this: under a thin layer (up to 5 cm) of slightly decomposed vegetation lies a humus layer (10-20 cm) of a brownish or grayish shade of a lumpy structure. Below it, starting from the transitional (15-20 cm), there is a metamorphic (clayey) dense horizon of yellow or red color (40-100 cm). Even lower is the parent breed.

As for the genesis, the formation of both types occurs in an acidic environment under deciduous or grassy vegetation. Thanks to the litter, a significant amount of biomass is accumulated - up to 21 tons per 1 hectare. The genesis involves ash elements and nitrogen, which form the basis of the root nutrition of plants. The type of soil formation is podzol-forming and soddy. True, in the red soils, the process of podzolization itself is weakly manifested, in contrast to the yellow soils.

Classification and use

Depending on the climate, vegetation, topography and the specific location of yellow soil and red soil are divided into subtypes. These lands are classified according to the degree of saturation, structure, thickness of the humus horizon and other features.

Main types of yellow soils:

• typical;
• podzolic-yellow earth;
• yellow earth gley;
• podzolic yellow earth gley.

Main types of red soils:

• typical;
• podzolized.

Agrarians adapted both types of soil for growing heat-loving agricultural crops. Due to the warm and humid climate, citrus fruits, tobacco, cotton, grapes, wheat, tea bushes, essential oil and various fruit plants grow well on these lands. True, to obtain a good harvest, regular application of organic matter and mineral fertilizers (nitrogen, potash, phosphorus) is recommended. In the dry season, artificial irrigation is necessary. But the warm climate allows growing two crops a year.

Besides the poor mineral composition, there is another problem. The acidity of such soil is not suitable for growing the desired crops. In acidic lands, only tea bushes can be planted. Liming is required for the cultivation of citrus fruits, cereals and fruit crops. During the development of territories, anti-erosion measures are carried out in parallel.

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