Where in China are chernozem soils distributed, and what crops are suitable for growing on them?
Where in China are chernozem soils distributed? What are they suitable for growing? Chernozem is a soil developed under meadow steppe and steppe vegetation in temperate semi-humid and semi-arid regions. It is the more humid type among calcareous soils, named for its dark, almost black soil color, and it lies at the easternmost edge of the steppe. Its main feature is that the accumulation of organic matter in the soil exceeds its decomposition. The upper part of the soil profile has a black or grayish-black fertile humus layer, and below this layer or in the middle-lower part of the soil there is a calcium-accumulating horizon enriched in lime, hence the name.
Where in China are chernozem soils distributed?
Chernozem is mainly distributed in the western parts of Eurasia and North America. In China, it is mostly found in the western part of the Northeast region and eastern Inner Mongolia, and is especially concentrated on both the east and west sides of the middle-southern section of the Greater Khingan Range, in the central part of the Songnen Plain, in the watershed area of the Liao River, and extending westward onto the northern slopes of the Yanshan Mountains and in the vertical zonation of the Yinshan Mountains. In Xinjiang, Gansu and Qinghai, it mostly occurs in mountainous areas, such as the northern slope of the Tianshan Mountains, the southern slope of the Altai Mountains, the northern slope of the eastern Qilian Mountains and the northern slope of the Xiqing Mountains; on flat land, only part of the Zhaosu Basin has it.
To the west and south, and downhill in mountainous areas, chernozem is surrounded by chestnut soil. To the northeast, it connects with the black soil belt formed by humid meadow vegetation, and upward it often intermingles with forest soils on shady slopes and gradually transitions to gray forest soil or dark brown forest soil. In Xinjiang and Qinghai, its lower boundary is also chestnut soil, while upward it first intermingles with gray-brown forest soil on shady slopes and then gradually transitions to subalpine meadow soil. This neighboring relationship also shows that the environmental conditions in which chernozem occurs are relatively humid.
What is chernozem suitable for growing?
In China, chernozem regions contain both large areas of farmland and vast, high-quality natural grassland, and are also key areas for building shelterbelts, giving them the foundation and advantages for developing crop farming as well as forestry and animal husbandry. As far as crop farming is concerned, chernozem is a soil with relatively high potential fertility, and a considerable portion of it is suitable for developing grain and oil crops (such as corn, millet, wheat, sunflower and sugar beet), especially wheat, which yields high returns; therefore, the zone where this soil is distributed is called the world's granary.
The main limiting factor of chernozem is insufficient water, with frequent droughts, making supplementary irrigation necessary. The piedmont platform on the eastern slope of the Greater Khingan Range and the central part of the Songnen Plain are rich in groundwater resources that can be extracted and used. In areas without irrigation conditions, crop-grass rotation and the planting of shelterbelts can be carried out.