Where in China is dark loessial soil mainly distributed, and what crops is it suitable for growing

Dark loessial soil is a type of chernozem-like soil developed on loess parent material with a residual argillic horizon (commonly known as the dark loessial soil layer). The upper part of the dark loessial soil profile has a dark gray humus layer with cryptic argillic characteristics; although this layer is relatively thick and loose, its humus content is not high.

In China, dark loessial soil is mainly distributed in northern Shaanxi, eastern Gansu, southern Ningxia, northern Shanxi and Inner Mongolia, on the Loess Plateau in loess tablelands, loess hills and high river terraces where soil erosion is relatively light and the terrain is relatively flat. It is most common in tableland areas with flat terrain and lighter erosion, such as the Dongzhi Tableland, Zaosheng Tableland and Luochuan Tableland, and is one of the main soil types in China's Loess Plateau region.

Because the humus layer of dark loessial soil is thick and its workability is relatively good, it has all been turned into cultivated soil. There are many crops suitable for growing in dark loessial soil, mainly wheat, millet and broomcorn millet, beans and corn. However, to prevent soil erosion, measures should be taken during use to stop soil and water loss, make full use of surface and groundwater resources, expand the irrigated area and increase the application of organic fertilizers.

Related reading: Types of dark loessial soil

In addition to typical dark loessial soil, the following subtypes can also be distinguished:

1. Dark burnt soil

It is mostly found in the northern and western parts of the Loess Plateau, connecting with chestnut soil and sierozem respectively. It develops on sandy loess. The humus layer is 1-1.5 m thick, coarse in texture and dark in color; physical clay is 20%, about 4 times that of the parent material. The lime deposition layer is obvious, the soil pH is about 8.5, and the lime content is 0.2-2.8%. The cation exchange capacity is low. The soil is dry and warm, sprouts seedlings quickly, but has poor staying power.

2. Argillic dark loessial soil

It is mostly found in the southern part of the Loess Plateau, connecting with ? soil. The humus layer is 40-80 cm thick, with obvious argillic phenomena, and is grayish brown. The deposition layer has more bean-shaped and nodular lime concretions, and the entire profile shows a strong lime reaction, with a lime content of 1-12%. It has relatively strong water and fertilizer retention capacity and high fertility.

3. Dark hemp soil

It is mostly found west of the Liupan Mountains in flat areas of high hills at an altitude above 2000 m. The humus layer is more than 1 m thick, relatively black in color, with an organic matter content of 2-3%, and the entire profile has a strong lime reaction; the soil is wet and cool, drought-tolerant but not waterlogging-tolerant.