Where is the yellow brown soil distributed in China? What is suitable for growing?

Where is the yellow brown soil distributed in China? What is suitable for growing? To understand these two problems, we must first find out what yellow brown soil is.

Yellow brown soil is developed under the mixed forest of evergreen broad-leaved and deciduous broad-leaved forests in the subtropics. Its main feature is that there is a brown or reddish brown B layer in the profile, that is, a clayey layer with a large amount of clay, and there are iron-manganese nodules in the soil. Chinese soil science literature once called yellow-brown soil as gray-brown clayey soil, which has been named since the 1950s. For similar soil, the Soviet Union called it yellowish brown forest soil, Japan named it yellowish brown soil, and the United Nations Food and Agriculture Organization and UNESCO named it leachate soil.

Distribution area of yellow brown soil in China

The distribution range of yellow brown soil in China is roughly as follows: Qinling Mountains and Huaihe River in the north, Dabashan Mountain and the Yangtze River in the south, the southeast edge of the Qinghai-Tibet Plateau in the west, and the lower reaches of the Yangtze River in the east. Yellow brown soil is distributed in the northern margin of subtropics, with high temperature in summer and warm temperate zone in winter, with an annual average temperature of 15 ℃, accumulated temperature of more than 10 ℃ and frost-free period of 210-250 days. The annual precipitation is 750mm to 1000mm, and the mountain area is more than 1000 mm. The zonal vegetation is deciduous broad-leaved forest, but there are evergreen broad-leaved tree species. The parent materials of soil formation are mostly weathered granite, gneiss, dry phyllite and sand shale.

From the perspective of specific areas, yellow brown soil is mainly distributed in Shandong Peninsula and Liaodong Peninsula, and also in the vertical zone of cinnamon soil zone. The climatic conditions of the yellow brown soil region are warm, hot and rainy in summer, cold and dry in winter, the annual average temperature is 5: 14 ℃, the accumulated temperature above 10 ℃ is 3400-4500 ℃, the seasonal frozen layer depth is 50-100 cm, the annual precipitation is about 500-1000 cm, and the dryness is between 0.5-1.0 cm. The primary forest here has long been destroyed, and at present it is mostly secondary coniferous forest and broad-leaved mixed forest.

The topography of yellow brown soil is mainly low mountains and hills, and the parent materials of soil formation are mostly residual slope deposits of granite, gneiss and sand shale, or thick alluvium. In the brown soil area, due to the high temperature and rainfall in summer, not only the viscous action in the soil is strong, but also the leaching effect is obvious, so that the soluble salt and free calcium carbonate are leached, and the clay particles move downward along the profile and deposit. The high ash content of litter in deciduous broad-leaved forest prevents the development of soil ashing, but albinism often occurs in hills and mountains.

What is suitable for planting in yellow brown soil

The yellow brown soil area has superior hydrothermal conditions and high natural fertility. It is very suitable for the growth of many kinds of forests. it is not only a concentrated producing area of economic forest in China, but also an important farming area, rich in a variety of grain and cash crops.

In order to restore and develop the mountain yellow brown soil suitable for local economic forestry production, attention should be paid to the characteristics of its distribution in the north-south transition zone when introducing economic trees, and afforestation should be carried out according to the specific conditions. In the shallow soil layer, it is appropriate to plant drought-tolerant Pinus massoniana, Robinia pseudoacacia, poplar and so on. Oak, Cunninghamia lanceolata, camellia oleifera, paulownia, lacquer tree, bamboo tea, mulberry and other economic trees can be developed in places with thick soil layer and good fertility, and Sapium sebiferum with high economic value can be planted in places with poor drainage.

The mountainous area with large slope, coupled with deforestation and unreasonable reclamation in the past, caused serious soil erosion and greatly reduced soil fertility in some areas, especially in the Dabie Mountains. Therefore, the work of soil and water conservation should be vigorously strengthened. first of all, small watershed planning should be made. in those places with bare soil and many gullies, fast-growing and lateral root-developed tree species should be selected to build slope protection forest (such as Masson pine, Robinia pseudoacacia, etc.) and gully bottom anti-erosion forest (such as Sapium sebiferum). In the tea, mulberry and orchard on the slope, the methods of contour planting and building terraces should be adopted, combined with green manure mulch, which can not only prevent soil erosion, but also achieve a bumper harvest of forest and animal husbandry.

For the yellow brown soil distributed in a large area in the hills, because of its heavy texture and poor physical properties of water, such as heavy volume, low porosity, stagnant water in rainy season and poor ability of water conservation and water supply in dry season, it is the main obstacle to the utilization of agriculture and forestry. It is generally adopted to deepen the plough layer year by year, re-apply organic fertilizer and increase phosphorus fertilizer to make the soil mature gradually, or apply cinder, furnace ash and use Kang field and fumigated soil in leisure season, so as to improve the ventilation and water permeability and tillage performance of the soil.