What are the types of soil? What are the characteristics of each, what is the distribution?

The types of soil are sandy, clayey, and loam. Sandy soil refers to coarse-grained soil, which refers to soil with a large particle content of more than millimeters.

Land is the atmosphere, soils and basic geology, hydrology and flora above and below the surface of a given area of the Earth, as well as the results of past and present human activities within that area, as well as the significant influence of animals on the present and future use of land by humans.

According to the differences in the character, region and use of the land, the land is divided into a number of different categories according to certain laws.

There are currently three broad classifications of land in China:

1. Classification according to the natural attributes of the land, such as landform, vegetation, soil, etc.;

2.Classification according to the economic attributes of the land, such as the production level of the land, the ownership of the land, the right to use, etc.;

3 Comprehensive classification of land according to its natural and economic attributes, as well as other factors, such as land-use status classification.

<> soil refers to a layer of loose material on the earth's surface, composed of various granular minerals, organic matter, water, air, microorganisms, etc., which can grow plants. Minerals, animals and plants formed by the weathering of rocks, organic matter produced by the decomposition of microbial residues, soil organisms, and humus from water, air, and oxidation.

and so on. The main characteristics of the soil:

1. The soil is fertile;

2. The soil has buffering properties;

3. The soil has the function of purification.

Soil can be divided into three types: sandy soil, clayey soil, and loam.

The properties of sandy soil: high sand content, coarse particles, fast water seepage, poor water retention performance, and good aeration performance.

The properties of clayey soil: low sand content, fine particles, slow water seepage, good water retention performance, poor aeration performance.

The nature of loam: general sand content, general particles, general water seepage rate, general water retention performance, general ventilation performance.

Differentiation and assemblage of soil species on the Earth's land surface. It is closely related to the comprehensive change of physical geographical conditions.

Soil is one of the basic elements of land, which is composed of minerals, organic matter, water (soil solution), air (soil air), and organisms including microorganisms.

Understanding and mastering the types of soil and adapting measures to local conditions is of great significance to the development of agriculture, forestry, animal husbandry, sideline and fishery industries. China has a vast territory, complex climate, different topography and landforms, so there are many kinds of soil, which is suitable for the growth of various crops.

The basic ideas of the theory of soil-forming factors can be summarized as follows:

1. Soil is an independent natural body, which is formed under the very complex interaction of various soil-forming factors.

2. For the formation of soil, various soil-forming factors are equally important and irreplaceable. Organisms play a leading role in it. Soil is formed by the action of living organisms on the parent material of soil formation in a certain period of time, under certain climatic and topographical conditions.

Soils are not born with fertility characteristics to grow green plants. Like biological development, soil development has a series of processes. Among them, parent material, climate, biology, topography and time are the five key soil-forming factors for soil formation.

The three main characteristics of soil are as follows:

1. Dispersion.

There is no or weak bond between the bulk particles, and there are a large number of pores, which can be permeable to water and breathable.

2. Polyphasicity.

Multiphase refers to the fact that soil is often a three-phase system composed of solid particles, water and gas, and the changes in quality and quantity between the three phases directly affect its engineering properties.

3. Natural variability.

Natural variability refers to the fact that soil is a multi-mineral assemblage formed by the evolution of a long geological history in nature, which is complex, uneven, and constantly changing over time.

1. Sandy soil is not susceptible to waterlogging due to its good permeability;

It is easy to cultivate, with low tillage resistance and low energy consumption; The sand content in sandy soils is overwhelmingly dominant, so the nutrients required by crops are deficient.

The water and fertilizer retention performance of sandy soil is poor. 2. Clay soil has fine soil particles, nitrogen, phosphorus, potassium and other mineral nutrients, poor permeability, and strong fertilizer retention ability, which is conducive to the accumulation of organic matter.

Due to the strong water retention of the soil, it has poor aeration and is prone to hypoxia.

3. Soil is organically composed of four components: solid phase (minerals, organic matter), liquid phase (soil moisture or solution) and gas phase (soil air).

In terms of volume, minerals account for about 38-45%, organic matter accounts for about 5-12%, and pores account for about 50% in the ideal soil. By weight, minerals account for more than 90-95% of the solid part, and organic matter accounts for about 1-10%.

Soil genesis Soil formation factors parent materials, climate, living organi**s, relief and time

Parent Factors Soils can evolve from rocky in-situ weathering or any deposits.

The nature, structure, colour and composition of rocks or deposits have a direct impact on the soil.

The difference in the parent material affects the rate of soil formation and the thickness of the soil layer.

As the soil matures, the influence of this factor gradually decreases, and its influence is eventually completely masked by other factors.

Topographic factors Topography has an impact on the climate, causing changes in the moisture and temperature conditions of the soil. The height rises, the temperature drops, and the amount of moisture decreases.

Topography affects the distribution of surface and groundwater and affects the transfer of substances in the soil.

Topography influences soil erosion. The slope is large, the scouring effect is serious, the water and nutrients are lost, and the upper layer is thin.

The orientation of the hillside affects heat and humidity. The sunny slope has low temperature, high humidity and a large amount of sunshine.

Soil catena Changes in soil profiles on different terrains. On steep slopes, the thickness of the soil layer decreases. On flat land, the soil layer is thick. In swampy areas, peat layers are formed.

The undulations of the mountain affect the drainageOn the slopes of the hills, the drainage is rapid, and the soil moisture content is low. On flat ground, if the soil or rocks are poorly drained, the groundwater level rises to the surface, allowing organic matter to accumulate.

In gently undulating terrain, drainage is ideal and the soil profile remains stable. On steep slopes, there is excessive water loss and the soil profile is stunted.

Time Factor The properties of the soil take time to develop.

In young soils, the characteristics of each soil layer are not obvious.

The soil develops over a long period of time in a stable climate, resulting in a mature soil profile.

Time affects the importance of other soil-forming factors. In the early stages of soil formation, the parent material factor is most important. However, after the formation of soil, other factors become increasingly important.

Note: The above three factors slowly and intrinsically affect the change of soil essence, which is called negative factors. The following two groups of factors (climatic and biological) will affect soil formation more sharply and externally, and are called positive factors.

Climatic factors Regardless of the parent material of the soil, the characteristics of the soil will be very similar over time under the same climatic conditions.

Precipitation Moisture status.

Water affects chemical processes and biological activities in the soil.

Humid and rainy areas, salt leaching and acidic soils. Soil nutrients move down and fertility declines.

In dry areas, evaporation is greater than precipitation, and the moisture in the soil rises, causing salt to accumulate on the surface, forming a hard pan

In areas with high precipitation (rainfall of 600 mm), leaching soil or bauxite is formed. (pedalfer soil)

Areas with low rainfall (rainfall.