The composition of soil is complex, how should you correctly distinguish between soil types?

Soils are all produced by the weathering of rocks over hundreds of millions of years, and different rock parent materials produce different soils, and then produce more soil types in the process of natural wind and rain erosion and accumulation. There are many types of soils, but there are relatively stable components. What is the composition of farmer's soil?

Solid matter is made up of inorganic and organic matter. Inorganic matter is a variety of minerals produced by rock weathering, organic matter includes animal carcasses, residues after plant decay, organic matter produced by microorganisms, etc., of which minerals account for more than 90% of the total weight of solid matter, and organic matter accounts for 1-10%. There are also various microorganisms and insects in the soil.

Liquid substances. In other words, water and soil are soil solutions composed of water and dissolved matter, which are the medium for plants, organisms and microorganisms to absorb nutrients, and are also an important means of soil pollution. The solid, liquid, and gaseous substances in the soil form a contradictory community and restrict each other, providing the most basic fertility, water and support for plant growth.

Different climate types form different soil types, different soil soil fertility is different, and appropriate crops have also changed a lot, creating more opportunities and futures for specialty agriculture and agricultural production.

Different flowers have different soil requirements. Some flowers have low soil requirements, good tolerance to barrenness, strong adaptability, and low requirements for soil fertility. For example, pepper orchid, aloe vera, cactus, etc.

Some flowers need to prefer acidic and fertile soil to grow well. Otherwise, there will be problems with poor growth of camellias, gardenias, bean rat eyes, etc. Some people require good water permeability and drainage, otherwise it is easy to hydrate with rotten roots such as various succulents.

Peat is simply the layer of soil that some aquatic plants accumulate in water without completely decomposing. Peat soil is rich in organic matter, humic acid and nutrients, peat soil is light in weight, good in conservatism, and conducive to various microbial activities. Peat soil colors are usually brown, black, brown, black-brown, etc.

Usually when we plant flowers, we mix most of the peat in the soil in order to increase the nutrient and organic matter content of the soil. Long-term maintenance of the fertilizer efficiency of the soil promotes better growth of plants. But peat is very conservative and cannot be used alone for flowers that do not have water tolerance, so as not to produce rotten roots.

Decaying leaf soil is the soil formed by fermentation of deciduous leaves, dead branches, straw and other substances and the original soil. It takes more than a year for decaying leaf soil to form to blend with the soil. Humus soil has good air permeability, lightness, strong conservative moisturizing ability, contains organic matter, humic acid and other nutrients, which can well promote plant growth and development.

At present, the two most common soil classification methods are occurrence classification and systematic classification, and the more common one is occurrence classification, which is classified according to the geographical location, natural characteristics and development process of soil formation and development.

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 aeration performance.

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.

First of all, it should be distinguished according to the color of the soil, and there is a lot of soil now, and for some reason, there is no fertility at all, but the fertility of red soil is indeed very sufficient, and when growing crops, you can get a high yield.

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.

According to its genesis type, it can be divided into: residual soil, slope soil, alluvial soil, silt soil, glacial soil and aeolian soil.

There are many kinds of soil on the earth's crust, in order to facilitate research and practical application, it can be approximately classified according to the engineering properties of the soil, and the particle size composition has always been the basic basis for the classification of soil.

According to the particle size, the soil is first divided into coarse-grained soil with a particle diameter greater than 50% of the millimeters and fine-grained soil with a particle diameter of less than 50% of the millimeters, and the standard for the subdivision of coarse-grained soil is still the particle size composition, and the particle diameter is greater than 2 millimeters and accounts for more than 50% of the gravel soil, otherwise it is sandy soil. However, the relationship between the properties of fine-grained soil and particle size is not as close as its relationship with water, so plasticity index is widely used as the standard for dividing fine-grained soil in countries around the world.

Soils can be divided into three categories: sandy soil, clayey soil, and loam.

Sandy soil properties:

The sand content is high, the particles are coarse, the specific surface area is small, and the number of large pores between the grains is large, so the soil has good aeration and permeability, and the drainage in the soil is smooth, and it is not easy to produce water support, waterlogging and water retention in the upper layer.

Poor storage capacity. The performance of water retention, water holding and fertilizer retention is weak, and it is easy to cause water and fertilizer loss after rain, and the water evaporation rate is fast, and the loss of moisture is easy to cause soil dryness.

Clayey soil traits:

Poor permeability. The particles are fine, the intergranular pores are small, the ventilation and water permeability are poor, and the drainage is not smooth, which is easy to cause surface water accumulation, water retention and waterlogging.

Strong retention. The soil particles are fine, the colloidal substance content is large, the soil solid surface area is huge, the surface energy is high, and the adsorption capacity is strong. The performance of water absorption, water retention, water retention and fertilizer retention is good, but the fertilizer efficiency is slow.

Loam soil properties: aeration, water permeability, water retention, fertilizer retention. Loam soils contain medium and large particles, moderate voids, and moderate drainage and culverts. Good loam contains up to 50% voids, half water and half air, and the rest is gravel, sand and clay in the appropriate proportions.