What are the characteristics of the soil, the characteristics of the soil resources

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.

The shape of the soil: Soil particles are formed by the different ways in which they are stacked together to form the soil structure. In addition to sand, soil particles are aggregated together in the form of soil structure under natural conditions, and the influence of soil texture on soil production traits is also expressed through soil structure.

Characteristics of soil: After the formation of the soil, each soil layer is different in composition and properties, so it is reflected in the morphological characteristics of the profile, and the layers are also different. In the field, some important properties of soil can be judged through the observation of soil profile morphology.

The important morphological characteristics of soil are: solidity, porosity, moisture, new organisms, intrusives, animal porosity, etc.

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.

1.Soil resources have a certain degree of productivity, and the level of its productivity, in addition to being related to the natural properties of soil, is largely determined by the level of human production science and technology. Different types and properties of soil have different suitability for agriculture, forestry and animal husbandry.

2.Soil resources are renewable and cultivateable, and human beings can make use of the law of soil change and development, apply advanced technology, promote the continuous improvement of fertility, produce more abundant products, and meet the needs of human life. If soil is not used properly, its fertility and productivity will decline.

3.The location of soil resources is fixed, the area is limited, and at the same time, it has the nature that other resources cannot replace. In the case of a growing population, soil resources should be used and protected rationally.

4.The spatial existence of soil resources has the law of regional differentiation, which is manifested in the periodicity of seasonal changes in time, and the soil properties and production characteristics also change periodically with the change of seasons.

This paper briefly describes the characteristics of soil resources in China.

China's cultivated land is only 100 million mu, and the per capita is only 100 mu. Less than 1 3 of the world average. The area of grassland is only 1 3 of the world per capita, and the area of forest land is only 1 5 of the world average per capita. The per capita resources are low.

Moreover, the area of arable land is decreasing and the population is increasing. Land degradation is serious, soil desertification, grassland degradation is serious, and soil erosion and soil pollution are also very large.

Soil formation is related to topography, climate, vegetation, soil parent material and soil age. To put it simply, soil is also the result of weathering of surface rocks. But it also includes the role of microorganisms and plants, which obtain water and nutrients from the original weathering matter, which in turn accumulates nutrients such as organic matter and nitrogen to create fertility and form soil.

Human activities have accelerated the evolution of soils.

Soil is the product of the combination of five factors: rock, climate, biology, topography and time: the release and loss of nutrients under weathering, the accumulation of organic matter under the action of lower organisms and microorganisms, and the enrichment of nutrients (resynthesis of humus from organic matter) under the action of higher organisms. Organisms play a leading role in the process of soil formation, and reasonable human farming can improve soil fertility and promote soil to become a renewable resource for sustainable use.

Irrational use can degrade soil (desertification, salinization, soil erosion, etc.).

Then the common soil is some small microorganisms, to decompose the soil, the effect on us is particularly large, but also the need of our living environment.

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%.

1. Soil formation factors: Soil is the product of climate, parent material, vegetation (biology), topography and time.

2. The role of soil: 1. The role of nutrient bank: soil is an important source of nutrients necessary for terrestrial organisms;

2. Biological support: including mechanical support for green plants, and at the same time, it also has a wide variety and a huge number of biological groups in the soil, which supports underground organisms to live and breed here;

3. Rainwater conservation plays a regulating role in water and solute flow;

4. Nutrient transformation and circulation: realize the circulation and turnover between nutrients and organisms, and maintain the life cycle and reproduction of organisms;

5. Stabilizing and buffering environmental changes: including buffering capacity to changes in external environmental temperature, humidity, acidity and alkalinity, redox properties, filtration, buffering, degradation, fixation and detoxification of organic and inorganic pollutants;

6. Maintain biological activity, diversity, and productivity.

3. Soil formation: Rocks are weathered to form soil parent material (a small amount of minerals are released in the process). Because of the accumulation of organic matter and nutrients, the lower plants settle on the soil parent material to form the original soil (in the process, the organic matter is more abundant and humus is formed).

The formation of the original soil allows the higher plants to form mature soil, which is what we call soil.

The characteristics of loam soil: good aeration and water permeability, water retention and thermal insulation performance, drought and waterlogging resistance, strong stress resistance, wide adaptability, long tillage period, easy to cultivate into high-yield and stable-yield soil.

There are several basic components of good loam:

1. Porosity.

Loam soils contain medium and large particles, moderate voids, air, and moderate drainage and culverts. Good loam soils contain up to 50% voids, half water and half air.

2. Moisture. The pores of loam contain a lot of air, can attach a lot of water, and store nutrients, which can be eaten by plants for a long time and are not easy to lose.

3. Living organisms.

In addition to the above-mentioned inanimate substances, there are countless living organisms that depend on organic matter for survival and reproduction. They work together to convert large molecules into small molecules that plants can absorb.

4. Nutrients.

Most of the more than 90 elements in the earth's air, soil and rocks are needed for the survival of living things. Carbon, oxygen, and hydrogen are essential elements for all life. Plants and animals, including humans, must need a large number of elements.

It is nitrogen, phosphorus, potassium, calcium, magnesium, sulfur.

Characteristics of loam: 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.

In addition, there is a large amount of humus. The humus inside is like a net, which can net soil particles, can absorb 5 times more water, and can also gently grasp minerals - calcium, copper, zinc, manganese, cobalt and other nutrients inside, and will not be easily washed away by water.