What is the structural nature of soil, and what are the four categories of soil structure

Self-aware.

You can refer to it, mainly from the definition of this aspect to explain what is the structure of soil, which is more popular.

Soil fertility mainly includes four aspects: water, fertilizer, gas and heat.

The physical properties of the soil are compared by three (solid, liquid, and vapor phase volume ratios) and texture (according to the mass percentage of solid sand, silt, and clay particles.

Division), bulk density (undisturbed soil dry mass per unit volume), porosity, structure (block, columnar, prismatic, nucleus, flake, agglomerate, micro-agglomerate) and other components. These soil indicators are interlinked, and their impact on soil fertility cannot be evaluated in isolation.

In pedology, soil structure is defined as the arrangement and combination of soil particles (single and multi-grain). Soil structure contains soil structure.

and soil structural, usually referring to soil structural.

Block, columnar, prismatic, nucleated, and flake are poor structures, with small total porosity, mainly small inactive pores, and large ventilation pores between structures, which often become channels for water leakage and fertilizer leakage. Plant roots are difficult to pierce, and dry cracks often tear off the root system.

The aggregate structure is a good structure, not only the total porosity is large, but also there are a large number of large and small pores in the interior, the aggregate is loosely arranged between the aggregates, and there are many large pores, which has the dual roles of water storage and aeration.

Soil structure refers to the arrangement and combination of soil particles, including aggregates. In the field, it is often referred to as structures of different shapes and sizes that can be separated from each other. Soil structure is formed by the comprehensive action of physical, chemical and biological factors in the process of soil formation or utilization, and can be divided into three types: block, sheet and columnar according to the shape. According to its size, degree of development and stability, etc., it is further divided into clumps, clumps, lumps, and blocks

The soil structure can be divided into four categories, namely block structure, sheet structure, columnar structure and prismatic structure, and aggregate structure, among which the aggregate structure is the most suitable structure soil type for plant growth, which indicates the level and utilization value of soil fertility to a certain extent.

Soil structure type refers to the type that is divided according to the external properties of the soil structure, such as its shape and size. Soil structure is the arrangement and combination of different particles in the soil, and it is the shape formed by the comprehensive action of physical, chemical and biological factors in the process of soil formation or land use. According to its size, degree of development and stability, it is further divided into agglomerate, clumpy, blocky, prismatic, columnar and sheet structure.

Soil structure refers to the arrangement of solid particles, the number, size and stability of pores and aggregates. It can be divided into micro-aggregate structures (less than millimeters in diameter), aggregate structures (millimeters) and structures larger than agglomeration structures. The agglomerate structure is the humus in the mound.

The mineral soil particles are bonded into small clumps of millimeter diameter, and have the characteristics of water stability that does not disperse when soaking in water. The soil with aggregate structure is a well-structured soil box, which can coordinate the relationship between water, air and nutrients in the soil box, unify the contradiction between fertilizer preservation and fertilizer supply, is conducive to root activities and absorption of water and nutrients, and provides good conditions for the growth and development of plants. The soil with no structure or poor structure has a solid soil body, poor aeration and water permeability, the activities of microorganisms and animals in the soil are inhibited, and the fertility of the soil is poor, which is not conducive to the rooting and growth of plant roots.

The texture and structure of the soil are closely related to the moisture, air and temperature conditions of the soil.

Soil structure refers to the cleanliness and contact between soil particles. The soil structure includes aggregate structure, block structure, nuclear structure, columnar structure, prismatic structure, sheet structure, etc.

Soil particles are formed by sticking to each other in different ways of accumulation. 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. The types of soil structure are flaky, lumpy, columnar, and small-grained.

In the surface layer of drylands, flakes of soil crusts and lamination often occur. Interestingly, in desert and semi-desert areas, the soil surface is formed by the growth of mosses, lichens, fungi, bacteria and other lower plants, also known as desert biological crusts, which is an important indicator of the fixed status of sandy land. Block-like structures and columnar structures have few internal pores and are dense and compact, all of which belong to poor structures.

Farmers call large clods of soil as kola, and as the saying goes, "crops are not only afraid of grass, but also afraid of kola's bite". The best soil structure in agricultural production is the aggregate structure, which is a small soil mass that is approximately spherical and porous, with a diameter of between, and the diameter is called micro-aggregate.

The aggregate structure is generally more in the cultivated layer, and the masses call it "ant eggs" and "rice grits". The number and deterioration of aggregate structure reflect the level of soil fertility to a certain extent. In paddy fields, the number of micro-aggregates is more important than the number of aggregates, and the more fertile the paddy field, the more micro-aggregates in the soil.