What are the controlling factors of soil secondary halo formation and output

Controlling factors for the formation and production of soil secondary halos include:

1.Mineral properties: The secondary dispersion of elements in the ore is the result of the weathering of ore minerals, so the weathering resistance of the minerals will inevitably affect the secondary dispersion of the elements.

2.Physicochemical environment: The influence of physicochemical environment on the secondary dispersion of elements is mainly reflected in the control of hydrogen ion concentration, redox potential, etc. on the solubility and migration ability of elements in aqueous solution.

3.The role of organisms: Organisms also have a profound influence on the secondary dispersion of minerals. In particular, the effect of plant growth is more significant.

4.Climatic and topographic conditions: Climate determines moisture, vegetation and soil type, and therefore controls the migration and dispersion of elements.

Topography acts indirectly on the soil by causing the redistribution of matter and energy. For example, in mountainous areas, different climate and vegetation zones are formed due to the vertical changes of temperature, precipitation and humidity with the increase of terrain, resulting in significant vertical zone differentiation of soil composition and physical and chemical properties.

In summary, the controlling factors for the formation and production of soil secondary halos include mineral properties, physicochemical environment, biological processes, climatic conditions and topographic conditions. These factors interact with each other to affect the migration and dispersion of elements, thereby controlling the formation and production of soil secondary halos.

Landform is a general term for the various forms on the earth's surface, which can also be called topography. The main influencing factors of landform on soil formation are: mainly through the redistribution of matter and energy, and indirectly acting on the soil.

In the mountains, due to the temperature. The vertical variation of precipitation and humidity with the increase of terrain formed different climate and vegetation zones, resulting in significant vertical zone differentiation of soil composition and physicochemical properties. The study of soil characteristics in the mountainous areas of the southwestern United States showed that soil organic matter content, total porosity and water holding capacity increased with altitude, while pH decreased with altitude.

In addition, slope and aspect, which can affect soil development, can change water, heat and vegetation conditions. On steep slopes, it is difficult to develop deep soils due to gravity and the erosive force of surface runoff, which often accelerates the migration of loose surface materials. In the flat terrain area, the erosion rate of loose materials on the surface is slow, so that the parent material can gradually develop into deep soil under relatively stable climatic and biological conditions. Because the sunny slope receives more solar radiation than the shady slope, the temperature condition is better than that of the shady slope, but the moisture condition is worse than that of the shady slope, and the vegetation coverage is generally lower than that of the shady slope, which leads to the difference of physical, chemical and biological processes in the soil.

The formation of soil is the product of the combined action of climate, parent material, vegetation (biological), topography, and time. Parent material: the material basis of soil formation, the original material that constitutes the soil, and its composition and physical and chemical properties have a profound impact on the formation and fertility of the soil.

For example, rock weathering includes residual sediment and slope sediment; aeolian deposits; fluvial alluvium; Loess-like parent material. Climate:

Mainly temperature and precipitation. It affects the process of rock weathering and soil formation, the decomposition of organic matter in the soil and the migration of its products, and the hydrothermal status of the soil. (Example) Creatures:

The dominant factor in soil formation. In particular, green plants selectively absorb dispersed and deep nutrients, concentrate them on the surface and accumulate them, and promote the occurrence and development of fertility. Terrain:

It determines the degree and stage of soil formation and development, and affects the leaching and accumulation of substances in the soil. Soil is formed by the combined action of the above five soil-forming factors. The factors affect each other, restrain each other, and work together to form different types.

(1) Mountainous and hilly areas.

Mountains and hills are prone to soil erosion, and soil and water conservation measures are the primary importance of utilization management. The mountainous and hilly soil also has the characteristics of thin soil layer and coarse bones. The soil layer is shallow, and the hard bedrock is shallow to be buried, which limits the rooting of plants, and the soil has a low water and fertilizer storage capacity.

The soil contains a large amount of rock debris gravel, leaks water and fertilizer, has low storage capacity, and is prone to drought. There are also a large number of rocky outcrops in stony mountains, which affect farming, so it is generally not suitable for planting crops that need to be cultivated, but suitable for forestry or animal husbandry.

The following issues should be paid attention to in the evaluation of land resources and land use decision-making: first, the slope factor, which directly determines the quality grade of land resources and the choice of land use mode, and is also closely related to the potential danger of soil erosion; The second is the vertical distribution law of land resources in mountainous areas, because the distribution has a certain three-dimensionality, the types are rich and diverse, in the development of land resources, it is necessary to adapt measures to local conditions, and develop a variety of operations and three-dimensional ecological economic system in mountainous areas; Third, there is a problem of water shortage in mountainous and hilly areas, and land use methods and development and management methods should be rationally arranged according to the distribution characteristics of water resources.

2) Plains. The common characteristics of the plains are flat terrain, deep soil layer, and good soil moisture conditions. Therefore, the plain area is a good area for the development of agriculture because the land is fertile and the farmland is convenient for basic construction. The plain has convenient transportation and less investment in real estate development infrastructure, and it is also a good place for construction land.

Plains can be divided into piedmont fan plains, alluvial plains, coastal plains, etc. Each of these plains has its own characteristics.

The material composition and characteristics of the piedmont plain are generally as follows: the material at the top of the fan is coarser and the slope is large, and the middle and lower materials to the fan gradually become thinner, the slope gradually becomes smaller, and the area gradually becomes larger, and the transition from the piedmont plain to the alluvial plain gradually decreases with the decrease of altitude. The piedmont plain is generally gentle on the ground, with a certain slope drop, so the ground drainage is good, there is both abundant surface water, and there is abundant water volume, the groundwater resources that are not buried deep and are easy to exploit, and the water and soil conditions for the development of agriculture are relatively superior, so it is often an intensive agricultural production base.

Alluvial plain: When the river reaches the middle and lower reaches of the river, due to the smaller slope, the suspended material carried in the river water is further deposited, forming a vast alluvial plain, such as the Songnen Plain, Songliao Plain, Huanghuaihai Plain, Jianghan Plain, and the middle and lower reaches of the Yangtze River Plain in China. Due to the flat terrain, abundant water resources and fertile soil of the alluvial plain, they are the main agricultural areas, cultivated land and population concentrated distribution in China.