The relationship between plants and soil is like the relationship between people and food. The direct source of plant nutrients is the soil. Nutrients are transported to the branches and leaves of the plant through the plant's own conduits and sieve tubes, allowing it to grow. The soil It is the loose surface layer on the surface of the lithosphere and is the matrix for terrestrial plant life. It provides essential nutrients and water for plant life and is an important place for the exchange of matter and energy in the ecosystem.

Due to the huge contact area between plant roots and soil, there are frequent material exchanges between soil and plants, which strongly influence each other. Therefore, soil is an important ecological factor for plants. By controlling soil Factors can affect plant growth and yield. The distribution of plant roots in the soil is related to the structure, fertility, aeration and moisture conditions of the soil.

Composition

The materials in soil can be summarized into three parts: solid part, liquid part and gas part.

Soil minerals are mineral particles of different sizes (sand particles, soil particles and colloidal particles) formed by the weathering of rocks. There are many types of soil minerals with complex chemical composition. They directly affect the physical and chemical properties of soil and are one of the important sources of crop nutrients.

Soil is composed of minerals and humus. Solid soil particles are the main body of soil, accounting for about 50% of the soil volume. The pores between solid particles are occupied by gas and water.

The vast majority of soil gases are oxygen, nitrogen, etc. that enter from the atmosphere, and a small part are carbon dioxide and water vapor produced by life activities in the soil. The water in the soil mainly enters the soil from the surface, including many dissolved substances.

There are also various animals, plants and microorganisms in the soil.