What are the types of soil treatment?

1. Heating

The basic principle of heating is to raise the temperature of the soil to effectively kill pathogens, arthropods and pests in the soil, usually 70℃ treatment for 30-60mm can effectively kill most pests, but not effective for specific viral diseases TMV. In Europe the method was utilized in greenhouses before the 20th century. There are two key problems with this method: (1) the temperature must be at or above the temperature tolerated by the pests in the soil; (2) the temperature must not be too high. Temperatures above 70°C and especially 100°C may harm most of the organisms in the soil and cause the death of beneficial microorganisms (rhizobia, mycorrhizae, antagonistic bacteria). Heated soils may be more susceptible to disease than unheated soils if the temperature is not properly controlled. Therefore, distribution of temperature in the soil profile is important to minimize disruption of microecological activity in the soil.

2. Heavy water soaking

Heavy water soaking of soil is considered an effective pre-plant treatment for disease control. Reduced oxygen concentrations, increased carbon dioxide concentrations, and the interaction of various microorganisms are detrimental to the presence of soil-borne diseases, such as the production of toxic substances during anaerobic processes. The classic example is the control of banana wilt on a large scale, where the soil in banana plantations is soaked for 3 to 4 months or longer (water depth of at least 30 cm). However, this method is not effective in soils where large numbers of pathogens are present or where unknown factors favoring the presence of pathogens are present.Newhall conducted a study on the control of soil-borne diseases, including pathogens and nematodes, by soaking in large quantities of water. However, this method can only be applied in areas where water resources are relatively abundant. Prolonged high water soaking in summer can control the occurrence of Verticillium dahliae in rice fields, and the control of Verticillium dahliae directly reduces the occurrence of cotton yellow wilt and improves cotton yield. Rice plots rotated for 1 year could effectively inactivate Verticillium dahliae. Soil was soaked for 6 to 8 weeks in greenhouse and field trials, and its saturated infiltration had an important role in reducing Verticillium dahliae populations.

3. Deep tillage

Deep tillage reduces the connection between the plant root system and the pathogen, and improves the mortality of the pathogen by utilizing soil burial and exposing the pathogen to natural temperature and dry conditions. Deep tillage of organic matter is a non-polluting tillage practice that can effectively control white silk disease of peanut. Also deep tillage reduces the incidence of tomato blight and improves yields compared to shallow tillage.Newhall's research shows that deep tillage reduces disease incidence by exposing the soil to light during the hot season.

4. Light energy use

Solar disinfection reports began in 1976, the Israelis KatanJ use of solar disinfection to successfully control tomato and eggplant wilt and several weed trials. 1977, the United States, the University of California at Davis researchers KatanJ on this basis, the application of solar disinfection on the field of cotton wilt control trials Is the first application of solar disinfection. Subsequently, solar disinfection has received widespread attention and application around the world. During the 10-year period 1976-1986, solar disinfection was attempted in at least 24 countries, most of which were located in the tropical regions most suitable for solar disinfection applications. The research on soil solarization technology became more and more in-depth, and by the mid-1970s, the technology was gradually formed. Before planting to borrow light energy to heat the soil to prevent diseases, the method is to cover the soil with plastic film to increase the temperature of the soil, thereby controlling the occurrence of diseases. Greenhouses utilize this principle to reduce the incidence of pests and diseases. In traditional agriculture, farmers use the disinfecting effect of sun-exposed soil to reduce soil-borne pests and diseases. The SoilSolarizatiom technology currently used abroad was developed on this basis. It is a technology that "applies plastic film to cover the soil for more than four weeks during the hot season (summer) on moist soil that is ready for planting crops, raising the temperature of the soil at a certain depth, so as to kill or reduce harmful organisms in the soil". The main principle of this technique is to kill harmful organisms in the soil by applying Hydrothemal sterilization. There are three types of mulching technology: ① single film mulching technology (film thickness of 60-8μm). In subtropical climatic regions, the application of a single layer of film covering the soil is sufficient to achieve the effect of eliminating soil-borne pests. ② Double-layer membrane covering. In warm temperate regions, such as Japan and the Mediterranean region of Europe, the use of double-layer film covering in greenhouses can prevent the dissipation of heat, temperature and volatile gases, increase the indoor temperature by 3 to 10 ℃, increasing the effectiveness of pest control. ③ Black film covering plus soil hot water treatment. In Jordan, field application of black film covering combined with hot water treatment of the soil (in 10-20cm of soil, filled with warm water at 15-20℃) can raise the soil temperature to 56-60℃, increasing the effectiveness of control.

5. Soil hygiene

The main purpose of soil hygiene is to prevent or reduce the invasion of pathogenic bacteria into the soil using various methods. Farming attention to the hygiene of agricultural tools to prevent the spread of pathogenic bacteria caused by agricultural tools; many areas in order to better control soil hygiene, choose to plant in the greenhouse can be convenient to control a variety of conditions, thereby reducing the pollution from the outside of the soil, the emergence of diseased plants in a timely manner to deal with the removal of the disease, which can reduce the further infestation.

6. Application of soil additives

Soil additives are a kind of organic and inorganic nutrient mixture synthesized by organic matter of animal and plant bodies, chemical fertilizers and a small amount of inorganic salt. Inorganic additives can directly promote the growth of crops, but also inhibit the soil pathogenic bacteria; organic matter can enhance soil fertility, improve soil aeration and increase the total number of microorganisms. 1954 Vaugh reported that the application of yellow cedar pine bark ammonia compost fertilizer can be prevented and controlled by the epidemic caused by the mold of the strawberry red in the column of the disease; in 1977, Skiguchi found that the Japanese vegetable farmers use larch bark compost after , effectively prevented and controlled the brown rot of Chinese yam caused by Fusarium; in 1983 Kuter et al. reported that the use of broadleaf pine bark by open and recreational piles of two kinds of piles respectively produced the effect of inhibition of rice blight fungus. Use of green manure and plant and animal residues to control soil-borne diseases. Green manure has exuberant and developed root system, and various inorganic salts and organic matter secreted by its root system provide a good physicochemical environment for the growth of microorganisms; Gibert's research in 1970 reported that purple clover quiz added to the soil can alleviate root diseases caused by Phtophthora, Fusarium, and Thielaviopsis, etc., and the addition of a large amount of alfalfa, after 50d can destroy all the fungus nuclei in the soil, add a small amount of alfalfa, after 80d 90% of the fungus nuclei were destroyed, while only 25% of the fungus nuclei were victimized by those who did not add; in 1971 Lewis et al. pointed out that the use of kale, chard, and mustard pomace added to the soil can significantly reduce the incidence of root rot of peas; in 1965 Khalifa reported that cultivation in the greenhouse and the additive application of chitin controlled pea wilt caused by Fusarium. Antagonistic microorganisms can also be added to the additives, taking advantage of the advantages of rapid reproduction of microorganisms, a large number of artificial propagation and then applied to the soil, which can regulate the root micro-ecological environment, limit the reproduction of soil-borne pathogenic fungi and inhibit the occurrence and development of soil-borne diseases, and also enhance its inherent antagonistic effect.