Soil fumigation can also be one of the more commonly used methods for soil restoration and sterilization, reducing the frequency of spraying, killing soil-borne pathogens, and preventing dead and rotten seedlings. Sometimes the operation is wrong, and the control effect of pesticide fumigant is not ideal. Don't worry, today we will tell you how to operate soil fumigation! What are the factors of soil fumigation effect? How to choose soil fumigation disinfectant?
1. Factors affecting the effect of soil fumigation
The correct soil preparation is an important factor that affects the effect of soil fumigation. Make sure that there are no crop stalks, no large clods, especially residual roots in the soil. Because most pesticide fumigants cannot penetrate the residual roots of crops, and kill the pathogenic bacteria in the residual roots.
The depth of loose soil is more than 35 cm. Maintaining the permeability of the soil will help the pesticide fumigant move in the soil, to achieve a uniform disinfection effect.
In a piece of land, the structure of the soil should be consistent. The soil should be level, not too dry or too wet.
To obtain a better weeding effect, the soil can be drenched before rotary tillage to facilitate the germination of weed seeds, and when the topsoil is dry, perform rotary tillage. Rotate the land at least one week before fumigation to ensure sufficient time to correct the soil moisture.
Soil temperature has a great influence on the movement of pesticide fumigant in the soil. Proper soil temperature helps the movement of pesticide fumigant. The ideal temperature is to keep the target organism in a "live" state to facilitate better killing. Usually, the ideal soil temperature is 15 cm, 15 ℃ ~ 20 ℃.
The proper soil moisture is to ensure the softening and germination of the seed coats of weeds; the pests are in a "growth" state; there is sufficient humidity to "activate" the pesticide fumigant. In addition, humidity helps the movement of pesticide fumigant in the soil. Generally, the soil moisture should be around 60%.
Because the penetration of pesticide fumigant to different plastic cloths is very different, the quality of the film significantly affects the fumigation effect. It is recommended to use virgin membranes over 0.04mm, and regenerated membranes are not recommended.
Second, the timing of soil fumigation
The timing of using soil pesticide fumigant for soil disinfection must be grasped well, and it is effective to choose to proceed immediately after the previous crops are harvested. Such as fumigation to kill root-knot nematodes, at this time most of the root-knot nematodes gather on the soil surface, which is easier to kill in a concentrated manner. Otherwise, the soil disinfection after the pests and diseases migrate to the deep layer of the soil will reduce the effect, causing some pathogens to escape by chance and reoccur in the coming year.
After fumigation, prevent re-infection. Pesticide fumigant only eliminates the existing pests and diseases in the soil. It does not have a valid period and can do nothing about the re-introduced pests and diseases. In addition, do not turn the soil deeper after smoking than before. If you do not turn it before (shallow turning) and turn it deeply after smoking, it will turn up the nematodes and other pests that have not been killed in the deep layer.
3. Planting time after fumigation
The planting time after fumigation depends on the open air time after treatment so that the fumigation poisonous gas can be emitted to avoid phytotoxicity when planting crops. The planting time after fumigation is largely related to the characteristics of pesticide fumigant and soil conditions, such as soil temperature and humidity.
When it is cold and wet, the open air time should be increased; when it is hot and dry, the open air time can be reduced; the high organic matter soil should increase the open air time; clay requires a longer open air time than sandy soil.
4. Rural hygiene and management after fumigation
After soil fumigation and disinfection, avoiding the re-introduction of pests and diseases is very important. You may unintentionally bring pests in untreated soil, plant waste formed by previous crops, and irrigation water to the treated (fumigated). In the soil.