The method of disinfection of high temperature greenhouse in summer

In the season of changing stubble of vegetables in greenhouse, that is, in the high temperature season of July, August and September, the technology of high temperature canopy is adopted, which can not only mature the soil, increase the content of organic matter, improve the soil structure, but also eliminate the pathogenic bacteria and underground pests caused by continuous croping. and easy to operate, the effect is remarkable.

The method of high-temperature stuffing greenhouse disinfection is to use the high temperature of the sun and drug fumigation to disinfect the greenhouse in summer, generally from early July to late August. This method has the advantages of low cost, low pollution, simple operation, good effect and easy to be accepted by the masses.

? I. the concrete method of stuffing the shed at high temperature

Soil preparation and fertilization: the land should be leveled and fine, and combined with soil preparation and fertilization, in order to kill germs in organic fertilizer. Application of organic fertilizer, such as chicken manure, pig manure, cow manure, etc., or the use of plant straw such as corn straw, rice straw (cut into 3-5 cm long segments), plus lime nitrogen. The amount of organic fertilizer per mu is generally 3000 to 5000 kg, and lime nitrogen is 60 to 100 kg per mu. Spread it evenly on the surface of the soil, then turn it 25cm to 30cm deep. Organic fertilizer, such as chicken manure and dried cow manure, can improve the soil temperature and maintain the ground temperature, so that the germicidal effect is better. After the land is ready, ridging or making a high and low border according to the planting mode of the crops, which can form a small space between the plastic film and the ground, which is helpful to improve the ground temperature.

Irrigation: make a dam around the greenhouse, irrigation, the water surface had better be 3cm higher than the ground, cover the old film conditionally, close the greenhouse tuyere, cover the greenhouse film, prevent Rain Water from entering, strictly maintain the tightness of the greenhouse, so that the temperature of 10 cm below the surface reaches more than 70 ℃, and the ground temperature of 20 cm reaches more than 45 ℃, thus achieving the effect of sterilization and insecticidal. Soil water content is closely related to germicidal efficacy, if the soil water content is too high, it is disadvantageous to improve the soil temperature; if the soil water content is too low, it can not achieve a better germicidal effect. Practice has proved that when the soil water content reaches 60% of the maximum field capacity, the effect is the best.

Drug treatment: disinfect the soil covered with plastic film with chloropicrin to kill the germs in the soil. The method is to inject chlorinated bitter into the border, 50 square centimeters to dig a hole, a depth of 10 to 15 centimeters, 4 milliliters per hole. In addition, before the airtight greenhouse, the inner surface of the shed was sprayed with fungicides and insecticides to kill germs and pests hiding in the cracks in the wall.

Closed greenhouse: double-layer covering with greenhouse film and plastic film to strictly maintain the tightness of the greenhouse. Under such conditions, the highest ground temperature at 10 cm below the surface can reach 70 ℃, and the ground temperature at 20 cm can reach more than 45 ℃. The sterilization rate of such high ground temperature can reach more than 80%.

Disinfection time: most bacteria are not resistant to high temperature and can be killed after a short period of heat treatment (about 10 days), such as some Rhizoctonia solani, Sclerotinia sclerotiorum of cucumber, cucumber blight, eggplant Verticillium wilt and so on. However, some bacteria are particularly resistant to high temperature, such as root rot, root swelling, Fusarium wilt and other deep root soil infectious bacteria, because of their deep soil layer, they must be treated for 30 to 50 days to achieve better results. Therefore, when carrying out soil disinfection, the disinfection time should be determined according to the heat resistance of the crops grown in the greenhouse and their corresponding bacteria.

Post-disinfection treatment:

The main results are as follows: 1. Biological bacterial fertilizer must be applied after high temperature. If there is no increase in the application of biological bacterial fertilizer, then if bacteria invade after planting, there will be no beneficial bacteria to buffer or control the development of diseases, and vegetables are likely to have diseases in a large area, especially root diseases. Biological bacterial fertilizer was evenly applied to the planting hole according to the dosage of 80kg / mu and 120kg / mu before vegetable planting in order to protect the rhizosphere environment and enhance the disease resistance of the plant.

2. Solar thermal disinfection has the best effect on soil not more than 15 cm deep, and poor effect on soil more than 20 cm deep. Therefore, it is best not to plough the soil after disinfection, even if ploughing should be limited to a depth of 10 cm. Otherwise, the germs in the soil below will be turned over again, resulting in re-pollution. Although the solar thermal disinfection method can not completely sterilize the greenhouse, it can greatly reduce the density of germs in the field and greatly reduce the chance of crop disease, and its disinfection effect can last for 2 years, so the greenhouse can be sterilized once every two years.

Second, the effect after the high temperature stuffy shed

1. Significantly reduce more than 10 kinds of diseases caused by continuous cropping, such as Fusarium wilt, root rot, Verticillium wilt, Phytophthora, gray mold, stem rot, virus disease and so on.

2. Obviously reduce the invasion of root-knot nematode disease. After strict treatment, the greenhouse with serious continuous cropping obstacles can basically return to the level of vegetable yield and quality at the time of the new greenhouse.

3. The high temperature greenhouse and rapid retting of organic manure enrich the nutrients in the soil needed by vegetables, degrade the toxic and harmful components in the soil, especially the pesticide residues in the soil, and create favorable conditions for the realization of pollution-free production.

4. Rational application of lime nitrogen can significantly reduce the content of nitrate in agricultural products, reduce soil acidification and adjust soil pH value.