Soil health is essential for successful crop production, and ensuring that the soil is free from harmful pathogens is a crucial step. One effective approach is to replace the soil or implement proper crop rotation in the field. Additionally, maintaining good growing conditions through proper management helps prevent disease development. When soil treatment is necessary, annual disinfection is recommended, with methods such as steam, soaking, or chemical treatments being commonly used. The choice of method depends on factors like temperature, duration, and concentration.
Steam sterilization is particularly effective for treating soil up to 25–30 cm deep at a temperature of 80°C for at least one hour. Interestingly, weak-pressure steam tends to be more effective than high-pressure steam. This method can help control various diseases except for pyocyanosis. To enhance its effectiveness, it's often combined with specific bactericides. However, in soils with low pH, excessive manganese may become an issue. To address this, adding lime to adjust the pH or using short-term steam treatment can help keep manganese levels within acceptable limits.
In greenhouses, the immersion method is another option. First, crops like two-color plants are sown in May. By mid-June, when the plants reach about 50 cm in height, the soil is tilled to a depth of 20 cm. Then, 100 kg of calcium nitrate is applied per 1,000 square meters. By late July, a raised bed approximately 60–70 cm wide is formed, and the area is watered and covered with plastic. After 2–3 weeks, the soil is tilled again, and pH and electrical conductivity levels are checked to ensure they meet the required standards.
Chemical disinfection is also a viable option when feasible. Fungicides and other chemicals can be applied, but it’s important to do so when the soil temperature is between 10°C and 12°C. Once applied, the soil should be covered with plastic. After three days of warm weather, the plastic is removed, and the process continues for 7–10 days under cooler conditions.
Pythium, a common soil-borne pathogen, has a strong ability to regenerate, which means that a single annual treatment may not be sufficient. To manage fungal growth effectively, it’s advisable to apply fungicides before each planting cycle. These products should be evenly distributed by mixing them with sand and applying by hand, or by spraying with warm water using a watering can. This ensures coverage down to 15–20 cm below the surface. For best results, the fungicide should be thoroughly mixed into the soil either manually or with a rotary cultivator. Regular monitoring and proactive measures are key to maintaining healthy, disease-free soil.
FOSHAN PHARMA CO., LTD. , https://www.forepharm.com