Causes of Continuous Cropping Obstacles in Scallions and the Latest Prevention and Control Methods

Friends who grow vegetables all know that the same crop cannot be grown continuously in one plot of land for a long time, otherwise continuous cropping damage will occur, and the common scallion in our daily lives is no exception. In mild cases of continuous cropping of scallions, plant growth is insufficient and yield is affected; in severe cases, large areas of plants shed and there may even be basically no harvest. So what causes the continuous cropping obstacles in cilantro? How should they be prevented and controlled? Let's learn about it together.

I. Causes of Continuous Cropping Obstacles in Cilantro

1. Soil acidification

Scallions have high yields, reaching 6000-10000 kg per mu, and such large yields also remove base elements such as calcium, magnesium, and potassium from the soil. This causes excessive consumption of trace elements in the soil, making the soil acidic. In addition, applying large amounts of acidic fertilizers, as the cultivation years increase, causes accumulation of acid radicals in the soil, leading to soil acidification. Excessive application of nitrogen fertilizer and compound fertilizer also very easily causes nitrogen nitrification and acidification, leading to increased soil acidity.

2. Soil salinization

Somewhat similar to soil acidification, the main cause of soil salinization is also fertilizer and water management. Excessive chemical fertilizer application makes it impossible for cilantro to absorb nutrients, and salts accumulate on the surface layer of the soil, causing scallions to show symptoms of physiological drought. After applying human and livestock manure and urine, large amounts of ammonia volatilize and decompose, salt substances remain in the surface soil, and with frequent watering, the soil moisture is relatively high, leading to salt accumulation on the surface. Watering too frequently causes the soil to become compacted and cloddy, salts rise with water to the plow layer, and as water evaporates, salts accumulate.

3. Nutrient deficiency

Fertilization is single and only chemical fertilizers are applied, while the application of other elements and trace elements is neglected. Over time, nitrogen and phosphorus elements accumulate too much in the soil, and the proportion of trace elements becomes seriously imbalanced, which inhibits cilantro's absorption of other elements, causes an imbalance in nutrient proportions, forms nutrient deficiency disorders, and directly affects the quality and yield of scallions.

4. Soil-borne diseases

The main soil-borne diseases of cilantro include downy mildew, gray downy blight, leaf spot, purple blotch, leaf blight, root rot, verticillium wilt, and others. The pathogens of these diseases continue to accumulate in the soil, and the longer the continuous cropping period, the more severe the disease occurrence.

II. Prevention and Control Methods

1. Crop rotation and changing stubble

For scallion soil acidification, salinization, and soil-borne diseases, they can be rotated with rice for 2 years, and then cilantro can be planted for 2-3 years. This can play an excellent role in washing out acid, washing out salt, and controlling disease, reducing the degree of soil acidification, salinization, and soil-borne disease occurrence.

2. Disease prevention and control

Disinfecting the soil before planting can kill most soil-borne pathogens. When diseases are found, they should be controlled promptly, and different agents should be sprayed according to the specific disease.

The above is an introduction to the causes of continuous cropping obstacles in scallions and the prevention and control methods. We hope it can help you. If you want to learn more related knowledge, please stay tuned to us.