Vegetable fertilizer damage and prevention method

  　　

In vegetable production and cultivation, fertilizer damage occurs frequently, especially in the process of nursery, the damage is more serious.

    1. Trauma type of fat.

    1.1 Gas poisoning. Mainly refers to ammonia gas, ammonia gas volatilizes in the air, when its concentration reaches 5 mg / kg or more, the leaves will appear water-immersed spots, and the water will die with water loss, leaving dead spots. When the ammonia concentration of up to 40 mm / kg, vegetable acute injury, tissue damage of the inner blade, chlorophyll disintegration, massive injury between the veins appear dark brown spots. Ammonia poisoning is likely to occur when ammonium bicarbonate or ammonia water is applied , and it often occurs when urea is applied, and application of unfermented organic fertilizer can also cause ammonia damage.

    1.2 concentration damage. If the chemical fertilizer or human and animal excrement is applied too much, the soil concentration will be too high (high). When the total salt concentration in the soil solution exceeds 300 mm / kg, the absorption of nutrients and water by the crop is hindered, the cell penetration resistance is increased, and the roots are difficult to absorb water. The reason for this is that the fertilizer is applied dry, and the fresh livestock and poultry manure is not decomposed, but is directly applied to the vegetable field, and organic acid and heat are generated during the decomposition process, and the amount exceeds the standard.

    2 , internal injury type fat

    It refers to the destruction of ion balance in plants due to improper fertilization, causing physiological damage.

    2.1 Ammonia poisoning. When there is too much ammonium in the soil, the plant will absorb too much ammonia, causing ammonia poisoning and affecting the normal progress of photosynthesis.

    2.2 excessive nitrogen fertilizer. Excessive nitrogen fertilizer is applied in the vegetable field. During the digestion process, nitrous acid accumulation often occurs, and nitrous acid poisoning occurs, which is characterized by browning of the roots and yellowing of the leaves; when the nitrogen is excessive, the vegetables will be decalcified, such as large Cabbage dry heartburn; when too much nitrate nitrogen, causing vegetables to lose green and lack of molybdenum.

    2.3 Antagonism. Excessive application of potassium fertilizer hinders the absorption of calcium and magnesium, and also hinders the absorption of boron by crops. Such as causing stalks of celery.

    3 , prevention measures

    3.1 Apply fertilizer to the vegetable field. Must be applied in limited quantities and at specified concentrations. As long as the amount of fertilizer is controlled, the damage will be greatly reduced. Generally, ammonium bisulfate should not exceed 30 kg per acre , ammonium sulfate should not exceed 20 kg, and urea should not exceed 10 kg.

    3.2 When applying fertilizer to vegetable fields. Layered application must be used to achieve soil fertility. The fertilizer is evenly distributed throughout the tillage layer. Organic fertilizer must be fermented and decomposed, and pay attention to proper watering after application to keep the soil moist. Reducing the concentration of the solution is beneficial to the effect and absorption of the fertilizer.