How to prevent vegetable fertilizer damage in greenhouse in winter

Because of the particularity of greenhouse vegetables, it is easy to appear all kinds of phytotoxicity and phytotoxicity. The main phytotoxicity and phytotoxicity of several greenhouse vegetables are introduced below. 1. The harm of root fertilizer and its solution: 1. The use of a large number of chemical fertilizers has caused serious soil salinization, and the salt concentration in the soil is higher than that in the root system, resulting in poor water potential in the root system, physiological withering of plants due to water loss, and even burning of seedlings. 2. Use organic fertilizers that are not fully fermented, such as chicken manure, which contains a lot of harmful substances such as chloride ions and caustic soda. Poultry manure fermented in the soil will generate a lot of heat, which will cause plants to burn their roots. 3. In the process of producing compound fertilizer, urea generates biuret at high temperature. If biuret exceeds the standard, it will burn seedlings and roots, causing fertilizer damage. 4. In order to pursue the effect, some unscrupulous manufacturers add a lot of synthetic growth regulators to irrigation fertilizers. Excessive use or high concentration will cause root hormone poisoning and inhibit root growth. Solution: Water to reduce harm: water immediately at the early stage of fertilizer damage to promote the penetration of salt and fertilizer remaining in the soil plough layer, reduce their concentration in soil gaps and reduce their continuous impact on plant roots. Root irrigation treatment: biological fertilizers are used to stimulate the growth of roots, such as Ketuoyi organic water-soluble fertilizer of Guthrie Biology in Yantai, a patented product of pure biological rooting and root promotion, rich in chitin and amino acids, which can quickly restore the growth of plants and alleviate the phenomenon of burning roots and seedlings. In addition, the amino acids contained in it can be quickly absorbed and utilized by the root system, which can alleviate the nutritional deficiency caused by root burning and enhance the growth of plants. Second, the causes of foliar fertilizer damage and drug damage: 1. A large amount of nitrogen fertilizer is used in soil, and a large amount of ammonia is produced in the process of soil ammoniation. In addition, poor ventilation in greenhouses in winter causes ammonia damage to vegetable leaves and yellow leaves appear from bottom to top. 2. The harm caused by unreasonable use of bactericidal pesticides; For example, the use of chlorpyrifos in melon seedling stage is prone to phytotoxicity, and the high concentration of triazole pesticides on cucumber will lead to the contraction of cucumber faucet and poor growth of growing points. 3, hormone poisoning caused by dipping flowers, often leaves near dipping flowers appear curly, dark green, mostly caused by high concentration or residue of dipping flowers; If the leaves at the growing point are curly, shriveled and grow slowly, it is mostly caused by hormone accumulation poisoning. Especially in bad weather such as low temperature and cloudy days, the photosynthesis of plants is weakened, and the poisoning symptoms of plants will become more prominent. 4. In order to control the flourishing growth of greenhouse vegetables and promote reproductive growth, vegetable farmers often use growth inhibitors such as chlormequat chloride and mepiquat chloride for spraying, which often leads to hormone poisoning due to excessive control of flourishing growth; In order to pursue the effect of thick stems and dark leaves after use, some manufacturers add growth regulators to foliar fertilizers, which leads to hormone poisoning in unreasonable use by vegetable farmers. 5. In addition, in the process of ventilation, the greenhouse is also facing the elegant phytotoxicity of herbicides outside the greenhouse. Solution: For emerging pesticide hazards, such as bactericidal pesticides and hormone poisoning, spray water in time to reduce pesticide residues on plants.