Six key points to note for scientific fertilization in greenhouses

Greenhouse vegetable cultivation differs from open-field vegetable cultivation in the types and methods of fertilization. Greenhouse vegetables have stricter requirements for fertilization techniques. Improper fertilization can produce harmful gases that damage the vegetables, affecting not only vegetable yield and quality but also causing soil salinization in the greenhouse. Therefore, the following issues must be noted when fertilizing greenhouse vegetables:

1. Control the amount of nitrogen fertilizer applied and prohibit the use of nitrate nitrogen fertilizers. Nitrogen fertilizer is an indispensable fertilizer in vegetable production, but it must not be applied in excess. To achieve pollution-free standards for vegetables, the nitrate content in vegetables must be reduced. In addition, chlorine-containing fertilizers such as potassium oxide and ammonium chloride should not be applied. Chloride ions can reduce the starch and sugar content of vegetables, degrading quality and lowering yield, and when they remain in the soil they easily cause soil decalcification and lead to compaction.

2. Do not use volatile chemical fertilizers during topdressing. Greenhouse production is mostly carried out in cold seasons. The greenhouse has good airtightness, with little or no ventilation. If volatile fertilizers are applied, high concentrations of harmful gases can easily form inside, endangering the crops.

3. When used as base fertilizer or topdressing, undecomposed organic fertilizer must not be applied. This is especially true of undecomposed cake fertilizer, chicken manure, human urine and feces, and similar materials, because when these fertilizers decompose under the high-temperature conditions of the greenhouse they produce large amounts of ammonia gas, which is extremely harmful to plants.

4. Emphasize applying more organic fertilizer. Organic fertilizer can not only improve soil fertility, increase plant nutrition and increase carbon dioxide, but also prevent and control salt damage.

5. Implement formula fertilization. Determine the appropriate amounts of nitrogen, phosphorus, potassium and trace elements and the corresponding fertilization techniques according to the nutrient requirements of different vegetables and the soil's nutrient supply status.

6. After fertilization, promptly spray plant cationic activators (Zhuangdiling, Zhuangjingling) to activate the positive energy of plant ecological growth, broaden the plant's conduit pathways, enhance the plant's water and fertilizer absorption capacity, and improve yield and quality.