How to fertilize off-season vegetables in greenhouses
The use of greenhouses to grow off-season vegetables is naturally different from conventional open field or seasonal planting, and has higher requirements for the greenhouse environment and management technology. In this article, we mainly describe the key points of fertilization for off-season vegetable cultivation in greenhouses.
First, choose the appropriate fertilizer varieties:
Fertilize according to vegetable type. Cucumbers, peppers, tomatoes and other fruits and vegetables, in addition to nitrogen fertilizers, phosphorus and potassium fertilizers are also in great demand. The base fertilizer should be a nutrient-balanced compound fertilizer and an organic fertilizer.
Use organic fertilizers. The application of organic fertilizers can not only improve the physical, chemical and biological characteristics of the soil, ripen the soil, improve soil fertility, improve the quality of products, reduce the content of nitrate and nitrite in vegetables, increase the content of vitamin C, and increase the sugar content of fruits and vegetables. The application of organic fertilizers must be fully decomposed, especially chicken manure, which requires a high degree of decomposition and should be applied in advance.
2. Determine the economical fertilization amount
The premise of determining the economical fertilization amount to meet the demand of vegetables should be calculated according to the level of vegetable yield and soil fertility. For example, when the supply of nitrogen, phosphorus, and potassium in the soil can meet the needs of crops, the fertilizer application rate is calculated according to 20 percent -40 percent of the amount carried out by crops for the intensity of fertilizer supply. At the current fertility level, nitrogen control, phosphorus reduction, potassium stabilization, and targeted application of micro-fertilizers should be the fertilization principles.
3. Select the type of fertilizer
Generally, chlorine-based fertilizers, such as potassium chloride, ammonium chloride, etc., should not be used. Chloride ions can reduce the starch content in vegetables, making the quality worse, and residues in the soil can easily cause soil compaction. It is not suitable to use volatile nitrogen fertilizer varieties, such as ammonium nitrate, ammonium bicarbonate and other nitrogen fertilizers. If used, it is better to ditch and apply it to the deep soil.
4. Reasonable fertilization methods
The base fertilizer is preferably applied one week before the planting of greenhouse vegetables, and should be mixed with the soil evenly. Topdressing can be applied in furrows or holes 7-10 cm away from the plants. After topdressing, cover soil and water in time. Do not sprinkle fertilizers directly on the ground or plants to avoid fertilizer volatilization or burn vegetable seedlings.
