Technical guidance for topdressing in vegetable seedling

During vegetable seedlings, if the seedbed soil is not fertile enough, the seedlings will have symptoms of de-fertilization (such as thin stems, small leaves, light color, etc.), and should be topdressed in time. The specific requirements and practices are:

　　 1. The time of top dressing is generally appropriate after the seedlings are out and the cotyledons are flattened; in the middle of the day, it is better to take the sunny morning from 10 to 12 o'clock.

　　 2. Topdressing method Fertilizer and organic fertilizer can be applied as top dressing; topdressing fertilizer should be based on nitrogen fertilizer, better with compound fertilizer, watering can be applied first, or water can be applied, or fertilizer can be dissolved in splashed water facilities, chemical fertilizer and watering control ratio 0.1 to 0.3: 100; if the fertilizer is excessively large, a concentration of more than 0.5%, it is prone to "burn seedlings"; of organic fertilizer, a multi-use maturity Human excrement or ring fertilizer, first dilute the fertilizer with water 10 to 20 times, and then fill it into the seedbed; whether it is applied with fertilizer or organic fertilizer, it should be sprayed with water after fertilization to wash away the fertilizer attached to the leaf to prevent Burn the leaves and ventilate in time to prevent harmful gases (such as ammonia, hydrogen sulfide gas, nitrous acid gas, etc.) from escaping the vegetable seedlings.

　　 3. When the root dressing temperature is low and the seedling root temperature is weak, it is not suitable for root topdressing. It can use 0.1% potassium dihydrogen phosphate or 0.3% urea solution, or 0.2 to 0.3% superphosphate leaching solution. Shi.