It is not suitable to fertilize greenhouse vegetables in winter.

In greenhouse vegetable cultivation in winter, there are many kinds of deficiency, such as charred edge of calcium deficiency, zinc deficiency leaflet, iron deficiency etiolation, boron deficiency terminal bud necrotic root growth and so on. As we all know, vegetable nutrient deficiency is abnormal because the root system does not absorb enough nutrients in time, but the root absorption obstacle is not necessarily due to the lack of this element in the soil. In most cases, improper management measures such as fertilization and watering lead to the deterioration of soil properties, or the effective activity of nutrient elements in the soil decreases, half-cooked food is difficult to swallow, or the root system grows poorly. Although the food is delicious, I can't eat it. Therefore, the fertilization of greenhouse vegetables in winter should pay attention to ten unsuitable.

1. It is not suitable to apply a large amount of unripe cake fertilizer.

Because the cake fertilizer contains more nitrogen, the ratio of carbon to nitrogen is small, and the decomposition is fast, it is easy to produce high temperature and high concentration of ammonia and organic acid, and it is easy to burn roots. The cake fertilizer should be crushed and added to the crushed straw, soaked in human feces and urine for about 3-5 weeks, and then used after high temperature fermentation.

2. Ammonium sulfate is not suitable and ammonium bicarbonate is prohibited.

Ammonium sulfate is a physiological acid fertilizer, which will increase the acidity of soil and destroy soil structure after application. A large amount of ammonia is volatilized after the application of ammonium bicarbonate, which is disadvantageous to the growth of vegetables in the airtight greenhouse.

Third, it is not suitable to apply chemical fertilizers containing chlorine.

Chloride ion can reduce the starch and sugar content of vegetables, deteriorate the quality of vegetables, reduce the yield, and chloride ions remain in the soil, which can lead to soil acidification and soil decalcification.

Fourth, it is not suitable to apply fertilizer under dry conditions.

Vegetables are water-loving crops. Fertilizing when the soil is dry, not only the fertilizer effect can not be brought into full play, but also the concentration of soil solution will suddenly increase, which is easy to make vegetables burn roots. Therefore, vegetable fertilization should be combined with irrigation, or open ditches to fertilize, bury the fertilizer firmly and then irrigate, or follow the water and topdressing.

Fifth, it is not suitable to apply diammonium phosphate.

Most vegetables need less phosphorus, but excessive phosphate fertilizer inhibits the absorption of trace elements. Diammonium phosphate should not be mixed with plant ash and other alkaline fertilizers to avoid ammonia volatilization and ammonia damage.

6. it is not suitable to apply potash fertilizer in the later stage of vegetable growth.

Vegetables generally need more potash fertilizer before and after flowering, and then gradually decrease.

7. It is not suitable to apply phosphate fertilizer separately.

Phosphorus is easily absorbed and solidified by the soil and loses its fertilizer effect. therefore, when phosphorus fertilizer is used as base fertilizer, it is best to use it in trench or concentrated in the soil layer with dense roots in the early stage of vegetables.

It is not suitable to apply a large amount of zinc and iron fertilizer in the soil.

Zinc and iron are trace elements, and they are difficult to be absorbed by roots in soil, and their transmission is slow. Therefore, an appropriate amount of zinc and iron fertilizer can be added to the base fertilizer, and when vegetables are deficient in zinc, the foliar spray of micro-fertilizer containing zinc (such as Zhongbao Imperial Doctor) will be more effective.

It is not suitable to spray potash fertilizer and calcium fertilizer at the same time.

The encounter of potassium and calcium is more difficult to be absorbed by vegetable leaves, so the co-spraying of boron and calcium, zinc and iron is better.

It is not suitable to apply a large amount of water-soluble fertilizer at one time.

In winter, the soil temperature is low, the root absorption capacity is slightly poor, one-time application of a large amount of fertilizer, the root can absorb very little, the fertilizer gradually accumulated in the soil will in turn worsen the soil properties and reduce the root absorption capacity. Therefore, if you apply fertilizer in winter, you should eat less and eat more.