There are those vegetables that like fat and water

Vegetable fertilization also needs to pay attention to many problems, and it is necessary to apply fertilizer by classification [1] and fertilization at different times.

1. The application of ammonium nitrate to green leafy vegetables such as cabbage, Chinese cabbage, amaranth, celery, spinach, etc., has a short growth period and is easy to absorb nitric nitrogen fertilizer, which will lead to excessive nitrate content in vegetables. Ammonium nitrate should not be applied to green leafy vegetables.

2. The spraying of pure nitrogen fertilizer on green leafy vegetables should not be foliar spraying of nitrogen fertilizers such as urea or ammonium sulfate, nor should it be sprayed with human urine. Urea, ammonium sulfate or human urine sprayed on the leaf surface will significantly increase the nitrate content, affecting human health.

3. After applying urea, urea can not be irrigated immediately, and only under the action of urease secreted by soil microorganisms, it can be converted into ammonium carbonate or ammonium bicarbonate, which can be absorbed and utilized by vegetable roots, or absorbed and preserved by soil adsorption. Immediately after urea application, irrigation or rain shower, amide nitrogen will be lost with water, resulting in loss of nitrogen nutrients. Generally, urea is applied for 5-7 days before irrigation, which can avoid unnecessary nitrogen loss.

4. Do not apply ammonium sulfate to acidic soil or calcareous vegetable fields for many times in a row, if ammonium sulfate is applied many times in a row, it will make the acidic soil more acidic; Limestone soils cause soil compaction, which hinders the normal growth of vegetables.

5. Ammonium bicarbonate should not be applied for water shortage in vegetable fields Ammonium bicarbonate is extremely unstable and volatile loss, especially in the case of drought and water shortage in vegetable fields, the loss is more serious. The application of ammonium bicarbonate in vegetable fields, whether as base fertilizer or top dressing, should be applied deeply under the condition of wet vegetable fields, and the soil should be covered immediately after application.

6. The amount of phosphorus fertilizer should not be too much in vegetable fields, such as a large number of phosphate fertilizers are applied in successive years, and there is too much phosphate fertilizer, especially in the case of more than 40 kg per mu, which will seriously affect the growth and development of vegetables, so that vegetable plants will be prematurely senescent, poor growth, reduced yield, and poor quality. Generally, 15-20 kg per mu is appropriate.

7. Green leafy vegetables should not be applied to non-rotting human manure to produce human feces, especially in the manure tanks of hospitals, stations, docks, restaurants and public toilets, which contain a variety of infectious bacteria and parasite eggs. If this kind of manure is directly poured on green leafy vegetables without being prepared or treated, the vegetables will be seriously contaminated and even lead to the transmission of a variety of infectious diseases and parasitic diseases. With this manure, it can be applied after harmless treatment such as sealed piles, digester fermentation and drug treatment.

8. Livestock pen manure should be applied to pigs and cattle after the feed is mostly crop straw and weeds, and there are many weed seeds mixed with straw and weeds, and the weed seeds in the livestock manure manure are extremely vigorous, and can still germinate and reproduce with the manure circle manure into the vegetable field, which is very harmful to vegetables. The manure should be lifted out of the circle and piled at high temperature to kill the weed seeds, parasite eggs and pathogenic bacteria in the livestock pen. Generally, it can be applied after about 2 months of natural stacking, and it can be fully decomposed after 10 days of treatment with biological starter culture.

Cabbage, yam, rape, lotus root, radish.