Q: What are the main points of application technology of compound fertilizer?

A: One of the main points of the compound fertilizer application technology is that it should be used as a base fertilizer. The reason is: â‘  base fertilizer deep application can help absorb in the crop root against nutrients. 2 Compound fertilizers are ternary compound fertilizers containing nitrogen, phosphorus and potassium. The base fertilizer can meet the maximum needs of phosphorus and potassium nutrients in the middle and late crops. 3 The application of base fertilizer can overcome the difficulty of chasing phosphorus and potassium fertilizer in the middle and late stages .

Q: If the compound fertilizer is not used in the base fertilizer, can it be used as a top dressing after emergence?

Answer: The second technical point of application of compound fertilizer is that, in principle, it is not recommended to use ternary compound fertilizer as top dressing, but emphasize the use of single nitrogen fertilizer as top dressing, so that the ratio of nitrogen, phosphorus and potassium nutrients can be adjusted. The reason for not advocating the use of ternary compound fertilizer for topdressing is to avoid the waste of phosphorus and potassium resources, because it is difficult to exert phosphorus and potassium fertilizer on the surface of the soil, and the utilization rate in the season is not high. If no compound fertilizer is applied to the base fertilizer, it can be properly applied after emergence, but it is best to apply the ditch and cover the soil after application.

　 Q: Some places now advocate the use of compound fertilizer to make fertilizer for greenhouse vegetables. Is this right?

A: Cucumbers, green peppers, tomatoes and other vegetables are harvested many times. After each harvest, appropriate nutrients should be added . This can be done by applying fertilizer. However, the soil available phosphorus content in the general vegetable greenhouse is extremely high, and it is not necessary to use the ternary compound fertilizer for the fertilization. Of course, it is used as fertilizer nitrogen fertilization should be used, a high content of potassium, the whole water-soluble fertilizer.

Q: So, can you use compound fertilizer to make fertilizer?

A: compound fertilizer administration of three technical points, the principle can be used to make highly concentrated fertilizer types of fertilizer, seeds and fertilizers because of the high concentration mix easily burn seedlings. If it is necessary to make a fertilizer, it is necessary to separate the seed from the fertilizer. Farmers in some places in the Northeast have used compound fertilizers with a total nutrient content of 30% in the same ditch. The results have an impact on the emergence of maize. This lesson should be learned.

Question: What problems should farmers pay attention to when applying compound fertilizer?

A: should pay attention to three issues:

First, although the compound fertilizer is a good fertilizer, the application amount should not be too large. According to a farmer in Hubei Province, the application of 12-6-7 compound fertilizer per mu is as high as 200-250 kg. As a result, the cabbage is not ideal. It is recommended that farmers should consciously get rid of the misunderstanding that “the more fertilizer is applied, the more the production will increase”.

Second, we must choose according to crop types for compound fertilizer, some farmers regardless of cabbage is also kind of radish, all with a 12-6-7 fertilizer is inappropriate. Because leafy vegetables are good for nitrogen, and root vegetables are like potassium, you should choose different compound fertilizers. The fertilizer is highly targeted and the effect is natural.

　 Third, the calculation of the amount of compound fertilizer should be based on phosphorus and potassium nutrients. The insufficient nitrogen can be adjusted by topdressing nitrogen fertilizer, so that balanced fertilization can be achieved.

Expert tips

　　 1. The compound fertilizer is best used as a base fertilizer to meet the large demand for phosphorus and potassium in the middle and late crops.

　　 2. In principle, compound fertilizer cannot be used as seed fertilizer. If it is necessary to make seed fertilizer, it must be done “fertilizer and seed separation” to avoid burning seedlings.

　　 3. In principle, compound fertilizers are not recommended for topdressing because the phosphorus and potassium resources are wasted in the current season.

This issue Expert: Lun Chen Shou (China Agriculture University Professor)