Types and characteristics of fertilizers

   scientific and rational fertilization must understand the types and characteristics of fertilizers. At present, the fertilizers commonly used in various parts of our country mainly include organic fertilizer and inorganic fertilizer.

   organic manure mainly includes barnyard manure, human manure, livestock and poultry manure, compost and green manure and so on. Organic fertilizer contains a variety of nutrient elements, which belongs to complete fertilizer, but it must be decomposed and decomposed before it can be absorbed and utilized by trees. Organic fertilizer can increase the content of organic matter in soil, improve the water, fertilizer, gas and heat status of soil, promote the activity of soil microorganisms, and thus play the role of soil fertility, water storage and fertilizer conservation, and sustainable supply of nutrients. The fertilizer effect of organic fertilizer is slow, and it is mainly applied as base fertilizer to increase the storage and accumulation of nutrients, promote root growth and enhance the overwintering resistance of trees. Among them, green manure is a kind of good organic fertilizer, which is rich in a variety of nutrient elements. planting and applying green manure can increase the content of organic matter in soil, improve the available state of soil nutrients, improve soil structure and promote material circulation.

The picture shows walnut

   inorganic fertilizer, also known as chemical fertilizer, can be divided into nitrogen fertilizer, phosphate fertilizer, potash fertilizer and compound fertilizer according to its different nutrient elements. Nitrogen fertilizer mainly includes urea, ammonium bicarbonate, ammonium chloride, ammonium sulfate, etc.; phosphate fertilizer mainly includes calcium superphosphate, phosphate rock powder, etc.; potassium fertilizer mainly includes potassium sulfate, plant ash, etc.; compound fertilizer mainly includes diammonium phosphate, potassium dihydrogen phosphate, nitrogen phosphorus potassium compound fertilizer and so on. Chemical fertilizers generally contain single nutrients, but they have high nutrient content, high fertilizer effect and quick effect, so it is suitable to apply a small amount of fertilizer for many times. Chemical fertilizer is easy to lose, volatilize or be fixed by soil after application, so it is a quick-acting fertilizer, which should be applied in the period before the tree needs fertilizer. It is mainly used as topdressing and foliar spraying fertilizer in production, and can also be mixed with organic fertilizer as base fertilizer. For example, the topdressing of ammonium nitrate, urea and ammonium bicarbonate before the flowering of walnut can play the role of flower and fruit protection, and nitrogen and phosphate fertilizer after anthesis can effectively prevent physiological fruit drop. The fertiliser containing only one nutrient element must be applied in combination with other kinds of chemical fertilizer in order to give full play to its fertilizer effect.