Fertilisers are food for plants, substances that directly or indirectly supply crops with the nutrients they need to improve soil properties in order to increase crop yield and quality. There are many ways to classify fertilisers, which are generally divided into inorganic, organic and microbial fertilisers. At present, inorganic fertilisers play a decisive role in production, followed by organic fertilisers, with microbial fertilisers taking up a smaller share.
Inorganic fertilisers, as opposed to organic fertilisers, are fertilisers made up of inorganic substances, also known as chemical fertilisers, or chemical fertilisers for short. In chemical fertilisers are divided into nitrogen, phosphorus, potash, calcium, magnesium and sulphur fertilisers, compound fertilisers and trace element fertilisers according to the type of nutrients they contain. Commonly used phosphate fertilizers are calcium superphosphate, calcium superphosphate, calcium magnesium phosphate, phosphate powder, etc., commonly used potassium fertilizers are potassium chloride, potassium sulfate, kiln ash potash, etc., commonly used compound fertilizers are ammonium phosphate, diammonium phosphate, phosphate nitrate, potassium dihydrogen phosphate and a variety of blended compound fertilizers, commonly used micronutrient fertilizers are zinc sulfate, ferrous sulfate, manganese sulfate, borax, ammonium molybdate, etc..
Since the reform and opening up, the amount of chemical fertilizers applied in China has increased rapidly, contributing 35-40% to agricultural products. However, the average utilization rate of chemical fertilizers in China is only about 32%, compared with 50-60% in developed countries, which not only causes a huge waste of financial resources, but also brings negative impact on the environment and the safety of agricultural products, so the reasonable application of chemical fertilizers and the improvement of the utilization rate of chemical fertilizers has become an urgent issue. To vigorously promote balanced formula fertilization; emphasize the importance of both chemical fertilizers and organic fertilizers, the application of the two together; nitrogen fertilizers should be reasonably distributed and applied according to soil conditions, crop types and the characteristics of fertilizers, the universal implementation of nitrogen fertilizer deep application and timely mulching, advocate the combination of fertilizer and fertilizer chasing, not blindly "a shell", try to avoid and reduce ammonia volatilization, nitrate The application of potassium should be based on a base fertiliser, together with a follow-up fertiliser, and the limited potassium fertiliser should be applied to soils with low potassium content and to potassium-loving crops. The range between deficiency, moderate and excess of various micronutrients is narrow, so the application of micronutrients must strictly follow the technical requirements, and effective methods are seed dipping, seed mixing, foliar spraying, and some can be applied directly into the soil.