Fertilizer is the provision of one or more plants necessary mineral elements, improve soil properties, soil fertility level of a class of substances, is one of the material basis of agricultural production. Early Western Zhou dynasty in China know when weed after rotting in the fields, have a role in facilitating the growth of proso. Qi min Yao Shu introduces green manure between Gramineae and legume crop rotation methods, etc; also refers to crop stalks blended with cow urine, after violation and compost fertilizer. In terms of fertilization, the Pan WINS as detailed in the book, emphasizing the effects of basal fertilizer and topdressing on foot the importance of crop growth. After Tang and Song dynasties with the promotion of rice in Yangtze River basin and fertilization increasing accumulation of experience, and concludes that "to date, soil adaptability and natural development" principles of fertilization, fertilization should change with climate, soil and crop factor. With the modern development of the chemical industry, all kinds of chemical fertilizers have come out. By the middle of 18th century,Phosphorus fertilizer is divided into units (containing only one nutrient) and compound fertilizers (containing two or more nutrient elements), such as nitrogen, phosphate and potash fertilizer; the latter such as nitrogen and phosphorus, nitrogen and potassium binary compound fertilizer of potassium and phosphorus and nitrogen, phosphorus and potassium fertilizer. Organic fertilizers include organic nitrogen fertilizer, organic fertilizer and so on. China used some livestock and poultry manure, green manure, manure, compost, composting and biogas fertilizer and so on. Organic fertilizer in organic and inorganic fertilizer which, as organic fertilizer mixed with inorganic fertilizers through mechanical or chemical fertilizers.
As a fertiliser often have a variety of properties, in addition to the above classification, there are other common classifications:
① classified according to the physical state of fertilizer of solid and fluid fertilizers. Solid fertilizer is made up of powdered and granular fertilizers. Fertilizer is liquid at room temperature and pressure of the fluid fertilizer.
② property as fertilizer, can be divided into acidic, alkaline and chemical chemistry neutral fertilizer.
③ fertilizer absorbed by the plants on the effects of soil, can be divided into physiological and physiological neutral, alkaline acid fertilizer. II effectiveness of nutrient in fertilizer on plants can be divided into quick-impact, efficiency and long-lasting fertilizer.