Nitrogen fertilizer can be divided into animal nitrogen fertilizer and plant nitrogen fertilizer. Animal nitrogen fertilizer, such as human excrement, horse, cow, sheep and pig manure, fish fertilizer, horseshoe, etc., plant nitrogen fertilizer, such as bean cake, rapeseed cake, cottonseed cake, sesame residue, etc., both of which belong to organic fertilizer; inorganic fertilizer, such as urea, ammonia water, ammonium nitrate, ammonium sulfate, etc., are all quick acting nitrogen fertilizer, which are generally used as external topdressing, but often used to cause soil hardening..
Nitrogen fertilizer can promote the growth of trees, increase chlorophyll, and supplement the nutrition of plant growth. Too much nitrogen fertilizer will lead to soft tissue, long stems and leaves, easy to be damaged by diseases and insect pests, and reduce the cold tolerance of plants; too little nitrogen fertilizer will make plants short, yellow and green leaves, slow growth, unable to bloom.
Bone meal, rice bran, fish scale and poultry manure are organic fertilizer with more phosphorus, while calcium phosphate, phosphate rock powder and calcium magnesium phosphate are inorganic phosphate fertilizer.
Phosphate fertilizer can promote plant stem and branch tenacity, flower bud formation and flowering, fruit precocity, and improve plant cold and drought resistance. When the plant lacks phosphate fertilizer, it grows slowly, the leaves are small, the flowers and fruits are small, and the fruits are late.
Plant ash is a kind of organic potassium fertilizer, which can be used as base fertilizer and top dressing.
Potassium fertilizer can promote the stem of plant to be strong, improve the plant's resistance to disease, insect, drought and lodging, make its root system developed, and improve the quality of fruit. Too much potassium fertilizer will shorten the internode, dwarf the plant, turn yellow the leaf color, which will cause serious withering and death; lack of potassium fertilizer will cause necrosis spots on the leaf margin of the plant, and then scorch and necrosis.
