Organic fertilizer classified by raw materials

Organic fertilizer mainly contains rich organic matter, including amino acids, organic acids, peptides and other organic components, and also contains a certain amount of nitrogen, phosphorus, potassium and other inorganic nutrients. The raw materials of organic fertilizer mostly come from plant residues or animal excrement, and are often referred to as farmyard manure.

At present, organic fertilizers can be divided into six categories according to the different raw materials: manure, straw, green manure, biogas manure, mineral fertilizer and some miscellaneous fertilizers.

1. Manure and urine fertilizer

Generally, the mixture of human or livestock manure and urine is directly used. The excrement of humans, livestock and poultry is the residue excreted after digestion of food. Its main components are lignin fiber and hemicellulose, fats, proteins, organic acids and phosphorus, silicon, calcium, magnesium, potassium, sodium and other salts and Chloride, as well as  a small amount of fecal odor, fecal bile, and pigment.

2. Straw

Straw returning to the field is a measure to increase fertility that is generally valued in the world today. It eliminates the air pollution caused by straw burning and also increases fertility and yield. Returning straw to the field can increase soil organic matter, improve soil structure, make soil loose, increase porosity, reduce capacity, and promote microbial activity and the development of crop roots. Returning straw to the field has a significant effect on increasing fertilizer and yield, generally increasing yield by 5% to 10%. However, improper methods can also lead to increased soil pathogens, aggravated crop diseases and seedling shortage (stiff seedlings). Therefore, taking reasonable measures to return straw to the field can achieve a good effect. Straw returning to the field can be divided into two types: direct returning to the field and indirect returning to the field.

3. Green manure

Green manure is a kind of fertilizer made from green plants. It is a biological fertilizer source with complete nutrients. It is divided into wild green manure and cultivated green manure, such as milk vetch, vetch and vine bean etc. Planting green manure is not only an effective way to increase fertilizer sources, but also has a great effect on improving soil. Green manure can transform the insoluble nutrients in the soil to facilitate the absorption and utilization of crops.

4. Biogas fertilizer

Biogas fertilizer is the residue of crop straw, grass and human feces after the biogas is produced by microbial fermentation in the biogas digester. It is the collective term for biogas slurry and biogas residue. Biogas fertilizer is a kind of aseptic and pollution-free high-quality organic fertilizer. The residues generated by anaerobic fermentation of biogas digesters, such as crop straws and human and livestock manure, have comprehensive nutrition and high fertilizer efficiency. Biogas fermentation is slow, and organic matter consumption is low. There is little loss of nitrogen, phosphorus and potassium, the nitrogen recovery rate is 95%, and the potassium is more than 90%. Biogas water fertilizer is used as topdressing for dry land, and slag fertilizer is used as base fertilizer for paddy fields. If it is used as base fertilizer for dry land, it should be covered with soil. After the biogas fertilizer comes out of the pond, it should be piled up for several days before use. Otherwise, it will compete with crops for oxygen in the soil, which results in yellowing and withering of crop leaves.

The main raw material of household biogas in rural areas around the world is livestock manure. Since biogas fertilizer itself is produced in an anaerobic environment, many germs have been killed, and it also has the effect of inhibiting the growth of germs, thus improving the ability of crops to resist pests and diseases. The comprehensive utilization technology of biogas slurry and biogas residue is playing an increasingly important role in increasing farmers' income, realizing pollution-free agricultural production, and building a well-off society in rural areas. Biogas fertilizer is worthy of our vigorous promotion.

5. Mineral fertilizer

Mineral fertilizer refers to a new, environmentally friendly, high-efficiency fertilizer that contains minerals containing phosphorus, potassium, and a variety of middle and trace elements. It is rich in nitrogen, phosphorus, potassium and 15 other elements such as calcium, magnesium, sulfur, iron, zinc, manganese, molybdenum, boron and strontium. The application of mineral fertilizers can effectively improve soil fertility, improve soil structure, and increase crop nutrient absorption efficiency. Mineral fertilizers can effectively change the habit of "eating refined grains" of crops in the past, allowing crops to "eat coarse grains" to achieve full nutrient absorption. Such products must pass organic certification and be produced in strict accordance with organic standards before they can be used in organic agriculture.

6. Miscellaneous fertilizers

Including municipal waste, sewage sludge, industrial waste and humic acid substances etc.