Organic fertilizers are those that come from manure, vegetable matter, human excreta, and other organic matter. Some organic fertilizer exists naturally like peat, guano, and others. It is a form of fertilizer that was used by humans when they first discovered farming but has since largely fallen into disuse due to the easier availability of chemical fertilizers.
Organic fertilizers improve the soil even after the plants have used the nutrients in them and improve the composition and texture of the soil so that it assists in further farming activities. Chemical fertilizers provide rapid nutrition and can leach into the soil, burn plants if applied heavily and buildup toxic salt concentrations. Their production also requires the use of fossil fuels that produce greenhouse gases and disturb the environment. The process of making organic fertilizer requires no fossil fuels.
Organic fertilizers are made up of carbon compounds and ensure that the food produced from them is free of any harmful chemicals. This food is healthy to eat and digest. Organic fertilizers can be produced on the farm itself and this can help in saving of transport costs and make for easy availability. Their use also allows farmlands to remain fertile for hundreds of years, while the use of chemical fertilizers degrades the land.
For the production of organic fertilizer, the raw materials used are many. Use is made of wheat straw, sawdust, chips form bark, cotton waste, poultry manure, sheep litter, cow manure, food waste, plant waste like grass clippings, kitchen wet waste, and many other organic materials. The process of producing the fertilizer requires gathering all the required raw material and allowing them to go in for a process of compost fermentation. As the raw material being used for organic fertilizer production is accumulated, it decomposes and produces heat that assists the further fermentation. It is necessary to turn over the material at regular intervals and ensure that it is moist, without having excess water. Once the fermentation is completed, the raw material used turns brown and the temperature reduces until it reaches the ambient temperature of the environment in which it is.
Organic fertilizer can also be produced in plants with equipment that uses the same processes of decomposing of organic material in a continuous manufacturing process. So you will have crushers that crush the raw materials to smaller sizes that increase the contact areas of the various raw materials to hasten the fermentation and decomposing of the organic material, turners that will mix the compost evenly during fermentation, and stirrers to evenly stir the materials.
Once the organic fertilizer is produced, granulators make the fertilizer into granules, screen it into various sizes, driers dry it so that the moisture content is reduced, while before it is packed into bags the organic fertilizer needs to be cooled. In large plants, all the various processes are automated, and this helps to further reduce the cost of production.
Farmers who produce their organic fertilizers can do so in pits or bins that will contain layers of wet and dry organic material but will require to do all other activities through manual labor.