Fertilizer are substances that applied to the cultivation substrate of the plants or directly injected to the plant in order to increase the growth and crops of a cultivation. Organic and synthetic are the two types of fertilizers. Manufacturing process of organic and synthetic fertilizers is discussed in this tutorial.
Written by: Hasitha Eranga, (undergraduate), Department of Chemical and Process Engineering, University of Peradeniya, Sri Lanka
As people came to understand about the nutrient demand of plants, they started to find ways to feed plants with nutrients. That was the point where first concept of fertilizing comes into the human civilizations.
Fertilizer are substances that applied to the cultivation substrate of the plants or directly injected to the plant in order to increase the growth and crops of a cultivation.
There are several factors when it comes to the classification of fertilizer. For the purpose of describing production method, it is more obvious to classify them as below.
Organic fertilizers considered as environmentally friendly nutrients for plants. Modern manufacturing methods are carried out for mass production of organic fertilizers to supply the increasing demand. Below given a major industrial procedure of organic fertilizer manufacturing.
Organic fertilizer can be defined as naturally produced fertilizer from biodegradable raw materials. All organic materials can be used in production
process except high toxins. Food waste, animal waste, palm oil waste, biogas residue are commonly used raw materials for organic fertilizer production.
To increase soil organic matter, materials with high carbon:
nitrogen ratio are used. They are mainly obtained from dead plants and trees
(timber wastes such as sawdust, trunks, straws of plants etc.)
In this stage selected materials are half processed and stored near to the production plant. Particle size is reduced in this stage in order maintain uniform size distribution and accurate mixing purposes to get desired properties from fertilizer. Grinders, shredders and chippers are used in this stage to increase production capacity and efficiency.
Windrow method is the major method used for composting process. Raw materials are dumped onto the ground making piles of average height of 2m which cover a large area. Material are started to biodegrading in this stage. It is an aerobic process. Microorganisms such as mesophilic and thermophilic are involved in this process.
Turning piles frequently increases the speed of composting process. It allows oxygen to contact with microorganisms which accelerate decomposition process. Several weeks of composting will make it matured, this can take up to 7 weeks.
In this stage compost undergoes final finishing processes. Compost is grind into proper size using crushers and large particles are removed by screening. Finally mixture is dried using industrial dryers.
Granulation is allowed compost to avoid nitrogen starvation and improve slow acting properties. Also, this process make compost easy to transport store. In this stage compost is granulated into predefined sizes using specific equipment. There should be certain moisture content to granulate compost. In post processing stage amount of moisture content is desired and maintained when drying.
Then granulated compost is cooled to remove remaining moisture content.
Manufactured compost are distributed to farmers from different ways.