Know the stages of the composting process

Compost is one of the most well-known methods for the production of fertilizers by agricultural producers and gardening lovers, to obtain a good compost the organic materials that are used are transformed through a biological process carried out by microorganisms. For this reason, to obtain an excellent final product, the conditions must be ensured throughout the process, these would be the temperature, humidity, aeration and the carbon-nitrogen ratio of the organic materials used.

This type of fertilizer provides agricultural producers and gardening lovers with economic and ecological advantages such as the reduction of synthetic products for a more economical and ecologically elaborated product that contributes to preserving the resources of the agroecosystems. Through the commercialization of compost in a solid waste management system, part of the costs of collection can be recovered, and the amount of solid waste can be reduced by a considerable percentage.

Let's start by pointing out that the microbial transformation of organic matter in composting is an exothermic process, that is, it generates heat. In the composting process, the temperature varies depending on the metabolic activity of microorganisms. According to this parameter, the composting process can be divided into 4 stages: mesophilic, thermophilic, cooling and maturation.

The first stage known as Mesophilic the temperature ranges between 10 and 40 °C, the organic materials when stored to begin with the process are logically at room temperature and microorganisms begin to develop that adapt to that temperature using the carbohydrates and proteins found in the organic material, in this way they begin to multiply and decompose the organic waste, Due to the decomposing activity generated by the microorganisms, the temperature begins to increase, reaching values of approximately 40°C in the next few days. This stage can last between two and eight days, but everything will depend on the handling that is given to the compost pile with aeration, maintaining humidity and the type of material that you use.

In the same vein, as the microorganisms carry out their process, the temperature begins to increase a little more until reaching approximately 70°C, this stage is known as thermophilic and other types of microorganisms that are resistant to these temperatures begin to proliferate, known as thermophilic microorganisms. At this stage, according to Urbano (2008), the bacteria and fungi that proliferate in this medium begin to degrade cellulose and partially lignin, which causes, as mentioned above, an increase in temperature. After 60 °C, thermophilic fungi cease their activity and actinomycetes increase. For several days the temperature is kept high and the biological activity decreases, pasteurization of the medium occurs, that is, pathogenic bacteria are destroyed.

After the intense biological activity in the compost, a decomposed material begins to be obtained and the temperature begins to decrease, since microbial activity ceases in a large percentage, As a consequence of this temperature decrease mesophilic bacteria and fungi reinvad the compost and degrade the remaining cellulose and lignin. This phase is recognized when after turning the battery there is no subsequent temperature increase.

Finally, the maturation stage is found, this period requires some time at room temperature in which chemical reactions take place, humus could be obtained. At this stage, some organic acids produced in the thermophilic phase are also degraded, which can become toxic to plants. In this way an excellent, very efficient organic fertilizer is obtained for biological and nutritional balance of crops.