The food crisis in Indonesia has spurred the government to issue policies for developing an economy based on agriculture, including an intensification / extensification program of agriculture and the use of idle land to pursue increased food production towards worries about food procurement. This fact resulted in an increase in fertilizer requirements, so the presence of fertilizers on the market became scarce. Other policies to abolish subsidies for inorganic fertilizers have resulted in soaring prices of fertilizers, making it difficult for farmers to reach.


One effort to overcome the problem of providing fertilizer for farmers is through the use of waste to be processed into compost. This effort is very appropriate and wise because not only environmental problems can be addressed, but the resulting compost products can also help answer the scarcity and high cost of inorganic fertilizers on the market. 

Composting is a biological process by the action of microorganisms that convert solid waste into a stable material like topsoil, which is primarily used as soil plaster. The use of municipal waste as raw material in the composting process is in line with the increase in waste dumped into the environment as a result of cultural changes and increased activities carried out by the community.

The magnitude of the negative impact arising from waste that is not managed properly needs to be given attention and sought for solutions. One effort to deal with the waste problem is through the use of raw materials for organic fertilizer (compost).

The advantage that will be obtained is to overcome environmental problems caused by garbage and obtain organic fertilizers which are very useful to increase crop productivity. Compost as a product of the decomposition process of organic matter, has good properties to fertilize the soil and provide nutrients for plants.

Processing of waste for composting has begun but generally uses a conventional system with the windrow method. The disadvantage of this method is that the aeration process is done manually so that the processing time is long enough so that if there is a considerable amount of waste to be treated, a large amount of land is needed. In order to avoid buildup, most of the organic waste is burned directly without being processed first.

Then what is the solution?

To overcome these obstacles, we can make compost conventionally, from organic waste from vegetables and fruits from traditional markets using the in-vessel non flow reactor method. With this method, aeration can be improved so that the composting process is expected to be accelerated. 

The mechanism of the composting process takes place in a closed container / reactor (in vessel non flow reactor). This system is designed to overcome odor problems and speed up processing time by regulating environmental conditions, such as air flow, temperature and oxygen concentration.

In this closed system it is usually used  forced aeration  to increase oxygen concentration. One of the advantages of the in vessel method is that it is easier to control process parameters so that process performance can be maximized. In addition to the closed reactor, the heat generated during the process can accumulate so that the temperature becomes higher than the open system. This causes the inactivation process of pathogenic microorganisms to be more perfect, besides that high temperatures will also increase the rate of degradation so that the composting process runs faster.

As a material used to fertilize soil and plants, compost must meet the requirements so that it can be used and useful properly. The following are good compost requirements to use:

1. Compost maturity Compost maturity is indicated by the following:
  • C / N ratio has a value (10-20): 1;
  • Temperature according to groundwater temperature;
  • Blackish in color and texture like land; 
  • Smells of land. 
2. Does not contain foreign ingredients Do not contain foreign ingredients as follows:
  • All organic or inorganic impurities such as metals, glass, plastic and rubber;
  • Environmental pollutants such as heavy metal compounds, hazardous and toxic materials (B3) and organic chemicals such as pesticides.
3. Micro Elements, Values ​​related to these micro elements are issued based on:
  • Concentration of micro elements that are important for plant growth (specifically Cu, Mo, Zn);
  • Heavy metals that can harm humans and the environment depend on the maximum concentration allowed in the soil.
4. Pathogenic Organisms Pathogenic organisms do not exceed the following limits:
  •  Fecal Coli 1000 MPN / gr total solid in dry conditions;
  • Salmonella sp. 3 MPN / 4 gr total solid in dry conditions. This can be achieved by maintaining composting operating conditions at 55 C.