BioCycle February 2009, Vol. 50, No. 2, p. 40
Study examines effectiveness of an easy to use vermicomposting system to reduce waste and produce fertilizer in a Mexican community.
Esperanza Huerta, Ruth del Angel and Aaron Jarquin

A PROJECT at the “Rancheria Guineo” in Tabasco, Mexico installed minihouse vermicomposting systems in three schools and with six families, targeting mothers and students for composting organics. The minihouse composting system consists of a box with earthworms and a “mill,” which grinds materials to reduce particle size. Results from the study show a high degree of acceptance of the technique for separating wastes and producing compost. The minihouse system was easy to use and did not produce foul odors.
A production of 920 grams/person/ day of garbage was recorded recently in Mexico, of which 50 percent, depending on the place, is organics. The vermicomposting process began in Mexico in the 1980s when E. Aranda, a biologist familiar with composting, started treating coffee waste for INMECAFE, the national coffee industry. Although more than 20 years have passed since then, a big gap still exists between the concept of what waste is and how it can be used.
In the state of Tabasco, in southeastern Mexico, the development of big cities occurred with the boom of the oil industry. The state capital, Villahermosa, began to grow in the 1970s, reaching a population of 2,100,000 inhabitants in 2000. Unfortunately, the customs of big cities also arrived, and waste management remains a problem. “Co-urban” villages, where urban and rural customs combine, lie near Villahermosa, and their wastes reflect a mixture of city and country consumption habits. “Rancheria Guineo” is an example of this kind of village in Tabasco, where people still cultivate the land but prefer to work in the big city, where money is earned and spent easily.
The minihouse composting system used in this study, a system ideal for the tropics, uses earthworms and a “mill” to produce compost. The system allows a more accelerated production of compost (18 days) than that of the traditional vermicompost system (30 to 45 days). The aim of the study was to validate the production of compost by women and children at Rancheria Guineo.
Women were chosen as the focus for the study because they are the home supporters in the region. More than 60 percent of the men in the region spend their daily salary on drink, whereas the women strive to distribute their money among their basic needs. This project also provided environmental education for children to understand the importance of waste separation and compost production.
MATERIALS, METHODS AND RESULTS
Rancheria Guineo has six schools and a population of 2,686 inhabitants (1,315 are women, according to 2005 data). Nine minihouse composting systems were handed out: three to schools (one primary school and two kindergardens), and six to mothers. One woman was established as a primary contact, serving as a communication bridge between the population and the research institute, El Colegio de la Frontera Sur, Unidad Villahermosa. The selected woman, a single mother, was also able to help demonstrate the production of compost in the future, as an aid to domestic monetary input.
An environmental workshop was organized for the mothers and students participating in the project, after which the minihouse composting systems were donated to them. Each minihouse composting system was provided with 20 earthworms (Eisenia foetida).
Compost production was faster than expected, with finished product ready after 15 days, and the earthworms placed on fresh waste. Apparently, the size of the particles generated by the mill (3 to 5 cm) helped the aerobic bacteria and the earthworms to accelerate the mineralization of the organic matter. A drawer at the bottom of the box enables easy removal of the compost.
Organic waste from the schools was more heterogeneous than from the women, and contained 21 percent passion fruit, 17 percent chives, 17 percent hibiscus, 17 percent grapefruit and 15 percent orange; the rest included melon, pineapple, papaya, watermelon, banana and carrot wastes. The organic waste selected by the women had 19 percent pumpkin, 17 percent banana, 16 percent orange, 16 percent hibiscus, 10 percent watermelon and 10 percent cucumber; the rest had small amounts (1 or 2 percent) of papaya, melon, pineapple, carrots and prickly pear fruit.
Compost produced at the schools also presented a greater organic matter content (27.1±6.7 percent) than that produced by the mothers, although the C/N ratio of 11 to 12 was similar in both types of compost. Researchers found a great acceptance of the minihouse composting system by the students and the mothers.
The minihouse composting system tested in this study turned out to be an easy alternative for compost production due to the fact that the boxes could be disposed. It was also important that the students and mothers could see for themselves that compost was produced from fresh waste after 15 to 18 days. In regard to this type of model, this minihouse composting system is the only one that integrates the use of earthworms and a mill.
The project has now been running for almost a year. Compost quality was evaluated and was found to lie within international norms (20 to 40 percent organic matter) and the Mexican government’s specifications for vermicompost (PROY-NMX-FF-109-SCFI-2007). The C/N ratio was also stable (11 to 14), considered inside the Mexican vermicompost C/N ratio norm (less than 20).
Now that the students and mothers are using compost to grow peppers, flowers and vegetables, further studies are required to test the effect of compost on plant growth. Because of the positive results of the study, the researchers expect that this project will be replicated in different areas across Mexico.
Esperanza Huerta, Ruth del Angel and Aaron Jarquin are researchers at El Colegio de la Frontera Sur, Unidad Villahermosa, in Tabasco, México. The authors would like to thank Fondos Mixtos Tabasco for financing the project, and Andrea Raz-Guzman for the English revision.