Worm composts in need of sorting regulations

By Liang Meilan 

After failed trials in 2001 and 2009, worm composting is back in home trials.

On August 11, three neighborhoods in Dongsi, Dongcheng District, began a one-month trial with improved equipment in preparation for a wider promotion of the technology in 50 families. Experts said strict waste sorting is vital to the widespread of the technology.

Proposed by the Global Village of Beijing Environment Education Center (GVB), the trial  is conducted at GVB’s office, a rooftop in the Dongsi Residents’ Committee office building and at the home of resident Li Yulan.

The past two trials failed due to worm death.

“This time, the experiment is being conducted both indoors and outdoors to discern the most favorable ventilation and humidity environment for raising the worms,” said Hou Fei, GVB initiator of the trial project.

Unlike prior trials, the new containers used will be coded plastic boxes drilled with holes to ensure ample oxygen.

“To ensure a good survival rate, we also invited an earthworm expert from China Agricultural University, Sun Zhenjun, to design and direct the trial,” Hou said.

“If the trial is a success, we hope the method can be promoted in more communities,” Hou said, adding that its promotion may rely on the municipal government and experts.

Dealing with organic waste is one of the top challenges facing Beijing’s city management. While the government has already established biodegradation stations for collected organic waste, it hopes to find a feasible, resident-driven method to address the issue.

Deng Jun, deputy director general of the Committee of Beijing Municipality and City Appearance, welcomed the promotion as innovative.

“But before it can become widespread in the city, it will have to be made more feasible and less costly. The current waste-sorting reality should also be taken into consideration to create a sustainable refuse disposal system,” he said.

Feng Jianguo, a researcher at the Beijing Municipal Research Center for Rural Economy, agreed.

“Improper waste sorting may lead to the mixing of hazardous substances into organic waste, which will turn the worm-waste fertilizer into something that may one day be harmful to humans,” he said.

Looking back to the 2009 trial, which lasted three months in 20 families, “it appears that we were too imprudent,” said Han Baisheng, team leader of the China Community Volunteer who carried out the 2009 trial.

“Problems with the techniques and poor research caused the failure. The biggest problem was poor air permeability of the containers, which caused everything to turn rancid and attract parasitic insects that were fatal to the red wiggler worms,” he said.

Improper care of the worms was another cause. “Some families put the containers on the balcony where the worms drowned and died,” he said.

The trial is now in its 16th day. “Everything looks normal,” said Li, hostess of the experiment family.

“The worms in the two boxes have already grown from 1 inch to 3 inches long in such a short time. Sweet food waste, like watermelons, is their favorites. I don’t think it’s such a burden. You only need only to feed them every three days. When there is rain, the first thing I do is cover the boxes with plastic cloth to prevernt the worms from drowning,” she said.

“To ensure a healthy ‘diet’ for the worms, my family is carefully sorting the waste to prevent the worms from being exposed to detrimental bacteria,” she said.

“But some of my neighbors don’t like it. They are afraid that improper breeding of the worms will draw flies and mosquitoes,” she said.

Though relatively new in China, worm composting has long been used in the US and Japan. “Worm composting boxes are commonly seen in Japanese families,” said Feng, the researcher.

Ideally, 1 kilogram of organic food waste can be decomposed by an equal weight of earthworms into a half-kilogram of waste. This waste can be used as rich, dark soil for plants.