The invertebrates and their dung are generating big business in Guangdong

In Lee Ka-lam's earthworm breeding base in Huiyang district of Huizhou city, Guangdong province, dozens of ridges are covered with a thin film in the greenhouses.

Under each film is a mixture of cow dung and soybean dregs, which creates a hotbed for the growth of earthworms.

When the films are lifted and the dung piles are removed, there is almost no smell, and groups of worms can be seen wriggling.

In an open space, a cylindrical separator rotates continuously. Workers shovel the worms and the dung, which by then has been consumed and excreted by the worms, into one end of the machine.

As the drum keeps turning, the screen at the front end will filter out the dung, which can be used as an organic fertilizer, and centrifugal force will force the worms into the plastic basket on the side of the separator.

Each day, Lee and his workers are usually busy packing the worms into special boxes for shipment in the evening.

"Afternoons are usually the busiest time for me and my colleagues," said Lee, a young entrepreneur from the Hong Kong Special Administrative Region.

The worms are sent directly to fishing gear stores and fishing grounds.

Although the market price for the worms sits at 2 yuan (31 cents) a box, Lee's worms can sell for 2.5 yuan a box due to their large size and high quality. Those sales represent about 10 percent of the market share in Guangdong.

In addition to the bestselling worms, the organic fertilizer made from their dung is screened out by the separator.

Lee gets the cow dung for his greenhouses in Guangzhou's Zengcheng district, located more than 100 kilometers from his earthworm farm.

After fermentation, the dung becomes a hot spot for earthworms to reproduce.

Their growth accelerates the decomposition and transformation of nutrients in the dung, making it an efficient and green organic fertilizer.

"After the cow dung is digested and excreted by the worms, organic matter such as humic acid that is required for plant growth is present in high amounts, and this plays a role in disease resistance and yield increase," Lee said.

Located in Xiajiao village, Huizhou city, Lee's earthworm farm now sits on 2 hectares of land.

Born in 1985, Lee, who is also a certificated stand-up paddling coach in Hong Kong, decided to venture into organic agricultural entrepreneurship.

In 2013, he returned to Huiyang, his hometown, taking with him earthworms and cow dung and focusing on developing his business of turning waste into treasure.

Lee started off planting dragon fruit and breeding worms simultaneously, but after talking to local experts about other cultivation ideas in 2017, he rented 6,667 square meters of land to expand his breeding operation in Huiyang's Pingtan township.

"Earthworms reproduce quickly, and after organic fertilizer is formed, earthworms can be filtered out and sold," Lee said.

In order to sell his surplus earthworms, he drove to nearby fishing gear stores and fishing grounds. Unexpectedly, his worms were very popular.

Because the profits from worm breeding were considerable, Lee decided to abandon dragon fruit altogether.

In 2019, he registered and established a biotechnology development and research company. He attended a training course and became a certified farmer in the Guangdong-Hong Kong-Macao Greater Bay Area.