Small Earthworms in Shenzhou, Hebei, Cultivate a New Path to Environmental Protection and Wealth

Earthworms, animals once highly praised by Darwin, are now "trying their hand" in rural environmental pollution control in Hebei, thanks to their ability to consume livestock and poultry manure through their own digestive tracts and promote soil improvement.

Walking into the Zhongxiang Earthworm Breeding Professional Cooperative in Shenzhou City, Hebei Province, rows of cow dung piles are neatly arranged across more than 100 mu of land, and inside them are earthworms busily decomposing the cow dung and growing.

Breeding worker Ding Hanzhi is collecting earthworms in the field. She and her husband are responsible for breeding earthworms on more than 10 mu of land, totaling 54 rows. She spreads plastic sheeting between the field rows, uses a manure fork to shovel the fully degraded cow dung onto the plastic, and scrapes away the cow dung layer by layer to let the earthworms crawl out. "When the cow dung changes from clumps into fine granules, it means degradation is complete and the earthworms can be collected. Generally, one batch can be produced in 20 days, and each row can produce 200 jin of earthworms per batch."

Manure stacked at will, a pungent smell, and sewage flowing everywhere - this is a common scene at many rural livestock and poultry farms. It not only seriously affects the rural environment but also causes certain pollution to the atmosphere and groundwater. "After being digested and absorbed through the earthworm gut, cow dung becomes 'earthworm castings' and basically no longer smells. The manure problem that gives farmers headaches now has a solution," said Ma Ligong, head of the cooperative.

Not only that, "earthworm castings" are a very good organic fertilizer. Ma Ligong said that cow dung is generally alkaline, with a pH value of 9.5. When farmers ferment and compost cow dung before using it in farmland, some pathogens can be removed, but the pH value remains unchanged. However, after it becomes "earthworm castings," the pH value is between 6.8 and 7.2 and is neutral, and it is rich in beneficial microorganisms and trace elements, which greatly helps soil improvement and increased agricultural yields.

The author learned that this cooperative currently has a breeding area of more than 120 mu, can digest 14,000 cubic meters of cow dung a year, and can produce 5,000 tons of earthworm castings organic fertilizer. "Earthworm castings can be sold directly in bags for 600 yuan per ton. When trace elements are added and processed into special fertilizer, it can sell for 1,200 yuan. At present, it is mainly used for growing vegetables, forest fruits, and other crops," Ma Ligong said.

In addition to environmental benefits, earthworms themselves can bring considerable economic benefits. In traditional Chinese medicine, earthworms are called "dilong," and their extracts can be used to treat cardiovascular and cerebrovascular diseases. "The cooperative produces 200 tons of earthworms a year. 80% are sold to pharmaceutical factories at 14 yuan to 15 yuan per kilogram. The rest are sold to the aquaculture industry and others. The earthworm industry chain is very long," Ma Ligong said.

"Earthworms do best eating cow dung, but pig manure and chicken manure also work." Shenzhou City is a key city for livestock and poultry breeding, with about 20,000 cattle, more than 7 million laying hens, and more than 350,000 pigs. The annual amount of livestock and poultry manure produced is huge. Ma Ligong is thinking about how to expand the scale of earthworm breeding and continuously extend the industry chain.

"Turning waste into treasure, regenerating resources, and being environmentally friendly - these are the characteristics of the earthworm breeding industry, and it has great development prospects in the current important period of environmental governance in our country." Ma Ligong is full of confidence in the earthworm industry. He said that in addition to treating livestock and poultry breeding pollution, some places have now tried using earthworms to treat urban household waste and sludge from sewage treatment plants.