Exploring natural solutions for farmland sustainability

BEIJING, July 6 (Xinhua) -- Li Xiaoxuan, a former deputy to the National People's Congress, China's top legislature, was glad to see his suggestion on protecting earthworms and ensuring farmland and food security included in this year's "No. 1 central document."

Outlining the key tasks for developing agriculture and comprehensively promoting rural revitalization, the document urges a severe crackdown on soil destruction behaviors, including earthworm hunting through electric machinery.

The move came after China has managed to ensure its farmland area stay above the red line of 1.8 billion mu (about 120 million hectares), reflecting a greater policymaking emphasis now more than ever on farmland quality, Li noted.

Kong Xiangbin, a professor at the China Agricultural University, echoed that Chinese farmers and agro-technicians are keen on seeking natural methods for preserving soil ecosystems and improving farmland fertility to promote sustainable agriculture, as there is a growing awareness of earthworm protection, corn straw reuse, and the development of circular farming.

PROTECTING SOIL ECOSYSTEM

Tiny as it is, the earthworm works as the "engineer" of the soil ecosystem. As the largest fauna in this ecosystem, it is also a vital biological indicator in China's soil census, according to Kong.

However, many have been hunted in recent years for use in medicine, feed, bait, and liquid fertilizer, and the cost of breeding is high.

"Orders of electric machinery for earthworm hunting received by some e-commerce companies can be as many as 1 million," said Li. "With these machines, people can kill 7.5 billion earthworms in one year, making about 250,000 hectares of land unable to degrade pollutants."

"Earthworms play a vital role in improving soil fertility, promoting the degradation of organic matter, the cycle of nutrients, and optimizing the conditions of the microbial community," said Kong. "The balance of the farmland ecosystem will be damaged if earthworms are hunted."

"If the farmland ecosystem is destructed, grain production will reduce," Li said, noting that prohibiting earthworm hunting helps remove hidden dangers that threaten food security.

China's crackdown on earthworm hunting shows that the country not only focuses on securing the quantity of farmland but also aims at ensuring the ecological quality of the land, said Yang Zhaoxia, a professor at the Beijing Forestry University.

USING NATURAL FERTILIZER

In the hot summer months, corn thrives in the thick black soil of the Xinjuqiang Machinery Planting Cooperative. Zhao Xinkai, director of the cooperative, has full confidence in this year's harvest.

Located in Jilin Province, one of China's northeastern provincial-level regions with rare black soil resources and producing a quarter of China's grain, the cooperative has set a typical example in preventing soil erosion and degradation through crop straw mulching to promote conservation tillage.

"Before we cover the farmland with corn straw, farmers could clearly see soil deteriorate due to wind and water erosion. And the quality of the crops grown in such soil also downgraded," Zhao recalled.

Each year when harvesting the corn in autumn, Zhao and his colleagues use machines to scatter the straw on the land between the plants. When the next spring comes, there is no need for plowing and ridging before sowing new corn.

Compared with the traditional way of planting, about 100 kg of chemical fertilizer could be saved per hectare this way. But the output of corn, rather than shrinking, even increased.

"The fertility of the land was improved two to three years after we adopted the measure of crop straw mulching," Zhao was excited to see the change, "the black soil is back!"

In the Black Soil Protection Law, which took effect in August 2022, China proposed the principle of coordinating land use and conservation and urged improving the quality of the black soil with conservation tillage measures, such as zero-tillage, reduced tillage, subsoiling, as well as covering the land with crop straw or burying deep the powder of the straw.

The country has initiated a five-year action plan on conservation tillage in the northeastern black soil region. By the end of this year, the land area that adopted conservation tillage is expected to top 6 million hectares, and the figure will reach 9.3 million hectares by 2025, accounting for about 70 percent of suitable farmland in this region.

PROMOTING CIRCULAR AGRICULTURE

At the Lubang Planting Cooperative in Zhongxiang City, central China's Hubei Province, Li Peng and his brother have formed a cycle of organic farming after years of experimentation to tap into the massive healthy food market.

By feeding cattle with corn, raising earthworms with cattle manure, nourishing soil with fertilizer produced by earthworms, and feeding geese with leftover vegetables, the farm has made its production sustainable and economical.

Taking soil fertility as its priority, the Green Fire Ecological Farm in the Miyun District of Beijing further expanded the sphere of the ecological chain for farming.

Cooperating with a nearby dairy factory and a cattle farm, it made organic fertilizer rich in plant protein from expired milk and collected biogas residue fermented from cattle manure for land cultivation. It also recycled its own waste by crushing and fermenting organic vegetable and fruit straw to make natural fertilizer.

"We'd like to restore the organic planting method with the help of modern technology and bring back the natural taste of farm produce," said Hou Binbin, head of the farm. "Organic products are popular as people are paying more attention to food safety nowadays."

Last year, the farm's organic product sales in Beijing topped 50 million yuan (about 6.94 million U.S. dollars), jumping over six times from 2017. Its customers also expanded from young moms to more groups, including senior citizens and young people.

"Having higher demand for quality life, Chinese people are more into a healthy diet," Kong said. "Healthy food and healthy land have become indispensable."

Earlier this year, the Ministry of Agriculture and Rural Affairs urged efforts to pilot a green cycle of planting and breeding, develop ecological farming, and cultivate a batch of national ecological farms to promote rural revitalization.

"The output of ecological farming is not at the cost of soil fertility," said Shi Yan, head of the Beijing Shared Harvest Organic Farm. "It is a sustainable way of production that can last for decades, centuries, or even longer."