Zhoushan mussel shells: The secret to firm waxberries

Waxberries planted by Zheng Shenghua are now firm. [Photo/wifizs.cn]

Early on July 10, Zheng Shenghua, head of the Zhoushan Dengbu Waxberries Base, inspected his 57 experimental waxberries trees with a flashlight. After picking a basket’s-worth of the fruit, he shared his joy, "This is the last batch of the season. We've solved the 'soft fruit' problem, and next year's crop will be even better!"

Zheng demonstrated the difference by handing out firm and soft waxberries for comparison, revealing, "The firm waxberries were treated with nutrients derived from Zhoushan mussel shells."

The research team from Zhejiang Ocean University's School of Food and Medicine, led by Guo Jian, was delighted with the successful trial. This breakthrough not only solves the softening problem seen in waxberries grown on the islands but also provides a new use for discarded mussel shells.

Sixteen years ago, Zheng brought waxberries from Xianju to Zhoushan Dengbu Island, only to find the fruit became overly soft and juicy due to the island's climate and soil, with a shelf life of less than a day. The challenge of preventing waxberries from "bleeding" juice had long stumped him.

In December 2023, Guo's team tested the soil at the Dengbu Waxberries Base and found it to be acidified and lacking in trace elements. They developed a high-calcium soil conditioner using calcium, iron, and strontium extracted from mussel shells, and applied it to 57 waxberries trees.

"Just like humans, plants need the right nutrients to stay healthy," Guo said. Now, the shelf life of waxberries has increased to 2-3 days at room temperature.

Mussel shells, which are solid waste and do not readily degrade naturally, pose environmental hazards when piled up. Zhoushan's mussel farming produced over 23.2 million metric tons in 2023, generating more than 6,000 tons of waste shells. Reusing these shells has become a research focus in Shengsi county.

The initial soil conditioner made from mussel shells, developed in 2019 by Guo's team, was later used in tea gardens in Taizhou and Wenzhou, producing "rich-strontium tea".

Experts like Wang Qiang from the Zhejiang Provincial Agricultural Academy believe that if the effectiveness of mussel shells in improving soil can be widely validated, it will significantly boost agricultural development along the southeastern coast.

Mussel shells are solid waste and do not readily degrade naturally. [Photo/wifizs.cn]