Rice harvesting in Lanzhou's Yuzhong county. [Photo/lzbs.com.cn]

This autumn, over 300 mu (20 hectares) of rice fields on the Qingxiangpu Plateau Rice Research Base in Qingcheng town, Yuzhong county, Lanzhou, welcomed their first large‑scale harvest, marking a turnaround of previously saline‑alkali land and realizing the long‑held goal of producing local, high‑quality rice for Lanzhou residents.

Faced with soil salinity and a challenging high‑altitude climate, Zhang Tong, the head of the project, partnered with researchers from Northwest A&F University and Gansu Agricultural University. After seven years of trials, the team developed an integrated ecological model combining saline‑soil improvement with a rice‑crab coculture system. Methods included digging drainage canals, applying organic fertilizer, and irrigating with water from the Yellow River to reduce salt content. They also introduced salt‑tolerant rice varieties suited to the plateau climate and adopted mechanized transplanting, raising seedling survival rates to 85 percent.

Rice‑crab symbiosis eliminated the need for chemical fertilizers and pesticides, as the crabs loosened the soil and consumed pests. The rice produced is glossy, tender, and aromatic, meeting premium quality standards.

The reclaimed land now yields a "double harvest": rice output has increased by nearly 50 kilograms per mu, with an additional 100 kg of crabs per mu. Overall, planting costs have dropped by 80 percent, and income per mu has reached 15,000 yuan ($2,100). With an organic rice yield of 650 kg per mu, the project effectively fills a key gap in the local supply of high‑quality rice.