A decade ago, nothing would grow on a large expanse of saline-alkaline land in an agricultural district of Dongying, Shandong province. The land was considered worthless. “The once white, barren land is now transforming into golden, high-yield fields,” a local farmer named Wang said. Nestled on the shores of the Bohai Sea where the Yellow river empties into the ocean, Dongying’s landscape has been shaped by an unusual geographical legacy. The gradual retreat of seawater over time left behind salt deposits that have so far created 227,330 hectares of saline-alkaline land. This area accounts for 38% of the total saline-alkaline land in the province. “In the autumn harvest season, Shandong’s landscape resembles a colorful palette, but the last color we want to see is the white of saline-alkaline land,” said Wang Jingdong, Deputy Director of the Shandong Provincial Department of Agriculture and Rural Affairs. The utilization of saline-alkaline land is part of efforts to increase the quality and efficiency of agricultural production to safeguard China's food security. Shandong province is exploring a path characterized by ecological prioritization, adaptation to local conditions, compatibility between seeds and land, and technological support.
Land was rehabilitated using irrigation and deep plowing. “It’s very difficult to increase grain yield during the first three to five years, but later with the local government’s support and also after accumulating some experience, the grain yield increased,” a farmer named Li who cultivates wheat, corn and soybeans said. “Trial results showed that the new variety of wheat performs better,” said Zhang Chengda, a staff member at Shandong Fengcai Seed Industry. “It has resistance to pests and diseases, while requiring less pesticide, adding new guarantees for stable and high yields on saline-alkaline land and bringing tangible hope for increasing farmers’ incomes.” Researchers keep developing salt-tolerant varieties, said Li Dianquan, a farmer in Dongying. Another piece of saline-alkaline land with about 100 hectares of selenium-rich rice also saw a bumper harvest. “I never imagined selenium-rich rice could grow on saline-alkaline land. After 180 days of growth, these grains are rich in selenium,” said Song Xinye, a local farmer. Yin Shenghui, Director of the Agricultural Office in the subdistrict, said that through industrialization, standardized production, mechanized processing, and branded sales, the land has increased the village’s collective income by CNY130,000. The once barren land has turned into a breadbasket.
Managing saline-alkaline land is first and foremost a battle with the soil. “The soil was white in spring, waterlogged in summer, and red in autumn, making grain harvesting extremely difficult,” said Gai Junshan, Chairman of Shandong Qianshun Soil and Water Management Technology Co, voicing a shared memory of many Dongying natives. In spring, when it’s warm, dry and windy, water from deep in the soil is pulled to the surface and evaporates, leaving salt on the surface that forms a white crust on the ground, he said. In autumn, the saline-alkaline soil makes it hard for most crops to grow. Only very tough, salt-loving plants like Suaeda salsa can survive. This plant turns a bright red color in the fall, covering the fields in a red blanket. Born and raised in Dongying, Gai vowed to reclaim his hometown’s saline-alkaline land when he was 17. He traveled to countries including the Netherlands and Germany to study land rehabilitation techniques, eventually developing technologies suitable for the local conditions to reduce the soil’s salt content from 1.6% to 0.3%, reaching a standard suitable for various crops.
But this is merely the first step. Saline-alkaline land is not just salty, it’s also barren. At the Agricultural High-tech Industrial Demonstration Area of the Yellow River Delta of Shandong province, researchers from Qingdao Agricultural University have been focusing on making the soil healthy by increasing organic matter. They promote the cultivation of “green manure” crops, plants grown to be chopped and turned back into the soil to add organic matter. “As soil organic matter increases, the aggregate structure improves, enabling better water and fertilizer retention and suppressing salt rise, which naturally lowers surface salinity,” said Liu Xinwei, Professor at Qingdao Agricultural University. To verify the long-term effects of these measures, the researchers built 36 isolated cement pools at their experimental base in the demonstration zone. “This is to strictly control interference between different fertilizer treatment plots and ensure accurate and reliable data,” said Liu. This experiment is planned to last for decades, aiming to unravel the secrets of soil evolution and provide the most solid scientific basis for saline-alkaline land management. The research teams at the demonstration base have made a number of major achievements in breeding new varieties that can grow on saline-alkaline land, such as quinoa and alfalfa grass varieties, the China Daily reports.
