Growing crops in saline soil with a salt content of six parts per thousand may sound like science fiction, but it is already doable in Dongying.

Dongying in East China's Shandong province has 3.4 million mu (nearly 2,266.67 square kilometers) of saline-alkali land. The soil of the land is hardened, high in salinity and alkalinity, and poor in terms of permeability and does not permit many crops to harvest.

Now, the city has made progress in the comprehensive use of saline-alkali soil by cultivating salt-resistant crops at the Agricultural High-tech Industrial Demonstration Area of the Yellow River Delta, which greatly increased the productivity of soil in the region.

The Agricultural High-tech Industrial Demonstration Area of the Yellow River Delta, which is China's second national-level agricultural high-tech industrial area, was founded in 2015 and has an area of 350 square kilometers, more than 80 percent of which is saline-alkali land.

"The improvement and utilization of saline-alkali land is a long-term topic," said Luo Shouyu, an official at the National Saline-alkali Land Comprehensive Utilization Technology Innovation Center.

A view of saline-alkali region of the Agricultural High-tech Industrial Demonstration Area of the Yellow River Delta, Dongying. [Photo/Jinan Times]

Methods for saline-alkali land development have been developed in recent years. For example, instead of treating the soil of saline-alkali land, salt-resistant varieties were cultivated to fit the saline-alkali land; the seed cultivation direction shifted from traditional bulk crops to high quality forages and food and medicine homologous plants.

"With the improvement of technology and innovation, we not only cultivated salt-resistant bulk crops such as soybeans, but also alfalfa in the saline-alkali land, which is an essential food for lactating cattle and sheep," Luo said.

Last year, soybean production in the region reached a new high of 235 kg per mu (almost 0.07 hectares).

"The saline-alkali land can yield up to 150 kilograms per mu," a technician at the National Saline-alkali Land Comprehensive Utilization Technology Innovation Center said.

"The quinoa, soybeans, sorghum, alfalfa and ryegrass on the shelves are the new varieties of salt-resistant plants," Lin Shuang, a technician at the center said, while pointing to the rows of cultivation rack. "Planting crops in nutrient solution cultivation tanks, with precise nutrient supplies, can greatly shorten the growth cycle to achieve 'rapid seed breeding'."

According to data, potato output in the region's saline-alkali soil has reached 4,413 kg per mu, alfalfa hay is 595.4 kg per mu, sorghum is 5,288.7 kg per mu, and black wheat is 600 kg per mu.

According to Luo, the demonstration area will invest heavily in research and development to lower the cost of saline-alkali land improvement and increase efficiency, such as maximizing biological fertilizer and returning straw to the field.