Experts inspect tobacco planted on saline-alkaline land in the demonstration area in Dongying. ZHAO YIMENG/CHINA DAILY

In the same month, the area's soybean yield reached 3.5 metric tons per hectare, a record high on the "white land"－as it was dubbed by local people because of the high salt content that left a distinctive "frost" on the top layer of the soil－that once produced no more than 2.2 tons per hectare.

The soybean variety will soon be promoted in the provinces of Hebei, Henan and Anhui, covering 2,333 hectares of farmland.

The No 1 Central Document for 2022－the first policy statement released by the central authorities every year as an indicator of policy tools for work in rural areas－underscored the rising production capacities of soybeans and oil crops and ordered that the demonstration planting of soybeans should be launched on saline-alkaline soils.

Wang Jingshan, a professor at Qingdao Agricultural University, said her team has created 10 new saline-tolerant varieties of peanuts in Dongying, including one with high oil content, at the same time.

Sixty-eight percent of the edible oils used in China are imported. "So, when promoting new peanut varieties on saline-alkaline soils it is very important to use salty land and raise the production capacity of peanut oil. This is important for ensuring the national security of edible oils," Wang said.

Meanwhile, the Ministry of Agriculture and Rural Affairs said one-third of China's 100 million hectares of saline-alkaline land has the potential to enable increased grain production and ensure national food security.