Two agricultural machines work on a terraced field in Caiyuan village, Maying town, Minhe Hui and Tu Autonomous County, northwest China's Qinghai Province. (People's Daily/Cao Jiwei)

In late March, on the hillside fields of Caiyuan village, Maying town, Minhe Hui and Tu Autonomous County in northwest China's Qinghai Province, two mulching-side wheat seeders moved quickly across the land, leaving behind neatly formed ridges covered with plastic film. Interestingly, the seeds were not planted under the film, but in the furrows beside the ridges.

Minhe is a hilly, dry area with limited rainfall, where water is a key constraint for grain production.

According to Ma Jinfang, deputy director of the county's agricultural technology promotion center, by forming ridges and covering them with impermeable plastic film, rainwater flows along the film into the furrows on both sides, where the wheat can absorb enough moisture.

Because wheat requires dense planting, sowing it in side furrows improves ventilation and sunlight exposure, prevents restriction from the plastic film, provides more space for tillering, and reduces the risk of lodging.

Minhe began promoting the seeding method in 2023. With the wider use of modern agricultural machinery, planting has become simpler, while labor and costs have been reduced.

"Two years ago I used a single-ridge, two-row machine. Last year I upgraded to a modified double-ridge, four-row machine. This year I'm using an integrated machine that handles ridging, film mulching, seeding, and fertilizing all in one. Farming efficiency keeps getting better," said Bai Ruying, head of a planting cooperative in Minhe.

In 2026, the county introduced 50 dual-width integrated machines for ridging, film mulching, seeding, and fertilizing, which have become the main equipment for spring farming.

A farmer operates an agricultural machine on a terraced field in Caiyuan village, Maying town, Minhe Hui and Tu Autonomous County, northwest China's Qinghai Province. (People's Daily/Cao Jiwei)

Bai said that a single-ridge, two-row machine can sow about 6-7 mu (1 mu is about 667 square meters) per day, while the integrated machine can cover 15 mu a day.

In 2025, the average yield of wheat grown alongside film in Minhe reached 365.5 kilograms per mu, 129.2 kilograms higher than that of traditional open-field wheat.

To support further development, this year, the Qinghai Provincial Department of Agriculture and Rural Affairs allocated about 2.3 million yuan (about $334,604) in project funding to expand film-side wheat cultivation in Minhe.