After repeated experiments on a small piece of land, Hua found rye grass to be the right species for the Huashan construction site. The grass grows on almost all types of soil, sprouts in a week after seeding, and has proved to be hard to kill.

Hua and his colleagues started to plant rye grass in April last year. They closely observed the weather, sowing seeds when the rainfall was just right.

Hard work paid off. Four months later, the piece of brown soil was covered in lush green grass, adding life to the construction site while cleaning the air.

One summer's day, looking down from a hilltop at the grassland he personally cultivated, "Look at the grass! It's so glossy and green," Hua comments as he could hardly contain his excitement.

According to Wang, dust nets are prone to damage from rain and sunshine. They also have to be replaced every two weeks, which costs about 200,000 yuan ($29,669) each time.

Moreover, dust nets can be blown away on windy days, which could pose a danger to the cables of an adjacent railway network.

"Planting grass cost us 100,000 yuan, and once it's planted, it lasts forever," says Wang.

Huang Chaojie, who's in charge of the Huashan site project, says Hua and his team's grass-planting experience can be introduced to more construction sites in Wuhan. "Hua should be praised for his dedication and research achievement," he says.