Every morning, Pan Qingyong picks about 500 kilograms of fresh cucumber at his greenhouse and takes them to a nearby market.

He now grows around 15,000 cucumber plants in the new 196-meter-long structure, after investing more than 400,000 yuan ($61,000) to build it, and expects to have it paid off within two years.

In Pan's village－Panjiadao in the county-level city of Shouguang, in East China's Shandong province－there are around 80 similar new agricultural greenhouses, and nearly 400 smaller ones.

"New ones like mine can grow four times the amount than older ones, but more importantly, they are far easier to manage, because of the automation and technologies we use in growing our crops," he said.

Those latest techniques include using 100 special lamps during cloudy days to encourage photosynthesis.

The lamps increase yield and the quality of vegetables, according to Zhang Linxiang, the sales manager at Zhejiang Linan Jiayu Technology Co Ltd, the supplier of such lamps.

"A lot more growers are now willing to invest in various types of technology that can save labor and bring more profit. This year, we expect to sell 1 million such lamps," he said.

The use of this and other types of greenhouse technology is now enabling a far more efficient and reliable source of fresh vegetables during winter in the northern parts of the country.

The Shouguang Agricultural Product Logistics Park, where Pan's greenhouses are based, is now considered the country's leading wholesale vegetable center, and ensured about 20 million kg of vegetables hit markets nationwide daily during this year's Spring Festival holiday.

Temperatures inside the greenhouses can reach up to 30 C, even when it is below freezing outside, without any additional heating.

Since the first batch of greenhouses were built there in 1989, Shouguang's vegetable-planting sector has burgeoned, gaining it nationwide recognition.

Its total planting area now covers 53,330 hectares, but after decades of use, some of its older greenhouses are now in urgent need for updating.

The local government is rebuilding the entire complex of greenhouses to better use the land, increase output, and as a result deliver higher profits to farmers, according to Zhu Lanxi, Party chief of Shouguang, who said another 5,000 new greenhouses are expected to be built this year.

Nearly 1,000 families in the nearby Tunxi village have already been earning well from the greenhouses built there to grow vegetables, said Ge Maoxue, the village's Party chief, adding they own around 2,000 cars between them, and all live in new homes as a result.

Half of its farmers work for local companies and agricultural parks, but for those who want to, can rent their own greenhouses in the villages.