BAOLIGEN, China, Oct 8 (Reuters) - The steppes of Inner Mongolia are arid even at the best of times, but low rainfall as world temperatures rise is turning these grasslands into sand.

"The wild grass reached up to my knees in the past," said Chaogula, a 40-year-old herdsman as he pointed to barren fields in this remote part of China near the Mongolian border.

"But there's very little grass now. It hasn't rained here in six years and we have to buy fertilisers and feed for our livestock. We never needed these before," he said.

Deserts make up about 27.5 percent of China's total land area today compared to about 17.6 percent in 1994, experts say.

Many homes in Xinjiang, Inner Mongolia, Tibet, Qinghai and Gansu have been swallowed up by sand. In spring, dust storms dump sand not only on Beijing but also send dust particles as far away as Korea, Japan and even the United States.

Doctors are seeing the health effects as fine dust inhaled during increasingly frequent dust storms cause respiratory problems, especially for children and the elderly.

"Eye infections are getting more serious and common because of the sandstorms," Hai Mei, chief of the Xilinhot City Peoples' Hospital in Inner Mongolia, told Reuters.

China's "Green Great Wall", a 700 km (435 mile) barrier of shrubs and trees planted to hold back the advancing desert, has slowed down the desertification but hasn't stopped it completely.

Environmentalists say the government needs to do more than just plant trees, it needs to prevent overexploitation of the land which is another cause of the expanding deserts.

"With the pursuit of more profit and lack of regulation, some grazing is done all year round, when it should be seasonal to allow the land to recover. Pastures don't have a chance to rest and it leads to more degradation of the land," said Li Yan, climate and energy campaigner for Greenpeace in Beijing.

The problem has been compounded by agriculture projects and development such as mining, especially coal mining.

" (Past) campaigns pushed agriculture into the desert so rivers started drying up, lots of wells were dug and lots of water was used ... mining activities have also dried up the land," said Jennifer Turner, director of the China Environment Forum at the Woodrow Wilson Center in Washington.

Beijing is battling the problem in earnest, especially as the deserts are moving east, threatening even the capital city.

Bao Wendong, a local official, said the government was pushing hard to reduce exploitation of the fragile grasslands.

"We are urging herders to rear fewer livestock. If their land is small and grass quality is bad, they should have fewer animals," Bao told Reuters.

"In the last century, the directive was to rear as much livestock as possible. Now, we are more concerned with quality."

But for the herders living on the harsh, dry steppes, life appears unlikely to get better any time soon.

"The desert is becoming bigger and sandstorms very severe. It was really bad in the last two years, there was not enough grass for the animals. There is just no rain," said herder Xintouya.