This article is part of a series that explores life along the Hu Line, an imaginary diagonal line across China that has vast demographic, environmental, and political significance.

INNER MONGOLIA, North China — A powerful gale whips up dust from the earth, engulfing elm trees as they teeter back and forth. It’s supposed to be peak sowing season in the Horqin grasslands of Inner Mongolia. But the thick, opaque clouds of dust outside Tong Mandula’s windows mean all he can do is sit at home, idle.

Tong, 37, is an ethnic Mongolian farmer from Habasitai, a village in Horqin Youyi Middle Banner on the edge of the Horqin Steppe. This area — where grasslands meet desert — lies toward the northern end of the Hu Line, an imaginary demarcation dividing China into a densely populated eastern part and a sparsely populated western one.

As one traverses the line heading northeast, common themes emerge from farmers’ complaints. Fertile pastures are becoming harder to find, they say. Adequate sources of groundwater are more elusive, and the quality of land is deteriorating as the encroaching desert makes farming, and life in general, more difficult.

There are multiple often-interrelated factors underlying desertification, including climate change and increased human activity such as deforestation. In some places, cultivation of water-intensive crops and overgrazing by livestock also play a part.

In China, the problem is particularly acute, with some citing it as the most significant ecological issue facing the country. The statistics are staggering: Desertification affects around 2.62 million square kilometers — or roughly 27 percent of the country’s land area — and the livelihoods of some 400 million people. More than 95 percent of China’s desertified land is located in the northwest.

There’s some evidence to suggest that efforts to control desertification in China have yielded results. In the 1990s, for example, desertified regions were expanding by 3,436 square kilometers every year, according to a China Daily article quoting forestry administration officials. Now, affected land area is decreasing by around half that figure each year. Still, much remains to be done, especially to persuade more people like Tong that their actions — things like planting trees or changing grazing practices — can make a difference.

Studies show that Horqin once comprised lush woodlands and savannas, but hundreds of years of agricultural cultivation and other human activities, particularly in recent decades, have accelerated the desertification of the area, transforming it into a sandy steppe. Today, life here is a far cry even from the days of Tong’s youth. Back then, rain was plentiful. “All I would have to do is think of rain, and it would come pouring down,” he recalls. The grass would soak up the water and quickly grow knee-high. This vegetation would, in turn, provide a nearly never-ending source of food for livestock, he recalls.

Since around the beginning of the century, crucial rainfall has been replaced by droughts and sandstorms, Tong says. This year, for example, he says there have been only two instances of decent rainfall so far: the first in early May, and the second in early July. Yet Tong says he subsequently learned that the May downpour had been artificially triggered by the authorities.

The lack of rain has compelled Tong and his wife to irrigate their land using groundwater — a practice known as irrigation farming — to grow their crop of mung beans. The government has strongly encouraged irrigation farming and, in the last couple of decades, has drilled local wells free of charge so that crops are no longer completely reliant on regular rainfall. While these measures have led to an increase in the scale of cultivated land, they have also caused a serious decrease in groundwater levels.

The villagers all say that in the past, one only needed to drill 5 or 6 meters to find water, but now wells need to be at least 10 meters deep.

Excessive use of groundwater may be damaging the regional ecology, experts say, as short grasses and shrubs rely on this water source to survive. These dense grasses and their vast system of roots under the soil help prevent fires and stabilize the shifting sands. Without them — even when they’ve been replaced with crops — heat from the exposed earth rises, leading to more intense sandstorms.

Habasitai, Tong’s village, sits on the edge of Horqin’s national conservation area. The water basin there hasn’t yet dried up. Yellow sand, verdant forests, and dense wetlands all lie near one another. But not even this protected area is immune to aridity: Over the last 20 years, the surface area of the reserve’s wetlands has decreased by more than half, and the number of migratory birds has also dropped, according to the local conservation bureau. The bureau declined to provide further data.

A number of measures have been implemented to address the sandstorm crisis and soil erosion problems facing this part of China.

For one, restrictions on grazing have never been as stringent as they are now, with the government clamping down heavily on illegal grazing. Meanwhile, the decline in lamb prices in recent years has led to a decrease in the number of village sheep that graze on the grasslands. Last year, Tong sold off all his sheep; he kept only his goats, which eat less and are easier to raise. Still, in Tong’s village, people let their sheep feed on the grasslands regardless of the signs hanging on street corners all over the village that say, “Grazing Forbidden.”

Forests have also been introduced to break the wind in various villages throughout Horqin. Under a national plan launched by the central government in 1978, some 35 million hectares of forests will be planted by 2050, forming a chain sometimes referred to as the “Great Green Wall of China.”

Tong joined a task force involved in the forest-planting initiative around seven years ago. He rented a plot of sandy earth in his village that spanned 200 mu (around 13.3 hectares), on which he planted more than 10,000 poplars. Back then, the trees were only as long as his arm, but now the poplars have grown to over 10 meters tall.

The groves of poplars, whose trunks stand as tall and straight as a soldier’s back, are separated by plots of farmland. The windbreaking forests here are all made up of these trees. No one is willing to plant varieties native to the region, such as the painted maples and Mongolian elms whose immense branches loom over the grasslands below. These species are striking but not at all lucrative for locals, whereas under the forest-planting initiative, villagers can begin chopping down and selling the poplar trees 30 years after they have been planted. Those that are cut down may then be replaced.

Planting trees in the parched soil of Horqin’s sandy steppes is no easy feat. Tong recalls that half of the saplings he planted died within the first year, meaning he had to plant another 5,000 the following year. That year was extremely dry, so he was forced to irrigate the trees using groundwater. But by the third year, the trees’ roots had grown deep enough that he hardly needed to water them, he says. Of the 340 or so households that make up Tong’s village, approximately 50 have joined the planting efforts.

“For now, none of us can really say for sure if planting trees will be of any use,” Tong says. “It’s a question that only the scientists can answer.”

Translator: Lewis Wright; editor: Colum Murphy.

Over the coming weeks, Sixth Tone will publish stories, videos, photo galleries, and social media posts that chronicle our road trip across China along the Hu Line, as well as an interactive multimedia platform in the fall.

(Header image: Tong Mandula and his wife leave the fields after sowing mung bean seeds in Horqin, Inner Mongolia Autonomous Region, June 7, 2016. Chen Xi/Sixth Tone)