Chinese battle to save desert with hay

It once built the Great Wall to keep the Mongol hordes at bay.

Now China is setting up vast defences to halt a new, and perhaps more destructive, enemy.



It is halting the spread of the desert by covering the sand in hay.

In the Maowusu Desert workers build barriers in grid patterns, in an attempt to stabilise the dunes.

More than 400million people are at risk from the relentless spread of deserts, which already cover a quarter of China.