Gyan Maymi Shrestha shovels heaps of it out of a barrel and into a large straw basket. She hoists it on to her back and carries it into the fields, moving nimbly along the narrow ridges of earth that serve as pathways between the rice paddies.

When she reaches her own vegetable plot, which is cut as terraces into the slopes of the Kathmandu valley, she scoops out handfuls and throws it across a patch of freshly ploughed soil.