To provide for their families, many Afghan farmers turn to the relatively lucrative practise of poppy cultivation.

Initial capital costs for items such as seeds, can be high. Many are forced to take loans from unscrupulous lenders, the drug lords and the Taliban among them.

But growing the poppy plant is no definite route to success. There are risks. While the government's eradication program may not be far-reaching, those farmers that do feel the brunt are left with bare earth and no way to settle their debts.

Some resort to bartering their daughters in marriage to settle the loans. These daughters are known as the "loan brides" or even "opium brides."

Enforcement action against poppy growing often leaves farmers in a desperate financial plight

Afghanistan is the largest opium producer in the world, despite the trade being banned. About 93 percent of the country's population lives in the rural areas, relying on the land for a living.

Najibullah Qureishi, Frontline Correspondent, whose award-winning documentary Opium Brides took him to the remote countryside of Afghanistan, said many farmers had grown disillusioned with government promises about alternative forms of agriculture. "In 2001, there was great optimism in my country; the future looked bright," Qureishi told DW. "Farmers believed the public pronouncements and awaited major investment in agriculture, which would have allowed them to turn away from the poppy."

However, Qureishi said, many of those promises were not fulfilled. Instead, the government's eradication program had left farmers in a desperate situation.

"Many farmers had borrowed money from traffickers to grow poppy and, when the government turned up to destroy the crop, they had no way of paying back their loans to the drug lords. They were given a simple ultimatum: give us your young daughters or we will kill you."

Women suffer most

The fate of such women is uncertain. Some are married off to men twice their age, or simply sold on further.

Afghanistan is the largest opium producer in the world, and many rely on the trade for a living

"Normally, the girls are quickly transported to other countries, mainly Pakistan and Iran, where they are either sold and married off to older men as child brides or used as ‘mules' to transport drugs to other countries," Qureishi told DW. "In many cases, however, it became clear that they are also used as child prostitutes."

The Afghan government claims there is no large scale practice of selling opium brides, but that it typifies the social problems that opium can cause.

"I can tell you confidently that even if cases like that exist somewhere in Afghanistan, it is extremely limited. It is undeniable that the opium cultivation and opium production and the criminal networks that are engaged in that trade have caused tremendous suffering and hardship for the Afghanis people," Janan Mosazai, Spokesperson to the Ministry of Foreign Affairs of Afghanistan, told DW.

Problem wider than opium

However, Jean-Luc Lemahieu, Regional Representative for Afghanistan and Neighboring countries for the United Nations Office on Drugs and Crime (UNODC) said the issue of females being used to pay off loans part of a societal problem beyond the opium trade.

"You could call them 'loan brides,' because it is not restricted to opium only. In a very regretful situation where females are used to settle financial loans - it is not uncommon is this country and it's absolutely deplorable."

While girls in some parts of the country have benefited from changes since 2001, it's by no means universal

"It happens in many circumstances where people are not able to pay back loans and then use the females in the household as an economic transaction. It does happen mostly in the rural areas… and it does happen with regards to those farmers who are planting opium are not able to pay the loan back."

For Qureishi, part of the problem is that changes to improve the lives of women since the American-led invasion of 2001 have not been felt in the more remote parts of the country. He places the blame at the door of the government.

"The plight of those living in the countryside has hardly changed in centuries. Most importantly, for young girls, the future is bleak," said Qureishi. "With poverty rising, they will become more and more vulnerable as time goes on. These are the real victims of the failures by both the Afghan government and the West."