For most of his life, Gul Khal has eked out a meagre living from 10 hectares of dusty land not far from Kandahar city.
He douses his fields with enough fertilizer each winter to coax a modest harvest of wheat, beans and watermelon every spring. It is enough to feed his family of seven, and raise some cash at the local bazaar.
But a new law banning ammonium-nitrate fertilizers - which the Taliban use to build deadly roadside bombs - is stirring fury among farmers who say they need the chemical to nourish their crops.
Opposition to the law is spreading, threatening to complicate the West's new counterinsurgency strategy in its most crucial battleground - the southern provinces, where the Taliban and coalition forces are locked in a vicious battle for loyalty in Afghanistan's agricultural heartland.
"If they stop this fertilizer they will stop all agriculture in Afghanistan," says Mr. Gul, whose land lies in Dand district, where the Taliban is resurgent, posting written threats on mosques and mud huts in surrounding villages.
Mr. Gul doesn't believe the government ban will deter the insurgents from sowing explosives on the road.
"It will just punish the farmers, the poor people," he says. "The Taliban has ways of smuggling in anything they need."
However, for military commanders the fertilizer ban represents a hard-fought victory.
Roadside bombs have emerged as the single deadliest weapon used against NATO troops in Afghanistan. In recent months, Afghan President Hamid Karzai has come under increased pressure to clamp down on their chemical ingredients ahead of a U.S.-led troop surge. Out of the 139 Canadian soldiers killed in Afghanistan since the mission began, 81 died from improvised explosive devices, a trend that echoes across NATO forces.
Twenty of the 32 coalition troops killed in the first few weeks of January died from IEDs, the majority of them crude, home-made bombs made from ammonium nitrate fertilizer.
"It's something we've wanted for a long time, and we feel it's going to make a real difference," Major-General Nick Carter, the British commander of NATO troops in southern Afghanistan, says.
The decree issued by Mr. Karzai on Friday bans the use, production, storage or sale of ammonium nitrate, giving Afghans 30 days to surrender their supplies or face prosecution. NATO officials estimate just 5 per cent of the ammonium nitrate fertilizer that enters Afghanistan through Pakistan and Iran is currently being used for farming.
The insurgents, meanwhile, have become more inventive in designing the bombs, packing a deadly concoction of fertilizer and fuel into everything from cooking oil containers to plastic drums that are easy to bury and difficult to detect, according to military medics.
"They're everywhere out there," one soldier said. "The Taliban are just getting good at building them bigger and better."
The roadside bomb that killed Canadian journalist Michelle Lang and four Canadian soldiers last month left a crater two meters deep and three meters wide, flipping the armoured vehicle they travelled in.
Military commanders are convinced that if the insurgents are robbed of one of their main bomb-making tools, the death toll will drop.
"It's the best way we can fight the invisible enemy" one NATO official said.
Still, farmers in the area are furious. Ammonium nitrate, which costs the equivalent of $35 dollars for 50 kilos, is the most efficient way to fertilize their fields compared to other chemicals, they say. Diammonium phosphate costs twice as much. Urea, another fertilizer, is cheaper, but less effective, farmers say. "Ammonium nitrate is good quality, the others are too expensive or they don't work," said Abdul Bahri, who owns five acres of land in the Arghandab District, where he grows pomegranates, grapes and wheat.
Several farmers said they would rather risk jail by defying the ban than have their crops suffer with no fertilizer.
Some observers predicted the new law will harden attitudes toward coalition forces and the Afghan government, with echoes of their counternarcotics campaign several years ago, where the government destroyed poppy fields in an ill-fated effort to eradicate opium. Instead, the strategy fuelled protests and fanned support for the insurgency.
"Maybe the farmers won't like it, but slowly, slowly we will have to convince them," Amin Aziz, planning director of the department of Agriculture in Kandahar province, said of the new decree.
Ahead of the official ban, coalition forces have already been actively confiscating caches of fertilizer.
In November, they seized 250 tonnes of ammonium nitrate fertilizer in Kandahar - enough to make up to 200 roadside bombs.
The government, meanwhile, is offering to pay farmers to trade in their supplies for cash and an alternate fertilizer.
Still, at the bazaar in Kandahar city, sales of ammonium nitrate remain brisk, but have been driven underground.
"It is still possible to purchase," says a salesman named Hamidullah, who like many Afghans, goes by only one name.
"But only if you know the right people."