"Of all my vegetables, broccoli is the most sought after," she said. "Each kilogram sells for 90 rupees ($1.40)."

That's 15 to 30 cents more than broccoli imported from neighbouring India. Zam gets the higher price because her produce is grown without the use of chemicals, making it healthier, more flavourful and more in demand.

"I apply organic manure that I compost right at home," she said. "The imported vegetables do not taste so good."

After decades of subsistence farming, Zam went organic four years ago. Now she grows 21 crops on her 1.3-acre farm - including grains, fruits and vegetables - and sells them, as well as homemade compost, to hotels, local vendors and nursery owners.

She earns 40,000 rupees ($600) per month, three times more than she made before, she said.

Zam's success is part of Bhutan's plan to support sustainable farming as one key to build a thriving ‘green’ economy.

In 2011, the government launched the National Organic Program, which aims to make the country's agriculture 100 percent organic by 2020.

By teaching farmers good organic farming practices and how to earn more money by growing organic produce, and by providing financial support, Bhutan hopes to reduce waste, decrease the country's dependence on imported food, and ensure it remains climate-neutral, producing no more climate-changing emissions each year than its forests absorb.

Already praised by environmentalists for its low carbon emissions and heavy use of hydropower, Bhutan hopes to become even greener by showing that environmentally friendly farming can also make money.

Cash from trash

Zam's switchover came when a team of officials from the agriculture ministry told her they were offering women farmers in her village free training in organic farming, including composting and selling the compost for a profit.

After attending a three-day training course, Zam started her home compost heap. Today, she sells about 60 kilograms of compost - made of grass, leaves, cow dung and sawdust - every two months to tourist resorts and other buyers.

She also uses the compost at her farm, including in the two greenhouses she bought and installed with an 80 percent subsidy from the government.

Before learning how to compost, she would end every harvest season with two or three truckloads of dead leaves and other organic waste that she would either burn or pay someone to dispose of.

"Now, from leaves to cow dung to chicken poop, everything is used," she said. "I have no trash, only compost."

Nedup Tsering, executive director of the government-funded Clean Bhutan project, which aims to make Bhutan a zero-waste country by 2030, notes that the country generates over 100 tons of garbage daily but has no centralized waste management program. "We want citizens to practice the 5 Rs: Rethink, reduce, recycle, reuse and re-create."

The hurdles

According to Kesang Tshomo, coordinator of the National Organic Program, Bhutan faces some hurdles on its path toward fully organic farming, however. "We have to be practical and consider the realities facing our farmers."

One is that the country produces relatively little of its food. According to a 2014 study on food security by the Royal Bhutan College of Thimphu, less than 4 percent of Bhutan's total land is under food cultivation, which is why almost 50 percent of the country's rice is imported from India and Thailand.

To persuade Bhutan's farmers to use organic methods, showing that the switch can lead to higher production is key, Tshomo said.

In June, officials announced that the government had so far provided 176 greenhouses to farmers and planned to install 650 more. It said its combined policies of pursuing organic farming and modernisation – such as building greenhouses and fencing – had helped increase agricultural production 3 percent since the start of the organic push.

The government is banking on the Clean Bhutan Project to also help Bhutan keep its pledge to remain carbon neutral. Currently, the country's carbon emissions rate is a negligible 0.8 metric tons per capita, according to the World Bank.

Promoting organic farming practices like composting is a "logical step towards the goal of remaining carbon neutral," said Peldon Tshering, chief strategist of Bhutan's environmental commission.

Zam, the Paro valley farmer, supports the government's plan to convert its farmers to organic agriculture. But for the project to succeed, she said, the government needs to help widen the market for organic produce.

Most of the hotels near her farm still mainly buy imported vegetables from India because they are cheaper, she said.

"If the government could convince people to buy from local farmers, it would help us a lot," Zam said. "I could sell all my produce within hours, without spending extra on driving a wagon from one market to another."

Reporting by Stella Paul, editing by Jumana Farouky and Laurie Goering from the Thomson Reuters Foundation, the charitable arm of Thomson Reuters, that covers humanitarian news, climate change, women's rights, trafficking and corruption. Visit: www.trust.org/climate