(REUTERS) - After a peace accord between the Colombian government and Marxist rebels in 2016 ended a five-decade war, Colombia is now working to revive one of its most important industries - coffee.

Thousands of coffee farmers who fled their lands due to violence are now slowly returning, hoping the fertile soil of the Andes mountains will once again cultivate high quality beans known the world over for their smooth taste and rich aroma.

But the process won't be easy, says Reuters reporter Marcy Nicholson who just returned from the Andean region of San Carlos.

"Many of these coffee farmers fled for their lives during the height of the violence around 2000. The farmers I met had all lost family members over the years. This one farmer I spoke to in 2015 said there was a decapitated body not far from his farm. Now he says that's the last sign of violence that he's seen. But they are very cautious" said Nicholson.

The conflict between the Rebel Armed Forces of Colombia or FARC and the Colombian government killed at least 220,000 people and displaced millions.

About 16 million coffee growing families in the San Carlos region fled the bloodshed. Roughly 60 per cent have returned so far. Most of them are reviving their farms by planting new trees and even expanding their coffee acreage. Their young trees take three years to bear fruit.

Another hurdle is finding help when it comes time to harvest the beans.

Still the Colombian government's estimating the country's coffee output will grow by 40 per cent by 2020. The additional supply of beans is helping to push down global coffee prices for the world's top roasters such as Illy Cafe, Nestle's Nespresso and Starbucks who is cautiously entering Colombia's post-conflict zones to source its flavourful brews.