When the world's deadliest tsunami ravaged Indonesia's northern coastline on Boxing Day in 2004, it claimed the lives of almost 170,000 people.

The natural disaster left 62,000 farmers displaced.

Their fields were in ruins, swamped by debris, sediment and salt water, and stripped of vital nutrients.

Bapak Rahmad Kurniadi, an agriculture trainer in the hardest-hit region of Aceh, said the rice fields were covered in sand and mud.

"The biggest challenge we faced after the tsunami was returning the fertility to the soil," he said.

A collaboration between ACIAR and a local university has established demonstration sites to experiment with growing techniques. ( ABC News: Kallee Buchanan )

Following the tsunami, foreign aid poured into Indonesia from all over the world.

Non-government organisations were also quick to lend a hand.

But 14 years on, only one organisation remains: the Australian Centre for International Agricultural Research (ACIAR).

ACIAR has led a project helping farmers in Aceh province to not only repair their land but increase its productivity.

"We came here originally for a humanitarian project, but since the tsunami-relevant projects were completed, we looked for other opportunities and found things we can improve in the farming system," soil scientist and project leader Malem McLeod said.

At the core of the project is a push to increase dryland farming.

Common in Australia but rare in Aceh, dryland farming sees crops planted that can grow with little rain and no irrigation, such as corn, beans and peanuts.

The project aims to educate local farmers about the merits of dryland farming. ( ACIAR: Patrick Cape )

Farmers in Aceh would traditionally grow rice in the wet season and leave their fields bare for the rest of the year while they headed to the city to find other work.

"Typically, dryland soil is very suboptimal soil that's neglected and not even thought of in Aceh," Ms McLeod explained.

"To improve it is full of challenges, but the main ones are low carbon and nitrogen content and low water-holding capacity."

Improving soil quality was key to the project's success.

Soil scientist Malem McLeod helps a group of farmers. ( ACIAR: Patrick Cape )

The ACIAR team have partnered with Aceh's Syiah Kuala University, where researchers and 25 agriculture students use an experimental site to test how different fertilisers affect crop growth in dryland soil.

The students visit the farmers to show them what they've found through their research and share what works best.

"There is huge benefit to the farmers with this project but also for the students," agronomy professor Sabaruddin Zakaria said.

"They get real experience, seeing how the farmers work in the fields and the impact of new technology on farming practices."

Building local knowledge of dryland soil

The Australian-led project has the support of Aceh's Assessment Institute for Agricultural Technology, which has helped to teach 43 local workers how to improve the health of dryland soil.

These workers became trainers, tasked with passing their knowledge on to more than 700 farmers across the region.

"To be honest, the project doesn't provide unlimited funds, but we do have this concept of training the trainer and building the capacity of the local people," Ms McLeod said.

"That was one of the strategies we used to ensure there was a long-term benefit to the people of Indonesia.

"By the time the project is finished, they will have all the equipment, knowledge and skills to run on their own."

It is hard work, but the farmers say it is also happy. ( ABC News: Kallee Buchanan )

Using demonstration sites, the farmers work together and learn in groups, using new technology and farming methods, including the skipped-row technique in rice growing.

"It is very important to demonstrate how new technologies and techniques will work so the farmers can be confident that the methods are better," trainer Bapak Irhas said.

"We need to convince the farmers that it is possible and that it is better, both for their lives and their income."

"In most cases, we use organic fertiliser to improve the soil's water retention, so the crops produce a better yield — in some cases, they've doubled."

Having seen the proof at demonstration sites, the farmers are now embracing a collaborative, year-round approach in their own fields.

The rewards, both economic and social, are proving significant.

The project has helped the farmers increase their family income. ( ABC News: Rosie King )

"Where they would usually harvest four tonnes, they're now achieving six tonnes or seven tonnes per hectare," Mr Kurniadi said.

"There is a feeling of pride because what we have taught the farmers is being practiced.

"The farmers' quality of life is better now because of it."

The extra income means that instead of living week-to-week, the farmers are now saving money.

Instead of having to leave their family to find work in the dry season, they can stay in their hometowns.

"That brings the family together and when you bring the family together, the kids have better values in their lives and I think that's a good impact," Ms McLeod said.

The ACIAR project is set to finish at the end of the year, but its organisers hope the skills the farmers have learnt will be utilised long after Australian involvement.

"My hope is that, even after ACIAR leaves, we can continue working intensively with the farmers so that they will stay motivated to do it," Mr Irhas said.

Watch this story on Landline on Sunday at 12:30pm.

Rosie King travelled to Indonesia thanks a partnership between the ABC and the Australian Centre for International Agricultural Research.