Ten farming families in Battambang province are reaping the benefits of switching to organic fertilisers, with rice yields increasing and visibly healthier plants.

Sien Hieng, a 52-year-old rice farmer, is among those who are making the gradual change.

Standing in his lush green fields in Kampong Prieng commune’s Sambok village of Sangke district, Hieng describes the positive changes he has observed now that he turns to organic fertiliser, in this case activated carbon made from rice husks.

He explains that he farms 3ha of rice, and harvests twice yearly. In the past, he relied entirely on chemical fertilisers such as urea. 

About a year ago, he learned about the Cambodia Climate Change Alliance-Phase 3 (CCCA3) programme – run with the support of the Ministry of Environment – and made the switch.

“When I spray this organic fertiliser on my rice crop, it does not make my skin irritated like the chemicals did, or have any other effect on human health. When we sprayed large numbers of chemicals, it emitted a bad small and affected the environment,” he says.

He adds that during the period when he used chemicals, his yield per hectare was about six tonnes, at a cost of almost two million riel ($500) to purchasing the fertiliser. Since using the activated rice husk carbon organic fertiliser, each hectare now produces eight tonnes.

Hieng elaborates that the organic fertiliser helps to enrich the soil as it reintroduces carbon, noting that he is still blending one or two bags of chemical fertiliser into his mix as he makes the transition.

Sem Savuth, an outreach officer at the ministry’s Cambodian Climate Change Alliance (CCCA), says phases one and two of the programme ran from 2010-14 and 2014-19 respectively. The current phase is due to conclude in June.

He explains that each phase of the project integrated the provision of climate change information to stakeholders, especially vulnerable people. The programme is funded by the EU via Sweden, as well as the UN Development Programme (UNDP), for a total of almost $12 million.

According to Savuth, one of the 22 projects in Battambang province is related to capacity building, resilience and sustainable implementation, with a focus on agriculture. This means the ministry is supporting communities as they develop a climate change-resilient agriculture sector.

“The farmers use rice husk carbon fertiliser, which is made by burning rice husks at a temperature of 700 degrees Celsius. During the creation of this fertiliser, it does not emit greenhouse gases, methane or carbon dioxide into the atmosphere but rather keeps it in the ground,” he shares.

He says plants need carbon and nitrogen to grow, and the organic fertiliser is rich in carbon, which makes plants grow faster and provide higher yields.

He adds that its use not only contributes to fighting climate change, because as farmers earn extra income, their living conditions improve. 

Mom Tith, sales manager of Husk Ventures (Cambodia) Co Ltd, says the rice husk fertiliser retains nutrients in the soil for a long time for agricultural crops. This also helps the environment because insects living in the soil need carbon for food. The insects also help to fertilise the soil.

“Rice husk carbon organic fertilizer does not emit oxygen into the atmosphere. This fertiliser is usually ploughed by farmers and thus it emits zero carbon into the atmosphere,” he explains.

Tith Ker, 60, has observed the difference in rice yields as he still mostly uses chemical fertiliser, noting that he and his family of 10 farm 8ha and were able to harvest just over 20 tonnes of paddy rice in 2023.

“The price of paddy rice in Battambang province in December 2023 was around 1,300 riel per kilogramme, compared to the 1,000 to 1,100 riel we earned the year prior, and much higher than they were in previous years,” he said.