Farmers planting rice, potatoes, wheat, beans and maize can almost double their produce with the use of micronutrient fertilisers and lime, a new study indicates.

This is according to a study conducted in 2014 by the Ministry of Agriculture and Animal Resources (MINAGRI) in partnership with International Fertiliser Development Centre (IFDC).   

Revealing the findings of the study titled "The use of secondary and micronutrients fertilisers and lime”in Kigali, yesterday, Dr Charles Murekezi, the coordinator of the fertiliser programme at the ministry, said while there had been general use of NPK, DAP and IRE fertilisers, there has been little use of secondary micronutrient fertilisers despite the fact that their use could increase output.

The study, which was carried out in more than 200 sites across the country, used the ‘omission trials technique’ reach its findings.

The technique involves removing certain nutrients in the soil to assess their impact on productivity.

Athanase Rusanganwa, a researcher from Rwanda Agriculture Board, said while the average Irish potatoes yield is presently estimated at 22 tonnes per hectare, it can increase to 40 tonnes with the use of the micronutrients.

Applying micronutrients can also see maize yields rise from 3.8 tonnes a hectare to 6.5 tonnes, while wheat yields can increase from 2.3 tonnes to 4 tonnes a hectare. Rice yields can jump from five tonnes to eight tonnes a hectare. 

Cyprien Uwitije, a member of the research team, urged farmers to embrace the use of micronutrients. 

"If you invest Rwf1 on micronutrients, your profit is four times more. In volcanic soil, for example, by using 300kg of NPK (fertilisers) without micronutrients, we realised farmers could harvest only 26 tonnes per hectare; however, if both NPK and micronutrients were used they could harvest 32 tonnes per hectare,” he explained.

Dr Murekezi added that MINAGRI has already signed deals with private companies to distribute the micronutrients and lime to farmers.

"We are sensitising farmers on the benefits of using micronutrients. We want farmers to invest in the new methodology after they have understood all the benefits. The application (of the micronutrients) will depend on the soil type in the specific area,” he said.

However, some farmers are still skeptical, saying the study should first be undertaken on a larger scale.

"I want the study to be undertaken on a larger scale so I can be sure that yields will indeed increase. Sometimes when new seeds varieties are planted on small pieces of land, they give high yields, but when they are planted on bigger pieces of land the expected yields are not realised. We fear it might happen with the new fertilisers they want us to use,” said Joseph Gafaranga, a farmer in Musanze District.

Researchers agreed to apply the study on bigger plots of land during the next farming season to address farmers’ fears.

According to officials, investors have expressed interest in establishing blending factories for micronutrients next year.

Fertiliser prices have slightly decreased this year, with the cost of NPK going down to Rwf540 from Rwf550, and IRE to Rwf390 per kilo from Rwf410 previously.

Since 2007, the average usage rate of fertilisers has increased from 5,000 tonnes to 32,000 tonnes per year. The average usage of fertilisers in Rwanda is 35kg per hectare.