New blended fertilisers composed of micro-nutrients of Sulphur, Zinc, Boron and Copper added to NPK have potential to increase average yields of rice to 7 tonnes per hectare   from the current average of 5 tonnes per hectare, research has shown.

The results from the research, which started in 2014, were observed during field tour of farms on which blended fertilisers trials were carried out in Cyunuzi marshland on 460 hectares in Kirehe District.

The marshland is owned by 3,222 farmers in Kirehe and Ngoma districts.

The farmers used to harvest 2,667 tonnes of rice but now expect more produce once new blended fertilisers start to be applied, according to Patrick Maniraguha, head of a farmers cooperative COOPRIKI.

The research is being conducted on rice, Irish potatoes and maize gardens.

It will be extended to wheat, soya beans and beans, officials said. The exercise is supported by OCP-Africa, a Moroccan company committed to the development of the agricultural ecosystem in Africa.

Jeanne Uwizeyimana, one of the farmers whose pieces of land serve as demonstration farm, explained the difference between using only NPK and new blended fertilisers.

 "I used the same rice variety and grew one acre on one side with only NPK and produced only 60kg while the side where I used the new blended fertilisers produced 80 kilogrammes of rice,” she said.

Now in the current plantation where I used only NPK, one plant has ten stems and less while where I used blended fertilisers, a rice plant has over 20 stems each with ear of grains,” she told the media and researchers at Cyunuzi marshland.

John Kayumba, one of the researchers of Rwanda Agriculture Board (RAB) working on the project, said that by using new blended fertilisers and urea briquettes, farmers get additional 2.2 tonnes of rice yields per hectare to the current average of 5.2 tonnes per hectare.

He said the cost of new formula is $268.3 per hectare while the current cost without using new fertiliser formula is $225 per hectare.

This means that a farmer only needs additional $43.3 (about Rwf30,000) per hectare.

"Additional cost of investment of Rwf30,000 per hectare  by  adapting new blended fertilisers is very little money considering that it helps to add a profit of up to 2.2 tonnes per hectare,” he explained.

Soil testing and mapping

 Telesphore Ndabamenye, the Head of Crop Production and Food Security Department at RAB, explained that researchers had to test soil to know the causes of low yields per hectare and then carry out research on blended fertilisers suitable for each selected crop and each type of soil in different agro-ecological zones across the country.

 "We first carried out a test on why crop yields are still low considering that potential yields per hectare even fall to between two and five tonnes per hectare. We realised that although we use fertilisers of NPK, there is micronutrients deficiency in plants due to intensive cultivation and imbalanced application of fertilisers,” he noted.

He said they started carrying out research on fertiliser formulas from which the ‘ best  recommended blended fertilisers’  were selected which, together with good varieties of rice seeds and irrigation, increase to even over 8 tonnes per hectares.

He said the experiment was also carried out in Kanyonyombya and Bugarama marshlands with rice growing.

 "After successful results from the research, we have to extend to farmers who will be getting new blended fertilisers on a subsidy scheme. We will soon have a factory  that produces such blended fertilisers in Rwanda,” he said.

He said a local plant producing fertilisers will reduce cost on imported fertiliser. RAB imports fertiliser worth over Rwf6.3bn per year.

Peter Simon Bwire, an agronomist and soil scientist from OCP Africa, who is part of the research team, said they have been dealing with soil mapping, setting up fertilisers blending plant, fertiliser formula development, irrigation.

He said, with new blended fertilisers, they realised that Irish potatoes yields reached 40 tonnes per hectare while the current average is 25 tonnes per hectare.

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