Potato yields are highly-dependent on fertilizer use but pinpointing the amount of fertilizer to be used can be a challenge, especially for smallholder farmers.
This challenge is important in Rwanda where average potato yields are currently 8-10 tonnes per hectare (t/ha), compared to the 25-35 t/ha they might expect with improved potato varieties, better pest and disease management, and enhanced extension services and fertilizer use.
Potato is cultivated across Rwanda and growing in popularity. But the majority of the crop is produced in the northwestern region of the country in the districts of Burera, Musanze, Nyabihu, and Rubavu. For this reason, the International Potato Center (CIP) and Rwanda Agriculture and Animal Resources Development Board (RAB) are focusing their efforts in this area to release varieties that are high-yielding, pest and disease resistant, and climate-resilient.
But is this enough to overcome the low potato yields faced by Rwandan farmers?
The short answer is, “not alone.”
Fertilizer use continues to be sub-optimal among potato farmers who often use mineral fertilizers that are subsidized by the government. Current fertilizer recommendations in Rwanda are crop-specific but are not tailored to different soil types, farm types, or field histories. Furthermore, the recommendations used by farmers are based on research and advice now more than 30 years old. This lack of specificity often leads to under- and overuse of fertilizers, which leads to lower yields and a loss of revenue to farmers.
Better targeted and appropriate use of fertilizer based on field types could also produce environmental benefits by minimizing the loss of nutrients to the environment and add efficiency to the government’s fertilizer subsidy program.
To address this challenge, CIP, RAB, the International Institute of Tropical Agriculture (IITA) and the One Acre Fund have partnered to support and launch a digital platform called AKILIMO that helps farmers and extension workers develop tailored fertilizer recommendations.
The ACAI agronomy advice tool, Akilimo, was built to provide optimized and economically beneficial recommendations tailored to the biophysical and socioeconomic situation of cassava growers. The tool considers planting and harvest dates, local soil data, weather conditions, prices of available fertilizers, cost of land preparation operations, prices of cassava root produce, cropping objectives, risk attitude, and the investment capacity of the farmer.
ACAI has been conducting trials in Nigeria and Tanzania in collaboration with national research and development partners to find out how agronomic technologies affect the performance of cassava under different growing conditions. Results showed large variations in response to the variables, indicating the need for tailored recommendations for fertilizer regime, tillage operations, weed management, and advice on overall investments in a cassava cropping system.
Originally piloted by IITA with cassava in Nigeria and Tanzania, AKILIMO underwent than 5,000 validation trials and 75% of farmers reported yield increases having used the app. Following this successful launch, more than 2,000 extension agents have been trained to use AKILIMO and more than 150,000 farmers are registered for the service, which gives them access to tailored farming advice on fertilizer and other agronomic concerns.
The AKILIMO project was brought to Rwanda in 2020 to serve cassava and potato farmers. To date, the digital platform operates in three counties where it has undergone nearly 200 trials to evaluate variations in fertilizer use among sites. These data will be used to calibrate AKILIMO for crop and spatial models.
AKILIMO considers fertilizers that are commonly available to potato farmers and provides recommended use for those fertilizers to the individual farmers. Based on last year’s data, recommended fertilizer use rates exceed the government’s recommended rate 300 kilograms of NPK fertilizer per hectare but did have small differences across districts.
A second season of multilocation trials has begun in the same districts along with a set of farmer-managed trials to compare blanket fertilizer recommendations with the tailored fertilizer recommendations provided by AKILIMO.
The AKILIMO-tailored fertilizer recommendations can be delivered to farmers using a variety of tools, such as smartphone apps, printable guides, and/or IVR-based messages directly to farmers.
Enthusiasm for AKILIMO is high among researchers, extension agents, and farmers alike. Placide Rukundo, a senior principal researcher at RAB says, “AKILIMO will bring updated and more accurate fertilizer recommendations because the current recommendations were too low, out of date, and not site specific.”
Jean Claude Nshimyimana, a senior agronomist at CIP sees a brighter future for Rwanda’s potato farmers. “Compared to the blanket fertilizer recommendation, the site-specific, tailored recommendations will lead to more sustainable fertilizers use, high yields and profits for farmers, and long-term soil health benefits.”
It is expected that AKILIMO will be extended to cassava in the near future and possibly to rice (in collaboration with the Africa Rice Center) over the next five years.