This is the second of a two-part blog series following my visit to Africa supported by CABI’s development bursary


The first blog in this series described the Africa Cassava Agronomy Initiative (ACAI) and how it aims to improve cassava agronomy to increase production and productivity, as well as how ACAI partnerships could build a climate-smart cassava value chain. This second blog is about the role research, development and technology in building the resilience of the cassava value chain. It talks about how agricultural diversification can help farmers and other cassava value chain actors adapt to the uncertainties of climate change through intercropping and sustainably intensifying cassava production.

At the end of the 5-day ACAI planning meeting in Zanzibar (19 to 23 June), I had the opportunity to interview Dr Veronica NE Uzokwe – the lead scientist in charge of ACAI research activities in Tanzania.

Q: What is your specific role in the ACAI project?

“I coordinate ACAI’s research activities in Tanzania, while working closely with Agricultural Research Institutes and development partners in charge of implementing the ACAI’s use cases in Tanzania. Specifically, I supervise the establishment of field trials to demonstrate the cassava-sweet potato intercropping use cases. I also help develop tools for targeting improved agronomic technologies, such as fertiliser recommendation and high starch, to different farming systems and niches for crop production.”

Q: As a scientist/agronomist, do you consider cassava as a climate-smart crop in sub-Saharan Africa?

“In sub-Saharan Africa, the climate has been unstable, and most widely consumed food crops like maize (which is the basis of most food cultures) sometimes fail to reach maturity because of drought. Thus, farmers need alternative food security crops which can withstand and adapt to the effects of climate change.

Cassava is considered “a poor man’s crop” because it is commonly cultivated by smallholder farmers and also viewed as a product that is not easily commercialised – in as much as it widely consumed in Nigeria and Tanzania. Cassava has also been identified by industries as a raw material, such as, starch; high quality cassava flour; snacks (for nutritional diversification); used by textile industries; pharmaceutical industries; alcoholic beverages (beer); bio fortified cassava (yellow cassava). Cassava peels and chips are also used as a source of animal feed but the supply of cassava to feed producing companies has not matched demand even though there is always a demand for these materials.

Smallholder farmers believe that cassava can perform well under minimal or low soil fertility and moisture content. This is true to a large extent, especially when compared to other crops that farming households depend on for sustenance and trade. This means that producing cassava, in the face of climate change can help promote food security, improve livelihood and reduce poverty.

However, because cassava is mainly grown by smallholder farmers, its overall production and productivity is below its attainable potential. In addition, these smallholders do not usually go into large scale production of cassava because compared to other crops they grow, the income from cassava is very low, hence they only produce cassava for household consumption, as a substitute crop, rather than on a commercial scale. This means that in sub-Saharan Africa, a yield gap exists in cassava production which should be narrowed. There is a need to improve cassava productivity through best fit agronomy so as to extend the production and productivity of cassava beyond the current scale.”

Dr NE vPhoto: Dr Veronica NE Uzokwe – lead scientist in charge of ACAI research activities in Tanzania.

Q: As cassava has been identified as a climate- smart crop, how is ACAI helping to bridge this yield gap in cassava productivity?

ACAI’s major goal is to increase the production (the quantity of cassava produced irrespective of the land area) and productivity (quantity produced per unit area) of cassava. ACAI does not operate in isolation. This is why it is called a demand driven project in the sense that we work with development partners at different points of the cassava value chain to produce and put into use our agronomic technology and Decision Support Tools  to drive the demand for cassava. In this case, the ACAI development partners including Mennonite Economic Development Associates, Cassava Adding Value for Africa, Farm Concern International, Minjingu fertilizer limited were able to identify the gaps of cassava production in Tanzania.

In the ACAI project, each development partner is tasked with specific challenges towards increasing cassava productivity. For instance, the Mennonite Economic Development Associates identified improving the variety of cassava and appropriate fertiliser recommendations are key solutions to increasing cassava productivity. Cassava Adding Value for Africa identified that there is an inadequate supply of cassava root to cassava processing factories throughout the year. Farm Concern International works with extension agents who transfer new and existing knowledge to farmers and also help to link farmers to profitable markets.

In addition, CABI, as a strategic partner will help organise cassava value chain clusters and also promote the technology developed by ACAI through various communication channels. Through research, technology and partnerships, ACAI is able to generate and disseminate appropriate technologies which can help increase cassava productivity.”

Q: What are these technologies ACAI is developing to bridge the cassava yield gap in Tanzania?

“ACAI’s technology is referred to as use-cases. Each uses-case serves as a platform to solving a particular cassava productivity challenge. ACAI’s six use-cases are;

  1. Fertiliser recommendation – For some time now, there has not been appropriate fertiliser recommendation for optimum cassava production. Most smallholder farmers do not use fertiliser for cassava production. Hence, they do not achieve the optimum production and productivity of cassava. From preliminary studies from a sister project (Support to Agriculture for research and development in Africa) proved that cassava responds to fertiliser application. Therefore, the ACAI project is working on nutrient omission trials where we established over 300 field trials to develop site specific fertiliser recommendations. These recommendations will be scaled out to other areas where the project is not directly implemented.
  2. Fertiliser blending – One of the major constraints that smallholder farmers have in applying fertiliser to their cassava fields is poor access to complete fertiliser blends, as what is usually available is single fertilisers (fertiliser with single nutrients). Also, the fertiliser blends available were specifically produced for crops like vegetables and rice. Therefore, ACAI is partnering with fertiliser companies like Minjingu fertilizer Limited to be able to recommend appropriate fertiliser types and blend that are best suited to cassava production.
  3. Best planting practices – Another major constraint to increasing cassava productivity is unavailability of site specific information for land preparation, planting materials as well as planting practicing. Thus, ACAI is developing appropriate land preparation and planting methods such as ridging, stem-cutting length and planting orientation tillage practices to address the problems encountered in this area.
  4. Intercropping – Delayed harvest is another constraint to smallholder cassava production as cassava is a long duration crop. Hence, in Zanzibar, ACAI project is working in collaboration with Farm Concern International to generate appropriate cassava/sweet potato intercropping patterns to help farmers diversify their incomes and also sustainably intensify their food production. Farm Concern International has suggested sweet potato as an associate crop because of its commercial importance in Zanzibar. Therefore, the smallholder can harvest their sweet potato in the short term for income prior to harvesting their long duration cassava. As both cassava and sweet potatoes are root crops and heavy miners of soil nutrients, it is very important to have the right intercropping pattern in order to generate optimum cassava and sweet potato yield.
  5. Scheduled planting – Smallholder farmers need the drive to produce cassava as an income source. Most cassava factories, which smallholder farmers supply with cassava roots, complain about cassava supply from farmers not matching their yearly processing demand. Traditionally, the smallholder farmers harvest their field in piecemeal over a year. However, they are not sure of the best period to plant or harvest for optimum root and starch yield. It is for this reason that the ACAI project partnered with Cassava Adding Value for Africa to develop Decision Support Tools for scheduled cassava planting trial over different planting and harvesting windows of the year to determine the best planting and harvesting period as well as the minimum rainfall for optimum cassava  root and starch yield.
  6. High starch content – Due to different planting and harvesting periods, smallholder farmers are also curious to obtain Decision Support Tools or technologies that provide information on the best period to harvest cassava with high starch content. This is because most processing factories which these farmers supply cassava roots tend to pay farmers according to starch content and cassava quality. Usually, from experience, these smallholder farmers know that cassava harvested after a long drought with immediate rainfall prior to harvest tends to have low starch content. Therefore, the ACAI project is varying the planting of cassava at different times of the year to ascertain the possibility of planting and harvesting cassava over various periods. This will ensure that famers are able to supply cassava roots to the processing factories throughout the year.”


Q: Finally, how does ACAI hope to promote the uptake of these technologies along the value chain?

“The ACAI project will generate decision support tools to enable partners and extension workers to pass this knowledge to farmers. In this case, a household and farm based survey will be conducted using an electronic device – open data kit. This will generate information and also give feedback to smallholder farmers and value chain stakeholders through the use of mobile phones which an average smallholder farmer can afford.”

by Bookie Ezeomah, CABI

1 Comment

  1. Martin Buuri Kaburia on 14th September 2017 at 10:17 am

    Wonderful insights

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