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funder_partner: Norwegian Agency for Development Cooperation (NORAD)

It’s time to scale: Emerging lessons from decades of Conservation Agriculture research in Southern Africa

CA in action at the farmer level. (Photo: Christian Thierfelder/CIMMYT)

For decades, smallholder farmers in Southern Africa have battled the whims of a changing climate—from withered crops to yield reductions and looming food insecurity concerns. And the outlook is not improving. Based on the latest available science, the sixth assessment report of the Intergovernmental Panel on Climate Change (IPCC) reaffirms the projected negative impacts of climate change on livelihoods in Southern Africa.

Conservation Agriculture (CA) has been considered as an important step to make smallholder farming systems climate smart and resilient. The principles of CA are simple yet potent: minimal soil disturbance, crop cover, and diverse rotations, which tend to have lasting implications on rebuilding soil health, conserving moisture, and nurturing a thriving ecosystem. A strong evidence base from on-farm and on-station trials show that CA has the potential to build the adaptive capacity and resilience of smallholder farming systems to climate stress.

Yet, despite the positive results, significant scaling gaps remain. Key questions arise on what can be done to turn the tide, scale, and encourage uptake. What institutional, policy and economic incentives would enable scaling? Could mechanization be the missing link? The Understanding and Enhancing Adoption of Conservation Agriculture in Smallholder Farming Systems of Southern Africa (ACASA) project responds to these questions. With funding from the Norwegian Agency for Development Cooperation (NORAD) and implemented by the International Institute of Tropical Agriculture (IITA), and CIMMYT, the ACASA project goes beyond the narrow focus on promotion and technology delivery of past and ongoing interventions on CA in Southern Africa.

ACASA was designed to help stakeholders gain deeper understanding of the interactions between the socio-economic, biophysical, and institutional constraints and opportunities for adoption of CA practices. To do this, the project has undertaken extensive surveys aimed at understanding incentives, drivers, and barriers of CA adoption across Zambia, Malawi, and Zimbabwe.

Dialogues for change

Participants from across the region during the reflective meeting. (Photo: CIMMYT)

In December 2023, CIMMYT collaborated with IITA and the Ministry of Lands, Agriculture, Fisheries, Water and Rural Development of Zimbabwe to convene a highly engaging, reflective, and learning meeting, with the participation of government representatives, the private sector, and research institutes, among others. The primary objective was to share valuable insights accumulated over years of research and development on conservation agriculture in southern Africa. These insights are a result of collaborative efforts in social science, scaling, and mechanization work by CIMMYT, IITA, and extension and research partners in Malawi, Zambia, and Zimbabwe. Conversations centered on tracing the historical pathway of CA, leveraging mechanization, and identifying key enablers to transform smallholder agriculture.

Tracing the pathway of conservation agriculture

For decades, CIMMYT has been a leading force in promoting Conservation Agriculture. From the early stages in the 1990s, CIMMYT introduced CA principles and practices through on-farm and on-station field days, to undertaking robust research on biophysical impacts and developing adapted technologies in collaboration with national and global partners. As this research progressed and matured, efforts were made to integrate and focus on understanding the social and economic factors influencing CA adoption, while recognizing the significance of enabling environments. To date, linkages with mechanization and other innovations promoting CA-friendly equipment have been strengthened, ensuring inclusivity and empowerment. Questions remain around policy and institutional innovations to nudge and sustain adoption. In a nutshell, there is scope to borrow tools and methods from behavioral and experimental economics to better study and facilitate behavioral change among smallholder farmers. This snapshot highlights global efforts, grounded in scientific evidence, farmer centric approaches, and collaborative partnerships.

Insights from the field

Described as a data and evidence driven process, a notable highlight was the detailed gathering and analytical efforts using a large multi-country household survey involving 305 villages and 4,374 households across Malawi, Zambia, and Zimbabwe. The main thrust was not only to harvest data but listen to farmers and better understand their context while deciphering their decision-making processes concerning CA adoption, across the three countries. A compelling and hopeful story unfolds from the results. The adoption of CA practices such as crop residue retention, minimum tillage, crop rotation, and intercropping is much higher than previously thought, highlighting a crucial need for better targeted surveys. Key enablers to strengthen adoption include access to CA extension, hosting demonstrations, and access to credit. In addition, age, and extension in the case of Zambia were identified as important drivers of the speed and persistence of adoption. Demand for mechanization is rising, which is key to address drudgery associated with CA and to raise production efficiencies. Key recommendations centered on the need for investments in a dense network of farmer-centric learning centers that allow for experiential learning, facilitating equitable access to mechanization, promoting private sector participation, and developing integrated weed management options as weeds remain the Achilles Heel of CA adoption in the region. [1]

Emerging lessons

A deep dive on the findings reveals critical considerations for the widespread adoption of Conservation Agriculture (CA). Firstly, weed-related labor challenges pose a significant obstacle, with around 75% of farmers in three countries citing weeds as the most constraining issue during initial CA adoption. Addressing this weed management challenge is essential, emphasizing the need for environmentally safe, non-chemical solutions as a research priority. Secondly, there is a noticeable gap between scientific research on CA and farmer practices, primarily attributed to limited technical knowledge. Bridging this gap requires innovative approaches to translate scientific information into practical, farmer-centered products. Thirdly, incentivizing CA adoption through complementary input support programs, like payments for environmental services, may encourage farmers, especially when private returns are not immediate.

Fourthly, strengthening extension systems is crucial to facilitate farmer learning and bridge the awareness-to-know-how gap. Lastly, investing in improved machinery value chains can alleviate high labor costs and drudgery associated with CA practices, with economic estimates suggesting farmers’ willingness to pay for machinery hire services. These insights collectively highlight the multifaceted nature of challenges and opportunities for scaling up CA adoption.

Moving forward

ACASA’s research findings are not just numbers — they are seeds of hope. They point towards a future where CA adoption among smallholder farmers can transform the breadbasket of the three African countries, and beyond. CIMMYT and its partners remain committed to continuous learning, refining their approaches, and working hand-in-hand with farmers to nurture the CA revolution.

It will not be a pipe dream to transform agriculture in Southern Africa through CA by cultivating seeds of resilience, one at a time. This is because the experience from the region suggests that with the right political will, it is possible to mainstream CA as a critical adjunct to climate-smart agriculture strategies and resilience building. This broader institutional and political buy-in is important since CA programming cannot succeed without sector-wide approaches to removing systemic constraints to technology adoption.  A classic example is the Government-backed Pfumvudza program in Zimbabwe, which has seen adoption of planting basins conditioned on receipt of input subsidies soar to more than 90%.

[1] CIMMYT/IITA Scientists explore the weed issue in detail in a paper just accepted and forthcoming in Renewable Agriculture and Food Systems – Unanswered questions and unquestioned answers: The challenges of crop residue retention and weed control in Conservation Agriculture systems of southern Africa.

Unanswered questions and unquestioned answers

Over the past few decades, Conservation Agriculture (CA) has moved from theory to practice for many farmers in southern Africa. CA is a system that involves minimum soil disturbance, crop residue retention, and crop diversification among other complimentary agricultural practices. One reason for its increasing popularity is its potential to mitigate threats from climate change while increasing yields.

However, there are limits to the adaptation of CA, especially for smallholder farmers. Challenges are both agronomic (e.g. lack of sufficient crop residues as mulch, weed control, pest and disease carryover through crop residues), socio-economic, and political (both locally and regionally).

A recent paper, Unanswered questions and unquestioned answers: the challenges of crop residue retention and weed control in Conservation Agriculture systems of southern Africa, published in the journal Renewable Agriculture and Food Systems in February 2024, led by CIMMYT and CGIAR scientists examines two specific challenges to more widespread CA adaptation: how to deal with trade-offs in using crop residue and finding alternatives to herbicides for weed control.

For crop residue, the two most prevalent actions are using leftover crop residue for soil cover or feeding it to livestock. Currently, many farmers allow livestock to graze on crop residue in the field, leading to overgrazing and insufficient ground cover. This tradeoff is further challenged by other multiple household uses of residues such as fuel and building material. The most common way to control weeds is the application of herbicides. However, inefficient and injudicious herbicide use poses a threat to human health and the environment, so the research team set out to identify potential alternatives to chemical weed control as the sole practices in CA systems.

“The answer to the question ‘how should farmers control weeds?’ has always been herbicides,” said lead author Christian Thierfelder, CIMMYT principal cropping systems agronomist. “But herbicides have many negative side effects, so we wanted to question that answer and examine other potential weed control methods.”

What to do with crop residue

Previous research from the region found that ungrazed areas had long-term positive effects on soil fertility and crop yields. However, it is common practice for many farmers in Malawi, Zambia, and Zimbabwe to allow open grazing after the harvest in their communities. Livestock are free to graze wherever they wander, which results in overgrazing.

“Open grazing systems help keep costs down but are very inefficient in terms of use of resources. It leads to bare fields with poor soil,” said Thierfelder.

Maize on residues. (Photo: CIMMYT)

While it is easy to suggest that regulations should be enacted to limit open grazing, it is difficult to implement and enforce such rules in practice. The authors found that enforcement is lacking in smaller villages because community members are often related, which makes punishment difficult, and there is an inherent conflict of interest among those responsible for enforcement.

Controlling weeds

Weeding challenges in CA systems have been addressed worldwide by simply using herbicides. However, chemical weeding is often not affordable and, sometimes, inaccessible to the smallholder farmers and environmentally unfriendly.

Using herbicides, though effective when properly applied, also requires a degree of specialized knowledge, and without basic training, this may be an unviable option as they may pose a risk to the health of the farmers. Thus, alternatives need to be identified to overcome this challenge.

Some alternatives include mechanical methods, involving the use of handheld tools or more sophisticated tools pulled by animals or engines. While this can be effective, there is the possibility of high initial investments, and intercropping (a tenet of CA) forces farmers to maneuver carefully between rows to avoid unintended damage of the intercrop.

Increasing crop competition is another potential weed control system. By increasing plant density, reducing crop row spacing, and integrating other crops through intercropping, the crop competes more successfully with the weeds for resources such as light, moisture, and nutrients. When the crop seed rate is increased, the density of the crops increases, providing more cover to intercept light, and reducing the amount of light reaching the weeds thereby controlling their proliferation.

A holistic approach

“What we learned is that many of the crop residue and weed challenges are part of broader complications that cannot be resolved without understanding the interactions among the current scientific recommendations, private incentives, social norms, institutions, and government policy,” said Thierfelder.

Continuing research into CA should aim to examine the social and institutional innovations needed to mainstream CA as well as strengthen and expand the research on weed control alternatives and focus on the science of communal grazing land management to enhance their productivity.

Understanding and Enhancing Adoption of Conservation Agriculture in Smallholder Farming Systems of southern Africa (ACASA)

Conservation agriculture (CA) has increasingly been promoted in southern Africa to address low agricultural productivity, food insecurity, and land degradation. Despite significant experimental evidence on the agronomic and economic benefits and the large scaling-up investments by donors and national governments, the adoption rates of CA practices among smallholder farmers are low and slow.

With funding from the Norwegian Agency for Development Cooperation (NORAD) and implemented by the International Institute of Tropical Agriculture (IITA) and CIMMYT, ACASA strives to understand “why previous efforts and investments to scale CA technologies and practices in southern Africa have not led to widespread adoption.” It is a three-year project implemented in Malawi, Zambia, and Zimbabwe, where CA is part of national policy.

Since 2021, the project has undertaken extensive surveys aimed to understand incentives, drivers, and barriers of CA adoption across the three countries (Malawi, Zambia, and Zimbabwe) typifying much of the southern Africa smallholder systems. The aim of the project is to consolidate the lessons learned so far and provide a pathway to scaling and foster the next generation of social, crop, agronomic and climate research; to mainstream CA enabled by fundamental paradigm shifts in farming practices, markets, and social institutions for sustainable intensification of smallholder farming systems of southern Africa.

Project objectives include –

  • Understanding the contexts of smallholder farmer in southern Africa to identify the drivers and barriers preventing adoption of CA practices, including biophysical, socio-economic, institutional and policy constraints
  • Identifying labor-efficient mechanization options for smallholder farmers
  • Identifying opportunities and tools for better targeting of appropriate CA practices and options across heterogenous agroecologies and farm types, and
  • Identifying approaches and strategies for inclusive scaling of CA practices (policy, institutional and value chain entry points and pathways to promote and scale CA)

 

CIMMYT and IITA collaborate to increase adoption of conservation agriculture in southern Africa

Farmers going home for breakfast in Motoko district, Zimbabwe. (Photo: Peter Lowe/CIMMYT)
Farmers going home for breakfast in Motoko district, Zimbabwe. (Photo: Peter Lowe/CIMMYT)

The International Institute of Tropical Agriculture (IITA) and the International Maize and Wheat Improvement Center (CIMMYT) recently launched a project that aims to research the drivers and barriers to adoption of conservation agriculture in southern Africa, and to develop strategies for achieving adoption and impact at scale.

The project, Understanding and Enhancing Adoption of Conservation Agriculture in Smallholder Farming Systems of Southern Africa (ACASA), will apply social and scaling science to understand the biophysical, socioeconomic, institutional, and policy drivers and barriers to the adoption of conservation agriculture technologies and practices.

The ACASA project is supported by the Norwegian Agency for Development Cooperation (Norad) and will be implemented in Malawi, Zambia, and Zimbabwe in collaboration with partners and farmers in the region.

The project was officially launched online on September 16, 2020. Zambia’s Minister of Agriculture, Michael Katambo, noted that it is a timely intervention, as the livelihoods and food security of smallholder farmers in southern Africa are increasingly being threatened by climate change and variability, which have led to a steady decline in the production of food staples and an increase in the number of food and nutrition-insecure people.

“It is now clear that current productivity and production levels cannot be expected to meet our requirements for food and nutrition security,” Katambo said in a speech read on his behalf by Moses Mwale, Director of the Department of Agriculture. “Conservation agriculture has a proven potential to increase and stabilize crop yields, and to support sustainable and resilient production systems and rural livelihoods.”

Proven benefits

Conservation agriculture — a farming system that promotes minimum soil disturbance, permanent soil cover and diversification of plant species — can efficiently increase agricultural productivity while reducing land degradation and improving soil health for more productive, profitable, and sustainable farming.

Substantial on-farm evidence has been generated on the agronomic and economic benefits of conservation agriculture, first introduced in the 1970s in South Africa. Consequently, donors and governments have made a lot of investments to promote and scale conservation agriculture technologies and practices among smallholder farmers in the region. Despite all these efforts, however, the adoption rate among smallholder farmers remains low.

“We should not let the low adoption of conservation agriculture discourage us. Let us use this opportunity to reflect and identify the missing link and come up with more sustainable solutions to the problem,” said the IITA Director for Southern Africa, David Chikoye.

“Although adoption of improved practices by most resource-poor farmers is primarily determined by the potential immediate benefits on crop yields, profits, risk, and livelihoods, there are a number of biophysical, socioeconomic, institutional, and policy factors that promote or hinder adoption of conservation agriculture. The project, therefore, aims to identify the adoption drivers and barriers, and to develop pathways and strategies for inclusive scaling of conservation agriculture practices,” said  Arega Alene, Agricultural Economist at IITA and leader of the ACASA project.

Christian Thierfelder, Principal  Cropping Systems Agronomist at CIMMYT, highlighted some of the bottlenecks for conservation agriculture adoption, noting they were linked more to socioeconomic and cultural factors rather than biophysical. “Conservation agriculture is a viable and proven climate-smart farming system. Future research efforts should go towards understanding farmers’ decision-making and behavioral change, as well as profitability,” Thierfelder said.

Other key partners include the Food and Agriculture Organization of the United Nations (FAO), the African Conservation Tillage Network (ACT) and Centre for Coordination of Agricultural Research and Development for Southern Africa (CCARDESA).

The project launch was attended by policymakers, donors, members of national and regional conservation agriculture taskforces, national and international research institutions, universities, international development institutions, private seed companies, non-governmental organizations, and farmer organizations.


Interview opportunities:

Arega Alene, Agricultural Economist, IITA.

Christian Thierfelder, Principal  Cropping Systems Agronomist, CIMMYT

For more information, or to arrange interviews, contact the media team:

Genevieve Renard, Director of Communications, CIMMYT. g.renard@cgiar.org

Katherine Lopez, Head of Communication, IITA. k.lopez@cgiar.org

About CIMMYT:

The International Maize and What Improvement Center (CIMMYT) is the global leader in publicly-funded maize and wheat research and related farming systems. Headquartered near Mexico City, CIMMYT works with hundreds of partners throughout the developing world to sustainably increase the productivity of maize and wheat cropping systems, thus improving global food security and reducing poverty. CIMMYT is a member of the CGIAR System and leads the CGIAR programs on Maize and Wheat and the Excellence in Breeding Platform. The Center receives support from national governments, foundations, development banks and other public and private agencies. For more information visit staging.cimmyt.org.

About IITA:

The International Institute of Tropical Agriculture (IITA) is a not-for-profit institution that generates agricultural innovations to meet Africa’s most pressing challenges of hunger, malnutrition, poverty, and natural resource degradation. Working with various partners across sub-Saharan Africa, we improve livelihoods, enhance food and nutrition security, increase employment, and preserve natural resource integrity. IITA is a member of CGIAR, a global agriculture research partnership for a food-secure future.

New publications: Agro-ecological options for fall armyworm management

Fall armyworm, a voracious pest now present in both Africa and Asia, has been predicted to cause up to $13 billion per year in crop losses in sub-Saharan Africa, threatening the livelihoods of millions of farmers throughout the region.

“In their haste to limit the damage caused by the pest, governments in affected regions may promote indiscriminate use of chemical pesticides,” say the authors of a recent study on fall armyworm management. “Aside from human health and environmental risks,” they explain, “these could undermine smallholder pest management strategies that depend largely on natural enemies.”

Agro-ecological approaches offer culturally appropriate, low-cost pest control strategies that can be easily integrated into existing efforts to improve smallholder incomes and resilience through sustainable intensification. Researchers suggest these should be promoted as a core component of integrated pest management programs in combination with crop breeding for pest resistance, classical biological control and selective use of safe pesticides.

However, the suitability of agro-ecological measures for reducing fall armyworm densities and impact must be carefully assessed across varied environmental and socioeconomic conditions before they can be proposed for wide-scale implementation.

To support this process, researchers at the International Maize and Wheat Improvement Center (CIMMYT) reviewed evidence for the efficacy of potential agro-ecological measures for controlling fall armyworm and other pests, consider the associated risks and draw attention to critical knowledge gaps. Findings from the Africa-wide study indicate that several measures can be adopted immediately, such as sustainable soil management, intercropping with appropriately selected companion plants and the diversification of farm environments through management of habitats at multiple spatial scales.

Read the full article “Agro-ecological options for fall armyworm (Spodoptera frugiperda JE Smith) management: Providing low-cost, smallholder friendly solutions to an invasive pest” in the Journal of Environmental Management, Volume 243, 1 August 2019, pages 318-330.

Intercropping options for mitigating fall armyworm damage. (Photo: C. Thierfelder/CIMMYT)
Intercropping options for mitigating fall armyworm damage. (Photo: C. Thierfelder/CIMMYT)

Read more recent publications by CIMMYT researchers:

  1. Impact of conservation tillage in rice–based cropping systems on soil aggregation, carbon pools and nutrients. 2019. Rajiv Nandan, Vikram Singh, Sati Shankar Singh, Kumar, V., Kali Krishna Hazra, Chaitanya Prasad Nath, Poonia, S. P., Malik, R.K., Ranjan Bhattacharyya, McDonald, A. In: Geoderma v. 340, p. 104-114.
  2. Integrating genomic-enabled prediction and high-throughput phenotyping in breeding for climate-resilient bread wheat. 2019. Juliana, P., Montesinos-Lopez, O.A., Crossa, J., Mondal, S., Gonzalez-Perez, L., Poland, J., Huerta-Espino, J., Crespo-Herrera, L.A., Velu, G., Dreisigacker, S., Shrestha, S., Perez-Rodriguez, P., Pinto Espinosa, F., Singh, R.P. In: Theoretical and Applied Genetics v. 132, no. 1, p. 177-194.
  3. Modeling copy number variation in the genomic prediction of maize hybrids. 2019. Hottis Lyra, D., Galli, G., Couto Alves, F., Granato, I.S.C., Vidotti, M.S., Bandeira e Sousa, M., Morosini, J.S., Crossa, J., Fritsche-Neto, R. In: Theoretical and Applied Genetics v. 132, no. 1, p. 273-288.
  4. Soil dwelling beetle community response to tillage, fertilizer and weeding intensity in a sub-humid environment in Zimbabwe. 2019. Mashavakure, N., Mashingaidze, A.B., Musundire, R., Nhamo, N., Gandiwa, E., Thierfelder, C., Muposhi, V.K. In: Applied Soil Ecology v. 135, p. 120-128.
  5. Two main stripe rust resistance genes identified in synthetic-derived wheat line soru#1. 2019. Ruiqi Zhang, Singh, R.P., Lillemo, M., Xinyao He., Randhawa, M.S., Huerta-Espino, J., Singh, P.K., Zhikang Li, Caixia Lan. In: Phytopathology v. 109, no. 1, p. 120-126.