funder_partner: African Plant Nutrition Institute (APNI)

In sub-Saharan Africa, mineral fertilization and agroecology are not incompatible

Written by Julian Bañuelos-Uribe on October 10, 2023. Posted in Press releases.

Are agroecological approaches, based for example on the use of legumes and manure, enough by themselves to ensure a long-term increase in annual crop yields in sub-Saharan Africa (SSA), without using more mineral fertilizer?

The answer is no, according to a team of agronomists who have published an in-depth analysis of 150 scientific articles on annual crops (maize, sorghum, millet, rice, cassava, etc.) and tropical legumes, both annual grain legumes (cowpea, groundnut) and legume trees (acacia, sesbania) in tropical environments.

These publications collate 50 years of knowledge on nutrient balances in sub-Saharan Africa, biological nitrogen fixation by tropical legumes, manure use in smallholder farming systems and the environmental impact of mineral fertilizer.

“When we look at comparable climate conditions and physical soil constraints, yields of maize – the main source of calories for people – in sub-Saharan Africa are three to four times lower than elsewhere in the world. This is largely due to the fact that mineral fertilizer use (nitrogen, potassium) is on average four times lower there”, says Gatien Falconnier, a researcher at CIRAD based in Zimbabwe and lead author of the article. “On average, 13 kg of nitrogen are used per hectare and per year in sub-Saharan Africa, for all crops, bearing in mind that the poorest farmers have no access to nitrogen fertilizers and therefore do not use them. It is mainly agri-business and vegetable farmers that have access to fertilizers”, adds François Affholder, an agronomist at CIRAD based in Mozambique and co-author of the article.

Maize and cowpea intercropping in the Maravire field. (Photo: CIMMYT)

“Our objective is not to produce like Europe or North America, but to produce more and more regularly according to the seasons and the years, and thus to increase the economic sustainability of our farming systems. To do so, we must ensure a minimum level of nutrients for crops, which require essential mineral elements for efficient photosynthesis, and therefore growth. Soils are typically lacking in mineral elements in sub-Saharan Africa, and the largely insufficient organic inputs lead to nutrient deficiencies in crops. This is the main limiting factor for crop yields, excluding drought situations”, says Pauline Chivenge of the African Plant Nutrition Institute (APNI). “The work by Christian Pieri showed as early as 1989 that it is possible to restore high levels of fertility to African soils through a balanced approach to organic and mineral nutrient inputs”, says François Affholder.

The article highlights five reasons why more mineral fertilizer is needed in sub-Saharan Africa:

Farming systems are characterized by very low mineral fertilizer use, widespread mixed crop-livestock systems, and significant crop diversity, including legumes. Inputs of mineral elements to crops by farmers are insufficient, resulting in a widespread decline in soil fertility due to soil nutrient mining.
The nitrogen requirements of crops cannot be met solely through biological nitrogen fixation by legumes and manure recycling. Legumes can only fix atmospheric nitrogen if symbiosis with soil bacteria functions correctly, which requires absorption of different mineral elements by the plant. Ken Giller of Wageningen University highlights that the ability of legumes to capture nitrogen from the air through their symbiosis with rhizobium bacteria is a fantastic opportunity for smallholder farmers, “but the amounts on nitrogen fixed are very small unless other nutrients such as phosphorus are supplied through fertilizers”.
Phosphorus and potassium are often the main limiting factors of the functioning of plants and living organisms, including symbiotic bacteria: if there is not enough phosphorus and potassium in soils, then there is no nitrogen fixation. These nutrient elements, phosphorus, potassium and micro-elements, need to be provided by fertilizers, since they cannot be provided by legumes, which draw these elements directly from the soil. In the case of manure, this is simply a transfer from grazing areas to cultivated areas, which gradually reduces fertility in grazing areas.
If used appropriately, mineral fertilizers have little impact on the environment. The greenhouse gas emissions linked to nitrogen fertilizer use can be controlled through a balanced and efficient application. In addition, mineral fertilizers can be produced more efficiently in order to reduce the impact of their production on greenhouse gas emissions, keeping in mind that this impact is low, at around 1% of total anthropogenic emissions.
Further reducing mineral fertilizer use in SSA would hamper productivity gains and would contribute directly to increasing food insecurity and indirectly to agricultural expansion and deforestation. Producing for a population that will double by 2050 is likely to require the use of more agricultural land. An extensive strategy thus harms biodiversity and contributes to increasing greenhouse gas emissions, contrary to an agroecological intensification strategy combined with efficient and moderate mineral fertilizer use.

“If we take account of biophysical production factors, such as climate and soil, and shortages of land and agricultural workers, it will be impossible to reach a satisfactory production level by fertilizing soils only with manure and using legumes”, says Leonard Rusinamhodzi, an agricultural researcher at the Ghana International Institute of Tropical Agriculture.

However, “agroecological principles linked directly to improving soil fertility, such as recycling of mineral and organic elements, crop efficiency and diversity, with for example agroforestry practices and cereal-legume intercropping, remain essential to improve soil health. Soil fertility is based on its organic matter content, provided by plant growth that determines the biomass that is returned to the soil in the form of roots and plant residues. Efficient mineral fertilizer use starts a virtuous circle. These nutrients are crucial for the sustainability of agricultural productivity”, says Gatien Falconnier.

The researchers therefore argue for a nuanced position that recognizes the need to increase mineral fertilizer use in sub-Saharan Africa, in a moderate manner based on efficient practices, in conjunction with the use of agroecological practices and appropriate policy support. This balanced approach is aimed at ensuring long-term food security while preserving ecosystems and preventing soil degradation.

Référence
Falconnier, G. N., Cardinael, R., Corbeels, M., Baudron, F., Chivenge, P., Couëdel, A., Ripoche, A., Affholder, F., Naudin, K., Benaillon, E., Rusinamhodzi, L., Leroux, L., Vanlauwe, B., & Giller, K. E. (2023).

The input reduction principle of agroecology is wrong when it comes to mineral fertilizer use in sub-Saharan Africa. Outlook on Agriculture, 0(0). https://doi.org/10.1177/00307270231199795

*CIRAD, CIMMYT, International Institute of Tropical Agriculture (IITA), Wageningen University and the African Plant Nutrition Institute (APNI)

Contact: presse@cirad.fr

Scientists:

Gatien Falconnier
gatien.falconnier@cirad.fr

Pauline Chivenge
P.CHIVENGE@apni.net

Leonard Rusinamhodzi
L.Rusinamhodzi@cgiar.org

CIMMYT leads innovation sprint to deliver results to farmers rapidly

Written by Sarah McLaughlin on December 5, 2022. Posted in Features.

Smallholder farmers, the backbone of food systems around the world, are already facing negative impacts because of climate change. Time to adapt climate mitigation strategies is not a luxury they have. With that in mind, the Agriculture Innovation Mission for Climate (AIM4C) facilitates innovation sprints designed to leverage existing development activities to create a series of innovations in an expedited timeframe.

At the UN COP27 in Egypt, AIM4C announced its newest round of innovation sprints, including one led by the International Center for Maize and Wheat Improvement (CIMMYT) to enable smallholder farmers to achieve efficient and effective nitrogen fertilizer management. From 2022 to 2025, this sprint will steer US $90 million towards empowering small-scale producers in Africa (Kenya, Malawi, Morocco, Tanzania, and Zimbabwe), Asia (China, India, Laos and Pakistan), and Latin America (Guatemala and Mexico).

“When we talk to farmers, they tell us they want validated farming practices tailored to their specific conditions to achieve greater productivity and increase their climate resilience,” said Sieg Snapp, CIMMYT Sustainable Agrifood Systems (SAS) program director who is coordinating the sprint. “This sprint will help deliver those things rapidly by focusing on bolstering organic carbon in soil and lowering nitrous oxide emissions.”

Nitrogen in China

Working with the Chinese Academy of Agricultural Sciences (CAAS), the sprint will facilitate the development of improved versions of green manure crops, which are grown specifically for building and maintaining soil fertility and structures which are incorporated back into the soil, either directly, or after removal and composting. Green manure can significantly reduce the use of nitrogen-based fertilizers, which prime climate culprits.

“There are already green manure systems in place in China,” said Weidong Cao from CAAS, “but our efforts will integrate all the work being done to establish a framework for developing new green manure crops aid in their deployment across China.”

Triple wins in Kenya

The Kenya Climate Smart Climate Project, active since 2017, is increasing agricultural productivity and building resilience to climate change risks in the targeted smallholder farming and pastoral communities. The innovation sprint will help rapidly achieve three wins in technology development and dissemination, cutting-edge innovations, and developing sets of management practices all designed to increase productive, adaption of climate smart tech and methods, and reduce greenhouse gas (GHG) emissions.

Agricultural innovations in Pakistan

The Agricultural Innovation Program (AIP), a multi-disciplinary and multi-sectoral project funded by USAID, led by CIMMYT, and active in Pakistan since 2015, fosters the emergence of a dynamic, responsive, and competitive system of science and innovation that is ‘owned’ by Pakistan and catalyzes equitable growth in agricultural production, productivity, and value.

“From its beginning, AIP has been dedicated to building partnerships with local organizations and, smallholder farmers throughout Pakistan, which is very much in line with the objectives and goal as envisioned by Pakistan Vision 2025 and the Vision for Agriculture 2030, as Pakistan is a priority country for CIMMYT. However, a concerted effort is required from various players representing public and private sectors,” said Thakur Prasad Tiwari, senior scientist at CIMMYT. “Using that existing framework to deliver rapid climate smart innovations, the innovation sprint is well-situated to react to the needs of Pakistani farmers. “

Policies and partnerships for innovations in soil fertility management in Nepal

The Nepal Seed and Fertilizer (NSAF) project, funded by USAID and implemented by CIMMYT, facilitates sustainable increases in Nepal’s national crop productivity, farmer income, and household-level food and nutrition security. NSAF promotes the use of improved seeds and integrated soil fertility management technologies along with effective extension, including the use of digital and information and communications technologies. The project facilitated the National Soil Science Research Centre (NSSRC) to develop new domain specific fertilizer recommendations for rice, maize, and wheat to replace the 40 years old blanket recommendations.

Under NSAFs leadership, the Ministry of Agriculture and Livestock Development (MOALD) launched Asia’s first digital soil map and has coordinated governmental efforts to collect and analyze soil data to update the soil map and provide soil health cards to Nepal’s farmers. The project provides training to over 2000 farmers per year to apply ISFM principles and provides evidence to the MOALD to initiate a balanced soil fertility management program in Nepal and to revise the national fertilizer subsidy policy to promote balanced fertilizers. The project will also build efficient soil fertility management systems that significantly increase crop productivity and the marketing and distribution of climate smart and alternative fertilizer products and application methods.

Public-private partnerships accelerate access to innovations in South Asia

The Cereal Systems Initiative for South Asia (CSISA), established in 2009, has reached more than 8 million farmers by conducting applied research and bridging public and private sector divides in the context of rural ‘innovation hubs’ in Bangladesh, India, and Nepal. CSISA’s work has enabled farmers to adopt resource-conserving and climate-resilient technologies and improve their access to market information and enterprise development.

“Farmers in South Asia have become familiar with the value addition that participating in applied research can bring to innovations in their production systems,” said Timothy Krupnik, CIMMYT systems agronomist and senior scientist. “Moreover, CSISA’s work to address gaps between national and extension policies and practices as they pertain to integrated soil fertility management in the context of intensive cropping systems in South Asia has helped to accelerate farmers’ access to productivity-enhancing innovations.”

CSISA also emphasizes support for women farmers by improving their access and exposure to improved technological innovations, knowledge, and entrepreneurial skills.

Sustainable agriculture in Zambia

The Sustainable Intensification of Smallholder Farming systems in Zambia (SIFAZ) is a research project jointly implemented by the UN Food and Agriculture Organization (FAO), Zambia’s Ministry of Agriculture and CIMMYT designed to facilitate scaling-up of sustainable and climate smart crop production and land management practices within the three agro-ecological zones of Zambia. “The Innovation Sprint can take advantage of existing SIFAZ partnerships, especially with Zambia’s Ministry of Agriculture,” said Christian Thierfelder, CIMMYT scientist. “Already having governmental buy-in will enable quick development and dissemination of new sustainable intensification practices to increase productivity and profitability, enhance human and social benefits while reducing negative impacts on the environment.”

Cover photo: Paul Musembi Katiku, a field worker based in Kiboko, Kenya, weighs maize cobs harvested from a low nitrogen trial. (Florence Sipalla/CIMMYT)

A farmer shows maize growing in his field, in one of the communities in northern Nigeria which participated in the study. (Photo: Oyakhilomen Oyinbo)

Understanding decision support

Written by Rodrigo Ordóñez on September 9, 2021. Posted in Features.

Given the very heterogeneous conditions in smallholder agriculture in sub-Saharan Africa, there is a growing policy interest in site-specific extension advice and the use of related digital tools. However, empirical ex ante studies on the design of this type of tools are scant and little is known about their impact on site-specific extension advice.

In partnership with Oyakhilomen Oyinbo and colleagues at KU Leuven, scientists at the International Maize and Wheat Improvement Center (CIMMYT) have carried out research to clarify user preferences for tailored nutrient management advice and decision-support tools. The studies also evaluated the impact of targeted fertilizer recommendations enabled by such tools.

Understanding farmers’ adoption

A better understanding of farmers’ and extension agents’ preferences may help to optimize the design of digital decision-support tools.

Oyinbo and co-authors conducted a study among 792 farming households in northern Nigeria, to examine farmers’ preferences for maize intensification in the context of site-specific extension advice using digital tools.

Overall, farmers were favorably disposed to switch from general fertilizer use recommendations to targeted nutrient management recommendations for maize intensification enabled by decision-support tools. This lends credence to the inclusion of digital tools in agricultural extension. The study also showed that farmers have heterogeneous preferences for targeted fertilizer recommendations, depending on their resources, sensitivity to risk and access to services.

The authors identified two groups of farmers with different preference patterns: a first group described as “strong potential adopters of site-specific extension recommendations for more intensified maize production” and a second group as “weak potential adopters.” While the two groups of farmers are willing to accept some yield variability for a higher average yield, the trade-off is on average larger for the first group, who have more resources and are less sensitive to risk.

The author recommended that decision-support tools include information on the riskiness of expected investment returns and flexibility in switching between low- and high-risk recommendations. This design improvement will help farmers to make better informed decisions.

Community leaders talk to researchers in one of the villages in norther Nigeria which took part in the study. (Photo: Oyakhilomen Oyinbo)

Members of the survey team participate in a training session at Bayero University Kano, Nigeria. (Photo: Oyakhilomen Oyinbo)

One of the sites of nutrient omission trials, used during the development phase of the Nutrient Expert tool in Nigeria. (Photo: Oyakhilomen Oyinbo)

Extension agents go digital

While farmers are the ultimate recipients of extension advice, extension agents are most often the actual users of decision-support tools. In another study, the authors provided ex ante insights on the potential uptake of nutrient management decision-support tools and the specific design features that are more (or less) appealing to extension agents in the maize belt of northern Nigeria.

Using data from a discrete choice experiment, the study showed that extension agents were generally willing to accept the use of digital decision-support tools for site‐specific fertilizer recommendations. While extension agents in the sample preferred tools with a more user‐friendly interface that required less time to generate an output, the authors also found substantial preference heterogeneity for other design features. Some extension agents cared more about the outputs, such as information accuracy and level of detail, while others prioritized practical features such as the tool’s platform, language or interface.

According to the authors, accounting for such variety of preferences into the design of decision-support tools may facilitate their adoption by extension agents and, in turn, enhance their impact in farmars’ agricultural production decisions.

Interface of the Nutrient Expert mobile app, locally calibrated for maize farmers in Nigeria.

Impact of digital tools

Traditional extension systems in sub-Saharan African countries, including Nigeria, often provide general fertilizer use recommendations which do not account for the substantial variation in production conditions. Such blanket recommendations are typically accompanied by point estimates of expected agronomic responses and associated economic returns, but they do not provide any information on the variability of the expected returns associated with output price risk.

Policymakers need a better understanding of how new digital agronomy tools for tailored recommendations affect the performance of smallholder farms in developing countries.

To contribute to the nascent empirical literature on this topic, Oyinbo and colleagues evaluated the impact of a nutrient management decision-support tool for maize – Nutrient Expert — on fertilizer use, management practices, yields and net revenues. The authors also evaluated the impacts of providing information about variability in expected investment returns.

To provide rigorous evidence, the authors conducted a three-year randomized controlled trial among 792 maize-producing households in northern Nigeria. The trial included two treatment groups who are exposed to site-specific fertilizer recommendations through decision-support tools — one with and another one without additional information on variability in expected returns — and a control group who received general fertilizer use recommendations.

Overall, the use of nutrient management decision-support tools resulted in greater fertilizer investments and better grain yields compared with controls. Maize grain yield increased by 19% and net revenue increased by 14% after two years of the interventions. Fertilizer investments only increased significantly among the farmers who received additional information on the variability in expected investment returns.

The findings suggest including site-specific decision support tools into extension programming and related policy interventions has potential benefits on maize yields and food security, particularly when such tools also supply information on the distribution of expected returns to given investment recommendations.

The research-for-development community has tried different approaches to optimize fertilizer recommendations. In Nigeria, there are several tools available to generate location-specific fertilizer recommendations, including Nutrient Expert. As part of the Taking Maize Agronomy to Scale in Africa (TAMASA) project, CIMMYT has been working on locally calibrated versions of this tool for maize farmers in Ethiopia, Nigeria and Tanzania. The development was led by a project team incorporating scientists from the African Plant Nutrition Institute (APNI), CIMMYT and local development partners in each country.

Next steps

Some studies have shown that dis-adoption of seemingly profitable technologies — such as fertilizer in sub-Saharan Africa — is quite common, especially when initial returns fall short of expectations or net utility is negative, producing a disappointment effect.

In the context of emerging digital decision-support tools for well-targeted fertilizer use recommendations, it remains unclear whether farmers’ initial input use responses and the associated economic returns affect their subsequent responses — and whether the disappointment effect can be attenuated through provision of information about uncertainty in expected returns.

Using our three-year randomized controlled trial and the associated panel dataset, researchers are now working on documenting the third-year responses of farmers to site-specific agronomic advice conditional on the second-year responses. Specifically, they seek to better document whether providing farmers with information about seasonal variability in expected investment returns can reduce possible disappointment effects associated with their initial uptake of site-specific agronomic advice and, in a way, limit dis-adoption of fertilizer.

Cover photo: A farmer shows maize growing in his field, in one of the communities in northern Nigeria where research took place. (Photo: Oyakhilomen Oyinbo)

Smallholder farmer Sita Kumari holds fertilizer in her hands. (Photo: C. de Bode/CGIAR)

On-farm nitrogen management practices have global reverberations

Written by Rodrigo Ordóñez on April 9, 2021. Posted in Press releases.

An international team of scientists has strengthened our understanding of how better fertilizer management could help minimize nitrous oxide (N₂O) emissions while still achieving high crop yields in the new publication: Meta-analysis of yield and nitrous oxide outcomes for nitrogen management in agriculture. This research was conducted through a meta-analysis, where the results of multiple scientific studies were statistically combined.

To meet the world’s growing demand for food, farmers need fertile soil. Nitrogen, an essential element in plant fertilizer, can have extremely deleterious effects on the environment when not managed effectively. Numerous studies have confirmed that improving nitrogen use in agriculture is key to securing a food secure future and environmental sustainability.

“Society needs nuanced strategies based upon tailored nutrient management approaches that keep nitrogen balances within safe limits,” said Tai M Maaz, researcher at University of Hawaii at Manoa and lead author of the study.

When farmers apply nitrogen fertilizer to their crop, typically only 30-40% of it is taken up by the plant and the rest is lost the the environment. One byproduct is nitrous oxide (N₂O), one of the most potent greenhouse gases in the atmosphere. Global agriculture is a major contributor of greenhouse gas emissions, especially those derived from nitrous oxide emissions.

Although farmers are now commonly told to practice fertilizer rate reduction, or simply put, to apply less fertilizer, there are cases where that strategy is either not possible or not advisable.

Alternative predictors of emissions

The study found that output indicators such as partial nitrogen balance (PNB), an indicator for the amount of nitrogen prone to loss, and partial factor productivity (PFP), a measure of input-use efficiency, predicted nitrous oxide emissions as well as or better than the application rate alone. This means that in some cases, where nitrogen rate reduction is not possible, nitrous oxide emission can still be reduced by increasing yield through implementation of improved fertilizer management practices, such as the “4Rs:” right source, right timing, right placement and right application rate.

Tek B Sapkota, climate scientist at the International Maize and Wheat Improvement Center (CIMMYT) and co-author of the study, emphasized that “rate reduction is still important in the cropping systems where the current level of nitrogen application is excessively high. But, when comparing the systems at the same nitrogen application rates, nitrous oxide emission can be reduced by increasing yield.”

“The 4R nutrient management practices must be tailored to specific regions to help close yield gaps and maintain environmental sustainability: the win-win scenario. The future will require public and private institutions working together to disseminate such nutrient management information for specific cropping systems in specific geographies,” said Sapkota, who is also a review editor of the Intergovernmental Panel on Climate Change (IPCC) sixth assessment report.

The article was a collaborative effort from the International Maize and Wheat Improvement Center (CIMMYT), the University of Hawaii, the Environmental Defense Fund, Plant Nutrition Canada and the African Plant Nutrition Institute. It was funded by the CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS).

Read the full study:
Meta-analysis of yield and nitrous oxide outcomes for nitrogen management in agriculture

FOR MORE INFORMATION, OR TO ARRANGE INTERVIEWS, CONTACT:

Marcia MacNeil, Communications Officer, CGIAR Research Program on Wheat, CIMMYT. m.macneil@cgiar.org

About CIMMYT

The International Maize and Wheat 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 Research 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

Digital nutrient management tool reduces emissions, improves crop yields and boosts farmers’ profits

Written by Alison Doody on January 15, 2021. Posted in News.

A farmer in the Ara district, in India's Bihar state, applies NPK fertilizer, composed primarily of nitrogen, phosphorus and potassium. (Photo: Dakshinamurthy Vedachalam/CIMMYT) — A farmer in the Ara district, in India’s Bihar state, applies NPK fertilizer, composed primarily of nitrogen, phosphorus and potassium. (Photo: Dakshinamurthy Vedachalam/CIMMYT)

An international team of scientists, led by the International Maize and Wheat Improvement Center (CIMMYT), has demonstrated how better nutrient management using digital tools, such as the Nutrient Expert decision support tool, can boost rice and wheat productivity and increase farmers’ income while reducing chemical fertilizer use and greenhouse gas emissions.

Reported today in Nature Scientific Reports, the results show how the farmer-friendly digital nutrient management tool can play a key role in fighting climate change while closing the yield gap and boosting farmers’ profits.

The researchers tested the Nutrient Expert decision tool against typical farmer fertilization practices extensively using approximately 1600 side-by side comparison trials in rice and wheat fields across the Indo-Gangetic Plains of India.

The study found that Nutrient Expert-based recommendations lowered global warming potential by 12-20% in wheat and by around 2.5% in rice, compared to conventional farmers’ fertilization practices. Over 80% of farmers were also able to increase their crop yields and incomes using the tool.

Agriculture is the second largest contributor of greenhouse gas emissions in India. To tackle these emissions, crop scientists have been working on new ways to make farming more nutrient- and energy-efficient. Of the many technologies available, improving nutrient-use-efficiency through balanced fertilizer application — which in turn reduces excess fertilizer application — is key to ensuring food security while at the same time contributing to the UN’s Sustainable Development Goals on climate change.

The work was carried out by CIMMYT in collaboration with farmers, and funded by the CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS), the CGIAR Research Program on Wheat (WHEAT), and the Indian Council of Agricultural Research (ICAR). Scientists from the Borlaug Institute for South Asia (BISA), the International Rice Research Institute (IRRI), the Alliance of Bioversity International and CIAT, and the former International Plant Nutrition Institute (IPNI) also contributed to this study.

Researchers tested the Nutrient Expert decision tool against typical farmer fertilization practices extensively using approximately 1600 side-by side comparison trials in rice and wheat fields across the Indo-Gangetic Plains of India (Graphic: CIMMYT).

Precise recommendations

Nutrient Expert, which was launched back in 2013, works by analysing growing conditions, natural nutrients in the soil, and even leftover nutrients from previous crops to provide tailored fertilizer recommendations directly to farmers phones. The tool also complements the Government of India’s Soil Health Cards for balanced and precise nutrient recommendations in smallholder farmers’ fields.

Each farmer’s field is different, which is why blanket fertilizer recommendations aren’t always effective in producing better yields. By using nutrient management tools such as Nutrient Expert, farmers can obtain fertilizer recommendations specific to the conditions of their field as well as their economic resources and thus avoid under-fertilizing or over-fertilizing their fields.

“While efficient nutrient management in croplands is widely recognized as one of the solutions to addressing the global challenge of supporting food security in a growing global population while safeguarding planetary health, Nutrient Expert could be an important tool to implement such efficient nutrient management digitally under smallholder production systems,” said Tek Sapkota, CIMMYT climate scientist and first author of the study.

Sapkota also argues that adoption of the Nutrient Expert tool in rice-wheat systems of India alone could provide almost 14 million tonnes (Mt) of extra grain with 1.4 Mt less nitrogen fertilizer use, and a reduction of 5.3 Mt of carbon (CO2) emissions per year over current practices.

However, technological innovation alone will not achieve these positive outcomes.

“Given the magnitude of potential implications in terms of increasing yield, reducing fertilizer consumption and greenhouse gas emissions, governments need to scale-out Nutrient Expert-based fertilizer management through proper policy and institutional arrangements, especially for making efficient use of the nearly 200 million Soil Health Cards that were issued to farmers as part of the Soil Health mission of the Government of India,” said ML Jat, CIMMYT principal scientist and co-author of the study.

Read the study:
Crop nutrient management using Nutrient Expert improves yield, increases farmers’ income and reduces greenhouse gas emissions.

A farmer assesses soil on his plot in Ethiopia. (Photo: Simret Yasabu/CIMMYT)

Taking stock of the national toolbox

Written by Emma Orchardson on November 19, 2020. Posted in Features.

The Government of Ethiopia has consistently prioritized agriculture and sees it as a core component of the country’s growth. However, despite considerable efforts to improve productivity, poor management of soil health and fertility has been an ongoing constraint. This is mainly due to a lack of comprehensive site-and context-specific soil health and fertility management recommendations and dissemination approaches targeted to specific needs.

The government envisions a balanced soil health and fertility system that helps farmers cultivate and maintain high-quality and fertile soils through the promotion of appropriate soil-management techniques, provision of required inputs, and facilitation of appropriate enablers, including knowledge and finance.

So far, a plethora of different research-for-development activities have been carried out in support of this effort, including the introduction of tools which provide location-specific fertilizer recommendations. For example, researchers on the Taking Maize Agronomy to Scale in Africa (TAMASA) project, led by the International Maize and Wheat Improvement Center (CIMMYT), have created locally calibrated versions of Nutrient Expert® (NE) — a tool for generating fertilizer recommendations — for maize farmers in Ethiopia, Nigeria and Tanzania.

Nutrient Expert® is only one of the many fertilizer recommendation tools which have been developed in recent years covering different levels of applicability and accuracy across spatial scales and users, including smallholder farmers, extension agents and national researchers. However, in order to make efficient use of all the resources available in Ethiopia, there is a need to systematically evaluate the merits of each tool for different scales and use cases. To jump start this process, researchers from the TAMASA project commissioned an assessment of the tools and frameworks that have been developed, adapted and promoted in the country, and how they compare with one another for different use-cases. Seven tools were assessed, including Nutrient Expert®, the Ethiopian Soil Information System (EthioSIS) and RiceAdvice.

For each of these, the research team asked determined how the tool is currently being implemented — for example, as an app or as a generic set of steps for recommendation generation — and its data requirements, how robust the estimates are, how complicated the interface is, how easy it is to use, the conditions under which it performs well, and the spatial scale at which it works best.

Farmer Gudeye Leta harvests his local variety maize in Dalecho village, Gudeya Bila district, Ethiopia. (Photo: Peter Lowe/CIMMYT)

Combining efforts and information

The results of this initial assessment indicate that the type of main user and the scale at which decisions are made varied from tool to tool. In addition, most of the tools considered have interactive interfaces and several — including Nutrient Expert® and RiceAdvice — have IT based platforms to automate the optimization of fertilizer recommendations and/or analyze profit. However, the source codes for all the IT based platforms and tools are inaccessible to end-users. This means that if further evaluation and improvements are to be made, there should be a means of collaborating with developers to share the back-end information, such as site-specific response curves and source codes.

Because most of the tools take different approaches to making fertilizer application site-specific, each of them renders unique strengths and trade-offs. For example, Nutrient Expert® may be considered strong in its approach of downscaling regionally calibrated responses to field level recommendations based on a few site-specific responses from farmers. By contrast, its calibration requires intensive data from nutrient omission trials and advice provision is time consuming.

Overall, the use of all the Site-Specific Decision-Support Tools (SSDST) has resulted in improved grain yields compared to when farmers use traditional practices, and this is consistent across all crops. On average, use of Nutrient Expert® improved maize, rice and wheat yields by 5.9%, 8.1% and 4.9%, respectively. Similarly, the use of RiceAdvice resulted in a 21.8% yield advantage.

The assessment shows that some of the tools are useful because of their applicability at local level by development agents, while others are good because of the data used to develop and validate them. However, in order to benefit the agricultural system in Ethiopia from the perspective of reliable fertilizer-use advisory, there is a need to develop a platform that combines the merits of all available tools. To achieve this, it has been suggested that the institutions who developed the individual tools join forces to combine efforts and information, including background data and source codes for IT based tools.

While the COVID-19 pandemic has disrupted efforts to convene discussions around this work, CIMMYT has and will continue to play an active advocacy role in supporting collaborative efforts to inform evidence-based reforms to fertilizer recommendations and other agronomic advice in Ethiopia and the wider region. CIMMYT is currently undertaking a more rigorous evaluation of these tools and frameworks as a follow up on the initial stocktaking activity.

Breaking Ground: Jordan Chamberlin avidly explores the changing landscapes of Africa

Written by Jérôme Bossuet on October 1, 2020. Posted in Features.

Sub-Saharan Africa is undergoing important transformations, including climate change, population growth, urbanization and migration flows, and growth in digital technologies. What can we say about the likely development trajectories that African rural economies are on, and the implications for poor farming households? These are central questions for Jordan Chamberlin, an economist at the International Maize and Wheat Improvement Center (CIMMYT) in Kenya.

Chamberlin’s desk is covered with screens teeming with numbers, complex mathematical equations, lines of code and aerial views of African landscapes. He combines traditional microeconomic analysis with geospatial modelling skills to study some of the ways in which rural transformations are occurring. In this era of big data, he examines the wealth of spatial and socioeconomic datasets to explore the relationships between drivers of change and smallholder welfare, sometimes revealing surprising insights on how rural communities in Africa are evolving.

“Are commercial farms good or bad for neighboring smallholder farmers? Which households can benefit from the rapidly evolving rural land markets in Africa? What drives migration between rural areas? These are some examples of the complex but increasingly important questions that inform how we understand the evolution of agri-food systems in developing countries,” Chamberlin explains. “Fortunately, we also increasingly have access to new data that helps us explore these issues.”

In addition to household survey datasets — the bread and butter of applied social scientists — today’s researchers are also able to draw on an ever-expanding set of geospatial data that helps us to better contextualize the decisions smallholder farmers make.

He cites current work, which seeks to understand input adoption behaviors through better measurement of the biophysical and marketing contexts in which small farms operate. “Evidence suggests that low use rates of inorganic fertilizer by smallholders is due in part to poor expected returns on such investments,” he explains, “which are the result of site-specific agronomic responses, rainfall uncertainty, variation in input-output price ratios, and other factors.”

We are increasingly able to control for such factors explicitly: one of Chamberlin’s recent papers shows the importance of soil organic carbon for location-specific economic returns to fertilizer investments in Tanzania. “After all, farmers do not care about yields for yields’ sake — they make agronomic investments on the basis of how those investments affect their economic welfare.”

Better data and models may help to explain why farmers sometimes do not adopt technologies that we generally think of as profitable. A related strand of his research seeks to better model the spatial distribution of rural market prices.

Jordan Chamberlin (left) talks to a farmer in Ethiopia’s Tigray region in 2019, while conducting research on youth outmigration from rural areas. (Photo: Jordan Chamberlin)

A spatial economist’s journey on Earth

Ever since his experience as a Peace Corps volunteer in Paraguay, where he worked as a beekeeping specialist, Chamberlin knew he wanted to spend his professional life working with smallholder farmers. He wanted to better understand how rural development takes place, and how policies and investments can help rural households to improve their welfare.

In pursuit of these interests, his academic journey took him from anthropology to quantitative geography, before leading him to agricultural economics. “While my fundamental interest in rural development has not changed, the analytical tools I have preferred have evolved over the years, and my training reflects that evolution,” he says.

Along with his research interests, he has always been passionate about working with institutions within the countries where his research has focused. While working with the International Food Policy Research Institute (IFPRI) in Ethiopia, he helped establish a policy-oriented GIS lab at the Ethiopian Development Research Institute (EDRI). Years later, as part of his work with Michigan State University, he served as director of capacity building at the Indaba Agricultural Policy Research Institute (IAPRI), a not-for-profit Zambian research organization. He continues to serve as an external advisor on PhD committees, and considers mentorship a key part of his professional commitments.

He joined CIMMYT at the Ethiopia office in 2015 as spatial economist, part of the foresight and ex ante group of the Socioeconomics program.

As part of his research portfolio, he explores the role of new technologies, data sources and extension methods in the scaling of production technologies. Under the Taking Maize Agronomy to Scale in Africa (TAMASA) project, one area he has been working on is how we may better design location-specific agronomic advisory tools. Working with the Nutrient Expert tool, developed by the African Plant Nutrition Institute (APNI), he and his research team have conducted randomized control trials in Ethiopia and Nigeria to evaluate the impacts of such decision-support tools on farmer investments and productivity outcomes. They found that such tools appear to contribute to productivity gains, although tool design matters — for example, Nigerian farmers were more likely to take up site-specific agronomic recommendations when such information was accompanied by information about uncertainty of financial returns.

Jordan Chamberlin (center) talks to colleagues during a staff gathering in Nairobi. (Photo. Joshua Masinde/CIMMYT)

Creative rethinking

While Chamberlin’s research portfolio is diverse, one commonality is the drive to use new data and tools to better guide how development resources are allocated.

“Given the scarcity of resources available to governments and their partners, it is important to have sound empirical foundations for the allocation of these resources. Within CIMMYT, I see my role as part of a multidisciplinary team whose goal is to generate such empirical guidance,” he says.

This research also contributes to better design of agricultural development policies.

“Even though many of the research topics that my team addresses are not traditional areas of emphasis within CIMMYT’s socioeconomic work, I hope that we are demonstrating the value of broad thinking about development questions, which are of fundamental importance to one of our core constituencies: the small farmers of the region’s maize and wheat-based farming systems.”