New drought-resistant sorghum varieties bring hope for farmers in Africa
Scientists have identified drought-resistant, high-yielding sorghum genotypes that have the potential to revolutionize agriculture in dry regions of Africa. Sorghum, a staple food for millions in sub-Saharan Africa, has long been threatened by devastation from drought.
But now, researchers from the African Centre for Crop Improvement, the Institute of Agricultural Research (IAR), the International Maize and Wheat Improvement Center (CIMMYT), and the University of Life Sciences have discovered genetic resources that thrive under adverse conditions, yielding promising results and providing hope for a future that is more sustainable.
The study looked at 225 sorghum genotypes in various conditions, including non-stressed conditions and pre- and post-anthesis drought stress. The researchers used advanced statistical analysis, such as the additive main effects and multiplicative interaction (AMMI) method, to identify the most resilient and high-yielding genotypes.
The results revealed a vast diversity in the genetic resources of sorghum and provided a pathway for selecting promising genotypes for regions prone to drought. In addition, the study highlighted the significant impact of environmental conditions on grain yield, with genotypes showing variable responses to different growing environments.
A farmer inspecting sorghum on his farm in Tanzania. (Photo: CBCC)
For example, genotypes G144 (Kaura Short Panicle-1) and G157 (Kaura Mai Baki Kona) displayed higher grain yield in drought-stressed environments and were among the top performers. Not only do these genotypes outperform registered cultivars, but they also possess traits valued by farmers, making them ideal candidates for future breeding programs. In addition to drought tolerance, genotypes G119 and G127 displayed remarkable stability and high yield under non-stressed conditions, showing their potential as all-around performers in a variety of environments.
Farmers in dry areas of sub-Saharan Africa that are characterized by pre- and post-anthesis drought stress stand to gain a great deal from these newly identified sorghum strains. Adoption of these high-yielding and drought-resistant genotypes could increase food production and strengthen farmers’ resilience against the effects of climate change.
The findings of these super sorghum genotypes offer farmers facing the challenges of climate change a glimmer of hope. By adopting these new drought-resistant strains, African farmers can improve their food security and strengthen their communities, paving the way for a more resilient and sustainable future.
The Seed Production Technology for Africa (SPTA) project, led by CIMMYT, has been selected by the CGIAR Gender Impact Platform as a successful case study of integrating gender into crop breeding.
The case study, published in Frontiers in Sociology, is one of fourteen that the CGIAR Genetic Innovation Gender strategy is drawing on to showcase lessons learned from practical experience. These case studies form a critical part of the efforts to pursue gender responsive or gender-intentional breeding and explore how these can inform larger breeding pipelines.
Maize is widely grown by both women and men in Africa. Evidence of gender-differentiated preferences for maize varieties remains inconclusive; however, there is evidence of gendered differences in management practices. Hybrids produced using SPTA segregate 1:1 for pollen producing and non-pollen producing plants referred to as 50% non-pollen producing (FNP) varieties. Previous research showed FNP offered a yield benefit under low input conditions. In the early stage of its inception, the project quickly recognized the potential implications of hybrids produced using SPTA for women and other resource-constrained smallholders in Africa.
Understanding gender-based differences
From the start, the SPTA team conducted a gender review that underscored the fact that women in the region often use less fertilizer than men, a challenge that is further compounded by cultivation of smaller plots and lower quality soils. This review led the breeding team to explicitly target women and resource-poor farmers with an ambition to increase yields on women’s fields. From here henceforth, SPTA made it a priority to understand gender-based differences in performance and preference for new FNP maize varieties. This process involved ensuring both women and men farmers host trials to evaluate and attest to the performance of the FNP hybrids.
But these efforts were not without challenges. The team also found significant gender differences, particularly among women farmers in crop management practices and between farmers’ stated preferences during participatory varietal selection exercises and the varieties they used at home. This suggested that initial on-farm evaluations were not adequate for predicting real world demand for varieties. Moving forward, the evaluation strategy of SPTA evolved to enable variety evaluations under farmers’ preferred management practices.
The success of the SPTA team in ensuring that gender considerations were strongly embedded into the breeding program is attributed to strong collaboration across disciplines that included social scientists and gender researchers working closely with breeders, allocating funding to allow exploration, testing of gender topics and responsive variety evaluation tools and strong buy-in from leadership and donors. As the SPTA case highlights, there is value in starting small, building productive partnerships and collaborating to pilot and develop proof of concept for new models.
This article uses research into the organic food market in France to show that biological factors can play an important part in influencing the structure and organization of markets. The authors use this to point out that while many studies of market agencing discuss in detail the role played by social and material agents, biological agents should be an equally important part of such research.
Over the last four decades, there has been considerable research into Actor-Network Theory (ANT), which looks at the effect of various agents on markets. However, in the majority of cases, the agents discussed have been material (for example, shopping trolleys) or social (human habits or economic motives). The research which forms the basis of this article was originally carried out as a study of how French organic-produce collectives tried to influence markets to suit their needs and ideals. On reviewing the data, it appeared to the authors that there were additional agents affecting their marketing, which derived from biological factors. Unlike the material and social agents, farmers were only able to control these biological factors with great difficulty, if at all. For example, the inability to use chemical inputs on crops meant that crop rotation over a multi-year period was essential; however, wholesalers’ traditional structures expected a farmer to supply the same produce in the same quantity year after year. In cases such as this, altered supply chain arrangements needed to be negotiated between the suppliers and the wholesalers.
The authors made four sets of observations showing the market-shaping effect of biological agents.
Measures taken by established organic farmers to avoid price competition from new market entrants — the well-established farmers had chosen to start growing crops which required more expertise, time or equipment (such as Belgian endives or onions), rather than less complex standard crops such as potatoes.
Biological processes which necessitate altering the traditional market production and supply structures — for example, the need for crop rotation as mentioned above.
Natural agents will affect crop yields and introduce variability in quality and quantity, which the market needs to allow for. The authors give examples of pests, viral infections and weather as agents that affect all farming, but in the case of organic farming are particularly troublesome.
After harvest, produce will naturally experience ripening/aging, and then degradation in quality. Standard industrial ways of controlling these biological processes utilize methods and agents that are unacceptable or even harmful when dealing with organic produce, for instance, spraying with chemicals.
Following these observations, the authors make a series of propositions and suggest research questions which could result from them, for instance:
How does the action of biological entities affect the establishment of market norms/the way prices are set?
How do representations of the market take account of biological processes?
In conclusion, the authors demonstrate how the effect of biological agents on markets is already inextricably intertwined with the effects of material and social agents. Future research, to be truly comprehensive, needs to look in equal depth at all other possible influences on the market.
Intention, collaboration and commitment are critical to bridging the research and practice gap. Gender development practitioners and researchers from CGIAR centers, universities, national agricultural research and extension systems (NARES), civil society, and donor representatives this week shared insights from their research and work at the gender conference in New Delhi, India.
The discussion and exchange promises to create collaborations and opportunities devoted to improving the conditions and agency of women, youth and Indigenous communities in the Global South. “Transformative research can lead to meaningful impact,” said Angela Meentzen, senior gender researcher at CIMMYT. “We have been looking forward to this conference because coming together as researchers, scientists and development practitioners, we can discuss and share insights from each other’s practices and experiences from the field.”
Angela Meentzen (third from left) with CIMMYT colleagues from Asia and Africa at the CGIAR Gender 2023 conference in New Delhi. (Photo: Nima Chodon/CIMMYT)
Leading researchers and scientists from CIMMYT Asia and Africa presented their research and enriched the gender discussions at the conference. Meentzen said that CIMMYT is proud to support gender research that contributes meaningfully to transformative change and impact.
Below are highlights of four research poster presentations by our researchers (of the six presented by CIMMYT) at the conference:
Scientist Vijayalaxmi Khed examined how women manage excess workload (working inside and outside the house), a clear trade-off between productive and leisure time without change in domestic responsibilities. Due to domestic workload, she found that women’s time away from farms does not translate into leisure. Another important finding was that women with more agency had less time for leisure, unlike for men.
In her poster presentation, she concluded that rural women’s nexus of time poverty and decision-making has “clear implications for the development and diffusion of laborsaving technologies in agriculture.”
Working on the same study with Khed, Vijesh Krishna explored the relationship between women’s involvement in agricultural activities and decision-making. His presentation, ‘Farm managers or unpaid laborers?’, from the study covering 347 wheat-farming households across two years, concludes that “despite playing a crucial role in wheat farming in central India, most women lacked the ability to influence decisions.”
Michael Euler, agriculture and resource economist, in his poster presentation explained how an on-farm trial to improve gender-intentional breeding and varietal adoption in maize was designed by CIMMYT breeders and researchers.
The study hypothesized that gender dynamics in household labor allocation and decision-making in maize systems influence trait preferences and farmers’ adoption of varieties. So, researchers conducted on-farm trials and household surveys with individual women and men household members to capture differences in their trait preferences in maize cultivation—production systems, seed demand and seed access—with 800 smallholder farmers in Zimbabwe and Kenya.
Euler emphasized the influence of socioeconomic and agroecological factors, including biotic–abiotic stress, in the household decisions on maize varietal adoption.
He concluded that the study results will help “guide the product development of regional maize breeding programs and strengthen communities’ adaptation to the changing environmental conditions for maize cultivation.”
Adoption of a weeding technology may lead to labor displacement of marginalized women laborers
Presenting a poster for the same session as Euler, Maxwell Mkondiwa—in a study coauthored with colleagues Khed and Krishna—highlighted how rapid diffusion of a laborsaving technology like herbicides could exclude the marginalized further. The study occurred in India’s state of Bihar, looking at nonfarming rural poor, primarily women, from socially marginalized groups.
From data on chemical weeding, the study analyzed the technology’s impact on inequality— highlighting how marginalized women laborers who work on manual weeding are then replaced by men who apply herbicides.
He stressed that not enough research is devoted to understanding whether farmer adoption of laborsaving technologies worsens economic inequalities or reinstates labor into better tasks. “We hope the evidence we generated will help researchers and policymakers develop relevant actions toward more inclusive innovations, and support laborers with new skills for the transitions,” said Mkondiwa.
Maxwell Mkondiwa presents his poster under the session Gender Dynamics in Agri-Food System Innovation at the CGIAR Gender 2023 conference. (Photo: M Mkondiwa/CIMMYT)
Women exhibit limited technical knowledge and experience social benefits differently in male-headed households of CASI technology adoption
Emma Karki, in her poster, explained that there is limited knowledge of the impact of technology adoption on women in a male-headed household in South Asia—with decision powers generally resting with male household members. The research tried to understand the gendered differences in the evaluation of technology adoption in male-headed households using conservation agriculture-based sustainable intensification (CASI) technology as a case study.
The study focused on identifying the commonalities and differences in the experiences and evaluation of CASI technology. Results indicated that “despite technology adoption, women had limited mechanistic understanding compared to men, with similar limitations on women’s time use and capacity development,” said Karki.
For future CASI promotion, Karki concluded: “Reducing information gaps and incorporating technological preferences of women needs prioritizing, including creating opportunities for them to access knowledge and engage both men and women in critical discussions surrounding gender norms.”
Similarly, Moti Jaleta’s research presentation highlighted the challenges of mechanization adoption for smallholder farmers in Ethiopia, primarily women. “Intentional research, whether in gender or social development, helps identify problems and opportunities for change,” endorsed Jaleta.
Meaningful research helps achieve gender and social inclusion goals
The ‘From Research to Impact: CGIAR GENDER Impact Platform and ICAR Conference 2023’, between October 9-12, 2023, in New Delhi, gathered researchers from 68 countries. In her inaugural address at the conference’s opening, the President of India Smt. Draupadi Murmu affirmed, “For ecologically sustainable, ethically desirable, economically affordable and socially justifiable production, we need research which can enable conditions to reach these goals.”
At the end of the four-day conference—with 60 research presentations and six plenary sessions—the organizers and participants reflected on their resolve ‘From Research To Impact,’ and the promise to recognize and collectively address the gender and social inequities in agrifood systems development.
Climate change poses a significant challenge to agricultural production and food security worldwide. “Rising temperatures, shifting weather patterns and more frequent extreme events have already demonstrated their effects on local, regional and global agricultural systems”, says Kevin Pixley, Dryland Crops Program director and Wheat Program director a.i. at CIMMYT. “As such, crop varieties that can withstand climate-related stresses and are suitable for cultivation in innovative cropping systems will be crucial to maximizing risk avoidance, productivity and profitability under climate-changed environments.”
In a new study published in Molecular Plant, scientists from CIMMYT, Alliance of Bioversity International and CIAT, the International Institute of Tropical Agriculture (IITA) and national agricultural research programs in Burkina Faso, Ethiopia, Nigeria, Tanzania and Uganda to predict novel traits that might be essential for future varieties of popular crops. Having surveyed nearly 600 agricultural scientists and stakeholders, they identify likely agronomic changes in future cropping systems seeking sustainability, intensification, resilience and productivity under climate change, as well as associated essential and desirable traits, especially those that are not currently prioritized in crop improvement programs.
Focusing on six crops which hold vital importance for African food security and CIMMYT and CGIAR’s mission—maize, sorghum, pearl millet, groundnut, cowpea and common bean—the authors review opportunities for improving future prioritized traits, as well as those they consider ‘blind spots’ among the experts surveyed.
Predicting future essential traits
The results of the study speak to the need for considering cropping systems as central to climate change resilience strategy, as well as the need to reconsider the crop variety traits that will eventually become essential.
Overall, experts who participated in the survey prioritized several future-essential traits that are not already targeted in current breeding programs — mainly water use efficiency in pearl millet, groundnut, and cowpea; adaptation to cropping systems for pearl millet and maize; and suitability for mechanization in groundnut. The survey confirmed that many traits that are already prioritized in current breeding programs will remain essential, which is unsurprising and consistent with other recent findings. While smarter and faster breeding for currently important traits is essential, the authors suggest that failure to anticipate and breed for changing needs and opportunities for novel characteristics in future varieties would be a big mistake, compromising farmers’ resilience, improved livelihood opportunities, and food security in the face of changing climate.
Groundnuts. (Photo: CIMMYT)
Importantly, the authors explain, the predicted future-essential traits include innovative breeding targets that must be prioritized. They point to examples such as improved performance in inter- or relay-crop systems, lower nighttime respiration, improved stover quality, or optimized rhizosphere microbiome, which has benefits for nitrogen, phosphorous and water use efficiency.
The authors emphasize that the greatest challenge to developing crop varieties to win the race between climate change and food security might be innovativeness in defining and boldness to breed for the traits of tomorrow. With this in mind, they outline some of the cutting-edge tools and approaches that can be used to discover, validate and incorporate novel genetic diversity from exotic germplasm into breeding populations with unprecedented precision and speed.
The widespread availability of chemical nitrogen fertilizers is a prime driver of the vast improvement of crop yields over the past 50 years. However, their use has come with a price, as nitrogen escaping into surrounding soil and air has negative impacts on the environment and human health, including water pollution, depletion of soil-fertility, and greenhouse gas emissions.
Researchers from CIMMYT and JIRCAS (Japan International Research Center for Agricultural Science) examined ways to curtail the leakage of nitrogen into ecosystems, through a process called biological nitrification inhibition (BNI) in the paper “Genetic variation among elite inbred lines suggests potential to breed for BNI-capacity in maize,” published in the journal Scientific Reports on August 17, 2023.
César Daniel Petroli, leader and specialist in high-throughput genotyping/sequencing at the Genetic Analysis Service for Agriculture (SAGA) laboratory at CIMMYT with scientists. (Photo: Alfredo Sáenz)
BNI is a plant-based natural process that reduces nitrogen losses, which can reduce fertilizer demand while sustaining agricultural systems. The roots of plants that exhibit BNI activity release natural substances that inhibit the activity of nitrifying bacteria in soil, thus reducing the amount of nitrogen lost to the surrounding ecosystem. Many plant species have natural BNI activity in their roots.
Although synthetic chemical nitrification inhibitors are commercially available to reduce nitrogen losses, the high costs of this approach have limited its adoption. By contrast, breeding new varieties with increased natural BNI activity can offer a practical and economical approach to reduce nitrogen fertilizer need and waste.
“We are in the discovery phase regarding BNI activity and its determining traits for maize. Such information is crucial to pave the way for breeding programs and genetic improvement efforts,” said Kevin Pixley, co-author of the paper and former director of CIMMYT’s Genetic Resources Program. “We need to identify genetic markers for BNI compounds including ‘zeanone’, which will enable breeders to develop maize varieties that require and waste less nitrogen fertilizer, while achieving high yields.”
Doubles haploids prepared for evaluation and further analysis at CIMMYT’s headquarters, El Batán, Mexico. (Photo: Araceli Balderas)
This research identified 18 single nucleotide polymorphisms (SNP) that act as genetic “signposts” for breeders to use to accelerate and increase the accuracy of breeding to increase BNI activity for maize. The researchers also identified six “candidate” or putative genes associated with BNI activity and related to nitrogen use efficiency, thereby enhancing the understanding of the genetics controlling BNI activity.
“Our identification of SNPs and genes that regulate how maize processes nitrogen begins to draw a road map to guide the development of molecular markers for use in breeding new maize varieties that meet farmer and consumer needs at a lower environmental cost,” said senior author Cesar Petroli. “Building on the results obtained and reported in our recent publication, we are developing maize (doubled haploid) populations to refine the genetic map for BNI activity in maize”.
This research was conducted with partners from JIRCAS and the Universidad de la República, Uruguay.
In plant breeding, efforts to increase the rate of genetic gains and enhance crop resilience to the effects of climate change are often limited by the inaccessibility and costs of phenotyping methods. The recent rapid development of sensors, image-processing technology and data analysis has provided new opportunities for multiple scales phenotyping methods and systems. Among these, satellite imagery may represent one of the best ways to remotely monitor trials and nurseries planted in multiple locations, while standardizing protocols and reducing costs.
This is because relevant data collected as part of crop phenotyping can be generated from satellite images. For instance, the sensors onboard the SkySat satellite constellation of Planet Labs have four spectral bands—blue, green, red, and infrared—which can be used to calculate the normalized difference vegetation index (NDVI), which is a measure of vegetation and its greenness, and various canopy traits like ground cover, leaf area index and chlorosis. It can also be used to monitor plot establishment and phenological parameters.
High-resolution RGB orthomosaic of wheat experiments, assessing the effect of plot size and spacing in the spectral signature, collected from SkySat satellite images. (Photo: Gilberto Thompson)
The use of satellite-based phenotyping in breeding trials has typically been restricted by low resolution, high cost and long intervals between fly-overs. However, the advent of a new generation of high-resolution satellites—such as the SkySat constellation—now offers multispectral images at a 0.5m resolution with close to daily acquisition attempts on any place on Earth. This could be a game changer in terms of the scale at which yield trials can be conducted, enabling more precise variety placement and thereby increasing genetic diversity across farmer’s fields and reducing the probability of disease epidemics. It could also revolutionize the capacity for research in realistic field conditions, since traits can be measured throughout the cycle in a highly standardized way, over multiple sites at low cost. For example, an image which covers 25 km2 can monitor an entire research station at a cost of about US$300.
To test the suitability of this technology, a team of researchers from CIMMYT set out to evaluate the reliability of SkySat NDVI estimates for maize and wheat breeding plots of different sizes and spacing, as well as testing its capacity for detecting seasonal changes and genotypic differences.
Both their initial findings, recently published in Frontiers in Plant Science, and more recently acquired data, show that the SkySat satellites can be used to monitor plots commonly used in wheat and maize nurseries. While wheat yield plots usually are 1.2m wide, maize plots tend to consist of at least two rows, resulting in a width of 1.5m. Plot length ranges from 2-4m. The authors also discuss on other factors to be considered when extracting and interpreting satellite data from yield trials, such as plot spacing.
Through the successful collection of six satellite images in Central Mexico during the rainy season and parallel monitoring of a maize trial in Zimbabwe, the researchers demonstrate the flexibility of this tool. Beyond the improvement of spatial resolution, the researchers suggest that the next challenge will be the development and fine-tuning of operational procedures that ensure high quality, standardized data, allowing them to harness the benefits of the modern breeding triangle, which calls for the integration of phenomics, enviromics and genomics, to accelerate breeding gains.
This research was supported by the Foundation for Food and Agriculture Research, the CGIAR Research Program on Maize, the CGIAR Research Program on Wheat, and the One CGIAR Initiatives on Digital Innovation, F2R-CWANA, and Accelerated Breeding.
The United Nations Sustainable Development Goals (SDG) are broad mandates for transitioning to fair and sustainable agrifood systems. However, because of their global view, they often operate at a scale not clearly seen or understood by local stakeholders.
New research led by the International Maize and Wheat Improvement Center (CIMMYT) scientists offers participatory action research (PAR) as a potential bridge between the macro scope of the SDGs and the needs and desires of local communities.
Trying out conservation agriculture wheat rotation alongside conventionally grown maize, farmer’s field, Mexico. (Photo: E. Phipps/CIMMYT)
“Participatory research is known for giving voice to farmers, for accelerating adaptation and for impact,” said lead author Sieglinde Snapp, director of the Sustainable Agrifood Systems program at CIMMYT. “What is novel in this study is that new discoveries were documented, showing the scientific contributions possible through PAR.”
Co-creation
Participatory action research is a knowledge generation process, characterized by a series of steps to facilitate improved understanding and development of innovations, within a local context. The PAR approach involves engaging stakeholders, to co-create solutions with researchers.
Because knowledge is often local, access to natural resources is highly heterogeneous, climate variability is unpredictable and socioeconomic circumstances are context-dependent, any intervention must be flexible and locally specific to ensure sustainability.
PAR prioritizes empowerment of marginalized communities to build long-term partnerships which support transformational changes at local, regional and national levels.
Yet the evidence base for PAR methodology remains fragmented and is often inaccessible.
“This is the first paper that shows how action research produces new knowledge through a systematic, iterative process that derived ‘middle ways’, such as shrubby food crops as a farmers preferred form of agroforestry,” said Snapp.
Solving wicked problems
Participatory research is well-suited to address conflicts and trade-offs that are key aspects of so-called wicked problems. For instance, annual crops—maize and soybean—are excellent producers of food but feature limited aboveground vegetation and belowground activity to regenerate soil nutrients, while perennials provide soil regeneration services but no food products.
By engaging closely with local stakeholders, PAR identifies “goldilocks options,” or middle ways, such as semi-perennial shrubs and vines that produce food while also promoting soil health.
Genetic and agronomic improvement efforts have almost entirely overlooked semi-perennial plant types to address food–soil trade-offs.
Challenges
Building relationships between researchers and stakeholders; the investment required in selecting representative sites, action learning activities, synthesis of findings, communication and documentation; and the inherent variability of research conducted under real-world conditions are barriers to establishing PAR systems. Living laboratories and education on PAR approaches need investment. Reward structures may need to shift, with greater attention to considering research impact on SDGs and awareness that time lags may occur in publishing scientific findings through PAR.
Demonstrating conservation agriculture to other farmers in Malawi. (Photo: T. Samson/CIMMYT)
“Our findings detailing the efficacy of PAR shows that the potentially high upfront costs to invest in relationship building and learning across disciplines, this is a worthwhile trade-off,” said Snapp.
Through PAR, human condition and social-science questions can be addressed, along with biological and environmental science questions, as illustrated in this Malawian case study.
The findings generated by PAR have relevance beyond the sub-Saharan Africa context because they provide new insights into the development of nature-based solutions that meet local needs, a critical requirement for rural communities in many parts of the globe.
CIMMYT principal scientist Frédéric Baudron has two main research interests: making mechanization appropriate to smallholders and biodiversity conservation.
Wondering how these two intersect, a colleague of Baudron once asked him what the link was between an elephant and a tractor?
Now, in the recent report, “Addressing agricultural labour issues is key to biodiversity-smart farming research,” published in Biological Conservation, Baudron and other contributors have answered that question, examining trade-offs between labor and biodiversity conceptually, as well as in the specific context of Indonesia and Ethiopia.
Innovations in agricultural technology have led to undeniable achievements in reducing the physical labor needed to extract food from fields. Farm mechanization and technologies such as herbicides have increased productivity, but also became on the other hand major threats to biological diversity.
Adopting technologies that improve the productivity of labor benefits farmers in multiple ways, including a reduction of economic poverty, time poverty (i.e., lack of discretionary time, reducing labor drudgery), and child labor. Conversely, technologies that promote biodiversity often increase the burden of labor, leading to limited adoption by farmers. Therefore, there is a need to develop biodiversity-smart agricultural development strategies, which address biodiversity conservation goals and socio-economic goals, specifically raising land and labor productivity. This is especially true in the Global South, where population growth is rapid and much of the world’s remaining biodiversity is located.
“Without accounting for labor issues biodiversity conservation efforts will not be successful or sustainable,” said Baudron. “Because of this, we wanted to examine what biodiversity-smart agriculture might look like from a labor point of view.”
Research has quantified that farming families in Africa who use tractors expended an average of 640 labor hours per hectare in maize cultivation. In contrast, farmers not using tractors spent over 1100 hours for the same yield.
Practicing tractor operation at Toluca experiment station (Photo: X. Fonseca/CIMMYT)
Trade-offs
While that is a clear win for reducing the heavy physical toil of farming, there are potential negative effects on biodiversity. In many countries in the Global North, the rise of tractors and other big machinery has led to larger and more rectangular fields and the removal of farm trees and hedgerows, all of which is associated with lower biodiversity. The same is now happening in parts of the Global South.
“A trade-off implies that one goal can only be achieved at the expense of another goal,” said Baudron. “It is not always a conscious choice; however, as farmers often adopt labor-saving techniques without considering the effects on biodiversity, simply because they lack options, and sometimes the necessary context.”
In Indonesia, the transition from harvesting rubber to producing palm oil has reduced the amount of physical labor, but biological diversity has decreased. However, innovations such as reducing fertilizer usage to avoid nutrient leaching into soil have been possible without compromising yield, and with the benefit of lower costs to farmers.
In Ethiopia, labor-saving technologies like the use of small-scale combine harvesters have been compatible with high biodiversity.
“I tell my colleagues a two-wheel tractor that allows mechanization with little negative environmental consequence (compatible with a mosaic of small, fragmented fields, with on-farm scattered trees, etc.) contributes to a landscape that works for people and biodiversity, including elephants,” said Baudron.
Integrated management of organic and inorganic nitrogen sources in high- to low-yield cereal production could bring yearly savings in nitrogen fertilizer of over 1 million tons in India, some 90,000 tons in Ethiopia, and more than 20,000 tons in Malawi, according to a new scientific paper, “Spatially differentiated nitrogen supply is key in a global food-fertilizer price crisis.”
“Global policies and governments should prioritize nitrogen supplies to low-yield, low-fertility cropping systems, such as smallholder maize and rice farms in Malawi, which are representative of the highly N-deficient cereal systems relied upon by over 100 million people in sub-Saharan Africa,” said Sieglinde Snapp, director of the Sustainable Agrifood Systems Program at the International Maize and Wheat Improvement Center (CIMMYT) and first author of the paper. “Those farmers should also ramp up organic nitrogen inputs, such as manure and legume crops.”
In the intensive, high-yield cropping systems of India, farmers generally over-apply N fertilizer on 90% of the rice and wheat crops and more than half of maize crops. Less than half the nitrogen is taken up and used by the crops and the rest is lost into the environment, contaminating water, land, and the atmosphere. “Simply saving the excess fertilizer from over-fertilized areas and shifting it to low-application areas could increase global crop yields by 30%, with huge reductions in greenhouse gas emissions,” said Tek Sapkota, co-author of the paper and climate change leader at CIMMYT.
This study is based on evidence of achievable shifts in nitrogen management over 1-2 years, for a modest proportion of cropped area (10%). “We did not assess interventions with longer time horizons or large investment requirements such as precision agriculture, mechanization, or deep placement of fertilizer,” Snapp explained.
Snapp and her colleagues used evidence from the scientific literature to estimate N-fertilizer savings from the above interventions for maize, wheat, and rice cropping systems in India, Ethiopia, and Malawi. Integrated organic and inorganic nitrogen management was estimated by considering manure and legume N inputs along with N fertilizers. The effect of reallocating public subsidies to more cost-effective, high-N fertilizer was calculated as the extra nitrogen that could be made available through a lower unit cost of nitrogen.
Food production vs healthy environment?
According to Snapp, humanity is caught in a bind. Food crops grown using synthetic nitrogen fertilizer have fed expanding world populations since the 1960s, fertilizer use has increased nearly 10-fold since then, and significantly higher food demands lie ahead to mid-century. At the same time, poor use of N fertilizer is hurting the environment and, most recently, geopolitical conflicts have disrupted N fertilizer supplies and exposed the vulnerabilities of the global fuel-fertilizer-food nexus.
“In regions where cropping systems are highly deficient in nitrogen, investment is needed in policies and extension education to promote the use of organic nitrogen residues and legume crops,” Snapp said.
Extension agencies, she suggests, can extend their reach using digital tools and bi-directional communication approaches that engage local knowledge and farmers, including advisories regarding local soils and crop and fertilization requirements.
Leading crop simulation models used by a global team of agricultural scientists to simulate wheat production up to 2050 showed large wheat yield reductions due to climate change for Africa and South Asia, where food security is already a problem.
The model predicted average declines in wheat yields of 15% in African countries and 16% in South Asian countries by mid-century, as described in the 2021 paper “Climate impact and adaptation to heat and drought stress of regional and global wheat production,” published in the science journal Environmental Research Letters. Climate change will lower global wheat production by 1.9% by mid-century, with the most negative impacts occurring in Africa and South Asia, according to the research.
“Studies have already shown that wheat yields fell by 5.5% during 1980-2010, due to rising global temperatures,” said Diego N.L. Pequeno, wheat crop modeler at the International Maize and Wheat Improvement Center (CIMMYT) and lead author of the paper. “We chose several models to simulate climate change impacts and also simulated wheat varieties that featured increased heat tolerance, early vigor against late season drought, and late flowering to ensure normal biomass accumulation. Finally, we simulated use of additional nitrogen fertilizer to maximize the expression of these adaptive traits.”
Wheat fields in Ankara, Turkey, where data was used for crop model simulation (Photo: Marta Lopes/CIMMYT)
The wheat simulation models employed — CROPSIM-CERES, CROPSIM, and Nwheat within the Decision Support System for Agrotechnology Transfer, DSSAT v.4.6 — have been widely used to study diverse cropping systems around the world, according to Pequeno.
“The DSSAT models simulated the elevated CO2 stimulus on wheat growth, when N is not limiting,” he said. “Our study is the first to include combined genetic traits for early vigor, heat tolerance, and late flowering in the wheat simulation.”
Several factors, including temperature, water deficit, and water access, have been identified as major causes in recent wheat yield variability worldwide. The DSSAT wheat models simulate the impact of temperature, including heat stress, water balance, drought stress, or nitrogen leaching from heavy rainfall.
“Generally, small and low-volume wheat producers suffered large negative impacts due to future climate changes, indicating that less developed countries may be the most affected,” Pequeno added.
Climate change at high latitudes (France, Germany, and northern China, all large wheat-producing countries/region) positively impacted wheat grain yield, as warming temperatures benefit wheat growth through an extended early spring growing season. But warmer temperatures and insufficient rainfall by mid-century, as projected at the same latitude in Russia and the northwestern United States, will reduce rainfed wheat yields — a finding that contradicts outcomes of some previous studies.
At lower latitudes that are close to the tropics, already warm, and experiencing insufficient rainfall for food crops and therefore depending on irrigation (North India, Pakistan, Bangladesh), rising heat will damage wheat crops and seriously reduce yields. China, the largest wheat producer in the world, is projected to have mixed impacts from climate change but, at a nation-wide scale, the study showed a 1.2% increase in wheat yields.
“Our results showed that the adaptive traits could help alleviate climate change impacts on wheat, but responses would vary widely, depending on the growing environment and management practices used,” according to Pequeno. This implies that wheat breeding for traits associated with climate resilience is a promising climate change adaptation option, but its effect will vary among regions. Its positive impact could be limited by agronomical aspects, particularly under rainfed and low soil N conditions, where water and nitrogen stress limit the benefits from improved cultivars.
Extreme weather events could also become more frequent. Those were possibly underestimated in this study, as projections of heat damage effects considered only changes in daily absolute temperatures but not possible changes in the frequency of occurrence. Another limitation is that most crop models lack functions for simulating excess water (e.g., flooding), an important cause of global wheat yield variability.
This study was supported by the CGIAR Research Program on Wheat agri-food systems (CRP WHEAT; 2012-2021), the CGIAR Platform for Big Data in Agriculture, the International Wheat Yield Partnership (IWYP115 Project), the Bill & Melinda Gates Foundation, the World Bank, the Mexican government through the Sustainable Modernization of Traditional Agriculture (MasAgro) project, and the International Treaty of Plant Genetic Resources for Food and Agriculture and its Benefit-sharing Fund for co-funding the project, with financial support from the European Union.
Use of lightweight, 5-9-horsepower mini-tillers by smallholder farmers in Nepal’s mid-hills cut tillage costs and boosted maize yields by facilitating timely maize cultivation, thus enhancing food self-sufficiency and farm profits and reducing rural poverty, a new study by an international team of scientists shows.
Published in the Journal of Economics and Development, the study reports findings of an on-farm survey involving more than 1,000 representative households from 6 districts of the mid-hills, a region of steep and broken terrain where rainfed maize is a staple crop, outmigration of working-age inhabitants makes farm labor scarce and costly, and farmers on small, fragmented landholdings typically till plots by hand or using ox-drawn plows.
“Conventional two- or four-wheel tractors are difficult to operate in the mid-hills’ rugged topography,” said Gokul P. Paudel, researcher working together with the International Maize and Wheat Improvement Center (CIMMYT) and Leibniz University, Hannover, Germany, and lead author of the study. “Farms are small and the mini-tillers are a good fit. Very small farms — those comprising less than 0.4 hectares of land and normally not served by hired farm labor or larger machinery — benefited the most from mini-tiller adoption.”
The paper is the first to provide empirical linkages between small-scale farm mechanization and the UN Sustainable Development Goals, particularly No Poverty (SDG-1) and Zero Hunger (SDG-2).
“Given its rural poverty and the resulting outmigration from farm areas to cities and to other countries, Nepal has increasingly become a labor-exporting country,” explained Paudel, who partnered in this study with researchers from the Asian Development Bank Institute and Cornell University. “Our research can help guide investments by Nepal and other developing countries in scale-appropriate farm mechanization, supporting those who wish to remain on rural homesteads and make a go of it.”
Machine operators starting the mini-tiller in the Kavrepalanchok district in the mid-hills of Nepal. (Photo: CIMMYT)
The science team found that farm size, labor shortages, draft animal scarcity, and market proximity were major factors that facilitate the adoption of appropriate mechanization in Nepal, according to Tim Krupnik, CIMMYT systems agronomist and study co-author.
“Smallholder farms dominate more than two-thirds of agricultural systems globally,” Krupnik said. “Interest in scale-appropriate farm mechanization is growing rapidly, particularly among donors and governments, and practical empirical measures of its impact are crucial.” The findings of the latest study fill this knowledge gap and provide sufficient evidence to prioritize the spread of appropriate technologies among smallholder farmers.
Krupnik noted that, through its office in Nepal and strong shared research and capacity-building activities, CIMMYT has worked for almost four decades with Nepali scientists and development partners, including the Nepal Agricultural Research Council (NARC) and the Ministry of Agriculture and Livestock Development (MoALD), to raise the productivity and sustainability of the country’s maize- and wheat-based farming systems.
In addition to strong government partnerships, CIMMYT works closely in Nepal with a range of non-government organizations, and importantly, hand-in-hand with private farm machinery manufacturers, retailers, and mechanics.
The study described was supported by the Bill & Melinda Gates Foundation, the US Agency for International Development (USAID), the Academy for International Agricultural Research (ACINAR) commissioned by the German Federal Ministry for Economic Cooperation and Development (BMZ) and carried out by ATSAF e.V. on behalf of the Deutsche Gesellschaft fur Internationale Zusammenarbeit (GIZ) GmbH, the One CGIAR Regional Integrated Initiative Transforming Agrifood Systems in South Asia (TAFSSA), and generous funders who contribute to the CGIAR Trust Fund.
Rising global temperatures due to climate change are changing the growth cycles of crops worldwide. Recent records from Europe show that wild and cultivated plants are growing earlier and faster due to increased temperatures.
Farmers also influence the timing of crops and tend to grow their crops when weather conditions are more favorable. With these periods shifting due to climate change, sowing calendars are changing over time.
Over thousands of years of domesticating and then breeding crops, humans have also managed to artificially change how crop varieties respond to both temperature and day length, and in turn have been able to expand the area where crop species can be grown. Farmers can now choose varieties that mature at different rates and adapt them to their environment.
Including farmers’ decisions on when to grow crops and which varieties to cultivate are vital ingredients for understanding how climate change is impacting staple crops around the world and how adaptation might offset the negative effects.
“For long time, the parametrization of global crop models regarding crop timing and phenology has been a challenge,” said Sara Minoli, first author of the study. “The publication of global calendars of sowing and harvest have allowed advancements in global-scale crop model and more accurate yield simulations, yet there is a knowledge gap on how crop calendars could evolve under climate change. If we want to study the future of agricultural production, we need models that can simulate not only crop growth, but also farmers’ management decisions.”
Using computer simulations and process-based models, the team projected the sowing and maturity calendars for five staple crops, maize, wheat, rice, sorghum and soybean, adapted to a historical climate period (1986–2005) and two future periods (2060–2079 and 2080–2099). The team then compared the crop growing periods and their corresponding yields under three scenarios: no adaptation, where farmers continue with historical sowing dates and varieties; timely adaptation, where farmers adapt sowing dates and varieties in response to changing climate; and delayed adaptation, where farmers delay changing their sowing dates and varieties by 20 years.
The results of the study, published last year in Nature Communications, revealed that sowing dates driven by temperature will have larger shifts than those driven by precipitation. The researchers found that adaptation could increase crop yields by 12 percent, compared to non-adaptation, with maize and rice showing the highest potential for increased crop yields at 17 percent. This in turn would reduce the negative impacts of climate change and increase the fertilization effect of increased levels of carbon dioxide (CO2) in the atmosphere.
They also found that later-maturing crop varieties will be needed in the future, especially at higher latitudes.
“Our findings indicate that there is space for maintaining and increasing crop productivity, even under the threat of climate change. Unfortunately, shifting sowing dates – a very low-cost measure – is not sufficient, and needs to be complemented by the adaptation of the entire cropping cycle through the use of different cultivars,” said Minoli.
Another important aspect of this study, according to Anton Urfels, CIMMYT systems agronomist and co-author of the study, is that it bridges the GxMxE (Gene-Management-Environment) spectrum by using crop simulations as an interdisciplinary tool to evaluate complex interactions across scientific domains.
“Although the modeled crops do not represent real cultivars, the results provide information for breeders regarding crop growth durations (i.e. the need for longer duration varieties) needed in the future as well as agronomic information regarding planting and harvesting times across key global climatic regimes. More such interdisciplinary studies will be needed to address the complex challenges we face for transitioning our food systems to more sustainable and resilient ones,” said Urfels.
Cover photo: Work underway at the International Maize and Wheat Improvement Center in Zimbabwe (CIMMYT), is seeking to ensure the widespread hunger in the country caused by the 2015/6 drought is not repeated, by breeding a heat and drought tolerant maize variety that can still grow in extreme temperatures. CIMMYT maize breeders used climate models from the CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS) to inform breeding decisions. (Photo: L. Sharma/Marchmont Communications)
The vital tasks for each country to reduce its greenhouse gas (GHG) emissions and limited carbon outputs are daunting, especially with 2030 deadlines imposed by the Paris Climate Agreement only eight years away. National stakeholders would benefit greatly from roadmaps that identify realistic and achievable milestones to point the way forward.
Researchers at the International Maize and Wheat Improvement Center (CIMMYT) have provided just such a road map. Using easily available data, they developed rapid assessment methods and adoption costs for mitigation related to crops, livestock, and forestry to identify priority locations and actions. Their article, “Quantification of economically feasible mitigation potential from agriculture, forestry and other land uses in Mexico”, was published in Carbon Management.
Applying these methods for Mexico, researchers found a national mitigation potential of 87.88 million metric tons (Mt) of carbon dioxide equivalents per year.
“Faced with such an overwhelming issue like climate change, it can be difficult for an individual, an organization, and especially an entire nation to know where to start. We developed a rapid assessment framework, tested in India, Bangladesh, and Mexico, but we believe other nations can use our methods as well,” said Tek Sapkota, the project leader and first author of the paper.
The research specifically focused on climate change mitigation in agriculture, forestry, and other land uses (AFOLU). Agriculture and related land use change contributed about 23% of the world’s anthropogenic GHG emissions in 2016, and that number is expected to increase as more food needs to be produced for the world’s growing population.
Chickpeas planted on wheat residue under conservation agriculture. (Photo: Ivan Ortiz-Monasterio/CIMMYT)
The researchers’ starting point was to quantify baseline emissions and analyze the major sources of emissions. Mexico’s AFOLU sector is responsible for 14.5% of its total national GHG emissions. In Mexico’s agricultural sector, methane and nitrous oxide emissions arise from livestock activities (enteric fermentation and fertilizers), as well as from agricultural activities (soil management and field burning of crop residues). For land use, carbon dioxide emissions and removals result from changes in forest lands, pastures, agricultural land, wetlands, and settlements.
Activities identified for GHG mitigation in crop production included avoiding fertilizer subsidies, since those tend reward inefficient nitrogen use. Subsidies could be of use, however, in encouraging farmers to adopt more efficient nitrogen management. Precision levelling of crop fields can help to lower GHG emissions by reducing cultivation time and improving the efficiency of fertilizer and irrigation water and adoption of conservation agriculture practices, such as zero tillage.
“Adoptions of these practices will not only reduce GHG emissions, but they will also help increase productivity,” said Ivan Ortiz-Monasterio, co-author and Mexico coordinator of the study.
In the livestock sector, mitigation possibilities identified are the creation of official programs, financial support, and capacity building on composting and biodigester. In FOLU sector, researchers identified options such as zero deforestation and C offset in the C market.
In addition to mapping out the mitigation benefits of specific activities, researchers also considered the costs associated with implementing those activities. “Looking at these efforts together with the cost of their implementation provide a complete picture to the implementing bodies to identify and prioritize their mitigation efforts consistent with their development goals,” said Sapkota. For example, some efforts, like increasing nitrogen use efficiency, do not provide the most climate benefits but are relatively inexpensive to realize, while establishing and maintaining carbon capture markets provides large reductions in GHG, they can be expensive to implement.
Researchers examined publicly available AFLOU spatial data for each Mexican state. At the state level, AFOLU mitigation potentials were highest in Chiapas (13 Mt CO2eq) followed by Campeche (8Mt CO2eq), indicating these states can be considered the highest priority for alleviation efforts. They identified an additional 11 states (Oaxaca, Quintana Roo, Yucatan, Jalisco, Sonora, Veracruz, Durango, Chihuahua, Puebla, Michoacán, and Guerrero) as medium priorities with mitigation potentials of 2.5 to 6.5 Mt CO2eq.
“Our data driven, and evidence-based results can help the government of Mexico refine its national GHG inventory and its Nationally Determined Contributions target and monitor progress,” said Eva Wollenberg, the overall coordinator of the study and research professor of University of Vermont, USA. “This analysis further provides an example of a methodology and results to help inform future efforts in other countries in addition to Mexico.”
Cover photo: Low nitrogen (at the front) and high nitrogen (at the back) maize planted to address nitrogen use efficiency. (Photo: Ivan Ortiz-Monasterio/CIMMYT)
Research for development organizations generate a wealth of knowledge. However, due to time and resource restraints, this knowledge has not been systematically analyzed, and the dynamics of how research is shared online have not been fully understood.
Today, technical advances in text mining, network analysis and hyperlink analysis have made it possible to capture conversations around research outcomes mentioned almost anywhere on the web. New digital research methodologies have emerged offering comprehensive approaches to leverage data across the web and to synthesize it in ways that would be impossible to carry out using traditional approaches.
In a study published in Nature Scientific Reports, scientists from the International Maize and Wheat Improvement Center (CIMMYT) teamed up with researchers from the University of Coimbra and University of Molise to investigate how CIMMYT research in climate change and climate sensitive agriculture is developing and the extent to which the center is exchanging knowledge with communities around the world.
Using text mining, social network analysis and hyperlink analysis to uncover trends, narratives and relationships in digital spaces such as research databases, institutional repositories, and Twitter, the team found that CIMMYT has steadily increased its focus on climate change research and is effectively sharing this knowledge around the world. The authors also found that CIMMYT’s climate research was centered on three main countries: Mexico, India, and Ethiopia.
The novel analytical framework developed by the team will help scientists track where their research is being shared and discussed on the web, from traditional scientific journal databases to social media.
“The web analytics framework proposed in this paper could be a useful tool for many research for development organizations to assess the extent of their knowledge production, dissemination, and influence from an integrated perspective that maps both the scientific landscape and public engagement,” said Bia Carneiro, first author of the paper.
The results of the study showed that sharing of CIMMYT’s climate science research was strongest on academic and research platforms but was also reflected in social media and government and international organization websites from across the Global North and South.
The findings from the study are important for the decolonization of science and the democratization of scientific debate. They show that CIMMYT is decolonizing climate science by sharing, creating, and co-creating knowledge with communities across the globe, particularly in Latin America, South Asia and Africa. On Twitter, the team noted that almost all countries were mentioned in CIMMYT’s Twitter conversations.
The study also shows that CIMMYT is bringing climate science and climate-sensitive agriculture into public debate, particularly through social media platforms, though they note there is potential to share more knowledge through these channels.
According to CIMMYT Agricultural Systems and Climate Change Scientist and coordinator of the study, Tek Sapkota, these types of analyses help research for development organizations to understand how people around the world view their expertise on subject matter, identify their comparative advantage and develop the value proposition of their work going forward.
Cover photo: Twitter mentions network for the International Maize and Wheat Improvement Center official account (@CIMMYT). (Credit: Nature Scientific Reports)
