Climate change threatens to reduce global crop production, and poor people in tropical environments will be hit the hardest. More than 90% of CIMMYTâs work relates to climate change, helping farmers adapt to shocks while producing more food, and reduce emissions where possible. Innovations include new maize and wheat varieties that withstand drought, heat and pests; conservation agriculture; farming methods that save water and reduce the need for fertilizer; climate information services; and index-based insurance for farmers whose crops are damaged by bad weather. CIMMYT is an important contributor to the CGIAR Research Program on Climate Change, Agriculture and Food Security.
Kansas is experiencing a record-breaking year for hot, dry, windy (HDW) â the nationâs largest winter wheat producer â hit worse than any other state. CIMMYT researchers act to avert food insecurity as temperatures climb, atmospheric pressure increases â generating faster and longer gusts of wind and unpredictable weather conditions.
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Several factors, including temperature, water deficit, and water access, have been identified as major causes in recent wheat yield variability worldwide. DSSAT wheat models showcase the impact of temperature, heat stress, water balance and drought stress in large wheat yield reductions due to climate change for Africa and South Asia, where food security is already a problem.
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Climate change will lower global wheat production with the most negative impacts occurring in Africa and South Asia, reveals a new study released by the International Maize and Wheat Improvement Center (CIMMYT).
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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 âClimate impact and adaptation to heat and drought stress of regional and global wheat production,â 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.
âStudies have already shown that wheat yields fell by 5.5% during 1980-2010, due to rising global temperatures,â said Diego N.L. Pequeno, wheat crop modeler at the International Maize and Wheat Improvement Center (CIMMYT) and lead author of the paper. âWe 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.â
The wheat simulation models employed â CROPSIM-CERES, CROPSIM, and Nwheat within the Decision Support System for Agrotechnology Transfer, DSSAT v.4.6 â have been widely used to study diverse cropping systems around the world, according to Pequeno.
âThe DSSAT models simulated the elevated CO2 stimulus on wheat growth, when N is not limiting,â he said. âOur study is the first to include combined genetic traits for early vigor, heat tolerance, and late flowering in the wheat simulation.â
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.
âGenerally, 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,â 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 â 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.
âOur 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,â 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.
By: Professor Lindiwe Majele Sibanda, Chair, CGIAR System Board
With conflict in Ukraine, Sudan and elsewhere, the relationship between instability, migration and food security is increasingly apparent.
The Russia Ukraine crisis, is affecting food systems around the world, driving up the price of grains and fertilizers with countries that can least afford it hit the hardest. At the same time, broader food insecurity is contributing to forced migration and rising social tensions.
Accelerating climate change amplifies the risks, with yields for some crops in sub-Saharan Africa set to fall by up to 35 per cent by 2050.
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This article was originally published in Swedish by Global Bar Magazine.
Mixed farming can boost Nepalâs income, food security and resilience to climate change.
CGIAR Research Centers such as the International Water Management Institute (IWMI) and the International Maize and Wheat Improvement Center (CIMMYT) are organizing pilot activities to promote sustainable intensification of mixed farming systems (SIMFS) as a vital strategy. SIMFS has the potential to enhance the current mixed farming system by utilizing the same quantity of natural resources and employing effective crop management.
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A well-functioning seed system is key to timely access to low cost and quality seed by farmers. Improved varieties are critical to increase grain production in terms of both quality and quantity.
CIMMYT is working with the National Agricultural Semi-Arid Resources Research Institute (NaSARRI) to strengthen seed systems for millet, sorghum, and groundnuts.
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Recent successful events in Beijing included the first annual meeting of the China-Pakistan Joint Lab on Wheat Molecular Breeding. The meeting was attended by six distinguished Pakistani wheat scientists who had been invited to China for a 10-day training.
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Wheat production is strained by rising temperatures, longer droughts, and emerging crop diseases. CIMMYT wheat researchers are leading what the Technology Times and scientists call a ‘wheat revolution’ by developing drought-tolerant and fungal-resistant wheat varieties.
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With the harmful effects of climate change, including drought and extreme temperatures moving from the abstract into the practical, the development and deployment of sustainable investments and support for climate action in agricultural and food systems must be accelerated. Â
A hotter and drier world will significantly affect the average yields of key staple crops. Researchers at the International Center for Maize and Wheat Improvement (CIMMYT) estimate that, without adaptation of climate-smart solutions, each Celsius degree increase in global mean temperatures will cut average maize yields by 7.4 percent and wheat yields by 6.0 percent.Â
âThose would be catastrophic losses, affecting every part of the global food system,â said CIMMYT Director General Bram Govaerts âAlready we see havoc being caused in food insecure regions like southern Africa. With that in mind, itâs time not only to keep developing climate smart solutions, but we need to speed up the distribution of innovations.â Â
CIMMYT is a partner in the Agriculture Innovation Mission for Climate (AIM4C) initiative, which aims to raise global ambition and drive more rapid and transformative climate action in all countries by bringing together policymakers, industry leaders, producers, civil society groups, and scientists and researchers.Â
The AIM for Climate Summit, May 8-10, in Washington DC, brought together a global coalition of climate partners, including CIMMYT, all working towards the mission of rapid dissemination of climate-smart innovations. Â
As part of its participation in the Climate Summit, CIMMYT is reshaping its strategy for contributing to the 2030 Agenda for Sustainable Development. Â
The new strategy places CIMMYT research within three main pillars: (1) discovery, (2) systems development, and (3) inclusivity, all within the framework of climate adaptation and mitigation. Â
âOur new approach ensures that CIMMYT will be a partner of choice and a contributor to science and technology development. All while keeping the focus on smallholder farmers and establishing guidelines to ensure advances are sustainable and fair, as we engage previously underrepresented stakeholders,â said Govaerts. Â
Establishing frameworks for rapid innovationÂ
At the Summit, CIMMYT updated partners on the progress of two Innovation Sprints, which are key components of the AIM and intended to achieve innovations for climate smart agri-food systems in an expedited time frame. Â
CIMMYT is leading two sprints: Climate-Resilient soil fertility management by smallholders in Africa, Asia, and Latin America and Fast Tracking Climate Solutions from CGIAR Genebank Collections.Â
The Right Fertilizer at the Right TimeÂ
The Climate-Resilient soil fertility management by smallholders in Africa, Asia, and Latin America Innovation Sprint provides targeted interventions for fertilizer application and overall soil health to smallholder farmers. Â
Fertilizers are essential for increasing crop yields and ensuring food security, yet fertilizer use for food and fodder is severely skewed at the global level, leading to over-fertilization in some regions and under-fertilization in others.Â
âWe need innovations that promote local adaptation and agency by smallholder farmers. By tailoring fertility management practices to specific conditions, smallholders will optimize productivity, enhance climate resilience, and mitigate greenhouse gas emissions,â said Sieglinde Snapp, Innovation Sprint Leader and Program Director of CIMMYTâs Sustainable Agricultural Systems. Â
Withdrawals from genebanksÂ
CIMMYTâs germplasm bank, also known as a genebank, is at the center of CIMMYTâs crop-breeding research. This living catalog of genetic diversity conserves over 28,000 unique seed collections of maize and 150,000 of wheat. Many other CGIAR institutions hold similar genebanks for other key crops. The Genebank Sprint unlocks potential climate smart solutions lurking in varieties held in genebanks.Â
Research has developed integrated approaches for six major crops (cassava, maize, sorghum, cowpea, common bean and rice), providing a scalable model for the rapid and cost-effective discovery of climate-adaptive alleles.Â
âGenetic diversity is a key part of our responses to climate change,â said Sarah Hearne, CIMMYT Principal Scientist. âBy utilizing the vast diversity catalogue in our CGIAR genebanks, we can disseminate climate resilient varieties to smallholder farmers around the world.âÂ
Working towards speeding up deployment Â
In addition, CIMMYTâs Accelerated Innovation Delivery Initiative (AID-I), a partnership with the United States Agency for International Development (USAID) and based on the MasAgro model in Mexico, works toward improving legume seed and maize varieties. So far, 35 local partners are employing solutions in Zambia, Tanzania, and Malawi, and there have been 125 mega demonstrations, a majority managed by women, for farmers of improved seeds. Â
In conjunction with the Summitâs focus on rapid implementation, CIMMYT is ready to deploy a similar project immediately in Central America, a historically under-funded region, which would improve livelihoods throughout the area. Â
âCIMMYT is dedicated to accelerating food systems transformation by using the power of collective action for research and innovation to foster productive, inclusive, and resilient agrifood systems that ensure global food and nutrition security,â said Govaerts.Â
As climate change threats accelerate, new technologies, products, and approaches are required for smallholder farmers to mitigate and adapt to current and future threats. Targeting smallholder farmers will benefit not only the farmers but the entire agri-food system through enhanced locally relevant knowledge that harnesses handheld sensors and advisories on management options, soil status, weather, and market information.
The Agriculture Innovation Mission for Climate (AIM for Climate / AIM4C) seeks to address climate change and global hunger by uniting participants to significantly increase investment in, and other support for, climate-smart agriculture and food systems innovation over five years (2021â2025).
The International Maize and Wheat Improvement Center (CIMMYT), as a partner of AIM for Climate, organized a breakout session titled “Smart Smallholder Fertilizer Management to Address Food Security, Climate Change, and Planetary Boundaries” during the AIM for Climate Summit in Washington DC, May 8-10, 2023.
Fertilizers are essential for increasing crop yields and ensuring food security, yet fertilizer use for food and fodder is severely skewed at the global level, leading to over-fertilization in some regions and under-fertilization in others.
Farmers in low-income countries are highly vulnerable to fertilizer supply shortages and price spikes, which have direct consequences for food prices and hunger. Improving fertilizer efficiency and integrated organic and inorganic sources is important globally as nutrient loss to the environment from inappropriate input use drives greenhouse gas emissions and pollution.
Innovation Sprint
Because smallholder farmers are the primary managers of land and water, the CIMMYT-led AIM4C Innovation Sprint, Climate-Resilient soil fertility management by smallholders in Africa, Asia, and Latin America is designed to implement and scale-up a range of climate robust nutrient management strategies in 12 countries, and to reach tens of millions of smallholder farmers in close collaboration with nearly 100 public-private partners organizations.
Strategies include innovations in extension where digital tools enable farmer-centered private and public advisories to increase the uptake of locally adapted nutrient management practices. Connecting farmers to investors and markets provides financial support for improved nutrient management.
By tailoring validated fertility management practices to their specific conditions, and integrated use of legumes and manure, smallholders will optimize productivity, enhance climate resilience, and mitigate greenhouse gas emissions. Research from other organizations has determined that improved fertilizer management can increase global crop yield by 30% while reducing greenhouse gas emissions.
Right place, right time
âWe need locally adapted fertilizer management approaches that work for smallholder farmers. By tailoring validated fertility management practices to their specific conditions, smallholders will optimize productivity, enhance climate resilience, and mitigate greenhouse gas emissions,â said Sieg Snapp, CIMMYTâs Sustainable Agricultural Systems Program Director. She continued, âWhat is needed now is major investment in data synthesis. Through this SPRINT we are exploring options to enable taking sensors to scale, to reach tens of millions of farmers with hyper-local soils information.â
Inequality is the core of the problem in fertilizer management: some regions apply more than the required amount, where in other regions fertilizer application is insufficient for plant needs, leading to low yields and soil degradation.
âFertilizer efficiency can be improved through application of the right amount of fertilizer using the right source employing the right methods of application at the right time of plant demand,â said Tek Sapkota, CIMMYT Senior Scientist, Agricultural System/Climate Change.
The session included presentations by the Foundation for Food & Agriculture Research (FFAR), UN Foundation, Pakistan Agricultural Research Council (PARC), Stockholm International Water Institute (SIWI), USDA, and Alliance of CIAT-Bioversity. Highlights sustainable and climate-smart practices in Pakistan, novel plant genetics for improved nitrogen cycling, and soil water and nutrient management in the Zambezi to tackle food security and climate change challenges.
Bram Govaerts, CIMMYT Director General, promotes 5 adaptation measures that can transform global agri-food systems, making them more resilient to climate shocks to help vulnerable regions cope with diminishing yields and forced migrations.
Public and private crop research organizations worldwide have worked behind the scenes for decades, bolstering the resilience of staple crops like maize and wheat to fight what is shaping up to be the battle of our time: feeding humanity in a biosphere increasingly hostile to crop farming.
In the case of wheat â which provides some 20% of carbohydrates and 20% of protein in human diets, not to mention 40% of total cereal exports â harvests spoiled by heat waves, droughts, and crop disease outbreaks can send food prices skyrocketing, driving world hunger, poverty, instability, human migration, political instability, and conflict.
Century-high temperature extremes and the early onset of summer in South Asia in 2022, for example, reduced wheat yields as much as 15% in parts of the Indo-Gangetic Plains, a breadbasket that yearly produces over 100 million tons of wheat from 30 million hectares of crop land.
Around half the worldâs wheat crop suffers from heat stress, and each 1 °C increase in temperature reduces wheat yields by an average 6%, according to a 2021 review paper âHarnessing translational research in wheat for climate resilience,â published in the Journal of Experimental Botany, which also outlines nine goals to improve the climate resilience of wheat.
Droughts and shrinking aquifers pose equally worrying threats for wheat, said Matthew Reynolds, a wheat physiologist at the International Maize and Wheat Improvement Center (CIMMYT) and lead author of the study. âWater availability is the biggest factor influencing potential yield in a majority of wheat environments globally,â Reynolds explained. âStudies predict severe water scarcity events for up to 60% of the worldâs wheat-growing areas by the end of this century.â
Science and sources to toughen wheat
Along with modernized, more diverse cropping systems and better farm policies, more resilient varieties are crucial for sustainable wheat production, according to Reynolds and a wheat breeder colleague at CIMMYT, Leo Crespo, who added that breeders have been working for decades to stiffen wheatâs heat and drought tolerance, long before climate change became a buzzword.
âBreeding and selection in diverse environments and at targeted test sites characterized by heat and natural or simulated drought has brought farmers wheat varieties that perform well under both optimal and stressed conditions and weâre implementing new technologies to speed progress and lower costs,â said Crespo, mentioning that the Centerâs wheat nurseries SAWYT and HTWYT target semi-arid and heat-stressed environments respectively and are sent yearly to hundreds of public and private breeders worldwide through the International Wheat Improvement Network (IWIN). “Retrospective analysis of IWIN data has shown that heat tolerance has been increasing in recent years, according to a 2021 CIMMYT study.”
âClimate change is a serious driver of potential disease epidemics, since changeable weather can increase selection pressure for new virulent pathotypes to evolve,â said Pawan Singh, a CIMMYT wheat pathologist. âWe must be ever vigilant, and the IWIN is an invaluable source of feedback on potential new disease threats and changes in the virulence patterns of wheat pathogens.â
In the quest to improve climate resilience in wheat, CIMMYT âpre-breedingâ â accessing desired genetic traits from sources like wheatâs grassy relatives and introducing them into breeding lines that can be crossed with elite varieties â focuses on specific traits. These include strong and healthy roots, early vigor, a cool canopy under stress, and storage of water-soluble carbohydrates in stems that can be used as stress intensifies to complement supplies from photosynthesis, as well as an array of traits that protect photosynthesis including âstay-greenâ leaves and spikes and pigments that protect the delicate photosynthetic machinery from oxidative damage caused by excess light.
Though elite breeding lines may contain genetic variation for such traits, in pre-breeding researchers look further afield for new and better sources of resilience. The vast wheat seed collections of CIMMYT and other organizations, particularly seed samples of farmer-bred heirloom varieties known as âlandraces,â are one potential source of useful diversity that cutting-edge genetic analyses promise to help unlock.
Rich diversity for wheat is still found in farmersâ fields in India, in the northern states of the Himalayan region, the hill regions, and the semi-arid region of Rajasthan, Gujarat, Karnataka. The landraces there show tolerance to drought, heat, and saline soils.
The so-called âsynthetic wheatsâ represent another plentiful source of resilience genes. Synthetics are the progeny of crosses of tetraploid wheat (having four chromosomes, like the durum wheat used for pasta) with wild grass species. CIMMYT and other organizations have been creating these since the 1980s and using them as bridges to transfer wild genes to bread wheat, often for traits such as disease resistance and heat and drought tolerance.
The study, creation, and use of bridging lines, landraces, and seed collections with useful traits as part of pre-breeding is described in the 2021 paper âProgress and prospects of developing climate resilient wheat in South Asia using modern pre-breeding methods,â published in the science journal Current Genomics.
Lines with new sources of heat- and drought-tolerance from CIMMYTâs pre-breeding are also distributed to public and private breeders worldwide via the IWIN for testing as the Stress Adapted Trait Yield Nurseries (SATYNs), according to the paper. These special nurseries are grown by national and private breeders throughout South Asia, for example in Afghanistan, Bangladesh, India, Iran, Nepal, and Pakistan. Lines from the nursery have on occasion been released directly as varieties for use by farmers in Afghanistan, Egypt, and Pakistan.
A critical challenge in pre-breeding is to identify and keep desirable wild genes while culling the undesirable ones that are also transferred in crosses of elite breeding lines with landraces and synthetics. One approach is through physiological pre-breeding, where complementary crosses are made to improve the crop performance under drought and heat stress. The second approach is using genomic prediction, on the basis of seeds, or accessions, in the gene bank collection that have gone through genomic and phenotyping analysis for target traits such as heat and drought tolerance. These approaches can also be combined to boost the speed and effectiveness of selecting strong varieties.
Breeding revolutions
Wheat breeding is being revolutionized by advances in âhigh-throughput phenotyping.â This refers to rapid and cost-effective ways to measure wheat performance and specific traits in the field, particularly remote sensing â that is, crop images taken from vehicles, drones, or even satellites. Depending on the wavelength of light used, such images can show plant physiochemical and structural properties, such as pigment content, hydration status, photosynthetic area, and vegetative biomass. Similarly, canopy temperature images from infrared photography allow detection for crop water status and plant stomatal conductance. Â âSuch traits tend to show better association with yield under stress than under favorable conditionsâ, said Francisco Pinto, a CIMMYT wheat physiologist who is developing methods to measure roots using remote sensing. âA remotely sensed âroot indexâ could potentially revolutionize our ability to breed for root traits, which are critical under heat and drought stress but have not been directly accessible in breeding.â
Innovative statistical analysis has greatly increased the value of field trials and emphasized the power of direct selection for yield and yield stability under diverse environments.
Initial results from genomic selection programs, particularly where combined with improved phenotyping techniques, also show great promise. The potential benefits of combining a range of new technologies constitute a valuable international public good.
New initiatives
Launched in 2012, the Heat and Drought Wheat Improvement Consortium (HeDWIC) facilitates global coordination of wheat research to adapt to a future with more severe weather extremes, specifically heat and drought. It delivers new technologies â especially novel wheat lines  to wheat breeders worldwide via the International Wheat Improvement Network (IWIN), coordinated for more than half a century by CIMMYT.
HeDWIC is supported by the Foundation for Food and Agriculture Research (FFAR) and is part of the Alliance for Wheat Adaption to Heat and Drought (AHEAD), an international umbrella organization set up by the Wheat Initiative to bring the wheat research community together and to exchange new germplasm, technologies and ideas for enhancing tolerance to heat and drought.
Cover photo: Night heaters to increase night temperature in the field, as increasingly warmer nights are diminishing yield in many cropping systems. (Photo: Enrico Yepez/CIMMYT)Â
The Livestock Production Systems in Zimbabwe (LIPS-ZIM) project promotes climate-relevant innovation to better manage livestock disease and production systems.
Through decades-long Asian and global partnerships, the International Maize and Wheat Improvement Center (CIMMYT) is refining and spreading a suite of resource-conserving, climate-smart innovations for highly diverse maize- and wheat-based cropping systems, including more precise and efficient use of water and fertilizer, as well as conservation agriculture, which blends reduced or zero-tillage, use of crop residues or mulches as soil covers, and more diverse intercrops and rotations.
âZero-tillage and residue management for cereals â that is, sowing the seed directly into unplowed soils and residues from the preceding rice crop â has been adopted on a significant area in the transact of Indo-Gangetic Plain, with positive impacts on crop yields, profitability, and resource-use efficiencies,â said Tek Sapkota, senior scientist in agricultural systems/climate change, CIMMYT.
The paper âConservation agriculture for sustainable intensification in South Asia,â published in the science journal Nature Sustainability reported that, compared to the conventional practice, conservation agriculture resulted overall in a 4.6% higher grain yield, a 14.6% improvement in water use efficiency, and a 25.6% greater net economic return. The net economic return was 40.5% higher for full conservation agriculture but, given the benefits of partial adoption of the practices, rigid adherence to an âall or nothingâ approach to spread conservation agriculture in South Asia does not seem warranted.
Conservation agriculture also offers several ecosystem services. In the study data, global warming potential was reduced by as much as 33.5% in rice-wheat systems, values that are consistent with other research. Moreover, conservation agriculture-based practices provide an economically feasible alternative to burning rice residues, a serious public health threat in northwestern India given the roughly 23 million tons of residues that are burned each year in the region.
âMore widespread adoption of zero-tillage in India has been made possible with the development of next-generation tractor-drawn implements that allow direct seeding into heavy residues, as well as business models whereby implement owners contract out with neighboring farmers to sow their crops and provide other services,â said Sapkota. âNational governments in South Asia are actively promoting conservation agriculture to address residue burning and other farming sustainability problems.â
Fitting conservation agriculture to maize farming in Mexico
Efforts to adapt conservation agriculture and promote its adoption by farmers operating highly-diverse, mostly rainfed maize-based cropping systems in Mexico have had mixed results. A recent study assessed soil health in 20 trials in starting between 1991 and 2016 in agro-ecologies ranging from handplanted traditional systems to intensive irrigated systems, contrasting conservation agriculture effects with those of local conventional practices, which commonly involve tillage, residue removal, and continuous maize production.
As reported in the 2021 paper âEffects of conservation agriculture on physicochemical soil health in 20 maize-based trials in different agro-ecological regions across Mexico,â published in the science journal Land Degradation and Development, conservation agriculture increased maize yields at most sites by 0.85 tons per hectare, on average. Organic matter and nitrates were higher in topsoils under conservation agriculture and soil aggregate stability was greater, meaning the soil more effectively moved air and water to plant roots. For other soil health parameters, such as nutrient content, pH, or compaction, most values were determined more by local soil type than by crop management.
âGiven the significant variation across agro-ecologies, local adaptive trials are important to assess the effects of conservation agriculture on soil health and fit it to local conditions,â said Simon Fonteyne, a CIMMYT cropping systems agronomist and first author of the paper.
Emissions control
Several recent studies have assessed the costs and potential of various sustainable intensification technologies for reducing greenhouse gas emissions in India, Bangladesh and Mexico. Their findings can help inform national policies on food security, economic development and environment, including those relating to the Paris Agreement.
In the 2019 study âCost-effective opportunities for climate change mitigation in Indian agriculture,â published in the journal Science of the Total Environment, CIMMYT and partners found that estimated total emissions from Indian agriculture were 481 tons of CO2 equivalent (MtCO2e) in 2012, with crops contributing over 40% and livestock nearly 60%. Under a business-as-usual scenario, agricultural greenhouse gas emissions in India would be 515 MtCO2e by 2030. This annual emissions could be reduced by 85.5 MtCO2e through adoption of mitigation practices and about 80% of that reduction could be achieved through measures that would actually save money and, in many cases, could be implemented with current technology. The efficient use of fertilizer, zero-tillage, and rice-water management could deliver more than 50% of the technical abatement potential.
âRealization of this mitigation potential will depend largely on the extent adoption by farmers,â said Sapkota, who was lead author of the study. âLarge-scale adoption of apparently win-win options is not happening, so the government of India will need to apply appropriate policy measures and incentives, consistent with its food security and emission reduction goals.
A similar study in Bangladesh, reported in the 2021 paper âQuantifying opportunities for greenhouse gas emissions mitigation using big data from smallholder crop and livestock farmers across Bangladesh,â published in the journal Science of the Total Environment, found greenhouse gas emissions from agriculture in Bangladesh of 76.8 MtCO2e for 2014â15. Yearly emissions by 2030 under a business-as-usual approach would approximate 86.9 MtCO2e and, by 2050, about 100 MtCO2e. Adoption of realistic, climate-smart crop and livestock management options to reduce emissions offer mitigation opportunities of 9.51 MtCO2e per year by 2030 and 14.21 MtCO2e by 2050. As much as 75% of this potential can be achieved through cost-saving options that benefit smallholder farmers. As is the case for India, realization of this potential largely depends on the degree to which supportive policies and measures can encourage farmer adoption.
A similar rapid assessment of costs for to mitigate greenhouse gas emissions from crops, livestock, and forestry in Mexico found a national mitigation potential of 87.9 MtCO2eq per year, fully 72.3 MtCO2eq from livestock. As reported in the 2022 paper, âQuantification of economically feasible mitigation potential from agriculture, forestry and other land uses in Mexico,â published in the science journal Carbon Management, implementing mitigation potential on Mexican cropland could bring net benefits, compared to livestock and forestry options, which involve net costs. In the 2021 paper “Reduced Water Use in Barley and Maize Production Through Conservation Agriculture and Drip Irrigation” a reduction of emissions caused by lower fuel use in conservation agriculture of 192 kg CO2 haâ1 Â was measured in farmers fields, as well as an increase in soil carbon and a reduction in water use.