funder_partner: Scotland's Rural College (SRUC)

Ecological farming a boon for staple crop farmers in Africa, new study finds

Written by Mike Listman on July 20, 2022. Posted in Press releases.

Elufe Chipande (left), a farmer at Songani in Zomba District, Malawi, is rotating maize (background) and pigeonpea (foreground) under conservation agriculture practices to improve soil fertility and capture and retain more water. Christian Thierfelder (center), a cropping systems agronomist working out of the Zimbabwe office of CIMMYT, advises and supports southern African farmers and researchers to refine and spread diverse yield-enhancing, resource-conserving crop management practices. Photo: Mphatso Gama/CIMMYTSRUC

An international team of scientists has found that eco-friendly practices such as growing a range of crops, including legumes such as beans or pigeonpea, and adding plant residues or manure to soils can raise food crop yields in places such as rural Africa, where small-scale farmers cannot apply much nitrogen fertilizer.

Published in the science journal Nature Sustainability and examining data from 30 long-running field experiments involving staple crops (wheat, maize, oats, barley, sugar beet, or potato) in Europe and Africa, this major study is the first to compare farm practices that work with nature to increase yields and explore how they interact with fertilizer use and tillage.

“Agriculture is a leading cause of global environmental change but is also very vulnerable to that change,” said Chloe MacLaren, a plant ecologist at Rothamsted Research, UK, and lead author of the paper. “Using cutting-edge statistical methods to distill robust conclusions from divergent field experiment data, we found combinations of farming methods that boost harvests while reducing synthetic fertilizer overuse and other environmentally damaging practices.”

Recognizing that humanity must intensify production on current arable land to feed its rising numbers, the paper advances the concept of “ecological intensification,” meaning farming methods that enhance ecosystem services and complement or substitute for human-made inputs, like chemical fertilizer, to maintain or increase yields.

Boosting crop yields and food security for far-flung smallholders

The dataset included results from six long-term field experiments in southern Africa led by the International Maize and Wheat Improvement Center (CIMMYT). Africa’s farming systems receive on average only 17 kilograms of fertilizer per hectare, compared to more than 180 kilograms per hectare in Europe or close to 600 in China, according to Christian Thierfelder, a CIMMYT cropping systems agronomist and study co-author.

“In places where farmers’ access to fertilizer is limited, such as sub-Saharan Africa or the Central American Highlands, ecological intensification can complement scarce fertilizer resources to increase crop yields, boosting households’ incomes and food security,” Thierfelder explained. “We believe these practices act to increase the supply of nitrogen to crops, which explains their value in low-input agriculture.”

The CIMMYT long-term experiments were carried out under “climate-smart” conservation agriculture practices, which include reduced or no tillage, keeping some crop residues on the soil, and (again) growing a range of crops.

“These maize-based cropping systems showed considerable resilience against climate effects that increasingly threaten smallholders in the Global South,” Thierfelder added.

Benefits beyond yield

Besides boosting crop yields, ecological intensification can cut the environmental and economic costs of productive farming, according to MacLaren.

“Diversifying cropping with legumes can increase profits and decrease nitrogen pollution by reducing the fertilizer requirements of an entire crop rotation, while providing additional high-value food, such as beans,” MacLaren explained. “Crop diversity can also confer resilience to weather variability, increase biodiversity, and suppress weeds, crop pests and pathogens; it’s essential, if farmers are to improve maize production in places like Africa.”

Thierfelder cautioned that widespread adoption of ecological intensification will require strong support from policymakers and society, including establishing functional markets for legume seed and for marketing farmers’ produce, among other policy improvements.

“Dire and worsening global challenges — climate change, soil degradation and fertility declines, and scarcening fresh water — threaten the very survival of humanity,” said Thierfelder. “It is of utmost importance to renovate farming systems and bring us back into a safe operating space.”

Click here to read the paper, Long-term evidence for ecological intensification as a pathway to sustainable agriculture.

For more information or interviews:

Rodrigo Ordoñez, Communications Manager

Email: r.ordonez@cgiar.org

Tel: +52 55 5804 2004, ext. 1167

Massive-scale genomic study reveals wheat diversity for crop improvement

Written by Mary Donovan on September 11, 2020. Posted in In the media.

Researchers working on the Seeds of Discovery (SeeD) initiative, which aims to facilitate the effective use of genetic diversity of maize and wheat, have genetically characterized 79,191 samples of wheat from the germplasm banks of the International Maize and Wheat Improvement Center (CIMMYT) and the International Center for Agricultural Research in the Dry Areas (ICARDA).

A new study analyzing the diversity of almost 80,000 wheat accessions reveals consequences and opportunities of selection footprints. (Photo: Eleusis Llanderal/CIMMYT)

Massive-scale genomic study reveals wheat diversity for crop improvement

Written by Rodrigo Ordóñez on September 11, 2020. Posted in Press releases.

The findings of the study published today in Nature Communications are described as “a massive-scale genotyping and diversity analysis” of the two types of wheat grown globally — bread and pasta wheat — and of 27 known wild species.

Wheat is the most widely grown crop globally, with an annual production exceeding 600 million tons. Approximately 95% of the grain produced corresponds to bread wheat and the remaining 5% to durum or pasta wheat.

The main objective of the study was to characterize the genetic diversity of CIMMYT and ICARDA’s internationally available collections, which are considered the largest in the world. The researchers aimed to understand this diversity by mapping genetic variants to identify useful genes for wheat breeding.

From germplasm bank to breadbasket

The results show distinct biological groupings within bread wheats and suggest that a large proportion of the genetic diversity present in landraces has not been used to develop new high-yielding, resilient and nutritious varieties.

“The analysis of the bread wheat accessions reveals that relatively little of the diversity available in the landraces has been used in modern breeding, and this offers an opportunity to find untapped valuable variation for the development of new varieties from these landraces”, said Carolina Sansaloni, high-throughput genotyping and sequencing specialist at CIMMYT, who led the research team.

The study also found that the genetic diversity of pasta wheat is better represented in the modern varieties, with the exception of a subgroup of samples from Ethiopia.

The researchers mapped the genomic data obtained from the genotyping of the wheat samples to pinpoint the physical and genetic positions of molecular markers associated with characteristics that are present in both types of wheat and in the crop’s wild relatives.

According to Sansaloni, on average, 72% of the markers obtained are uniquely placed on three molecular reference maps and around half of these are in interesting regions with genes that control specific characteristics of value to breeders, farmers and consumers, such as heat and drought tolerance, yield potential and protein content.

Open access

The data, analysis and visualization tools of the study are freely available to the scientific community for advancing wheat research and breeding worldwide.

“These resources should be useful in gene discovery, cloning, marker development, genomic prediction or selection, marker-assisted selection, genome wide association studies and other applications,” Sansaloni said.

Read the study:

Diversity analysis of 80,000 wheat accessions reveals consequences and opportunities of selection footprints.

Interview opportunities:

Carolina Sansaloni, High-throughput genotyping and sequencing specialist, CIMMYT.

Kevin Pixley, Genetic Resources Program Director, CIMMYT.

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

Ricardo Curiel, Communications Officer, CIMMYT. r.curiel@cgiar.org

Rodrigo Ordóñez, Communications Manager, CIMMYT. r.ordonez@cgiar.org

Acknowledgements:

The study was part of the SeeD and MasAgro projects and the CGIAR Research Program on Wheat (WHEAT), with the support of Mexico’s Secretariat of Agriculture and Rural Development (SADER), the United Kingdom’s Biotechnology and Biological Sciences Research Council (BBSRC), and CGIAR Trust Fund Contributors. Research and analysis was conducted in collaboration with the National Institute of Agricultural Botany (NIAB) and the James Hutton Institute (JHI).

About CIMMYT:

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