By Dr. Shoba Sivasankar, Director, CGIAR Research Program on Grain Legumes, ICRISAT
Essential since the beginning of agriculture
Domestication of pulses, also called grain legumes, occurred side by side with that of cereals in Neolithic history. “Legumes were companions of wheat and barley when agriculture began in the Near East,”1 and “the history of lentil reaches back as far as agriculture itself.”2 In the 19th century, the pea plant was the subject of Mendel’s experiments that led to the Laws of Inheritance and paved the way for modern genetics. Yet today, when more than a billion research dollars are spent annually on a single cereal crop like maize, only an estimated 175 million USD is spread across thirteen different pulse crops.3
Until recently, the substantial potential of pulses to combat persisting planetary challenges of food insecurity and malnutrition, and the intensifying challenge of climate change, has not been widely understood. The FAO’s declaration of 2016 as the International Year of Pulses recognizes their vital role in global sustainability. Grown in all parts of the world, the diversity of pulse species allows for adaptation to a wide range of geographies and environmental conditions. Pulses are crucial for food security, catering to food and fodder needs in subsistence-farming communities and providing a major source of dietary protein as well as numerous other health benefits. Their unique ability to fix nitrogen from the atmosphere makes them indispensable for sustainable intensification and diversification of cropping systems.
At present, we are not doing enough to understand and utilize this three-fold potential of pulses. Steady research investment, coordinated and complementary planning of scientific queries, and streamlined research pipelines can help in the fight against hunger, malnutrition, soil degradation, and greenhouse gas emissions.
Food security in developing nations
Pulse crops are necessary for achieving global food security, which is Goal 2 of the UN Sustainable Development Goals (SDGs). Most pulses are crucial dietary staples in smallholder farming households in Africa and Asia. The pursuit of food security requires research designed to enhance crop productivity for farmer- and consumer-preferred end uses.
Greater crop productivity enables smallholder farm families to have adequate food and shorter periods of hunger. With steady research investment, pulses could follow the example of major cereals like maize by streamlining and operationalizing pulse breeding pipelines that make use of untapped genetic potential to enhance and stabilize crop yields. This means increasing resistance to abiotic stresses, such as drought, heat, and soil nutrient deficiencies, and biotic stresses, such as diseases, insects, and weeds. Practical realization of improved genetic potential in farmers’ fields requires parallel agronomic research that is tailored to resource-poor subsistence agriculture. For example, the practice of micro-dosing helps meet crop needs while reducing farmers’ costs by placing minimal amounts of fertilizer close to the seed.
Pulses in human nutrition
Pulses are important for dietary protein to both humans and animals. As a rich source of plant proteins, pulses have high significance in vegetarian diets, as with ‘dal’ in India, which has the world’s highest vegetarian population. With protein contents ranging from 22 to 28%, pulse grain protein is double that found in cereals.4 Pulses are high in the amino acid lysine and cereals supply methionine and cysteine amino acids, creating a complementary balance. Pulse grains are low in saturated fats, while their high dietary fiber and complex carbohydrates make them low glycemic index foods.
Pulses are also key contributors to Goal 3 of the UN SDGs, namely, to ensure healthy lives and promote well-being for all at all ages. Their nutritional value is especially important to subsistence-farming communities in developing nations, where they are often the primary source of protein. Research is needed to identify pulse varieties with better protein digestibility as a complement to existing work on biofortification of micronutrients, such as iron in common bean, and iron bioavailability.5
Pulses, climate change and sustainable agriculture
“Sustainability is meeting today’s needs without compromising the needs of the future.”6 If we are to feed 9 billion mouths by 2050, while staying within planetary boundaries, we need to plan carefully at global and local levels to balance the role of agriculture in food security with its contribution to climate change.
Agriculture and land use change account for nearly 25% of global greenhouse gas emissions, contributing to climate change and its adverse impacts on food security. Almost two-thirds of this is attributable to energy-intensive production and in-field use of nitrogen fertilizers. Nitrogen-fixing pulses have a low dependence on fertilizer nitrogen and half the nonrenewable energy requirement of other crops. Nitrogen-fixation is such a valuable trait that, not only are researchers working to improve nodulation and nitrogen fixation in pulses, they are also trying to engineer it into crops that do not naturally possess it.7 In mixed crops or rotations, pulses can reduce the carbon footprint of cropping systems, while contributing to sustainable agricultural intensification and crop diversity.
The CGIAR Research Program on Grain Legumes
Through the CGIAR Research Program on Grain Legumes, scientists collaborate to improve eight priority grain legume crops – chickpea, cowpea, common bean, faba bean, groundnut, lentil, pigeon pea and soybean – grown by smallholder farmers in Africa, Asia, Latin America, and the Caribbean. To combat poverty, hunger, malnutrition, and environmental degradation, research is focused on increasing pulse crop resilience (to drought, heat, low nutrient availability) and nitrogen-fixing capacity, developing short-season and early-maturing pulse varieties suitable for inclusion in cereal-based systems, and optimizing pulses for specific growing conditions (such as herbicide-tolerant and machine-harvestable varieties).
Working hand-in-hand with a vast network of global partners to build on past research endeavors, in the 2012-2016 period the Grain Legumes program delivered high-impact research outputs, such as common bean varieties capable of tolerating 4°C higher temperatures and a bio-pesticide with proven effectiveness against the cowpea pod borer. Through a new precision phenotyping platform, physiological traits that allow adaptation to specific growth environments were identified. New extra-early chickpea and lentil varieties have been integrated into rice-based cropping systems in Bangladesh and Myanmar, increasing total production. Machine-harvestable chickpea in India, the first of its kind, was developed through research on plant architecture. Building on years of past research, the first hybrid pigeonpea was released, delivering step changes in yield. Since inception, the Grain Legumes program has released 256 new pulse crop varieties, including 4 hybrids, participated in the sequencing of four legume genomes, tested 7 management practices, managed close to 25,000 demonstration trials, hosted more than a million farmers at farmer field days, and delivered 583 scientific publications.
Research now and in the future
Globally, pulse crops are grown in a wide variety of farming systems ranging from subsistence to commercial-scale, market-oriented agriculture. It is critical to tailor research to the needs of each part of this continuum of pulse production. Analyses of prevailing socio-economic conditions, alignment of needs with technological feasibility and enabling environments, and coordinated planning and implementation together are necessary for success in the near and longer term.
The Grain Legumes program is a global partnership involving CGIAR Centers (ICRISAT as Lead Center, CIAT, ICARDA and IITA), other organizations/programs (EIAR, Embrapa, GDAR, Generation Challenge, ICAR, and the Feed the Future Innovation Labs Peanut and Mycotoxin, and Legumes), and several public and private institutes and organizations, governments, and farmers, which is supported by the CGIAR fund, and several bilateral projects, including Tropical Legumes III, funded by the Bill and Melinda Gates Foundation.
- Zohary D and Hopf M. (1973) Domestication of Pulses in the Old World. Science 182: 887-894
- Helbaek H. (1963) Opuscula Athieniensa (Lund) 4, 171
- Murrel D. (2016) Global research and funding survey on pulse productivity and sustainability. Prepared for the Productivity and Sustainability Committee, International Year of Pulses. Global Pulse Confederation.
- Asif M, Rooney LW, Ali R and Riaz MN. (2013) Application and Opportunities of Pulses in Food System: A Review. Critical Reviews in Food Science and Nutrition 53: 1168-1179
- Hmielowski T. (2016) Improving the nutritional value of pulse crops. CSA News 7 Oct 2016. doi:10.2134/csa2016-61-10-1
- Vance CP. (2001) Symbiotic Nitrogen Fixation and Phosphorus Acquisition. Plant Nutrition in a World of Declining Renewable Resources. Plant Physiol. 127: 390-397
- Stokstad E. (2016) The Nitrogen Fix. Science 353: 1225-1227