Grain legumes and dryland cereals contribute to carbon sequestration in the drylands of Africa and South Asia

Abstract

Grain legumes and drylands cereals including chickpea (Cicer arietinum), common bean (Phaseolus vulgaris), cowpea (Vigna unguiculata), groundnut (Arachis hypogaea), lentil (Lens culinaris), pigeon pea (Cajanus cajan), soybean (Glycine max), finger millet (Eleusine coracana), pearl millet (Pennisetum glaucum) and sorghum (Sorghum bicolor) are the leading sources of food grain in drylands of Africa and South Asia. These crops can help smallholder agriculture to become more resilient, productive, and profitable, but their quantitative impact on carbon sequestration is unknown. The aim of this review study was to quantify their contribution to carbon sequestration across the drylands of Africa and South Asia based on 437 publications with 1319 observations in studies conducted across 32 countries. Cropping systems with grain legumes showed the greatest increase in soil organic carbon (SOC) concentrations, while cereals (and pigeon pea) gave the largest amount of aboveground carbon stock (>2 Mg C ha 1). Estimated carbon stock in post-harvest residues of these crops was 1.51 +/- 0.05 Mg C ha 1 in Africa and 2.29 +/- 0.10 Mg C ha 1 in South Asia. These crops produced more aboveground carbon, and significantly increased SOC, when grown as intercrops. Soils with low initial SOC (<1%) and high clay content (>32%) showed the greatest potential for carbon sequestration when cropped with grain legumes and dryland cereals. This study is the first of its kind to provide evidence that grain legumes and drylands cereals improve carbon sequestration across Africa and South Asia.

Keywords

Aboveground carbon; Crop rotation; Intercropping; Soil organic carbon; Sustainable intensification

Published in

Agriculture, Ecosystems and Environment
2023, Volume: 355, article number: 108583Publisher: ELSEVIER

SLU Authors

• Kuyah, Shem

  • Department of Crop Production Ecology, Swedish University of Agricultural Sciences
    
  • Jomo Kenyatta University of Agriculture and Technology

• Muoni, Tarirai

  • Department of Crop Production Ecology, Swedish University of Agricultural Sciences
    
  • International Maize and Wheat Improvement Center (CIMMYT)

• Dahlin, Sigrun

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    

• Jonsson, Mattias

  • Department of Ecology, Swedish University of Agricultural Sciences
    

• Öborn, Ingrid

  • Department of Crop Production Ecology, Swedish University of Agricultural Sciences
    

Sustainable Development Goals

SDG2 Zero hunger


UKÄ Subject classification

Agricultural Science


Publication identifier

DOI: https://doi.org/10.1016/j.agee.2023.108583

Permanent link to this page (URI)

https://res.slu.se/id/publ/126365