Root traits for low input agroecosystems in Africa: Lessons from three case studies

Abstract

In many regions across Africa, agriculture is largely based on low‐input and small‐holder farming systems that use little inorganic fertilisers and have limited access to irrigation and mechanisation. Improving agricultural practices and developing new cultivars adapted to these environments, where production already suffers from climate change, is a major priority for food security. Here, we illustrate how breeding for specific root traits could improve crop resilience in Africa using three case studies covering very contrasting low‐input agroecosystems. We first review how greater basal root whorl number and longer and denser root hairs increased P acquisition efficiency and yield in common bean in South East Africa. We then discuss how water‐saving strategies, root hair density and deep root growth could be targeted to improve sorghum and pearl millet yield in West Africa. Finally, we evaluate how breeding for denser root systems in the topsoil and interactions with arbuscular mycorrhizal fungi could be mobilised to optimise water‐saving alternate wetting and drying practices in West African rice agroecosystems. We conclude with a discussion on how to evaluate the utility of root traits and how to make root trait selection feasible for breeders so that improved varieties can be made available to farmers through participatory approaches.

Root phenotypes for the future

“…Low-input agroecosystems rely on the efficient use of nutrients existing within field soils and/or limited environmental resources such as rainwater. In this issue, Ndoye et al (2022) review how root traits play a key role in the efficiency of resource capture under low-input agroecosystems in Africa, where small-holder farmers have limited access to fertilizers irrigation, and mechanization. The authors highlight three case studies that illustrate how crop improvement, through selecting for specific root traits, can improve food security and crop resilience under these challenging conditions.…”

Development and characterization of pearl millet (AHB 1200) starch nanoparticle‐based edible films: A paradigm shift in food packaging

“…Pearl millet, a staple crop in semi‐arid regions, exhibits remarkable adaptability to challenging agro‐climatic conditions (Satyavathi et al, 2021). Its robustness in low‐input agricultural systems, high nutritional value, and minimal water requirements make it an attractive candidate for sustainable food production (Ndoye et al, 2022). The AHB 1200 cultivar, in particular, stands out for its high starch content, rendering it an excellent source for biopolymer extraction.…”

Glutaredoxin regulation of primary root growth is associated with early drought stress tolerance in pearl millet

“…Breeding for root traits that could improve the crop root system efficiency has been proposed as one of the pillars of a second green revolution ( Den Herder et al, 2010 ; Lynch, 2007 ; Lynch, 2019 ). Improved crops with optimized soil resources acquisition might be particularly relevant in low-input and rainfed agrosystems found in the Sahelian region of Africa ( Ndoye et al, 2022 ). This strategy relies on the selection of root traits suitable for the specific characteristics of the target environment such as soil and climate but also agricultural practices ( Lynch, 2019 ; Ndoye et al, 2022 ; van der Bom et al, 2020 ).…”

“…Improved crops with optimized soil resources acquisition might be particularly relevant in low-input and rainfed agrosystems found in the Sahelian region of Africa ( Ndoye et al, 2022 ). This strategy relies on the selection of root traits suitable for the specific characteristics of the target environment such as soil and climate but also agricultural practices ( Lynch, 2019 ; Ndoye et al, 2022 ; van der Bom et al, 2020 ). It requires a better understanding of stress patterns and the performance of individual root traits in real conditions and in response to different constraints.…”