Building soil sustainability from root–soil interface traits. (July 2022)

• Record Type: Journal Article
• Authors: Hallett, Paul D.; Marin, Maria; Bending, Gary D.; George, Timothy S.; Collins, Chris D.; Otten, Wilfred
• Is Part Of: Trends in plant science. Volume 27:Number 7(2022)
• Page Start: 688
• Page End: 698
• Publication Date: 2022-07
• Subjects: rhizosphere -- soil -- soil structure -- exudate -- mucilage -- root hair; Botany -- Periodicals; Botanique -- Périodiques; Botany; Periodicals; 580.5
• DOI: 10.1016/j.tplants.2022.01.010
• Languages: English
• ISSNs: 1360-1385

Abstract

Abstract : Great potential exists to harness plant traits at the root–soil interface, mainly rhizodeposition and root hairs, to 'build' soils with better structure that can trap more carbon and resources, resist climate stresses, and promote a healthy microbiome. These traits appear to have been preserved in modern crop varieties, but scope exists to improve them further because they vary considerably between genotypes and respond to environmental conditions. From emerging evidence, rhizodeposition can act as a disperser, aggregator, and/or hydrogel in soil, and root hairs expand rhizosheath size. Future research should explore impacts of selecting these traits on plants and soils concurrently, expanding from model plants to commercial genotypes, and observing whether impacts currently limited to glasshouse studies occur in the field. Highlights: Root hairs and rhizodeposits are root traits that vary between plant species and crop genotypes and have a large impact on both plants and soils. Targeting these traits may benefit both plants and soil, improving food and environmental security at the same time. Soils may store more carbon (greenhouse gas mitigation), trap more water (drought tolerance) and nutrients, and resist erosion. From limited research, rhizosheath size has been maintained or improved in modern crop varieties, but potential exists to increase it further. Whether this will lead to improved yield or soil properties, however, requires greater field testing to verify. Laboratory and glasshouse research using root trait ideotypes has found marked impacts on soil biophysical properties. Rhizodeposits vary in behaviour between species from hydrogels to surfactants, and as soil dispersers (miners) or aggregators (builders).