Increased soil phosphorus availability induced by faba bean root exudation stimulates root growth and phosphorus uptake in neighbouring maize

Abstract

SummaryRoot growth is influenced by soil nutrients and neighbouring plants, but how these two drivers affect root interactions and regulate plant growth dynamics is poorly understood. Here, interactions between the roots of maize (Zea mays) and faba bean (Vicia faba) are characterized.Maize was grown alone (maize) or with maize (maize/maize) or faba bean (maize/faba bean) as competitors under five levels of phosphorus (P) supply, and with homogeneous or heterogeneous P distribution.Maize had longer root length and greater shoot biomass and P content when grown with faba bean than with maize. At each P supply rate, faba bean had a smaller root system than maize but greater exudation of citrate and acid phosphatase, suggesting a greater capacity to mobilize P in the rhizosphere. Heterogeneous P availability enhanced the root-length density of maize but not faba bean. Maize root proliferation in the P-rich patches was associated with increased shoot P uptake.Increased P availability by localized P application or by the presence of faba bean exudation stimulated root morphological plasticity and increased shoot growth in maize in the maize/faba bean mixture, suggesting that root interactions of neighbouring plants can be modified by increased P availability.

Integrating legacy soil phosphorus into sustainable nutrient management strategies for future food, bioenergy and water security

“…For example, faba beans (Vicia faba L.) can release a large amount of protons and carboxylates (citrate and malate) into the rhizosphere to mobilize sparingly soluble soil P for intercropped maize, or cereal crops (Li et al 2007;Zhang et al 2015). In one study, citrate exudation was controlled predominantly by shoot P concentration, and occurred in plants at a critical level of 2-3 mg P g -1 dry weight or less, indicating systemic signaling regulated by internal P supply ).…”

“…In one study, citrate exudation was controlled predominantly by shoot P concentration, and occurred in plants at a critical level of 2-3 mg P g -1 dry weight or less, indicating systemic signaling regulated by internal P supply ). Legumes often have stronger P mobilization ability than cereals, which could contribute to enhanced P acquisition by neighbouring cereals (Shen et al 2013;Zhang et al 2015).…”

Guiding phosphorus stewardship for multiple ecosystem services

“…, Zhang et al. ), which in turn is influenced by C and N availability and soil fauna. For example, soil biota in a maize field enhanced plant P uptake and reduced P leaching losses relative to biota‐limited treatments (Bender and van der Heijden ).…”

Advances in the rhizosphere: stretching the interface of life

“…intercropping systems (Li et al 2007(Li et al , 2014. Positive plant-plant interactions, such as root-root facilitation, have been shown to play a significant role for P acquisition (Li et al 2007;Brooker et al 2015;Li et al 2016;Zhang et al 2016). Tang et al (2016) further demonstrated the greater performance of such intercropping systems compared to single crop systems under field conditions along a P fertility gradient.…”