Effects of species and soil ‐nitrogen availability on root system architecture traits – study on a set of weed and crop species

Abstract
Better managing crop : weed competition in cropping systems while reducing both nitrogen and herbicide inputs is a real challenge that requires a better understanding of crop and weed root architecture in relation to soil‐nitrogen availability. An original approach was used which considered the parameters of a simulation model of root architecture as traits to analyse (a) the interspecific diversity of root system architecture, and (b) its response to soil‐nitrogen availability. Two greenhouse experiments were conducted using three crop and nine weed species grown at two contrasted concentrations of soil‐nitrogen availability. Plant traits were measured to characterise both overall plant growth and root architecture, with a focus on primary root emergence, root elongation and branching. The studied root traits varied among species (from a twofold to a fourfold factor, depending on the trait), validating their use as indicators to analyse the interspecific variability of root architecture. The largest interspecies differences were for two traits: ‘maximal apical root diameter’ and ‘interbranch distance’ (distance between two successive laterals on the same root). Conversely, most of the studied root traits varied little with soil‐nitrogen availability (from no variation to a 1.1‐fold factor, depending on the trait) even though soil‐nitrogen availability varied with a 17‐fold factor and impacted the overall shoot and root biomass. So, the root tra...

Source: Annals of Applied Biology - April 11, 2017 Category: Biology Authors: D. Moreau, F. Abiven, H. Busset, A. Matejicek, L. Pag ès Tags: RESEARCH ARTICLE Source Type: research