Soil microbial-root and microbial-rhizosphere processes to increase nitrogen availability and retention in agroecosystems

Increased reliance on biological processes and root interactions with soil biota through ‘ecological intensification’ in agroecosystems generates environmental benefits and decreases reliance on fossil-fuel based fertilizers. Here we give some examples of recent progress in understanding how agricultural management affects soil microbial-root and microbial-rhizosphere processes and nitrogen cycling. These include processes within the root (arbuscular mycorrhizal symbiosis), in the rhizosphere (biological inhibition of nitrification), and with the soil organisms surrounding the root (soil food webs in cultivated vs. grassland ecology). More such information will lead to new management options and site-specific solutions to cycle and retain nitrogen in agroecosystems.

Framework for improving nitrogen management using ecological intensification, showing that understanding soil ecological interactions among biota and roots offers more options for managing nitrogen availability and retention, which can then be attuned to site-specific and commodity-specific aspects of actual agroecosystems.Figure optionsDownload as PowerPoint slideHighlights
► Interactions among soil biota and roots underpin effective crop nitrogen management.
► Interactions include: within roots, at the rhizosphere, and with the soil food web.
► Research advances combine genomics, root responses, soil biota and biogeochemistry.
► Solutions depend on management options and agroecosystem complexity.