Plant and Soil

, Volume 187, Issue 2, pp 265–275

Rhizodeposition under ambient and elevated CO2 levels

  • Peter R. Darrah
Carbon Allocation Mechanisms and Controls Direct Carbon Losses from Roots

DOI: 10.1007/BF00017092

Cite this article as:
Darrah, P.R. Plant Soil (1995) 187: 265. doi:10.1007/BF00017092


As global CO2 levels rise, can soils store more carbon and so buffer atmospheric CO2 levels? Answering this question requires a knowledge of the rates of C inputs to soil and of CO2 outputs via decomposition. Below-ground inputs from roots are a major component of the C flow into soils but are still poorly understood. In this article, new techniques for measuring rhizodeposition are reviewed and discussed and the need for cross-comparisons between methods is identified. One component of rhizodeposition, root exudation, is examined in more detail and evidence is presented which suggests that current estimates of exudate flow into soils are incorrect. A mechanistic mathematical model is used to explore how exudate flows might change under elevated CO2.

Key words

carbon storage CO2 enrichment exudation mathematical model roots rhizodeposition 

Copyright information

© Kluwer Academic Publishers 1996

Authors and Affiliations

  • Peter R. Darrah
    • 1
  1. 1.Department of Plant SciencesUniversity of OxfordUK