Author
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Logsdon, Sally |
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Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only Publication Acceptance Date: 11/5/2009 Publication Date: 11/5/2009 Citation: Logsdon, S.D. 2009. Root Effects on Soil Properties and Processes: Synthesis and Future Research Needs [abstracts]. ASA-CSSA-SSSA Annual Meeting. Nov. 1-5, 2009, Pittsburgh, PA. CD-ROM. Interpretive Summary: Technical Abstract: The role of roots on soil is reviewed. As roots grow through soil, they may create pores or grow through the existing pore structure, extending the life of the pores or fractures. Actively growing roots may plug the pores through which they are growing, but the pores are re-opened as the roots die back. The pores may remain partially open if roots are smaller than the pores. As roots take up water and dry the soil, the fractures are re-inforced or re-created. When not plugged, these macropores facilitate rapid movement of water and air through soil, and provide pathways for future roots to grow. Bypass flow occurs through continuous macropores transporting solutes through the soil without much mixing of existing soil solution within peds. This can result in rapid leaching of chemicals applied at the surface, but reduced leaching of chemicals contained within the peds. Over time, the chemical composition within peds can re-equilibrate with that in pores and be subject to leaching. Since roots are concentrated in biopores and fractures, they are able to utilize some of the water that drains through these pores. Less energy is expended to take up water from larger pores than smaller pores, so roots intercept more of the drainage water than is intercepted under a bare area. Soil disturbance destroys the developed macropore system though new, unstable pores are created by the disturbance. Traffic can compress these unstable macropores, and destroy the continuity of the pores. |
