Compaction and Root Modifications of Soil Aeration
- G. H. Asady and
- A. J. M. Smucker
Soil compaction and the incipient aeration and mechanical impedance stresses are known to reduce root growth and function. Little is known, however, regarding the influence of root accumulations adjacent to a compacted area upon the aeration status of the soil profile below the root mass. This study was designed to measure plant root and soil aeration interactions with soil compaction. A clay soil was compacted to bulk densities in 1.1, 1.4 and 1.7 Mg m−3 in soil columns planted to dry edible bean (Phaseolus vulgaris L.). Mechanical resistances of these soil compaction treatments were 0.43, 2.14, and 5.50 MPa, respectively. Oxygen diffusion rates (ODR) were below the critical level for the 1.7 Mg m−3 treatment at all plant growth stages measured. As root accumulations increased at the 0.10- to 0.25-m depths, ODR dropped below critical values for all bulk densities. Lower O2 concentrations above the soil surface decreased ODR both earlier and at shallower depths. Root plugging of 5% or more of the aeration pores significantly reduced the diffusion of O2 into and CO2 out of the soil regions below and adjacent to areas with the greatest accumulation of roots.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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