Premium
Technique for Determining Root Elongation Rates through Soil Layers of Different Physical and Chemical Properties 1
Author(s) -
Batchelder A. R.,
Bouldin D. R.
Publication year - 1972
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1972.00021962006400010016x
Subject(s) - elongation , subsoil , loam , topsoil , penetration (warfare) , silt , materials science , soil science , soil horizon , chemistry , soil water , composite material , environmental science , mathematics , geology , paleontology , operations research , ultimate tensile strength
Abstract A technique is described for accurately and automatically measuring the rate of root elongation through soil layers having different physical or chemical properties, or both, without disturbing the root system. By utilizing the electrical conductance properties of a root, the time at which the tip of an elongating root penetrates a paraffin‐petrolatum membrane separating two successive soil layers is determined by the resultant changes in electrical resistance between the two soil layers. The technique was tested in two laboratory experiments with corn ( Zea mays L.). In one study the system was used to determine primary root elongation rates through columns of Honeoye silt loam consisting of five layers packed to a bulk density of 1.25 g/cm 3 and one layer at 1.40 g/cm 3 with a membrane separating each pair of soil layers. In the other study primary roots were allowed to grow in natural subsoil clods for specific times following penetration of the membrane that separated the clod and a layer of topsoil. Root penetration through the membrane was easily detected and was recorded with an automatic monitoring system. The technique proved to be an efficient, reliable, and sensitive method for determining root elongation rates through soil layers.