HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Gerard, C. J. Articles by Shaw, G. Search for Related Content PubMed Articles by Gerard, C. J. Articles by Shaw, G. Agricola Articles by Gerard, C. J. Articles by Shaw, G.

Physical Factors Influencing Soil Strength and Root Growth¹

Soil compaction is a major factor which influences root growth and crop yields. Studies were conducted to determine the influence of different factors on mechanical impedance and to determine the influence of mechanical impedance and other soil factors on root growth. Regression models for dependent variables, soil strength and root growth, vs. the independent variables, soil type, soil depth, clay content, bulk density, voids, and water content were computed using the maximum R² improvement by stepwise regression. The models for soil strength and root growth varied with soil type, soil depth, and/or clay content. The soils used were a Miles fine sandy loam, Udic Paleustalf and an Abilene clay loam, Pachic Argiustoll. Soil strength for both soils studied and at all depths was influenced by bulk density, voids, and clay content. The overall equational models accounted for 75% of the variability in soil strength and 76% of the variability in root growth. Root growth in both soils and at all depths was significantly influenced by soil strength, volumetric water content, voids, and clay content. The critical strength in bars, defined as the probe pressure at which root elongation stopped, was a function of % clay. The critical strength ranged from 60 to 70 bars in coarsetextured to 25 bars in clay soils. These data provide a better understanding of the influence of mechanical impedance on root growth, and a basis for determining the need for use of deep tillage to minimize the adverse effects of excessive soil strength or compaction.

Key Words: Critical soil strength • Mechanical impedance • Soil voids

² Professor and research technicians, Texas Agric. Exp. Stn., Texas A=M Univ. Agric. Res. and Ext. Ctr., Vernon, TX.

Received for publication October 9, 1981.

This article has been cited by other articles:

				R. Qin, P. Stamp, and W. Richner Impact of Tillage and Banded Starter Fertilizer on Maize Root Growth in the Top 25 Centimeters of the Soil Agron. J., April 27, 2005; 97(3): 674 - 683. [Abstract] [Full Text] [PDF]

				R. Qin, P. Stamp, and W. Richner Impact of Tillage on Root Systems of Winter Wheat Agron. J., November 1, 2004; 96(6): 1523 - 1530. [Abstract] [Full Text] [PDF]