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

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (17) Citing Articles via Google Scholar Google Scholar Articles by Munkholm, L. J. Articles by Kay, B. D. Search for Related Content PubMed Articles by Munkholm, L. J. Articles by Kay, B. D. GeoRef GeoRef Citation Agricola Articles by Munkholm, L. J. Articles by Kay, B. D. Related Collections Structure and Properties Water Content Soil Physics

DIVISION S-1—SOIL PHYSICS

Effect of Water Regime on Aggregate-tensile Strength, Rupture Energy, and Friability

^a Dep. of Crop Physiology and Soil Science, Danish Institute of Agricultural Sciences, Research Centre Foulum, P.O. Box 50, DK-8830 Tjele, Denmark
^b Dep. of Land Resource Science, Univ. of Guelph, Guelph, ON, Canada N1G 2W1

* Corresponding author (Lars.Munkholm{at}agrsci.dk)

The effect of water regime on aggregate-tensile strength, rupture energy, and friability index was studied in two experiments on sandy loam soils (Glossic Phaeozem/WRB 1998). In Exp. 1, soil from a long-term, 5-yr crop rotation receiving animal manure (dairy farm and grass, DFG) was compared with a soil (continuous cereal crop, CCC), which had grown almost continuous cereals and not received animal manure. In Exp. 2, soil from compacted plots (PAC) and uncompacted reference plots (REF) was sampled. The soil was air-dried and separated into four aggregate-size classes (i.e., 1–2, 2–4, 4–8, and 8–16 mm). Aggregate-tensile strength and rupture energy were measured on air-dry aggregates and on aggregates adjusted to -10, -30, -100, -350 kPa, and -166 MPa pressure potential. Soil friability index was estimated from the tensile strength or specific rupture energy results. Aggregate density was determined on 2- to 4-, 4- to 8-, and 8- to 16-mm aggregates. The CCC soil displayed a greater increase in strength and specific rupture energy with increased dryness than the DFG counterpart. This may be related to differences in organic matter content and dispersible clay. Generally, the relationship between tensile strength or specific-rupture energy and pressure potential could be described by a power function. However, the rupture energy results could not be fitted by a power function for the Exp. 2 soils. The Exp. 2 soils differed in the stress–strain relationship, i.e., the compacted soil displayed the highest Young modulus, (Y/) in all cases. Maximum values of the friability index were found between -10 and -100 kPa.

Abbreviations: CCC, continuous cereal crop • DFG, dairy farm with grass • PAC, compacted plots • REF, uncompacted reference plots

This article has been cited by other articles:

				Q. Ding, G. Pan, W. Ding, and C. Ji A Laboratory Rig and a Scale- and Energy-Controlled Procedure for Tender Soil Fragmentation Test Soil Sci. Soc. Am. J., June 29, 2009; 73(4): 1286 - 1290. [Abstract] [Full Text] [PDF]

				H. Blanco-Canqui, M. M. Mikha, J. G. Benjamin, L. R. Stone, A. J. Schlegel, D. J. Lyon, M. F. Vigil, and P. W. Stahlman Regional Study of No-Till Impacts on Near-Surface Aggregate Properties that Influence Soil Erodibility Soil Sci. Soc. Am. J., June 29, 2009; 73(4): 1361 - 1368. [Abstract] [Full Text] [PDF]

				L. J. Munkholm, E. Perfect, and J. Grove Incorporation of Water Content in the Weibull Model for Soil Aggregate Strength Soil Sci. Soc. Am. J., April 5, 2007; 71(3): 682 - 691. [Abstract] [Full Text] [PDF]

				H. Blanco-Canqui, R. Lal, and M. J. Shipitalo Aggregate Disintegration and Wettability for Long-Term Management Systems in the Northern Appalachians Soil Sci. Soc. Am. J., April 5, 2007; 71(3): 759 - 765. [Abstract] [Full Text] [PDF]

				E.-J. Park and A. J. M. Smucker Erosive Strengths of Concentric Regions within Soil Macroaggregates Soil Sci. Soc. Am. J., October 27, 2005; 69(6): 1912 - 1921. [Abstract] [Full Text] [PDF]

				L. Munkholm and E. Perfect Brittle Fracture of Soil Aggregates: Weibull Models and Methods of Parameter Estimation Soil Sci. Soc. Am. J., August 25, 2005; 69(5): 1565 - 1571. [Abstract] [Full Text] [PDF]

				H. Blanco-Canqui, R. Lal, L. B. Owens, W. M. Post, and R. C. Izaurralde Mechanical Properties and Organic Carbon of Soil Aggregates in the Northern Appalachians Soil Sci. Soc. Am. J., August 4, 2005; 69(5): 1472 - 1481. [Abstract] [Full Text] [PDF]