|
|
||||||||
Dep. of Crop and Soil Sciences, Michigan State Univ., East Lansing, MI 48824
* Corresponding author (parkeun2{at}msu.edu)
The stability of soil aggregate structures is very important for controlling aggregate dynamics and associated biogeochemical soil processes that respond to management and other physical disturbances. We examined the mechanical strengths of concentric soil layers from the surfaces to the centers of individual soil macroaggregates and compared them with polar tensile strengths (Ts), total soil C contents, soil texture, and bulk density of aggregates. Aggregates were sampled at depths of 0 to 5 cm from conventionally tilled (CT), no tilled (NT), and native forest (NF) ecosystems of a Wooster (fine-loamy, mesic Typic Fragiudalf) and a Hoytville (fine, illitic, mesic Mollic Epiaqualf) soils. Erosive strength (Es) of aggregates was defined as the surrogate for erosive forces required to remove 1 g of soil during 1 min from the surface of a soil aggregate rotating along the abrasive wall of a soil aggregate erosion (SAE) chamber. Total Es values of macroaggregates were consistent with Ts of whole aggregates and were controlled by aggregate size and treatment. The Es increased with decreasing aggregate size and from the exterior to the interior regions of aggregates. Measured changes in soil C content, texture, and bulk density across the different regions within aggregates did not completely explain the spatial distributions of Es among concentric layers within macroaggregates. Higher contents of C and clay contributed to the greater strengths of the Hoytville soil aggregates, regardless of bulk density. On the other hand, Es of soil aggregates from coarser-textured Wooster soils were correlated primarily with bulk density and appeared to be independent of C content.
Abbreviations: CT, conventional tillage Es, erosive strength NF, native forest NT, no tillage SAE, soil aggregate erosion Ts, polar tensile strength
This article has been cited by other articles:
![]() |
A. J.M. Smucker, E.-J. Park, J. Dorner, and R. Horn Soil Micropore Development and Contributions to Soluble Carbon Transport within Macroaggregates Vadose Zone J., May 17, 2007; 6(2): 282 - 290. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Kinyangi, D. Solomon, B. Liang, M. Lerotic, S. Wirick, and J. Lehmann Nanoscale Biogeocomplexity of the Organomineral Assemblage in Soil: Application of STXM Microscopy and C 1s-NEXAFS Spectroscopy Soil Sci. Soc. Am. J., August 22, 2006; 70(5): 1708 - 1718. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| The SCI Journals | Agronomy Journal | Crop Science | |||
| Journal of Natural Resources and Life Sciences Education |
Vadose Zone Journal | ||||
| Journal of Plant Registrations | Journal of Environmental Quality |
The Plant Genome | |||