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United States Department of Agriculture

Agricultural Research Service

Title: A Conceptual Model to Study Soil Aggregates Dynamics

Authors
item Garcia, V - IOWA STATE UNIVESITY
item Marquez, C - IOWA STATE UNIVERSITY
item Cambardella, Cynthia
item Schultz, R - IOWA STATE UNIVERSITY
item Isenhart, T - IOWA STATE UNIVERSITY

Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: October 25, 2001
Publication Date: October 25, 2001
Citation: Garcia, V.J., Marquez, C.O., Cambardella, C.A., Schultz, R.C., Isenhart, T.M. 2001. A conceptual model to study soil aggregates dynamics [abstracts]. American Society of Agronomy Meetings. s03garcia211819-0.pdf.

Technical Abstract: We present a conceptual model of soil aggregate dynamics that integrates the aggregation, disruption, stabilization and destabilization processes of soil aggregates in a framework that permits studying soil aggregate dynamics over time or comparing ecosystems such as aggrading, degrading or steady-state systems. A number of convenient indicators are developed to assess aggregation, disruption, stabilization and destabilization of soil aggregates. The predominant process driving the system from the reference state to the new state is identified and quantified through the aggregation-disruption index. Similarly a finite number of dynamic loops for soil aggregates are identified. Such loops may be useful in evaluating ecosystem response to disturbances such as land-management practices. To validate our model, samples were collected from a Coland soil (Fine-loamy, mixed superactive, mesic Cumulic Endoaqualls) in replicated cool-season grass filter sites between July and August, 1997. Our results point out that aggregation drives soil aggregate dynamics from July to August, which represent 3% more in August compared with July. The soil aggregates model can be used to determine present soil conditions, assess the degree of deterioration, and predict threshold conditions before soil perturbations push an ecosystem away from its steady state condition.

Last Modified: 7/23/2014