|Marquez, C - IOWA STATE UNIVERSITY|
|Isenhart, T - IOWA STATE UNIVERSITY|
|Schultz, R - IOWA STATE UNIVERSITY|
Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 4, 1999
Publication Date: N/A
Technical Abstract: Vegetation type can impact soil structural stability through effects on patterns of root distribution and exudation. This study quantified soil aggregation patterns for soil planted to three vegetation types. We collected surface soil samples every month in 1997 and 1998. The temporal pattern of macroaggregation under cool season grass was bimodal, reaching a maximum in July (50% of soil mass) and September (43%). Macroaggregation under switch grass peaked in July (45%) and stabilized at 20% by September. Hardwood forest soil macroaggregation peaked in July (50%), decreased to 30% by August, and remained constant. Maximum stability appears to coincide with periods of high photosynthate production. Future work will examine the relationship between temporal patterns in macroaggregation and biologically-active soil organic C.