Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: 10/25/2001
Publication Date: 10/25/2001
Citation: Marquez, C.O., Cambardella, C.A., Garcia, V.J., Isenhart, T., Schultz, R. 2001. Seasonal dynamics of soil macroaggregates in different vegetation [abstract]. American Society of Agronomy Meetings. s03-213438-P.pdf.
Technical Abstract: Seasonal variation of macroaggregate formation and disruption as well as macroaggregate stabilization and destabilization were evaluated under cool-season grass and switchgrass plots in a riparian buffer system and for a corn-soybean production system in north central Iowa. We collected surface soil samples every month from April through November in 1998. Aggregate size fractions were separated by wet sieving and the percent of the total soil in the stable and unstable macroaggregate fractions were calculated after correcting macroaggregate mass for sand content. Temporal patterns were different for each of the vegetation types we studied. In all cases, stable macroaggregate mass was maximized during periods of high photosynthate production. Generally, the formation of stable macroaggregates reached a maximum during August and a minimum during June and September. Destabilization of large macroaggregates reached a secondary maximum during July and consistently increases from August to September and from September to October. Destabilization of small macroaggregates reached a maximum during September and consistently decreased during June, July, and August.