Does long-term pasture management influence spatial distribution of soil characteristics in Oklahoma

Authors: Northup, Brian; Daniel, John; Phillips, William

Submitted to: Ecological Society of America Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 5/13/2009
Publication Date: 6/2/2009
Citation: Northup, B.K., Daniel, J.A., Phillips, W.A. 2009. Does long-term pasture management influence spatial distribution of soil characteristics in Oklahoma [abstract]. In: Proceedings of the Ecological Society of America Annual Meeting, August 2-7, 2009, Albuquerque, NM. Abstract No. PS 34-123. Available on-line: http://eco.confex.com/eco/2009/techprogram/p20305.htm

Interpretive Summary: Abstract only.

Technical Abstract: Native prairie and winter wheat pastures are among the primary resources used to graze cattle in central Oklahoma. These forage resources are subject to numerous stressors that affect land condition including grazing, climate, soil fertility, and farming operations. Understanding responses of soil characteristics to management is crucial to sustainable use of these resources. This study compared soil responses of an upland site in central Oklahoma to 26 y (1977-2003) of different forms of sustained management applied to 1.6 ha experimental paddocks situated along a common slope. Included were grazed, conventionally tilled winter wheat and three forms of management applied to paddocks of tallgrass prairie (light stocking rates over long grazing periods, high stocking rates over short grazing periods, and not grazed). Soil cores to 0.25 m depth were collected from paddocks under each form of management at 1.5 m intervals along 150 m transects (n=101 per paddock) situated between the ridge and the slope, and divided into 3 segments (0-0.05 m, 0.05-0.10 m, and 0.10-0.25 m depths). Soil bulk density and organic matter (OM) concentrations were determined, variogram analyses defined distribution patterns, and distribution maps were developed. Patch-scale organization of soil characteristics in wheat and native paddocks differed after 26 y. Soils of the grazed wheat paddock were 13% denser and contained 21% less OM than soils in the native prairie paddocks. Management effects on native prairie were largely confined to the upper 0.05 m of soil, with 9% denser soils under intensive management, and OM similar across management type. Intensive forms of management (wheat, intensive grazing of native pasture) tended to produce more simplified distribution patterns than extensive management, which may alter landscape function.