Wednesday, 9 November 2005
2

Electromagnetic Induction Soil Conductivity Measurements to Locate Nutrient Buildup on Feedlot Surfaces.

Roger Eigenberg, Bryan Woodbury, and John Nienaber. USDA-ARS, PO Box 166, State Spur 18d, Clay Center, NE 68933

Nutrient management of cattle feedlots is a topic of increasing environmental, sociological, and regulatory concern. Buildup of nutrients on feedlot surfaces with associated gaseous emissions, as well as runoff and leaching potential, pose challenges for both producers and regulators. This paper considers spatial and temporal aspects of feedlot surface nutrient distributions with methodologies to improve feedlot surface management. An electromagnetic induction soil conductivity meter was used to survey four feedlot pens at the U.S. Meat Animal Research Center. Soil conductivity was mapped and conductivity zones were identified. Analyses of soil cores from transects across each zone were determined. Initial results indicate correlations between ECa and associated volatile solids (r2 = 0.77 for volatile solids). Volatile solids are closely associated with nutrients (r2 = 0.92 for total N and r2 = 0.80 for total P). Methods were developed to establish repeatable management thresholds throughout seasonal changes and pen conditions. Geo-statistical methods are being evaluated to estimate the extent and amount of specific nutrients across the feedlot surface. Identifying areas of intense nutrient buildup holds the promise of site-specific management options, and a subsequent reduction of nutrient loss.

Handout (.pdf format, 418.0 kb)

Back to Nutrients and Water Quality
Back to A05 Environmental Quality

Back to The ASA-CSSA-SSSA International Annual Meetings (November 6-10, 2005)