Monday, November 13, 2006

Yield Loss Caused by Soil Compaction on a Loam Soil in Eastern Colorado.

Joseph Benjamin, Central Great Plains Research Station, 40335 Co. Rd. GG, Akron, CO 80720

The use of no-till cropping systems in the Central Great Plains has led to water savings that allow increased cropping intensity and more diversity of crop species. However, because no tillage is done to loosen the soil, concerns arise that the long-term effects of no tillage could result in increased soil compaction and possible degradation of the soil physical environment for crop production. The objective of this study was to determine the potential yield loss caused by degredation of soil physical quality due to compaction. Soil conditions and winter wheat (Triticum aestivum L.) yields were observed on the Alterative Crops Rotation study at Akron Colorado in 1996 and 1997. Quantification of changes in soil physical properties were determined by observing changes in the soil Least Limiting Water Range (LLWR), which incorporates limitations of water holding capacity, soil strength and soil aeration, on crop production. Grain yield decreased approximately 900 Mg ha-1 per 0.1 unit decrease in LLWR, showing that soil compaction can cause serious yield reductions if not managed properly. Methods such as controlled wheel traffic or the use of low-pressure tires should be used to reduce soil compaction and maintain soil productivity. Soil compression curves were developed to help predict the amount of soil compaction, and subsequent yield loss, to be expected with wheel traffic at various tire pressures and soil moisture conditions.