Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/20/2001
Publication Date: N/A
Technical Abstract: Intensive tillage has been practiced since crop production replaced native grasslands in the Pacific Northwest. The recent development of cropping systems that do not involve tillage presents a novel situation wherein wheat and other annually planted, introduced crop plants are being grown under soil conditions more similar to native prairie than ever before. I have found greater ponded infiltration rates and greater earthworm populations under no-till crop production. Surprisingly, the number of small (less than 1 mm) biologically generated soil pores was not different between recently tilled plots and plots not tilled for the past 17 years. This was true in both the surface soil and below the plow layer. Biopores of 0.05 to 0.5 mm diameter probably made up over half of total biopore volume. Soil carbon has increased slightly in cropping systems without tillage, and soil carbon is concentrated near the soil surface instead of being distributed throughout the plow layer. Plans for further investigations on soil physical and biological differences between tilled and untilled cropping systems include soil temperature and seedling growth, infiltration of rain and snowmelt into frozen soil, root growth and disease, weed competition, and pH decline.