|Zhang, Mingchu - UNIVERSITY OF ALASKA|
|Sparrow, Stephen - UNIVERSITY OF ALASKA|
Submitted to: American Society of Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: January 1, 2005
Publication Date: April 1, 2005
Citation: Sharratt, B., Zhang, M., Sparrow, S. 2005. Wind erodible and soil hydraulic properties affected by 20 years of tillage in subarctic Alaska. Annual Meeting Abstracts [CD-ROM] ASA-CSSA-SSSA, Madison, WI Technical Abstract: Wind erosion and lack of precipitation can impact crop production in arid and semi-arid regions of the world. A long term tillage and residue management was initiated 20 years ago in interior Alaska to identify practices that will minimize erosion and conserve soil moisture in a continuous barley cropping system. Conventional tillage (autumn and spring disk), spring disk, autumn chisel plow, and no tillage treatments, with straw either retained on or removed from the soil surface after harvest, were established on a silt loam in 1983 near Delta Junction (63ºN, 145ºW). Penetration resistance, soil water content, bulk density, random roughness, aggregate size distribution, saturated hydraulic conductivity, and infiltration were measured after sowing in spring 2004. No tillage resulted in larger aggregates, greater soil strength, wetter soil, and higher hydraulic conductivity compared to other tillage treatments. However, a thick organic layer has formed on the mineral soil surface of no tillage and appears to suppress infiltration. Infiltration was enhanced by retaining straw on the soil surface. Lack of weed control strategies and formation of an organic layer on the soil surface makes no tillage an unsustainable practice. Thickening of this organic layer may suppress soil warming and recharge of the soil profile in the future. Autumn chisel and spring disk appear to be viable options to conventional and no tillage in promoting roughness and soil aggregation for controlling erosion.