Submitted to: Soil & Tillage Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 10, 1996
Publication Date: N/A
Interpretive Summary: Conservation tillage systems in the subarctic region of the U.S. have been implemented by growers in the region since the early 1980's. Yet little is known about how these tillage systems affect soil erodibility and physical properties important for plant growth. No-tillage results in soils least susceptible to erosion compared to conventional and conservation tillage practices. In addition, tillage systems that maintain straw on the soil surface promote soil stability (minimize erodibility) as well as conserve soil water. Spring disking is a sustainable conservation tillage system for the subarctic, since this system is least susceptible to erosion and also promotes a seed zone environment conducive to early plant growth.
Technical Abstract: Little is known concerning changes in physical properties of subarctic soils subject to tillage practices. This study ascertained whether the physical properties of a newly-cleared subarctic soil are altered after seven years of continuous barley using different tillage and straw management strategies. Tillage and straw treatments were established in 1983 near Delta Junction, Alaska, and consisted of conventional tillage with fall and spring disk (CT), fall chisel plow (CP), spring disk (SD), and no-tillage (NT). Tillage plots were split to accommodate straw management practices which constituted straw and stubble, stubble only, and no straw or stubble. Soil samples were collected from the upper 0.15 m of the profile in the spring of 1990 to assess water content, bulk density, saturated hydraulic conductivity, dry aggregate and mechanical stability, penetration resistance, water retention, and particle size distribution. Percent nonerodible aggregates, mechanical stability, and penetration resistance were greater for NT compared to CT, CP, and SD. Soils subject to NT were also typically wetter, denser, and had a greater hydraulic conductivity. Spring disk was least susceptible to erosion and also conserved soil water compared with CP. Straw maintained on the surface conserved water and promoted soil stability.