Soil Science Commons^™

Overwinter Changes In Dry Aggregate Size Distribution Influencing Wind Erodibility In A Spring Wheat-Summerfallow Cropping System, Stephen D. Merrill, Alfred L. Black, Ted M. Zobeck

Journal of the Minnesota Academy of Science

A long-term study of the wind erodibility properties of a two-year spring wheat-summerfallow cropping systems was started in 1988 in south-central North Dakota as part of an USDA-ARS led effort to construct a process-oriented soil erosion predictive model. Observations were conducted on a conservation tillage experiment established in 1984 on soil classified in the U.S. as Typic-Pachic Haploborolls and in Canada as Brown to Dark Brown Chenozemic. The experiment included four residue-management treatments defined by targeted residue coverages: no-till, > 60% cover; minimal-till, 30% to 60% cover and undercutter dominated; conventional-till, < 30% cover and disk dominated; low-residue, < 5 % cover. Fall and spring measurements of dry aggregate size distribution (ASD) of surface soil (0 to 4 cm depth), and overwinter changes in ASD are reported here. A rotary sieve produced six size fractions ranging from < 0.42 mm to > 19.2 mm diameter. Measurements of ASD are expressed as geometric …