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A direct method of aggregate analysis of soils and a study of the physical nature of erosion losses

Yoder, R.E.
Agronomy journal 1936 v.28 no.5 pp. 337-351
Vicia, Gossypium hirsutum, soil analysis, soil erosion, losses from soil, clay soils, loam soils, particle size, pretreatment, particle size distribution, soil mechanics, fallow, rain, runoff, continuous cropping, seasons, strip cropping, erosion control, soil aggregates, laboratory techniques, width
1. The inherent weaknesses of the elutriation method of aggregate analysis are pointed out and the use of this method of aggregate analysis is questioned. 2. A mechanism is suggested to account for the slaking reaction of soils in the presence of excess water. 3. A direct method, with suitable apparatus for determining the water stable aggregate distribution in soils, is reported. 4. Several soils of the Cecil series with widely varying clay contents were found to have similar distribution of water stable aggregates. 5. Soils from different senses were found to be characterized by different distributions of water stable aggregates. 6. The physical nature of the erosion process was studied on carefully controlled field plats of Cecil clay located on several slopes. The losses from this strongly aggregated soil occurred primarily in the form of water stable aggregates. 7. Data are presented which show the effectiveness of winter legumes in controlling sheet erosion losses. The manner in which this type of "vegetative control" functions is reviewed. 8. Results on the use of various widths of strip crop for controlling sheet erosion are presented. The basic weakness of this type of "vegetative control" practice is pointed out.