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Compaction Characteristics of a Soil Cropped to Corn and Bromegrass
Author(s) -
Angers D. A.,
Kay B. D.,
Groenevelt P. H.
Publication year - 1987
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1987.03615995005100030037x
Subject(s) - compaction , porosity , ultimate tensile strength , soil water , bulk density , agronomy , saturation (graph theory) , soil compaction , bromus inermis , soil structure , environmental science , soil science , materials science , mathematics , composite material , poaceae , biology , combinatorics
This study was initiated in order to determine if the compaction characteristics of soils are modified by cropping history. Uniaxial compression tests were made on cores of aggregated soil. The tensile strength of individual aggregates was also measured. Four different cropping histories ranging from 15 yr of continuous corn ( Zea mays L.), C 15 , to 15 yr of continuous bromegrass ( Bromus inermis Leyss.), B 15 , were investigated. The bulk density of soil cores under standard compaction conditions (100 kPa load and 50% water saturation) did not vary with cropping history. However, interaggregate porosity under standard compaction conditions was 18% larger in B 15 than in C 15 , and the aggregate strength, which was positively correlated with interaggregate porosity, was 50% larger. The compression index was 12% larger in B 15 than C 15 and was positively correlated with interaggregate porosity under standard compaction conditions. This suggests that the loss of porosity on compaction was strongly influenced by collapse of interaggregate pores. Soils with a recent history of bromegrass had a greater proportion of interaggregate pores and this benefit persisted across a range of pressures that would normally be encountered in the field (<500 kPa). Changes in the compression index, tensile strength and interaggregate porosity appeared to occur rapidly when cropping practices changed.