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Soil structures produced by tillage as affected by soil water content and the physical quality of soil

Soil structures produced by tillage as affected by soil water content and the physical quality of soil

Authors :
Keller, Thomas
Arvidsson, Johan
Dexter, Anthony R.
Source :
Soil & Tillage Research. Jan2007, Vol. 92 Issue 1/2, p45-52. 8p.
Publication Year :
2007

Abstract

Abstract: Tillage experiments were carried out in order to study the effect of water content on the aggregate size distribution produced by tillage, and to investigate the relationship between the soil structures produced by tillage and Dexter''s index of soil physical quality, S. Tillage with a mouldboard plough was done on four different soils over a range of naturally occurring water contents. The aggregate size distribution and the specific surface area produced by tillage were obtained by sieving. We define the optimum water content for tillage, θ OPT, as the water content at which the specific surface area of the aggregates produced is maximum. This is consistent with the water content at which the amount of small aggregates produced is greatest and the proportion of clods produced is smallest. For the four investigated soils, θ OPT was found to be close to the water content at the inflection point of the water retention curve, and in the vicinity of 0.8θ PL (where θ PL is the lower plastic limit). At water contents either lower or higher than θ OPT, the specific surface area produced was smaller. The specific surface area produced at θ OPT was found to be strongly correlated with the index of soil physical quality, S. The specific surface area produced is larger the greater S, i.e. the better the soil physical quality. Consistently, the proportion of small aggregates produced at θ OPT is larger and the proportion of clods produced at θ OPT smaller, the greater S. No clods (>50mm) are produced on soils with good physical quality. [Copyright &y& Elsevier]

Details

Language :
English
ISSN :
01671987
Volume :
92
Issue :
1/2
Database :
Academic Search Index
Journal :
Soil & Tillage Research
Publication Type :
Academic Journal
Accession number :
22716456
Full Text :
https://doi.org/10.1016/j.still.2006.01.001