Abstract :
Optimal use of management systems including tillage and winter cover crops is
recommended to improve soil quality and sustain agricultural production. The
effects on soil properties of three tillage systems (as main plot) including direct
drilling (D), harrowing to a depth of 8 to 10 cm (H), and moldboard plowing
(MP) with and without a cover crop were evaluated in a long-term experiment
on a sandy loam soil in Denmark. Chemical, physical, and biological
soil properties were measured in the spring of 2012. The field measurements
included mean weight diameter (MWD) after the drop-shatter test, penetration
resistance, and visual evaluation of soil structure (VESS). In the laboratory,
aggregate strength, water-stable aggregates (WSA), and clay dispersibility were
measured. The analyzed chemical and biological properties included soil organic
C (SOC), total N, microbial biomass C, labile P and K, and pH. Reduced
tillage (D and H) resulted in a stratification of the chemical properties within
the 0- to 20-cm topsoil layer but a uniform distribution for MP. There was an
accumulation of SOC, total N, and labile P and K and reduced pH in the 0- to
10-cm layer. Reduced tillage increased soil strength in terms of greater MWD,
VESS, WSA, aggregate tensile strength, and rupture energy. Five years of using
a cover crop alleviated plow pan compaction at the 20- to 40-cm depth by
reducing penetration resistance. A significant interaction between tillage and
cover crop treatments indicated the potential benefit of using a combination of
cover crops and direct drilling to produce a better soil friability. The usefulness
of the VESS method for soil structural evaluation was supported by the high
positive correlation of MWD with VESS scores.
Title of Article :
Tillage System and Cover Crop Effects on Soil Quality:I. Chemical, Mechanical, and Biological Properties
Author/Authors :
Abdollahi, Lotfollah , Munkholm, Lars J.
