New Zealand Journal of Agricultural Research abstracts
Effect of simulated dairy cow treading on soil physical properties and ryegrass
pasture yield
J. J. DREWRY*
AgResearch
C/- Soil, Plant and Ecological Sciences Division
P.O. Box 84
Lincoln University
Canterbury, New Zealand
K. C. CAMERON
G. D. BUCHAN
Soil, Plant and Ecological Sciences Division
P.O. Box 84
Lincoln University
Canterbury, New Zealand
*Present address: AgResearch, Invermay Agricultural Centre, Private Bag 50034,
Mosgiel, New Zealand.
Abstract The effects of simulated dairy cow treading on soil
physical properties and perennial ryegrass pasture yield were studied in the
field, on a Wakanui silt loam in Canterbury, New Zealand. The study minimised
pugging damage common with grazing, to investigate effects of treading and soil
compaction on yield and soil physical properties. Pasture yield was decreased
by up to 14% for individual harvests, while the total yield for all harvests
was decreased by 9%, for the heavily treaded treatments. Treading reduced
macroporosity (the volumetric percentage of pores >30 μm diameter) at 0-5
cm, in summer, from 20.5% (v/v) in the control to 10.7% in the heavily treaded
treatments. In winter, macroporosity at 10-15 cm was reduced from 8.5% in the
control to 6.1% in the heavily treaded treatments. Similar trends for bulk
density, penetration resistance, and air permeability are presented. Treading
also increased root length by 36% compared with the control. A quadratic
relationship between macroporosity and pasture yield indicated that at 5% and
10% macroporosity, yield was 75% and 88% of maximum, respectively. Optimum
macroporosity was 16-17%, while a critical macroporosity was 9-11%. Penetration
resistance associated with 9% macroporosity was 1.4 MPa, while its optimum was
0.89 MPa.
Keywords compaction; pugging; treading; indicator; air-filled
porosity; oxygen diffusion rate
New Zealand Journal of Agricultural Research, 2001, Vol. 44: 181-190
0028-8233/01/4402&3-0181 $7.00/0 (c) The Royal Society of New Zealand
2001
PDF file of entire paper: medium quality (792K); (scanned from paper original: notes about this process)
This year's abstracts |
Journal home page |
All abstracts |
Publishing home page
