
Energy use and efficiency in two Canadian organic and conventional
crop production systems
J. W. Hoeppner1, M. H. Entz1,*,
B.G. McConkey2, R. P. Zentner2 and
C.N. Nagy3
Abstract
A goal in sustainable agriculture is to use fossil fuel energy more
efficiently in crop production. This 12-year study investigated effects
of two crop rotations and two crop production systems (organic versus
conventional management) on energy use, energy output and energy-use
efficiency.
The grain-based rotation included wheat (Triticum aestivum L.)-pea
(Pisum sativum L. )-wheat-flax (Linum usitatissimum L.),
while the integrated rotation included wheat-alfalfa (Medicago sativa
L.)-alfalfa-flax.
Energy use was 50% lower with organic than with conventional management,
and approximately 40% lower with integrated than with the grain-based
rotation.
Energy use across all treatments averaged 3420 MJ ha -1yr-1. Energy
output (grain and alfalfa herbage only) across treatments averaged 49,947
MJ ha-1yr-1 and was affected independently by production system and
crop rotation. Energy output in the integrated rotation was three times
that of the grain-based rotation; however, this difference was largely
due to differences in crop type (whole plant alfalfa compared with grain
seed).
Energy output was 30% lower with organic than with conventional management.
Energy efficiency (output energy/input energy) averaged to 17.4 and
was highest in the organic and integrated rotations.
A significant rotation by production system interaction (P<0.05)
indicated that energy efficiency increases due to crop input reduction
(i.e., shift from conventional to organic management) were greater in
the integrated than in the grain-based rotation.
Greater energy efficiency in the integrated rotation under organic
management was attributed to the fact that the forage component was
less sensitive to chemical input removal than grain crops.
Source
Renewable Agriculture and Food Systems: 21(1); 60-67 2006 DOI: 10.1079/RAF2005118.
Accepted 20 April 2006 Research Paper.
1Department of Plant Science, University of Manitoba,
222 Agriculture Building, Winnipeg, MB R3T 2N2, Canada.
2Semi-arid Prairie Agriculture, Law and the Environment,
University of Saskatchewan, Saskatoon, SK S7N 5A8, Canada.
*Corresponding author: m_entz@umanitoba.ca
Posted April 2007