
Organic and Conventional Production Systems in the Wisconsin Integrated
Cropping Systems Trials 1990–2002
Joshua L. Posner, Jon O. Baldock, and Janet L. Hedtcke
Abstract
During the last half-century, agriculture in the upper U.S. Midwest
has changed from limited-input, integrated grain–livestock systems
to primarily high-input specialized livestock or grain systems. This
trend has spawned a debate regarding which cropping systems are more
sustainable and led to the question: can diverse, low-input cropping
systems (organic systems) be as productive as conventional systems?
To answer this question, we compared six cropping systems ranging
from diverse, organic systems to less diverse conventional systems conducted
at two sites in southern Wisconsin.
The results of 13 yr at one location and 8 yr at the other showed
that:
The average yields for corn and soybean, however, masked a dichotomy
in productivity. Combining Wisconsin Integrated Cropping Systems Trial
(WICST) data with other published reports revealed that in 34% of the
site-years, weed control was such a problem, mostly due to wet spring
weather reducing the eff ectiveness of mechanical weed control techniques,
that the relative yields of low-input corn and soybean were only 74%
of conventional systems.
However, in the other 66% of the cases, where mechanical weed control
was eff ective, the relative yield of the low-input crops was 99% of
conventional systems.
Our findings indicate that diverse, low-input cropping systems can
be as productive per unit of land as conventional systems.
Source
Agronomy Journal, Volume 100, Issue 2, 2008 p. 253
Posted March 2008
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