Long-term vs. short-term conservation tillage
Lafond, G. P., H. Walley, J. Schoenau, W. E. May, C. B. Holzafel, J. McKell and J. Halford. 2008. 20th annual meeting and conference of the Saskatchewan soil conservation association
Abstract
Every year, 2-12 million hectares or 0.3-0.8% of the world's arable land is rendered unsuitable
for agricultural production through soil degradation. Wind and water erosion accounts for 84%
of this degradation (den Biggelaar et al., 2004a). Lal (2207) reported that 1966 Mha of land
worldwide is affected by soil degradation. Thus good management to protect the soil against
degradation is necessary to meet the world's future needs for food and fibre (den Biggelaar at al.,
2004b) and possibly renewable energy needs as well. Pimentel and Pimentel (2000) stated that
99% of food consumed by humans comes from the land. It is therefore imperative that we do
everything possible to sustain and enhance our soil resource.
The challenge for Canadian agriculture is to ensure economic viability while both satisfying
society's need for safe and nutritious food and conserving or enhancing the environment for
future generations (Gilson 1989). Sustainable development was defined by Brundtland (1987) as:
"economic growth that meets the needs of the present without compromising the ability of future
generations to meet their own needs". At the 2002 Earth Summit on sustainable development
held in Johannesburg, this definition was broadened and strengthened by linking global poverty,
the environment and the use of natural resources to sustainable development (Anonymous 2002).
We have ample evidence to show that the most effective way of reducing soil degradation from
wind and water erosion is by maintaining a residue cover and preferably with some standing
stubble hence the interest in no-till production systems (Smika and Unger 1986). However, a no-till production system is only one of many important aspects of sustainability. Lal (2007)
emphasizes that: "Sustainable use of soil resources does not depend solely on the use of
fertilizers, irrigation, improved varieties, and even no-till and mulch farming systems. It depends
on the adoption of a holistic approach, in which all recommended components are combined in
synergism. Judicious use of soil and water resources, based on soil-specific recommended
technologies, is the guiding principle."
The objective of the paper is to discuss some of the major effects of no-till on soil properties and
to also examine what we can expect after >25 years of no-till and continuous cropping on
overall crop production and what it means for the Canadian prairies.
