Soil conservation is crucial to the sustainability of agriculture.Organic producers, in particular, take this responsibility seriously. According to the International Federation of Organic Agriculture Movements, “soil and soil management is the foundation of organic production.
“Organic growing systems are soil based, care for the soil and surrounding ecosystems and provide support for a diversity of species while encouraging nutrient cycling and mitigating soil and nutrient losses.”
Soil is a complex and living system. Caring for the soil, then, is caring for the life of the soil. Reducing erosion is a fundamental first step.
Reducing wind and water speed can reduce erosion potential. Using narrow fields, shelterbelts, perennial grass barriers and even annual crop barriers can be helpful in reducing wind and water movement.
Reducing tillage is commonly advocated for reducing erosion potential.
But cutting tillage can be challenging for organic producers. For conventional producers, a reduction in tillage often goes hand in hand with herbicide use in spring or fall. In grasshopper-prone times, tillage reduction can increase insecticide use as well.
Nevertheless, many organic producers are experimenting with reductions in tillage frequency or intensity. More research would be helpful.
Reducing soil losses in organic systems hinges, as so much in organic agriculture does, on sound crop rotations.
Maintaining vegetative cover and increasing soil organic matter are key elements.
Soils that are covered with plant material, living or dead, are less susceptible to erosion. The benefits of soil organic matter are numerous. It is the source of most of the nitrogen, phosphorous and sulfur that is available for plants to take up. It is a food source for the life of the soil, with all its beneficial activities and it helps soil hold water, allows air flow and binds soil together in larger aggregates.
This last benefit is perhaps the most important for reducing erosion.
Rotations that reduce erosion are therefore likely to be those that most increase organic matter and lessen the time that the ground is left uncovered. It is recommended that summerfallow be replaced with cover crops, especially those that produce abundant biomass, or legumes that have a good balance of nitrogen and carbon in their residues. On highly erodible land, seeding long-term forages or permanent cover may be beneficial.
Alison Nelson is a graduate student at the University of Manitoba, working under the direction of professor Jane Froese.
Her research examines crop rotations in Canada and asks how these rotations influence soil conservation. The first part of her project characterizes organic rotations and practices that producers use to reduce soil loss. She has developed a survey she estimates will take about 45 minutes per producer. She hopes to find 200 participants.
The second part of her project involves visiting farms and measuring the soil’s resistance to erosion. She will visit farms that she identifies by the survey as representative of the rotational practices she discovers.
The two parts of her project, taken together, will help her identify effective soil conservation practices for organic producers that allow them to be more effective stewards of the soil.
To obtain a copy of the survey, contact me or contact Alison Nelson directly at 204-474-6073 or firstname.lastname@example.org.
Frick is the Prairie co-ordinator for the Organic Agriculture Centre of Canada located at the University of Saskatchewan. She can be reached at 306-966-4975, at email@example.com, or www.organicagcentre.ca.The opinions expressed in this column are not necessarily those of the Western Producer.