While Organic agriculture is often defined by what organic farmers don’t do –  it’s just as meaningful, however, to focus on what organic farmers do – they aim to grow crops and raise livestock in ways that are “sustainable and harmonious with the environment.”^[1]

Providing habitat for soil life by adding organic matter and rotating crops. Organic farmers can protect soil life by avoiding excessive tillage and compaction, and the use of fertilizers and pesticides that harm soil organisms.^[2]

Feeding the soil by adding organic matter and growing legumes, such as alfalfa and clover, which fix nitrogen from the air and make it available to growing crops. Compost, crop residues and rock powders are transformed by soil microorganisms into plant-available nutrients.

Rotating crops, rather than growing the same crop on a field year after year. Organic farmers design crop rotations to prevent the build-up of pests, disrupt weed life cycles, keep the soil covered, and use nutrients efficiently.

Protecting biodiversity by leaving wild areas, rotating crops and avoiding persistent pesticides. Compared to farms that don’t integrate organic practices, on average, organic farms have greater biodiversity of birds, insects and pollinators.^[3]

Footnotes:

^[1] Organic production systems — General principles and management standards. CAN/CGSB-32.310-2015. Introduction. I. Description

^[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4284392/

^[3] Tuck, Sean L,  Camilla Winqvist, Flávia Mota, Johan Ahnström, Lindsay A. Turnbull, & Janne Bengtsson. 2014. Land-use intensity and the effects of organic farming on biodiversity: a hierarchical meta-analysis. Journal of Applied Ecology. 51(3): 746-755.

A healthy farm ecosystem consists of many different types of lifeforms. Many insects, fungi and bacteria are called “beneficial organisms” because they help crops by pollinating plants, providing nutrients or attacking harmful insects. Plants that compete with crops are considered weeds. Some insects and diseases are considered pests because can harm crops. The key to managing pests and weeds on organic farms is to reduce their impact.

So what do organic farmers use instead of the agricultural herbicides, fertilizers and insecticides commonly used? The answer is complicated. Organic farmers don’t simply rely on organic alternatives to these chemicals –they work with nature to provide nutrients and control pests. When choosing planting dates, seeding rates and crop varieties, organic farmers consider what will work best to avoid pest and weed problems.

Common practices on organic farms to prevent and control pests, weeds and disease:

• Rotating crops disrupts the life cycles of pests. Pests and weeds thrive when the same crop is planted year after year. Crop rotation changes that. For example, potato beetles suffer when they emerge from winter hibernation and find themselves in a wheat field.
• Maintaining high levels of biodiversity creates habitat for birds and invertebrates that attack pests.^[1],[2]  Biodiversity (variety of lifeforms) can be enhanced by (i) growing many types of crops on a farm or even within a field, (ii) leaving wild hedgerows or meadows on the farm, and (iii) not spraying pesticides.
• Intercropping, the planting of two or more crops together, makes it difficult for harmful insects to find plants. For example, alternating rows of onions and carrots reduces damage by carrot rust flies, which find carrots by their smell.^[3]
• Strategic planting considers pest life cycles when deciding when to plant and harvest.^[4] Often organic farmers plant late to avoid the first flush of weeds and first generation of pests. They use high seeding rates because dense plantings leave less room for weeds to grow.
• Planting cover crops, unharvested crops grown solely for their benefit to the farm. They compete with weeds and provide habitat for beneficial organisms that attack pests.
• Choosing varieties bred or proven to perform well under organic conditions; these may be more resistant to pests and better able to compete with weeds.
• Tilling to uproots weeds; organic farmers use tillage when necessary but focus on preventing weed problems.
• Flame weeding uses a flame from a propane torch (tractor-mounted or backpack) to kill small weeds.^[5]
• Handweeding and hoeing are used on many market gardens.
• Mulching covers bare soil (e.g., with straw or a cover crop).
• Natural allies. Plants, insects and other organisms help organic farmers control pests. For example, a cover crop of ryegrass can smother weeds and tachinid flies can parasitize cabbageworms. Beneficial organisms are creatures that perform a beneficial role in pollinating plants or attacking harmful insects. To recruit the support of beneficial organisms, farmers can provide suitable habitat by sowing plants preferred by beneficial organisms, welcoming wildflowers, or increasing biodiversity in general.

When manual control and prevention isn’t enough:

Farmers consult the lists of substances permitted by the Canadian Organic Standards. To assess which substances are allowed, rigorous reviews are conducted that evaluate consequences as far-reaching as the environmental impact of a substance’s manufacture and disposal.^[6]

Organic farmers must develop a plan to prevent pests. This may include crop rotation, cover cropping or companion planting. If a pest problem arises despite preventative measures, farmers can use substances that have passed stringent reviews of the “social and ecological impact of the production and application of the substance.”^[7]

Examples of allowable products:

• Bacillus thuringiensis (BT): soil bacteria that kills certain soft-bodied pests.
• Bentonite, kaolin: clay applied to leaves to discourage insect pests.
• Diatomaceous earth (DE): fossilized diatoms (hard-shelled algae), which scrape the bodies of certain insects causing dehydration.
• Dormant oils: work by covering up the breathing tubes or damaging cell walls of certain insects.
• Floating row covers (lightweight fabric): inhibit pests from landing on plants.
• Pheromone traps: Attract and trap pests or prevent mating by using pheromones (chemicals released by insects).
• Pyrethrum: botanical pesticide derived from chrysanthemums.
• Soap: damages cell walls or suffocates certain pests.
• Spinosad: an extract from soil bacteria that kills certain pests.

Footnotes:

^[1] Marshall, Edward & K Brown, V & Boatman, Nigel & J W Lutman, P & R Squire, G & K Ward, L. 2003. The role of weeds in supporting biological diversity within crop fields. Weed Research. 43. 77 – 89.

^[2] Reddy P.P. 2017. Weed Manipulation. In: Agro-ecological Approaches to Pest Management for Sustainable Agriculture. Springer, Singapore

^[3] Uvah, I. I. I. and TH Coaker. 1984. Effect of mixed cropping on some insect pests of carrots and onions. Entomologia Experimentalis et Applicata. Vol 36. Issue 2. pp 159- 167

^[4] link.springer.com/article/10.1007%2Fs13593-011-0009-1

^[5] www.dal.ca/faculty/agriculture/oacc/en-home/resources/pest-management/weed-management/flame-and-steam-weeding.html

^[6] Organic production systems — General principles and management standards. CAN/CGSB-32.310-2015. 10.3: Table 8 — Substance review criteria for permitted substances in crop production

^[7]Organic production systems — General principles and management standards. CAN/CGSB-32.310-2015.  10.2.2 Substance reviews

Organic farmers provide livestock with fresh air, sunlight and access to the outside whenever weather conditions permit. “Livestock are provided with living conditions and space allowances appropriate to their behavioural requirements and organically produced feed. These practices strive to minimize stress, promote good health and prevent disease.”^[1]

Canadian Organic Standards have strict animal welfare requirements, including limits on housing densities. For example, poultry cannot be kept in row or battery cages; instead farmers must provide “living conditions that accommodate the health and natural behaviour of poultry” including “free access to pasture, open-air runs, and other exercise areas, subject to weather and ground conditions.”^[2]

The use of hormones and prophylactic antibiotics, to promote growth are prohibited, however “medical treatment shall not be withheld from sick or injured livestock to preserve their organic status.” ^[3]  If organic methods are not sufficient, appropriate medications should be used to restore health.” If antibiotics are used, meat from the animal won’t be sold as organic. Milk from the animal may be considered organic after a specified withdrawal period.

Footnotes:

^[1] Organic production systems — General principles and management standards. CAN/CGSB-32.310-2015. III. Organic practices. 6.13 Additional requirements for poultry: 6.13.1

^[2] Organic production systems — General principles and management standards. CAN/CGSB-32.310-2015.

^[3]Organic production systems — General principles and management standards. CAN/CGSB-32.310-2015.6.6.6

“Feed the soil, not the plant,” is a mantra of organic farmers. Organic farmers focus on creating fertile soil that is rich in organic matter and teeming with life. Plants take up nutrients from organic matter as it decomposes. The goal is to have to nutrients made available at the rate and time when needed by the plants. “Soil fertility is maintained and enhanced by promoting optimal biological activity within the soil and conservation of soil resources.”^[1]

Organic soil management practices

• Adding soil organic matter provides nutrients and improves soil structure. Organic matter helps soil particles clump together – this aggregation reduces the loss of topsoil by erosion, and creates channels through the soil that improve both the circulation and retention of air and water.^[2] Soil organic matter also provides habitat for soil life that perform such vital roles on organic farms.
• Growing cover crops to improve soil fertility. These plants are not harvested – just grown for soil improvement. Legume cover crops (green manures) fix nitrogen from the air. Other cover crops add organic matter take up soluble nutrients (to reduce nutrient leaching), or reduce soil erosion.
• Covering the soil by crops, cover crops, stubble or mulch protects topsoil, which is the foundation of soil health. Topsoil contains more nutrients and soil life than the rest of the soil. Farmers try to keep the soil covered as much as possible because bare soil is vulnerable to erosion, which occurs when soil particles wash or blow away.
• Rotating crops in a well-designed sequence keeps the soil covered, adds organic matter, and conserves nutrients. Crops that provide nitrogen (e.g., legumes) are followed by plants that take up a lot of nitrogen. Organic farmers often intercrop – planting two crops (or a crop and cover crop) together to make better use of the soil nutrients and cover the soil.
• Reducing tillage minimizes the potential harm to soil life and structure, but tillage can be carefully used to incorporate green manures, prepare soil for planting and control weeds.

Common soil amendments

• Compost provides nutrients, stimulates soil life and adds organic matter. To be permitted, the compost containing animal waste must reach at least 55°C for four consecutive days^[3] ; high temperatures can destroy pathogens and weed seeds.
• Manure is usually composted before application. If not, it must be incorporated into the soil at least 90 days before harvesting food crops with edible parts that do not contact the soil (or 120 days for food crops that contact the soil).^[4]
• Rock powders, such as limestone, add minerals.

Organic farming is a team effort

When you visit an organic farm, you might see a farmer on a tractor or people pulling weeds, but you won’t see the major work force.

Much of the work on an organic farm goes on beneath your feet. Abundant and diverse soil life is essential for the success of an organic farm. From microscopic organisms to earthworms, soil life is responsible for providing nutrients to plants, helping to control plant diseases, protecting the soil from erosion, and many other farm ‘chores.’ For example, earthworms create tunnels that help improve air and water circulation in the soil. Worms and insects recycle nutrients in plant tissues and animal manure through decomposition. Rhizobial bacteria capture nitrogen from the air and provide it to legumes – giving farmers free fertilizer. Mycorrhizal fungi improve the ability of plants to take up water and minerals in the soil.

The soil life helps farmers and in return, organic farmers provide habitat for the microorganisms and creatures in the soil. When farmers apply compost or plant a cover crop, they feed the soil life. To help protect soil life, farmers can keep the soil covered and avoiding excessive tillage and the use of synthetic fertilizers and pesticides.

Footnotes:

^[1] Organic production systems — General principles and management standards. CAN/CGSB-32.310-2015. Introduction. III. Organic practices. http://www.tpsgc-pwgsc.gc.ca/ongc-cgsb/programme-program/normes-standards/internet/bio-org/pgng-gpms-eng.html#a1

^[2] Bot, Alexandra and José Benites. FAO Soils Bulletin 80. The importance of soil organic matter: Key to drought-resistant soil and sustained food production. Food And Agriculture Organization Of The United Nations. 2005. http://www.fao.org/docrep/009/a0100e/a0100e00.htm

^[3] Organic production systems — Permitted substances lists. CAN/CGSB-32.311-2015. Table 4.2 – Soil amendments and crop nutrition

^[4] Organic production systems — General principles and management standards. CAN/CGSB-32.310-2015. 5.5.2.5