What does agronomy refer to?
build these competencies
growing crop plants with science
Plant science works to develop innovative solutions to agricultural challenges and issues. Some of these include climate change, soil health, water quality and crop yields.
Plant science includes the use of technologies that support farmers in adopting practices that reduce their impact on ecosystems and environments. Examples of these technologies include how and what types of pesticides are effective as well as tilling and harvesting practices.
Continuing work in plant science means that farmers have more efficient and effective tools and practices to use.
plant pest science
Pesticides are tools designed to deter or manage pests that threaten the health or quality of a particular plant, impact human health or pose a threat to physical structures. There are three main types of pesticides related to agriculture: herbicides, fungicides and insecticides.
Herbicides kill unwanted plants — weeds — so crops can flourish. Weeds and other invasive plants are actually the most damaging pests for many agricultural crops because they compete for essential nutrients, space, water and sunlight.
a case in point
Herbicides have been used widely in Canadian farming to control weeds since World War II, allowing farmers to harvest more crops, safely and efficiently.
Plant science uses biotechnologies.to develop herbicide-tolerant crops, such as canola.
The use of herbicide-tolerant crops means that farmers can use herbicides to control weeds without harming their crop. The crop is protected without the need to plough the fields, which leaves nutrients and water in the soil, increases soil fertility and reduces soil erosion. Today’s herbicide-tolerant varieties have allowed farmers in Canada to reduce the amount of herbicide they use by 20 percent since 1996.
Fungicides are pesticides that protect plants from fungi, like the one that caused the infamous Irish potato famine of the 1800s. On a farm, a fungus can spread quickly from one plant to destroy an entire field.
a case in point
Stripe rust is a disease that can affect wheat crops. It can also affect other cereal crops, such as barley. It is caused by a fungus. Fungicides must be applied after a crop flowers or they will not be effective. For example, one scientific project is studying the gene in wheat that is resistant to this fungus. Breeding the gene into wheat varieties can help reduce the amount of fungicide required, which can ultimately benefit the environment.
Insecticides control insects that can damage crops by eating the plants or infecting them with diseases. Fighting these pests is difficult because of the great variety of insects as well as the introduction of new invasive species of pests. Insecticides will kill, harm or repel these harmful insects.
What types of interactions can you identify between crop plants and insects?
Alberta Pulse Growers: Photo Credit: Shelley Barkley
a case in point
Alberta wheat and barley farmers are investing in research that can help farmers address crop production needs and challenges. One of these projects is a study of beneficial insects – those that eat insect pests, pollinate crop plants, eat or destroy weed seeds and contributes to nutrient cycling in the ecosystem.
Pulse farmers in Alberta are also looking at ways that insecticide affects the growth of field peas and faba beans, shown in the photo to the left. An insect pest – pea leaf weevil – feeds on root nodules that are essential to nitrogen fixation in a field pea crop. The second photo shows a pea leaf weevil.
The result from this pest infestation means that less nitrogen is fixed the first year. The following year’s crop (wheat, for example) would then require more nitrogen than if the wheat crop was planted after a healthy field pea crop.
The scientists also found that weevils prefer faba beans to peas. Faba beans are the best of all pulse crops at fixing nitrogen.
The researchers found that seed insecticides, which are added to the seeds before they are planted, were more effective than insecticides sprayed on the plants. Farmers who monitored the pea leaf weevil population at the end of the summer used this information to decide whether to get their seeds treated with insecticide.
Going forward, the researchers want to understand how beneficial insects like Rove beetles and Carabid beetles can play a role in managing pea leaf weevil. They caution that the environmental impact of chemical control should be carefully balanced with its crop yield protection benefits.
“The pesticides are not specific to the pea leaf weevil,” one of the researchers said. “When you use an insecticide – either a seed treatment or a [leaf spray] – you can expect some negative effects on the beneficial insects.”
Some information from Carcamo, H. Going deeper on pea leaf weevil management. Alberta Pulse Growers online.
seeding and harvesting
Zero tillage is a soil management and seeding practice that is used by many farmers.
It conserves the topsoil and protects the amount of moisture in the soil, as it keeps the soil covered with crop residue. It results in 10 to 20 times less erosion than conventional tillage.
According to research from Crop Life Canada, the use of zero tillage increased in Alberta by over 60 percent between 1991 and 2011. In 2016, it increased almost 17 percent, accounting for the largest percentage of the land across Canada prepared for seeding.
a case in point
Hannah Konschuh is an Alberta wheat farmer. This is her description of the seeding practices she uses on her farm.
Every decision we make for our fields is based on stewardship and sustainability, because what’s best for the land is best for our business and the grains, pulses and oilseeds grown there.
One example of environmental stewardship we practice is “no-till” seeding, where we disturb the soil the least amount possible when planting to conserve moisture, protect soil structure, prevent erosion and encourage soil organic matter development and resilient microbial communities. This practice also sequesters carbon – my fields are carbon sinks.
Tilling practices are split into three categories.
- Conservation tillage retains most of the residue from the previous crop on the surface.
- Conventional tillage incorporates most of the crop residue into the soil.
- No-till (or zero-till) seeding inserts seeds into minimally disturbed soil. No-till seeding requires fewer passes over the field, thereby reducing fuel and labour costs.
From Statistics Canada. Investing in the Soil: Seeding decisions harvest opportunities for Canadian farmers. Online: www150.statcan.gc.ca/n1/pub/95-640-x/2016001/article/14813-eng.htm
Watch this original project AGRICULTURE video interview to learn about innovative practices and technologies that help with seeding and harvesting.
How are these innovations and technologies examples of sustainable practices?
