What percent of the total land area of the world is used for agriculture?
learn and do
LEARN: HOW ARE NATURAL AND AGRICULTURAL ECOSYSTEMS CONNECTED?
DO: MAKING ECOSYSTEM AND AGRICULTURE CONNECTIONS
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finding crop ecosystems
Farms are agricultural ecosystems that include factors such as temperature, precipitation, the land, plant and animal wildlife. Agricultural ecosystems cover about 30 percent of the earth’s surface. Farms rely on natural ecosystems for things such as pollination, biological pest control, soil quality and fertility, nutrient cycling and the water cycle.
finding sustainability in crop diversity
There are more than 10 000 plant species in the world that are edible. Of these many different types of plants, there are three that provide most of the calories and protein that people across the globe get from plants. These three types of crops are:
- Rice
- Maize (corn)
- Wheat
At the same time, crops that may not have been as important for sources of food many years ago have become more important now.
Have you ever heard the saying, “putting all your eggs in one basket?” Relying on a few main crops can be compared to this saying. If one crop is affected by a pest or disease outbreak or does not grow as well in a changing climate, the food supply can be threatened.
A variety of different crops contributes to a sustainable food supply and helps farmers adapt to changing conditions. Some crop varieties, for example, are better than others at tolerating droughts or resisting certain pests. Crop diversity contributes to the health and productivity of all agricultural ecosystems.
Canadian farmers grow several different crops, with many growing more than one and most rotating or swapping these different crops on their land.
According to Statistics Canada, Canada’s major grain crops in 2016 included:
- Wheat (durum, spring and winter)
- Canola
- Corn for grain
- Barley
- Soybeans
- Lentils
- Oats
- Flaxseed
- Mustard seed
- Canary seed
- Chickpeas
- Sunflower seed
- Smaller crops such as quinoa, peas and various pulses
What do you know about the foods that come from each of these crops?
ecosystems and Alberta crop diversity
Farmers no longer just use any available land they can find for their crops. They consider the long-term effects of changing the land and the natural ecosystems that are part of their farm environments.
There is a limit to the land that is available for farming and farmers pay a lot of attention to ways they can use current, existing farmland to grow food more efficiently.
Ecosystem processes are continually going on in this farmland.
- Soil bacteria decomposes crop stubble and other dead plant material and provides nutrients for the soil.
- Natural predators like birds and bats help to control insect pest outbreaks.
- Wetlands collect water runoff, replenish groundwater and help with surface water quality. They reduce the impact of floods.
- Plants remove carbon dioxide from the air and using it to build plant material and produce oxygen.
Why do you think there are limits to the land that is available to be used for agriculture?
Watch this original project AGRICULTURE video interview to learn about diversity and the relationship between natural and farm environments on two Alberta farms.
What practices do these Alberta farmers use to protect natural ecosystems?
wetland ecosystems and farms
Sloughs, marshes, ponds, field water. Wetlands can hold water year-round while others hold water for one or two months. As Alberta continues to grow, wetland ecosystems and how they function in the environment are impacted. Organizations like Ducks Unlimited Canada work with farmers to reclaim and restore wetland environments on farmland.
Brad and Terry Mappin are family farmers who believe their farmland is at its best when native grasses and wetlands are intact. Ducks Unlimited restored wetlands that had been drained, filled or tilled by previous owners. The Mappins are an example of family farmers who work with Ducks Unlimited to make sure they have sustainable pastureland and perennial grass for grazing.
Information provided by Ducks Unlimited Alberta.
how spring and winter wheats grow in ecosystems
There are two basic types of wheat: winter and spring. Winter wheat is seeded in the fall, grows slowly during the winter months, accelerates in growth as spring arrives, and is ready for harvest in early summer. Where winters are harsh, spring wheat is planted in the spring and harvested in the late summer. It can also be sown in the fall where winters are very mild. There are winter and spring versions of the two main wheat varieties – hard wheat and soft wheat.
Winter wheats can help farmers with some ecosystem challenges. It grows earlier than spring varieties, so grassy weeds do not have a chance to get established. It also does not allow diseases brought on by wet spring weather that typically affect spring crops. It matures earlier so is not as affected by early frosts. Also, ducks prefer to nest in winter wheat, which has already been seeded and is growing when they build their spring nests!
How do you think climate change could affect the agricultural ecosystems in which wheat is grown?
crop combinations
Winter wheat and canola are a good crop combination. After canola is harvested, the stubble left in the field tends to be tall, strong and dense. This helps to trap snow throughout the winter, which adds moisture to the soil. Winter wheat that is seeded on fields previously used for canola get the benefit of the protection that the canola stubble provides. This is partly because winter wheat is seeded at a shallow depth.
The combination of canola and winter wheat also helps to reduce and manage weeds. Winter wheat improves the soil for canola crops that are planted after the wheat. Cereal crops like wheat are good for the soil in a variety of ways. They prevent erosion and reduce the loss of moisture in the soil.
pulses in ecosystems
Pulse crops have a unique role in agricultural ecosystems. When they are planted, soil microbes, known as rhizobia, are activated and boost soil fertility. The rhizobia microbes attach to the root hairs of leguminous plants and develop nodules. These nodules are like small nitrogen factories perched on the roots of the pulses. Rhizobia sets to work and converts nitrogen from the atmosphere into a form of nitrogen that can be used by plants for growth.
Where would you find the rhizobia in the illustration below?
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The process of activating soil bacteria to fix nitrogen means that the plant requires much less nitrogen fertilizer, if any. Pulses contribute this fixed nitrogen to the soil, increasing soil fertility and contributing to higher crop yields in other types of crops that are planted in a crop rotation. Pulses provide the most benefits when planted with other types of crops.
For example, a study conducted over 25 years in Saskatchewan found that pulses rotated with spring wheat required 29 percent less fertilizer to be applied to the wheat crop than if wheat was the only crop planted in a field. And pulses use half the energy inputs of other crops.
canola and bees
Canola fields and honey bees have a unique relationship. Bees prefer canola to other flowering plants because they like the colour and scent. Yellow is one of the most attractive colours to a honey bee, and the fluorescent anthers make canola blooms particularly enticing.
Even the size and shape of canola flowers are just right for bees. The petals are a convenient landing platform, and the reservoirs of nectar are located at just the right length for a honey bee proboscis.
Pollination from nearby bee colonies can encourage higher yields of canola crops. And canola provides an abundant supply of pollen with an ideal mix of amino acids, protein and fats for bees. The plentiful nectar has a good sugar profile for honey production. Because the blooms are so plentiful, bees can feed efficiently on canola without traveling far. Canola flowers longer than most other crops, and one field in bloom can nourish bees for up to a month.
Find out more on the Bees Matter website at www.beesmatter.ca.
How would you illustrate a canola field with a honey bee colony ecosystem?
