|Science Focus Topic 4 Notes: Meeting the Need for Food and Fibre||| Print ||
Because we grow more than we consume, Canada exports the excess to other countries around the world. Canada is also a leader in forestry and agricultural research science. Scientists, farmers and foresters are working together, developing practices that will reduce the negative effects that sometimes occur when we harvest plants for food and fibre. Sustainability (an ecological balance) is essential if we are to keep our natural resources healthy in the long term.
Agriculture in Alberta
Who's Who in Crop Country?
Alberta crops are worth almost $3 Billion. The food industry is second only to oil and gas in terms of earnings.
Growing Under Glass
The yield from crops that are grown outdoors is highly dependent on the environmental conditions, climate and soil types. In a greenhouse all of the growinging conditions can be controlled. There are obvious advantages, but there are also disadvantages. Make a list of those you are able to find out about and report your findings to the class to complete the chart. Advantages Disadvantages higher yield cost
To be economically sustainable, farmers need to make more money with their crops than they spend to grow their crops. They are able to do this by using very large machinery that can cover large parcels of land as they seed and harvest their crops. They also need to add fertilizer to the soil to increase the yield and irrigate to provide the need moisture for growth of the crop. Most farmers only grow one type of crop in one particular area - this is known as monoculture.
Farming Then and Now
Farming practices changed from using human and animal power in the early 1900's to total mechanization by the 1950's to modern computerized controls in the present. Comparison chart on p. 141.
Saving Soil Moisture
Irrigation is a technique that farmers use to make sure that moisture gets into the soil for crop growth. It is often a problem in grassland areas, where the moisture evaporated quickly. Irrigation systems (using natural waterways and irrigation canals) can often be the life or death of a crop and must be maintained, to ensure an adequate supply of water is available when it is needed.
Fibre Plants and the Forestry Industry
Canada has about 10% of the world's forests. From these forests come lumber and pulp and paper products. Natural forests have many different kinds of trees, shrubs, and smaller plants. There are many animals that make their homes in, around and under these plants. A natural ecosystem has a higher diversity, or variety, of plants and animals than a field of wheat or a stand of trees. The species within this ecosystem are all interdependent. Forestry practices can increase the diversity of forest species by careful cutting to let in more light and air.
Alberta tree species most valued for lumber and paper include:
Foresters explore a potential tree cutting area thoroughly before any work begins. They map the area indicating which trees to be cut and what special features should be noted. They also decide how to cut the trees, either clear cut (removing all the trees)- or, selective harvesting (removing only selected trees). See Figure 2.49 p. 146
Foresters attempt to improve the conditions (light, temperature, water and nutrients) within the forest. Leftover branches (from the logging operations) must be disposed of. They are chopped (shreaded) spread out over the forest floor and some smaller piles are burned. Replanting is always done by hand. When the trees begin to grow again, if too many of a particular kind compete, they must be removed by thinning or pruning. Fertilizer is dropped from a helicopter to improve the level of nutrients for the young trees. Forest fires are a natural development of forests, but foresters try to ensure that they burn in a controlled fashion (as much as possible).