Agriculture and the Environment Flashcards
What are mineral particles?
Rock fragments and other inorganic substances.
What is organic content?
Mixture of plants, animals, and microorganisms and their dead remains.
What makes up soil?
*oxygen(air)
*organic content.
*mineral particles.
*water.
The proportion of soil components depends on:
*type of soil.
*how it was managed.
*local climate.
*size of particles.
Size of sand:
2.0 - .02mm
Size of silt:
.02 - .002mm
Size of clay:
.002mm - anything smaller
What elements do plants require in soil?
*nitrogen.
*phosphorous.
*potassium.
Why are earthworms important?
*break down vegetation.
*mix the soil.
*aerate the soil.
*spread organic matter.
Why is fungi important?
*feeds on dead matter.
*digests woody items.
*aids plants to take up nutrients.
High levels of organic matter increase:
*air spaces.
*number of decomposers.
*water-holding capacity.
(prevents loss of mineral nutrients.)
Ease of cultivation:
How easy soil can be ploughed.
Types of agriculture:
*commercial.
*subsistence.
*arable.
*pastoral.
Difference between commercial and subsistence farming:
Commercial is cultivation of food to sell for cash.
Subsistence is cultivation of food to meet the needs of the farmers.
Difference between arable and pastoral farming:
Arable farming produces plants for humans.
Pastoral farming produces animals or animal related products.
What is mixed farming?
Farms that grow crops for animals.
What are yields?
The amount of crop harvested.
Increasing agricultural yields:
*crop rotation.
*leafy crops.
*fallow.
*irrigation.
*fertilizers.
*root crops.
*legumes.
Crop rotation:
Growing different crops in different plots each year.
Fallow:
Land ploughed and left for a period of time to restore fertility.
Legumes:
Nitrogen-fixing bacteria in root nodules.
Leafy crops:
Vegetables required for their leaves.
Root crops:
Deep root systems.
Advantages of inorganic fertilizers:
*meets particular need.
*easy to store.
*deals with deficiency problems.
*no need to reapply.
Disadvantages of inorganic fertilizers:
*cost.
*leaks in heavy rain.
*no immediate impact.
*transport cost.
*environmental impact(eutrophication etc)
Advantages of organic fertilizer:
*uses natural resources.
*supplies organic matter.
Disadvantages of organic fertilizer:
*harder to transport.
*variable in composition.
*unpleasant to handle.
Common water application methods:
*sprinklers.
*clay pot irrigation.
*trickle drip system.
*flood irrigation.
What is a pest?
An animal that attacks or feeds on crops.
Pesticides:
Used to control pests.
Weed control:
Weed-killing chemicals.
Alternatives to herbicides:
*hand weeding and hoeing.
*flame guns.
*weed barriers.
A crop disease is caused by?
Fungi, bacteria, or viruses(pathogens)
What is selective breeding?
Choosing parents that exhibit desired characteristics and breeding them so the offspring has the desired characteristics.(repeated)
Drawbacks of selective breeding:
Slow process and less success rate.
GMOs:
Genetically Modified Organisms.
Advantages of GMOs:
*disease and pest resistant.
*nutritional value increases.
*herbicide resistant.
*longer storage life.
*can be grown in inhospitable areas.
Disadvantages of GMOs:
*unknown impact of the new characteristics on human health.
*products are not natural.
*genes might get into wild plants if interbred.
*reduction in gene pool.
Impact of agriculture:
*overuse of herbicides, insecticides, and fertilizers.
*soil erosion.
*irrigation causing salinization and water logging.
*exhaustion of mineral ion content.
*cash crop replace food crops.
*desertification.
*overproduction and waste.
*loss of habitat.
Salinization causes:
Salt content of soil to increase.
Soil capping causes:
Soil to become hard.
What are cash crops?
Crops produced for cash.
What is desertification?
A process where fertile land becomes desert.
Causes of soil erosion:
*overgrazing.
*overcultification.
*water erosion.
*wind erosion.
*removal of vegetation.
Ways to manage soil erosion:
*terracing.
*contour ploughing.
*maintaining vegetation covers.
*‘no dig’ method.
*planting trees.
*mixed cropping.
*organic matter in soil.
*intecropping.
*crop rotation.
What is terracing?
Rows made along a slope to prevent soil erosion.
What is interctopping?
Different crops grown in between main crops.
Eutrophication process:
- fertilizers are washed off land by rain.
- they cause plants to grow rapidly when entering a body of water.
- this prevents light from reaching the bottom and kill the plants which kill the fish.
*the decomposition fish cause more oxygen loss.
Mineral ions in fertilizers:
*phosphate.
*potassium.
*nitrate.
Ways farmers reduce drought impacts:
*irrigation.
*drought resistant crops.
*rainwater harvesting.
Monoculture:
Growing one crop in a field at a time.
