Bio. Farming & Agriculture (Lecture 11, Unit 2)
What are some abiotic issues farmers have to deal with?
Soil degradation and irrigation
What are some biotic issues farmers have to deal with?
Insect pests and weeds
What is soil degradation?
Anything where soil becomes unfavorable
What is erosion?
The removal of soil by wind and water
What are some direct causes of erosion?
Water runoff=mudslides; wind=soil blows away
What is deposition?
The arrival of eroded material at a new location
What makes farms vulnerable to erosion?
Mostly annual plants are planted as crops; tiling the soil leaves dirt loose; livestock overgraze; crops are often planted in rows
What is topsoil?
The nutrient-rich layer beneath the leaf litter where plants grow
What is the difference between annual plant root length and perennial root length?
Annual plants have shallow roots; Perennial plants have long roots that keep the soil in place
What does "tiling the soil" mean?
Mixing the soil up before planting
What is the problem with tiling the soil?
It leaves nothing to hold the soil in place
What is the problem with crops being planted in lines?
Creates a line for water to run off in while carrying the soil with it
How can erosion be reduced?
Planting perennials around the forest
Where does soil come from in nature?
Decomposition, nitrification, weathering of rocks
What nutrients do plants need from the soil? How much of each nutrient is needed?
Macronutrients (large amounts), secondary macronutrients (medium amounts), micronutrients (small amounts)
What is soil compaction?
The compression of soil by either natural weight of overlaying sediments or human-related forces
What are three (3) types of legumes?
Soybeans, alfalfa, green beans
What is a synthetic fertilizer?
Derived from chemical processes in a lab
What is an organic fertilizer?
Tied up in a larger, naturally-occuring source
Are there bad side effects to using synthetic fertilizers? If so, what are they?
Yes. They leach into drinking water, they runoff into waterways and cause algae blooms
What is eutrophication?
Depletion of oxygen in the water from massive decomposition of algae in water
Is Ammonia harmful?
It isn't too bad, it doesn't directly hurt us in small amounts
What is the problem to mostly annual plants being planted as crops? What is the solution?
Problem: They don't hold very much soil in place
Solution: Add some perennials to the crops
What is the problem with tiling the soil? What is the solution?
Problem: Leaves dirt loose and vulnerable to being blown away
Solution: No till agriculture
What are shelter/wind belts?
Plants that block wind flow
What is the problem with livestock overgrazing? What is a solution?
Problem: Decrease in plant growth
Solution: Limit the amount of time grazers spend on a plot of grass
What is pivot farming?
Crops planted on flat surfaces. Reduces runoff because runoff is caught in all directions by crops
What is contour farming?
Crops planted in land with a gentle slope and follows the natural slope of the hillsides.