Agriculture Flashcards
(47 cards)
What is agriculture?
Agriculture involves the control of terrestrial ecosystems to divert energy and nutrients into the human food chain.
List the key principles of agriculture.
- Selection of species
- Control of abiotic and biotic environmental factors
- Manipulation of food species to improve productivity
What factors determine species selection for agriculture?
- Market demand and access
- Environmental conditions within the range of tolerance
- Control of environmental conditions for productivity
What are abiotic factors?
Abiotic factors are non-living environmental factors that affect agriculture, such as temperature, light, and water.
Why is temperature important in agriculture?
Temperature affects survival and growth; it must be warm enough for growth, not just survival.
What is the significance of the frost-free period for crops?
Crops like maize can be damaged by frost, so they cannot be grown in areas with late frosts.
How do higher temperatures affect evapotranspiration?
Higher temperatures increase the rate of evapotranspiration, leading to increased crop water requirements.
What role do frost fans play in agriculture?
Frost fans protect crops from frost damage by pulling warmer air from the inversion layer down to the ground.
What is photoperiodism?
Photoperiodism is the response of plants and livestock to the length of day, affecting growth and reproductive functions.
How does water affect plant physiology?
- Acts as a solvent
- Facilitates nutrient absorption
- Maintains cell turgidity
- Supports transpiration
What are the consequences of water shortages in crops?
Water shortages can cause stomata to close, stop growth, and lead to plant dehydration and death.
What methods can be used to increase water availability for crops?
- Crop irrigation
- Soil mulching
- Improving soil conditions for worms
- Reducing soil compaction
Define soil fertility.
Soil fertility is the ability of soil to support plant growth, influenced by nutrient availability, water, aeration, texture, and structure.
What are macronutrients?
Macronutrients are nutrients needed in large amounts for plant growth.
What are organic fertilizers?
Organic fertilizers are materials that release nutrients as they decompose, such as manure and compost.
What is hydroponics?
Hydroponics involves growing crops in a nutrient solution instead of soil.
List advantages of hydroponic production.
- Optimal nutrient supply
- Smaller roots
- No soil pathogens
- No weeds
- Fresh harvested crops
What causes soil compaction?
- Weight of machinery or livestock
- Trampling
- Reduced soil organic matter
- Shallow-rooted crops
How can soil salinity be controlled?
Avoid farming methods that increase salinity, especially using high salt content groundwater for irrigation.
What is the optimal pH range for most plants?
The optimal pH range for most plants is between pH 5 and pH 7.
How does altitude affect agriculture?
Altitude affects temperature, which influences plant growth; higher altitudes can lead to colder temperatures and lower crop yields.
What is the impact of wind on agriculture?
Wind increases turbulence, enhancing carbon dioxide supply for photosynthesis and altering hormone balance in plants.
Fill in the blank: The _______ is the time during the year that there is sufficient water to sustain growth.
hydrological growing season
What is the impact of wind velocity on crop growth?
Wind direction and velocity significantly influence crop growth.
