Unit 6 - Sustainable Agriculture Management Flashcards
*****What are the types of agriculture?
- Subsistence Agriculture:
-Small scale
-Family farms
-Common in developing nations - Industrialized Agriculture
-Large commercial farms to maximize profit
-Human presence changes the land
-No opportunity for the land to rest
-Intensive harvesting, and depleting nutrients and organic soil
**What is agriculture?
The practice of cultivating the soil, producing crops, and raising livestock
*****Arable vs Pastoral agriculture
Arable: Plant domestication (10 000 years ago in Asia)
Pastoral: Animal domestication (11 000 years ago in Iran)
Industrialized farming:
-How are yields enhanced?
-High levels of?
-The use of?
-Developed or developing nations?
- Through inputs of capital, energy, and labour
- Mechanization
- Pesticides, herbicides, fertilizers
- Developed
What is soil?
Ground up rock particles and organic materials
What are the types of soil?
Clay, sand, silt
What type of soil retains the most water and nutrients?
Clay
*****What are the 4 major components found in soil?
- Organic matter (5%)
- Minerals (45%)
- Water (25%)
- Air (25%)
*****What is the soil profile of soil that has not been plowed?
Which one is the most important?
- O-horizon :organic matter
- A-horizon: Topsoil
- B-horizon: Subsoil (clay and cations from A-horizon that leaked down accumulates here)
- C-horizon: Weathered rocks/groundwater
- D-horizon: Parent material (bedrock)
B-horizon: Subsoil accumulation is key to nutrient cycling and water filtration
***What is cation exchange capacity?
The ability of a soil to hold and exchange cations
When negatively charged clay particles hold minerals in the soil
-(+) charged decomposing organic material and (-) charged clay keeps minerals in the soil
Acidic soils (+) contribute to?
Nutrient loss
Soils low in cation exchange capacity have more leaching causing nutrients to?
Go deeper into the soil
What does tillage cause?
-Increased soil erosion
-Accelerated decomposition and loss of organic matter
Soils take ____ years to form but only _____ years to deteriorate
500
A few
Soil conservation strategies: Zero Tillage
Crops are grown with little disturbance of the soil so that plant residues are not being completely incorporated, to ensure most remain on top of the soil
What are the advantages and disadvantages of Zero Tillage?
A:
-Reduces erosion
-Saves fuel
-Holds more soil water
-Does not reduce yields
-Promotes carbon storage
D:
-Compact soil
-Poor drainage
-Need for herbicides
-Capital costs for new machines
What are alternative soil conservation strategies other than Zero Tillage?
- Fertilizer application
-Organic (manure): offers higher yields - Crop residue:
-Decomposes back into the soil, which recycles minerals
-Reduces erosion
-More pesticides are needed - Crop rotation:
-Nitrogen fixation occurs which enhances the storage of nitrogen and reduces the need for fertilizer application
**What is slash and burn?
Tropical forests are cut and burned to remove debris and use ash as fertilizer to grow crops
It increases crops in the area since it uses the remains as fertilizer but the soil loses productivity fast so you have to move to new areas, which are limited
Forest regrowth is not possible due to the poor soil quality
**What is intercropping/Alley cropping? Why is it better? What is the main challenge?
Intercropping is where you plant a variety of crops among rows of trees. The trees provide shade and prevent soil erosion
Crops can be harvested all year long, and it reduces the need to slash and burn new areas
The main challenge is that it is hard to convince local farmers that this method is better
What is the green revolution (1940s-1960s)? What new technologies were created and what problems arose?
A period of increased crop production to feed populations and avoid starvation following WW2
New technologies:
-Chemical fertilizers
-Synthetic pesticides
-Multiple cropping (more than one crop each year) to reduce production costs
Problems:
-Big financial investment for farmers and less developed nations
-Increased pollution and erosion
-Pressure on water systems
-Higher energy consumption rates
**What are the impacts of intensive agriculture on the environment?
- Water issues
- Air pollution
- Land degradation
- Loss of biological diversity
What is integrated pest management? Does it want to eradicate pests? What does it require?
Strategies used to manage pest damage by the most economical means, with the least possible hazard to people, property, and the environment
No, it focuses on management not eradication
Requires education and decision-making
How do modern agro-ecosystems differ from natural ecosystems?
-They require lots of energy input
-Are monoculture/have low biodiversity
-Crops are planted in rows
-Reduces soil community function and structure
-Increases erosion
What is ecological restoration?
Restoring ecological services that were historically provided by the environment
Ex:
-Erosion control
-Reintroduction of native species
-Habitat improvement
-Reforestation
