Agriculture and Soil Flashcards
How many crop species are there worldwide?
3000
How many crop species in the U.S.
200
AquaCulture
Production of food from aquatic habitats
Mariculture
Production of food from ocean habitats
Most Genetically Modified Crops are engineered to resist what?
Herbicides
What is soil
a thin part of earth’s surface that is a layer of mineral and organic matter
Soil produces and stores what?
Plant nutrients
What part of earth’s surface is soil in
lithosphere
How much inorganic material is in soil
45%
What does the inorganic material in soil make up
1/2 is small pieces of weathered rock fragments and 1/2 is small particles of minerals
How much organic material is in soil
5%
What does the organic material in soil make up
living and dead plants and animals and humus
What does humus do?
improves soil fertility
What is half the volume of soil
pore space
How is soil air different from atmospheric air?
1) soil air is always saturated since its surrounded by water
2) soil air is rich in carbon dioxide and poor in oxygen
What are the three functions of soil water
1) dissolves all nutrients making them available to plant roots
2) enables chemical reactions
3) Leaching; plant nutrients carried below plant roots
How does most water get into soil
By infiltration of precipitation
What is soil erosion
natural process initiated by both wind and water
Soil Erosion sequence
1) Rain erosion
2) sheet erosion
3) rill erosion
4) gully erosion
Methods to minimize soil erosion
1) Reducing erosion on slopes
2) Use ground cover
3) reducing tillage
Methods of reducing erosion on slopes
1) crop rotation
2) strip cropping and contour plowing
3) terracing
Methods of using ground cover
1) intercropping
2) crop residue
3) cover crops
4) mulch
Methods of terracing
1) minimum till
2) conservative till
3) no till
Problems with irrigation?
1) poor efficiency
2) over-watering
3) salinization
4) increases erosion
5) depletes aquifiers
Irrigation techniques
1) FLOOD THE FIELD
2) Sprinklers
3) Drip/Trickle irrigation
What is the worst irrigation technique?
Flood the field
What is the best irrigation technique
Drip/Trickle irrigation
What is an ineffective irrigation technique
Sprinklers
Two ways to keep soil fertile
Inorganic fertilizer
Organic fertilizer
Inorganic fertilizer
synthetically manufactured mineral supplements
Organic fertilizer
made of natural materials
What are the three most important plant nutrients
Nitrogen, Phosphorus, Potassium
What are the benefits of pesticides
1) Increases food production
2) decrease of disease caused by insects
What are the problems of pesticides
1) pests often develop a resistance to pesticides
2) runoff carrying pesticides contaminates water supplies
3) Poisonous to humans
How much do herbicides make up of weeds
55%
Benefits of herbacides
reduce cultivation costs and increase crop yields
Detriments of herbacides
create bare fields, resulting in high erosion
How much insectides are in bugs
25%
detriment of insecticides
more toxic to humans than herbicides
How much fungicides are used for fungus
15%
Benefits of fungicides
protects from fungal disease
What is the major use of fungicides
to prevent spoilage in fresh fruits and vegetables
How many fungicide pesticides were listed by EPA as the biggest human health problems
7/10
