Third hour exam ID: eee105 Password: prAIRie Friday April 12 noon here 100 points (of 500 for semester) 29 questions 57 bubbles If University-approved conflict Sign up with Karin Nelson by Wednesday’s lecture

SoilSoil Ch. 14 EEE Name: eee105 Password: prAIRie

Erosion - Wearing away and transportation of soil by wind and water. SoilSoil Worldwide removes 25.4 Billion tons/yr Made worse by deforestation Poor agricultural practices increase erosion and lead to the transport of associated fertilizers and pesticides and desertification

DesertificationDesertification

DesertificationDesertification

DesertificationDesertification

DesertificationDesertification

DesertificationDesertification Climate change Deforestation Overgrazing Poor farming practices

DesertificationDesertification The U.S.Inter-Mountain West

DesertificationDesertification

SalinizationSalinization

Calcium Sodium H2OH2OH2OH2O

SalinizationSalinization

Erosion SoilSoil Most current agricultural areas lose topsoil faster than it can be replenished Wind erosion Water erosion

Erosion - Wearing away and transportation of soil by wind and water. SoilSoil

Erosion SoilSoil

SoilSoil Sustainable farming Illinois Erosion & Sediment Control Law called “T by 2000” T = tolerable soil loss 3-5 tons/acre/year

Erosion SoilSoil Conservation tillage Sustainable farming

Erosion SoilSoil Conservation tillage Sustainable farming Hedgerows

Erosion SoilSoil Conservation tillage Sustainable farming Hedgerows Perimeter wetlands

Erosion SoilSoil Great Plains have had four serious bouts of wind erosion since late 1800’s.

Agriculture and Pest Management Chapter 15

Thomas Malthus time food population Doomsday Essay on Population 1798

Ancient Agriculture

Plant Breeding

Green Revolution

Norman Borlaug International Maize and Wheat Improvement Center, El Batan, Mexico Nobel Peace Prize 1970

Agricultural Methods Slash and Burn Particularly useful on thin tropical soils Vegetation is cleared for agriculture and burned to release nutrients

Agricultural Methods Slash and Burn Particularly useful on thin tropical soils But depletes soil nutrients Cleared soil useful for only 3-5 years Vegetation is cleared for agriculture and burned to release nutrients

Mechanized Agriculture Typical of industrialized countries Requires large amounts of energy and flat land.

Often monocultures Requires large amounts of energy and flat land. Typical of industrialized countries Mechanized Agriculture

Monocultures vulnerable to pest invasion to evolution of new pests

Monocultures elm trees lined the Quad in the 1940’s all died of the Dutch Elm Disease

Often monocultures Requires large amounts of energy and flat land. Typical of industrialized countries Mechanized Agriculture Hybrid crop varieties High technology

Mechanized Agriculture

Problems With Mechanized Agriculture soil erosion fertilizer runoff depletion of soil nutrients lead to increased fertilizer use irrigation depletes aquifer ground water monoculture often leads to increased pesticide use

PESTICIDES Pesticide - Any chemical used to kill or control populations of unwanted fungi, plants, or animals.

Insecticides Used to control insect populations yr. Ago Homer noted the use of Sulfur to control insects. Known for centuries that certain plant products produce repellant chemicals. –Nicotine (tobacco) Coevolution of chemical defenses

Coevolution Monarch, milkweed mimicry, mimicry

Herbicides Used to control unwanted plants. About 60% of pesticides used in US are herbicides. Weeds compete with crops for soil nutrients. Traditional weed control methods are expensive in terms of time and energy.

Herbicides Used to control unwanted plants. About 60% of pesticides used in US are herbicides. Weeds compete with crops for soil nutrients. Traditional weed control methods are expensive in terms of time and energy.

Herbicides transgenic herbicide resistant crops

Fungicides and Rodenticides Fungicides are an important defense against spoilage of both seeds and mature crops. In some parts of the world, governments place a reward on rats because they can destroy agricultural crops.

But pests evolve DDT resistance Herbicide resistant weeds escaped genes Warfarin-resistant rats

corn root borer But pests evolve Corn root borer starved on soy beans Alternate corn & soy beans annually But in late ‘80’s a new strain of borer evolved which could feed on soy beans

corn root borer But pests evolveevolve

corn rootborer But pests evolve