Hi APES Scholars: I am so sorry that I forgot to put this online sooner. See #11 answer, which is not in your book! Let me know if
you have any questions. Mrs. Delli Paoli
Soil, and Pest Management
APES: Chapter 10
ANSWER KEY
Date: 2/27/14
1. List four major types of agriculture. Compare the energy sources, environmental impacts, yields, and sustainability of traditional and
industrial agriculture.
Industrial Agriculture: High input agriculture, uses large amts. of fossil fuels, water, commercial pesticides & fertilizers to produce a
monoculture such as corn, wheat, etc.
Plantation Agriculture: form of industrial agriculture used primarily in tropical developing countries. Cash crops such as bananas,
Coffee,soy, sugarcane, cocoa and veggies.
Traditional Subsistence: Uses mostly human labor & animals to produce enough crops and livestock for a farm family’s survival.
Traditional Intensive Agriculture: Farmers increase their inputs of human labor, fertilizer and water to gain increased yields. They
Produce enough food to feed their families and to sell for income.
2. Describe the problems of soil erosion and desertification. Describe both world and U.S. soil erosion and desertification situations, and
explain why most people are unaware of this problem. Which laws currently would reduce erosion and desertification in the US?
Soil erosion: Erosion caused by overgrazing and digging up the land for agriculture (deep plowing/tillage). 3 types of erosion: sheet,
gully and rill erosion. Not using crop rotation farm techniques, Soybeans and corn leave soil exposed for much of the growing
season. The deep plowing and heavy herbicide leave fields subject to erosion. These are essentially gullies that are subject to
flooding and then erosion. Wind and water carry away topsoil.
World and US soil erosion: 1/3 of earth’s surface and the likelihoods of at least one billion people are threatened by desertification,
which contributes to food insecurity, famine and poverty. These affected individuals try to overgrow so they cultivate and
overgraze their land unfortunately causing erosion and loss of productive land for their crops. According to the UN, 80% of
world’s grasslands are suffering fr overgrazing and soil degradation and 75% of that area has undergone some degree of
desertification. Two areas of concern are Africa and China. Arid lands where rain is sporadic and infrequent and economy is
based on crop and livestock production, make up two-thirds of Africa. Rapid population growth & poverty create
“unsustainable pressures” on their fragile soil. Deforestation for farmland, fodder and firewood exposes the soil to erosion and
triggers climate changes that spread desertification.
Laws: Taylor Grazing Act of 1934 – private lands & Federal Land Policy & Management, Act of 1976- public lands
3. Describe the problems of salinization and waterlogging of soils and how they can be controlled.
a. Salinization is caused by mineral salts accumulating in the soil, occurs particularly when soils in dry climates are irrigated with
salty water. As water evaporates, it leave behind a salty crust on the soil that is lethal to most plants. Flushing with water can
wash away this salt accumulation but the result is even more saline (saltier) for users downstream.
b. waterlogging: Over exposure to water (saturated) in the plants and the roots. The roots cannot uptake their necessary
nutrients and/or water and they die from lack of oxygen.
4. Define soil conservation. List nine ways to approach the problem of soil erosion. Be sure to distinguish between conventional-tillage and
conservation-tillage farming.
Soil conservation is the collection of methods used to reduce soil erosion and restore soil fertility.
Conventional tillage is the plowing and breaking up and smoothing of soil. It is traditionally very disruptive to the soil.
Conservation tillage, however, attempts to use special tillers and planting machines to disturb the soil as little as possible while
planting crops.
The problem of soil erosion can be approached through terracing, contour farming, strip cropping, using crop residues, planting
cover crops, alley cropping, shelterbelting (new word: planting rows of shrubs or trees that would protect the crops from wind),
reducing water use, and reducing the number of cattle on farm land.
5.***Describe a plan to maintain soil fertility. Be sure to distinguish between organic and inorganic fertilizers. Summarize environmental
impacts from agriculture.
To maintain soil fertility, a farmer would employ a system involving organic fertilizers such as manure and compost, and use a
system of crop rotation in order to offset the depletion of topsoil in a given land area. Some of the main environmental impacts of
agriculture are soil erosion, loss of fertility in soil, rising salt levels, water supplies being polluted or depleted, and pests developing
immunity to various pesticides from overuse.
6. Describe the possibilities of increasing world food production by increasing crop yields, cultivating more land, and using unconventional
foods and perennial crops.
To increase crop yields, we can mix the genes of different organisms. Farmers and scientists have used crossbreeding and artificial
selection to develop genetically improved varieties of crop strains.
1. The current third green revolution – a gene revolution – involves using genetic engineering to develop improved strains of crops
and livestock.
2. Genetic engineering, which splices a gene from one species into the DNA of another species, is creating improved strains of crops
and livestock animals.
a. This process takes 6 times as much time as traditional methods to develop a new crop.
b. It cuts costs.
c. It allows for all kinds of potential product development.
d. More than 2/3rds of food products on the U.S. shelves contain ingredients made from genetically engineered crops.
e. Scientists are experimenting with cell cultures to produce a variety of food and medical
Perennial crops allow for the farmer not to have to plant seeds each year, which means the once the seed is planted, then the plant
will complete a life cycle and grow again. The roots from the plants are deep and hold the soil in place to prevent erosion.
Also see #4.
7. Define sustainable agriculture. Summarize how the United States could move toward creating a more sustainable agricultural system.
S.A. = ecologically sound economically viable, socially just and humane agricultural systems. Stewardship, soil conservation and
integrated pest management are essential for sustainability. In other words, sust agriculture is more eco-friendly and leaves the
soils healthier than intensive, chemical-based monoculture cropping. From class, we know that sustainable agriculture typically has
20% less yields due to not using chemical pesticides, herbicides and insectides. However, energy use is 56%less per unit of yield in
organic farming than conventional farming. Root fungi increased, earthworms were 3x as abundant and spiders and pest eating
predators were doubled in the organic plots. Currently less than 1% of American farmland is devoted to organic growing.
According to the USDA, products labeled 100% organic must be produced without hormones, antibiotic s, pesticides, synthetic
fertilizers or genetic modification. 95% of the ingredients must be organic. The US can begin implementing the sustainable
agriculture systems. It would need to reconfigure growing conditions, distribution and avoid the use of chemicals in their fields.
8. List the five types of pesticides and what they are used to treat.
a.Organophosphates: most abundantly used. Glyphosate (Roundup by Monsanto) . applied to 90% of US soybeans and corn.
Attack the nervous system of animals and can be dangerous to humans as well. Parathion, malathion, dichlovos and other
organophosphates were developed as an extension of nerve gas research during WWII. Less persistent in the environment.
b. Chlorinated hydrocarbons: (also called organochlorides) persistent and highly toxic to sensitive organisms. Atrazine is
applied to 96% of the corn crop in the US to control weeds in corn fields. Others include: DDT, chlordane, aldrin, dieldrin,
toxaphene and paradichlorobenzene (mothballs). Stored in fatty tissues – bioaccumulation and biomagnification.
c. Fumigants: small molecules such as carbon tetrachloride, ethylene dibromide and methylene bromide which can be delivered
in the form of a gas b/c it penetrates the soil and other materials. Strawberries and other low growing crops.
d. Inorganic pesticides: include toxic elements such as arsenic, sulfur, copper and mercury. Highly toxic and indestructible
remaining in the environment forever.
e. Natural organic pesticides: botanicals generally extracted from plants.
f. Microbial agents / biological controls: living organisms or toxins derived from them that are used in place of pesticides. Soil
bacterium, Bacilus thruingiensis is of the chief pest control agents in organic farming. This bacterium kills caterpillars and beetles
by producing a toxin that ruptures the digestive tract lining when eaten. Parasistic wasps attack moth caterpillars and eggs, while
lacewings and ladybugs are predators that control aphids.
9. Briefly describe the threat of pesticides to wildlife and human health. Name the U.S. law that controls pesticide regulation.
a. The effect of pesticides is the threat to non-target species of insects such as the bee, a necessary pollinator. The effects of pesticides
is seen through biomagnification of pesticides which are persistent in the environment such as DDT and other organochlorides
(otherwise known as chlorinated hydrocarbons).
b. The effects of atrazine, widely used pesticide, which drains into local/nearby ponds and streams and changes the sex of
amphibians such as the case study “Kermit to Kermette”. Remember?
c. The US law includes FIFRA and the Food Quality and Protection Act of 1996.
10. Summarize how the 1996 Food Quality Protection Act extends this law. List and briefly describe alternative pest management strategies.
EPA requires stricter guidelines on the production and distribution of pesticides on crops. The focus of this law is that the effects
these pesticides can have on human health. The intention of the law is that pesticide producing manufacturers produce the pesticides
with minimal effects on the environment and on human health.
Alternative pest mgt. strategies include:
a. crop rotation (such as soy/corn/hay rotation is very effective)
b. mechanical cultivation can substitute for herbicides but increases erosion.
c. Flooding fields before planting or burning crop residues and replanting with a cover crop can suppress both weeds and pests.
d. Creating windbreaks (shelterbelting), hedgerows and ground cover
e. Adjusting planting times can avoid pest outbreaks (if the weather permits)
f. Plant polyculture crops such as intercropping different types / sizes of crops instead of monoculture crops. The empty rows look
“pretty” but they do not prevent erosion or insect infestations. Smaller crops will be a ground cover to prevent erosion.
g. Use conservation tillage instead of conventional tillage operations. Will reduce pests.
h. Use of biological controls such as beneficial insects such as ladybugs or lacewing insects to kill aphids; use bacterium, Bacillus
thurigenesis that can kill larvae, worm tea, use of preying mantis, some plants produce natural pesticides and insect repellents.
i. The use of certain plants such as chrysanthemums or marigolds produce a natural odor that repels certain insects.
11. Define integrated pest management. Analyze the pros and cons of using IPM. List six steps which could be taken to help promote IPM.
IPM is a flexible, ecologically based strategy that is applied at specific times and aimed at specific crops and pests. It often uses
mechanical cultivation and techniques such as vacuuming bugs off crops vs using chemicals.
The pros of IPM include the fact that it reduces crop damage to an economically tolerable level. The cons include the fact that IPM
requires expert knowledge about each pest situation and acts more slowly than the regular pesticides. Additionally, methods
developed for one area may not be effective for the other.
Pros - contribute directly to our health through control of certain vector-borne diseases; contribute directly to the economy through
increased production of food and the production of many materials during storage. In some countries, greater and more dependable
production of food has eliminated famine and thus pesticides contribute as much to health as to the economy.
Cons - increased insecticide and chemical fertilizer dependence, Phenomenon of pest resistance, hazardous health effects
6 Steps
1. Determine acceptable pest levels
2. Preventive cultural practices
3. Monitoring
4. Mechanical controls
5. Biological controls
6. Chemical controls
12. Which agencies oversee Soil Conservation? What are their roles in maintaining sustainable agriculture?
a. EPA:
1) to regulate the use of pesticides. EPA is responsible for ensuring that the American public is protected from potential health
risks posed by eating foods that have been chemically treated
2) responsible both for the registration of new pesticides before they can be marketed and the re-registration of older pesticides to
ensure that they meet current scientific standards.”
3) propose and establish new laws to protect the American public from potential risks posed by eating foods that have been
chemically treated.
b. US Dept. of Agriculture: Food Safety ensures that the Nation's commercial supply of meat, poultry, and egg products is safe,
wholesome, and properly labeled and packaged. This mission area also plays a key role in the President's Food Safety Working
Group, a coordinated government-wide initiative to ensure a safe food supply for the American people for the 21st century.
c. Bureau of Land Management: Resp. for sustained and productive mgt. of diverse public lands & subsurface mineral rights. New
“ecosystem mgt" principles evaluate the total environment instead of the localized land use planning.
13. How does the Soil and Water Resource Conservation Act (now known as RCA) compare to the other US soil laws?
This law is the more broad respresentation of soil conservation.
Food, Soil, and Pest Management
1. What is the state of food security? The state of food security or the ability to obtain sufficient food on a day-to-day basis and
poverty is the greatest threat to food security. 1 in 5 Americans do not know where their next meal is coming from and 815
million people in developing countries suffered from chronic hunger and malnutrition. Africa has the largest food shortages.
2.
What type of agriculture is used and is it done sustainably?
Organic farming: Sustainable farms produce crops and raise animals without relying on toxic chemical pesticides, synthetic
fertilizers, genetically modified seeds, or practices that degrade soil, water, or other natural resources. By growing a variety of plants
and using techniques such as crop rotation, conservation tillage, and pasture-based livestock, sustainable farms protect biodiversity
and foster the development and maintenance of healthy ecosystems.
3.
Describe the major types of soil found in the country.
Soil is made up of a combination of weathered rock, plant debris, living fungi and bacteria. It includes:
 sand and gravel, silts and clays
 dead organic material such as decaying plant matter that stores nutrients and gives soil the black or brown color.
 Soil fauna and flora (living orgs including soil bacteria, worms, fungi, roots of plants, insects
 Water – moisture from rainfall or groundwater, essential for soil fauna and plants.
 Air – tiny pockets of air help soil bacteria and other organisms survive.

Major soil horizons : O, A, E, B, C and Regolith and then Bedrock which is impermeable.

On the soil triangle-know how to use this to determine which type of soil is present: combination of silt, clay and sand.
4. Describe the types of environmental problems associated with food production.
a. Eutrophication
b. Biomagnification
c. Bioaccumulation
d. Energy costs for transportation add carbon monoxide, carbon dioxide, nitrous oxide, sulfurdioxide into atmosphere.
e. Deforestation: cutting down trees leaves larger percentage of carbon dioxide in the atmosphere – greenhouse gases.
f. Production of methane from CAFO’s
g. Packaging factories which use coal as an energy source produce mercury and methane which contributes to air pollution.
h. High volume of water use to process foods may be contaminated with bacteria such as e-coli.
5.
Describe the major method of protecting crops from pests? Pesticides, herbicides and rodenticides.