Soil & Agriculture - Unit 4

Biological controls are frequently used to replace persistent chemical pesticides. Which of the following represents the greatest potential risk of using biological controls? A) control agent attacks not only its intended target but also beneficial species B) control agent mutates and is no longer an effective control agent C) Repeated applications or introductions are required to eliminate the pest population D) Residual pesticides in the environment kill the control agent before it can eradicate the pest. E) biological controls prove to be more costly to use than chemical pesticides

A) control agent attacks not only its intended target but also beneficial species

Acid deposition would most likely result in which of the following? A. The release of aluminum ions B. An increase in populations of mollusks C. The death of species tolerant of low pH levels D. An increase in buffering of lake water by sulfates E. An increase in the pH of unbuffered water

A. The release of aluminum ions

Overgrazing of grasslands can lead to reduced range quality. Two of the major effects of overgrazing are A. erosion and desertification B. higher fire potential and increased productivity C. eutrophication and increased methane production D. higher primary productivity and ammonification E. soil compaction and subsidence

A. erosion and desertification

Which of the following is the best explanation of the fact that agricultural production on floodplains is often relatively high? A. on floodplains, soils tend to be nutrient-rich and fertile B. on floodplains, high water tables make irrigation unnecessary C. periodic flooding leaches toxic pollutants out of floodplain soils D. periodic flooding prevents the pH of floodplain soils from becoming to high? E. floodplains are usually sparsely settled and thus more acreage is available for agriculture

A. on floodplains, soils tend to be nutrient-rich and fertile

Describe one environmental advantage and one environmental disadvantage of using GM crops.

Advan: The use of pesticide can be lowered, reducing its negative effects of runoff and killing of non-targeted species. Disadvan: GM crops have less genetic biodiversity than traditional crops, due to monocropping. As a result, these crop monocultures are more susceptible to disease, since most have the same genetic material.

Describe one economic advantage and one economic disadvantage of using GM crops.

Advan: With GM crops, farmers have higher yields, resulting in inexpensive crops for to buy. Diadvan: There is a chance consumers may reject buying GM products, causing for a low demand for GM crops, which results for GM farmers to lose profit.

Reasons that human populations historically have settled in floodplains include which of the following? I. The soil in floodplains is usually fertile II. The terrain in floodplains tends to be flat III. Floodplains are close to rivers for transportation

All of them

Which of the following is the best illustration of the pesticide treadmill? A) Sequence of several pesticides used by farmers to maximize effectiveness B) increased use of pesticides to eradicate genetically resistant pests C) Biomagnification of pesticides in the fatty tissue of primary consumers D) movement of pesticides following their percolation into the groundwater E) process that is used to manufacture pesticides

B) increased use of pesticides to eradicate genetically resistant pests

Which of the following is the correct order of soil particles in order of increasing size? A. Clay--sand--silt B. Clay--silt--sand C. Sand--clay--silt D. Sand--silt--sand E. Silt--clay--sand

B. Clay--silt--sand

Of the following methods of irrigation, the one that currently conserves the most water is: A. Conventional center-pivot irrigation B. Drip irrigation C. Laser-level irrigation D. Flood irrigation E. Gravity-flow irrigation

B. Drip irrigation

Rachel Carson contributes to the environmental movement include which of the following? A. Alerting the public to hazardous waste problem at Love Canal B. Increasing public awareness of the risks of using pesticides C. Starting the first Earth Day in 1970 D. Discovering the thinning of the ozone layer in polar regions E. Being the first female administrator of the EPA

B. Increasing public awareness of the risks of using pesticides

Which of the following would most effectively slow the loss of arable land? A. Increasing the efficiency of desalination practice B. Reducing urban development C. Increasing the efficiency of erosion control D. Using more extensive irrigation systems E. Discovering cheaper energy sources

B. Reducing urban development

Which of the following best describes soils in many tropical rain forests? A. They lack soil horizons. B. They are quickly depleted of nutrients when the forest is removed. C. They are similar to soils in grasslands. D. They are well suited for growing a wide variety of crops. E. They are deep and well drained.

B. They are quickly depleted of nutrients when the forest is removed.

An integrated pest-management approach to pest control that emphasizes which of the following? A. Eradication of the pest population B. Reliance on spraying broad-spectrum pesticides C. Reduction of crop damage to an economically tolerable level D. Use of plant monocultures to simplify spraying E. Elimination of the use of second-generation pesticides

C. Reduction of crop damage to an economically tolerable level

Which soil indicated on the soil triangle above would most likely have the highest water-holding capacity? A. Soil A - 100% sand B. Soil B - sand, silt C. Soil C - clay D. Soil D - silt, sand E. Soil E - silt

C. Soil C

Which of the following practices is consistent with the production of organic crops according to the United States Department of Agriculture? A. Using sodium nitrate as a fertilizer on green, leafy vegetables B. Using strychnine to prevent buildup of aphid populations in field crops C. Using chemicals known as pheromones to disrupt insect mating cycles D. Using sewage sludge to improve the fertility and structure of soil E. Using genetically modified plant varieties that kill insects that chew their leaves

C. Using chemicals known as pheromones to disrupt insect mating cycles

Although the use of DDT was banned in the United States in 1972, a test of the body tissue of an average United States resident today would most likely reveal the presence of DDT because A. DDT is the breakdown product of some newer pesticides on the market B. DDT is water soluble C. other countries that export produce to the United States still use DDT D. many farmers in the United States are still using DDT illegally E. DDT is naturally produced by many plants

C. other countries that export produce to the United States still use DDT

The following which are the three major sources of nutrient and calories for the global human population include A. Potatoes, fish, and barley B. Wheat, beef, and potatoes C. Oats, soybeans, and poultry D. Corn, wheat, rice E. Rye, beef, eggs

D. Corn, wheat, rice

The use of which of the following to control agricultural insect pests is most likely to have a negative and persistent impact on an ecosystem? A. Bacillus thuringiensis, a soil organism that kills insect larvae B. Braconid sp., a parasitic wasp C. Insecticidal soap, a surfactant that kills through suffocation D. Lindane, a chlorinated hydrocarbon E. Rotenone, a toxic plat derivative A. Urban areas trap more heat

D. Lindane, a chlorinated hydrocarbon

The water-holding capacity of soil is LEAST likely to be affected by the addition of which of the following? A. Clay B. Humus C. Manure D. Pesticide E. Sand

D. Pesticide

Which of the following describes a fundamental characteristic of the green revolution in food resources? A. The application of higher levels of organic fertilizers to increase rice production B. Deforestation to provide field crops with increased sunlight for photosynthesis C. The addition of calorie, fat, and fiber percentages to the information provided on food package labels D. The development of new strains of crops with higher yields E. The discovery that chlorophyll adds nutritional value to wheat, rice, and sorghum

D. The development of new strains of crops with higher yields

The land on a 100-acre farm is equally suited for grazing cattle and corn. Which would produce the greatest number of calories for human consumption? A. 100 cattle, 0 corn B. 80 cattle, 20 corn C. 50 cattle, 50 corn D. 20 cattle, 80 corn E. 0 cattle, 100 corn

E. 0 cattle, 100 corn

Which of the following is likely to minimize soil erosion? A. High-yield crops B. Deforestation C. Herbicide use D. Annual plowing E. No-till agriculture

E. No-till agriculture

An insect population in an agricultural field is affected by monthly application of a pesticide, the likely cause of the increase in the insect population over time is due to A. Increase in population of insect predators B. Increase in average temperature over the summer C. Increase in soil salinity D. Decrease in moisture content of soil E. Survival of increasing numbers of resistant insects

E. Survival of increasing numbers of resistant insects

A healthy soil ecosystem is of primary importance in sustainable agriculture. Describe TWO viable agricultural practices that farmers can use to maintain or improve soil quality

Planting rows of trees can reduce soil erosion, as the roots of the trees will hold the soil in place, preventing it from blowing away. Crop rotation is the practice of planting different crops in the same area during subsequent seasons. It improves soil quality by adding nutrients back into the soil.