APES FRQ 2

Soil erosion graph question

2021

(c) Describe one economic advantage and one economic disadvantage of using GM crops

Advtantage: Increased profits/reduced costs due to use of GM crops that have: • Higher yields per acre • Lower fertilizer/pesticide/herbicide requirements Disadvantage: Higher yields per acre often lead to greater soil depletion, requiring higher costs of mitigation or Research and development

Describe the type of survivorship curve expected for these fish species.

Low survival rate in early life, followed by increased chances of survival as the organism matures. Most offspring die at a very young age and few reach maturity.

Identify the dependent variable stated in the hypothesis.

The amount of sediment run‐off

(b) Describe one environmental advantage and one environmental disadvantage of using GM crops.

1. Advantage: Higher yields per acre and hence less acreage needed/impacted by agriculture 2. Disadvantage: Native plant diversity may be impacted by the spread of genes to nonengineered crops.

Identify and describe one chemical soil test and one physical soil test that could be performed and explain how the results of these tests will allow the cooperative extension service to make specific recommendations for sustainable agriculture.

1. CHEMICAL TESTS: pH -- Measures the acidity or alkalinity or hydrogen ion concentration 2. PHYSICAL TEST: Water-holding capacity/Porosity 3. RECOMMENDATION: Adding soil additives such as sand, clay, or humus to affect ion-exchange capacity as well as moisture content and water-holding capacity

(d) 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.

1. Contouring or terracing---Building/installing water bars, terraces, etc-- Reduces soil erosion 2. Crop rotation Planting different crops in subsequent planting periods--- Lower herbicide/insecticide requirements---Adds nutrients back to the soil and Takes advantage of nitrogen-fixers (e.g., legumes)

(c) The burning of fossil fuels has been shown to increase the concentration of carbon in the atmosphere. Discuss TWO other human activities that increase the concentration of carbon in the atmosphere.

1. Deforestation—cutting down trees reduces the reservoirs for carbon OR cutting down trees can result in carbon being released back into the atmosphere through the process of decay/decomposition 2. Trash/waste incineration can release carbon (CO2, CO, carbon particulates)

Climate change is causing far-reaching ecosystem changes, including soil degradation in many of the world's biomes. Describe TWO ways that climate change can degrade soil.

1. Increased global temperatures and decreased precipitation cause desertification. 2. Increased temperatures lead to increased evaporation of irrigation water, resulting in soil salinization.

Describe TWO viable strategies for reducing the amount of land needed for agriculture.

1. Increasing crop yield: • The development of crops that can be grown closer together, are more resistant to pests, more resistant to weather extremes, etc., via artificial selection or GM technologies could increase crop yields. 2. Cover-cropping/intercropping/strip farming/strip cropping/alley cropping/polycultivation/ allowing for multiple crops to be grown on the same plot of land/etc. could increase crop yield by using the same plot of land during different seasons/growing noncompetitive crops together to use the space between rows/inhibiting crop diseases or pests/etc.

Describe two soil conservation practices that are designed to decrease soil erosion.

1. No-till Inject seeds into slits or holes in the soil by machine- minimum soil disturbance 2. Contour farming or planting Plow in rows with the contour of gently sloped land to slow water runoff

(a) Describe how TWO climate factors affect the rate of soil formation.

1. Temperature High- Increases rates of biological activity (decomposition) and chemical activity - inceases rates of soil formation Low- Decreases rates of biological activity (decomposition) - decreases rates of soil formation Increases the rate of weathering (frozen water expands, breaking rock) - increases the rate of soil formation 2. Wind Can carry in particles - increases rates of accumulation Can hasten rates of soil erosion - decreases rates of accumulation

c) Soil quality is a critical factor in agriculture. Identify TWO physical and/or chemical properties of soils and describe the role of each property in determining soil quality.

1. pH/acidity/alkalinity • Different plants have different pH tolerances; many plants grow best in neutral soils. 2. Particle size/texture; soil density/type (e.g., silt, clay, sand, loam) • Dictates soil's: - available oxygen, which is needed by plant roots/soil organisms, - ability to be worked for agriculture, - -ability to hold moisture - ability to hold nutrients - ability to allow water to infiltrate

Reply to the following questions based on the data in the graph i) Calculate the increase in the area of land used for growing GM [genetically modified] crops in developing countries from 1999 to 2003. Express your answer as a percentage of the 1999 value.

1999 (10 million hectares) to 2003 (20 million hectares) Increase of 10 million hectares = 100 percent increase

iii) Using the rate you calculated in part (ii), project the area of land that would have been expected to be used for GM crops in industrialized countries in 2004.

1999 ------------------------ 30 million hectares 2004 80 million hectares (must have units) 5 years 10 million hectare increase/yr 50 million hectares

ii) Calculate the annual rate of increase in land area used for growing GM crops in industrialized countries from 1997 to 1999.

1999- 30 million hectares 1997- 10 million hectares ------------- 2 years- 20 million hectares 20 million/2 years= 10 mil ha/yr *10 million hectares a year Ave. Ann. 75 percent

Question 4: Suppose that you have just started a summer internship working for a cooperative extension service, where you will collect soil samples, conduct laboratory and field tests, and make recommendations on soil conservation and agricultural practices.

2004

Explain one advantage and one disadvantage to using inorganic commercial fertilizers.

ADVANTAGE: Increases crop yield Speeds up the growing process DISADVANTAGE: Releases nitrous oxide (N2O) a greenhouse gas

(ii) Describe one method for remediating soil affected by acid deposition.

Add crushed limestone / lime / marble dust / bone meal / crushed egg shells or oyster shells

Describe the effect of adding a cover crop compared to using the no‐till method.

Adding a cover crop reduces the annual rate of soil erosion compared to using the no‐ till method.

Identify one variable that was not discussed that could affect the results of the study.

Amount of rainfall

c) Nitrate levels exceeding the United States Environmental Protection Agency's primary drinking water standard have been found in the groundwater of areas with intensive agriculture. (i) Identify one agricultural practice that can lead to elevated nitrate levels in groundwater.

Application of fertilizer Improper sealing of feedlots Improper construction or maintenance of animal waste lagoons

b) As soils form, distinct layers known as horizons develop over time. One of these is the A horizon. (i) Identify one specific biotic component of the A horizon. (ii) Identify one abiotic component of the A horizon

Biotic Humus, microorganisms, bacteria, earthworms, macroinvertebrates, roots, fungi, beetles, decomposers, insects Abiotic Sand, silt, clay, water, air, nutrients (N,P, K compounds), decomposing parent material, minerals, rocks, pebbles

(b) Oceans and terrestrial systems are also important carbon reservoirs. (i) Explain how atmospheric carbon is incorporated into two oceanic sinks.

Carbon (CO2) can be taken up by organisms like phytoplankton for photosynthesis • Carbon can be taken up by marine organisms and used for shells, skeletons, coral, etc. • Biological pump (organisms in the upper ocean sink to the bottom of the ocean) • Atmospheric CO2 can dissolve directly into ocean water OR atmospheric CO2 can dissolve into precipitation and ultimately reach the ocean

Identify the agricultural practice that could be used on a 15% slope without leading to a higher than tolerable loss of soil.

Crop rotation

(i) Identify the scientific question that resulted in the data presented in the graph.

Does crop rotation/tilling/not tilling/using cover crops on various slopes ichange erosion rates?

(e) Identify and describe one environmental advantage and one economic advantage of consuming locally grown produce.

Environmental: Decreased transportation of food, which results in: • Decreased fossil fuel consumption • Decreased greenhouse gases, climate impacts, or carbon footprint Economic: Boost in local economy not big business farms

iv) Identify one likely cause for the difference between the projected land area for GM crops in industrialized countries in 2004 and the actual land area for GM crops in industrialized countries in 2004.

Genetically modified crops faced: Increased public resistance (toward perceived risks, due to increased awareness following labeling of products) Decreasing market demand for products containing genetically modified organisms (GMOs) Governmental regulation/controls/limitations/bans that limited the planting/use of GM crops

Identify one biome that is characterized by soil that is rich in humus. Describe how humus originated in the soils of this biome, and TWO ways that humus improves soil conditions for plant growth.

Grasslands (temperate and tropical), hummus is formed by grasses that form a large amount of organic matter that decomposes How hummus helps soil: Provides nutrients/fertility for plants and soil organisms • Helps topsoil hold water (water-holding capacity) • Makes root growth easier

(ii) Describe one method to prevent or remediate soil salinization

Improving drainage (e.g., installing drainage tiles) will prevent precipitation/irrigation water from pooling and evaporating. • Irrigate with water that is low in salt content

(d) Acid deposition has affected soil quality in many parts of the northeastern United States. (i) Explain one way acid deposition onto soil can affect plant health.

Increased soil acidity may be outside of the optimal range of tolerance for the plant, resulting in poor plant growth or death. • Acid can leach cations/metal ions/nutrients from soil, making them less available to plants, thus decreasing growth.

Describe one way to add a control to improve the design of the study.

Measure sediment discharge/runoff prior to placing straw bales or planting grass compared to discharge after the bales/grass are in place (pre‐/post‐tests).

Identify one natural mechanism of soil erosion.

Moving/flowing water/ rainfall

(ii) Describe how the practice you identified in (c)(i) leads to elevated nitrate levels in ground water.

Nitrates infiltrate/percolate/seep into ground water. • Nitrates entering surface waters that recharge aquifers (must connect surface with ground water).

Identify one terrestrial sink, other than fossil fuels, that stores carbon for thousands to millions of years.

Old growth forests/trees that live for thousands of years (just "forests" does not earn credit) Trapped/incorporated into ice caps/glaciers Limestone or sedimentary rocks

(e) Phosphorus is another element important to all organisms. (i) Describe one major way in which the phosphorus cycle differs from the carbon cycle.

Phosphorus cycle does not typically have a gas/atmospheric phase It is more difficult for living organisms to access phosphorus since it has to be weathered from rocks and minerals (phosphorus cycle is much "slower" than the carbon cycle; phosphorus has fewer sinks than carbon)

(ii) Identify one reason that phosphorus is necessary for organisms.

Phosphorus is a component of nucleotides/ATP in cells It is necessary for the formation of DNA and RNA

The atmosphere is one important carbon reservoir. (i) Describe a biological process by which carbon is removed from the atmosphere and converted to organic molecules

Photosynthesis: the process by which plants/autotrophs take in carbon dioxide from the atmosphere and convert it into food/glucose/sugar/complex carbohydrates; plants/autotrophs fix carbon into food/glucose/sugar/complex carbohydrates.

(d) Identify an environmental problem that results from elevated atmospheric carbon concentrations. Discuss one consequence of the problem you identified.

Problem: Global climate change/global warming/increased global temperatures Consequence: -some species of plants and/or animals will not be able to survive temperature changes -climate zones will shift so some species may not be able to adapt -sea level rise which will flood habitats

Question 4- 2009

Question 4- The major issues in modern agriculture include the use of genetically modified crops and the implementation of sustainable agricultural practices

(ii) Describe a biological process by which carbon is converted from organic molecules to a gas and returned to the atmosphere

Respiration breaks down food/glucose/sugar/complex carbohydrates and releases CO2 into the atmosphere • Animals digest food and produce gases such as methane that can be emitted either through belching or flatulence

(e) One problem that can result from agriculture is soil salinization. (i) Describe how salinization occurs.

Salinization can occur when irrigation water evaporates (or is used by plants), leaving the salts behind in the soils. Misuse of salt-containing fertilizers and/or other soil amendments that contain salts (e.g., lime) may lead to soil salinization

Explain why the input of sediment to a stream can negatively affect reproduction of fish that lay their eggs in the gravel of the streambed.

Sediment can cover/bury eggs, which reduces the amount of oxygen, causing them to die.

Question 2016:

Soil is a complex mixture of living organisms and organic material, along with minerals and other abiotic components. Soils help sustain life and provide ecosystem functions.

Based on the data in the table above, make a claim about the stated hypothesis.

The data in the table shows that the grass is more effective at reducing sediment runoff. The hypothesis should be rejected.

2011- As the world's population increases and availability of new arable land decreases, providing sufficient food for the world's human population is becoming increasingly difficult. The table below shows the area of land needed to feed the world's population from 1900 projected to the year 2060.

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