AP Human Geography Quiz: Consequences Of Agricultural Practices

What this quiz covers

This quiz focuses on Consequences Of Agricultural Practices, giving you a quick way to practice the rules, question types, and explanations that matter most for AP Human Geography.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

Question 1

1. Terracing inevitably eliminates pest outbreaks by creating microclimates, so the main environmental consequence is universal biodiversity recovery on all farms.
2. Monoculture can increase vulnerability to pests and diseases, often encouraging heavier pesticide use and risking episodic crop failure when uniform crops lack resistance. (correct answer)
3. The key consequence is regional river salinization from canal seepage, because monoculture requires constant flooding that raises groundwater everywhere.
4. The main effect is global deforestation, since any single-crop system automatically expands into forests regardless of land tenure and yield levels.
5. Because the impacts are only local, monoculture cannot affect surrounding ecosystems; it simply changes farm profits without altering soils or pest dynamics.

Explanation: This question tests understanding of consequences of agricultural practices, specifically monoculture. The stimulus describes continuous soybean production leading to uniform genetics, simplified mechanization, but also nutrient depletion and pathogen susceptibility. Answer B correctly identifies that monoculture increases vulnerability to pests and diseases, encouraging heavier pesticide use and risking crop failure when uniform crops lack resistance. Answer C incorrectly focuses on river salinization from canal seepage, which is an irrigation consequence, not a monoculture consequence. Agricultural consequences questions require recognizing TRADEOFFS—most practices have both benefits and costs. Analyze at appropriate SCALE—some impacts are local (soil erosion), others regional (water depletion), others global (GHG emissions).

Question 2

1. CAFOs eliminate pollution because confinement makes manure disappear, ensuring clean water and air regardless of waste storage practices.
2. CAFOs mainly cause soil salinization by pumping irrigation water onto feedlots, making salt crusting the dominant environmental issue.
3. The primary impacts occur only at the global scale, since local nutrient runoff is negligible compared with worldwide ocean currents.
4. CAFOs can increase localized water and air pollution from concentrated manure and emissions, even as they improve production efficiency. (correct answer)
5. Any CAFO inevitably contaminates all regional aquifers, regardless of lining, treatment, setback distances, or regulatory oversight.

Explanation: This question tests understanding of consequences of agricultural practices, specifically CAFOs (concentrated animal feeding operations) and their pollution impacts. The stimulus describes how high-density livestock facilities reduce production costs but create concentrated waste that can pollute water and air. The correct answer (D) accurately identifies these consequences: CAFOs can increase localized water and air pollution from concentrated manure and emissions, even as they improve production efficiency. Answer A incorrectly claims CAFOs eliminate pollution because confinement makes manure disappear, ignoring the reality that concentrating animals concentrates waste and its environmental impacts. Analyze at appropriate SCALE—CAFO impacts are most severe locally (water contamination, air quality) and regionally (nutrient loading in watersheds), showing how industrial agriculture creates geographically concentrated environmental costs.

Question 3

1. Pollution occurs because animals are confined, concentrating manure in small areas that can exceed local absorption and treatment capacity. (correct answer)
2. CAFOs are purely beneficial since concentrating animals automatically eliminates manure and guarantees clean water regardless of storage or application practices.
3. The problem is mainly shifting cultivation, because short fallow cycles near forests create manure lagoons and nutrient runoff on tropical frontiers.
4. The key impact is global desertification, since CAFOs immediately remove all regional rainfall and permanently dry climates at continental scales.
5. Water contamination is inevitable in every CAFO, because management choices and regulations cannot alter nutrient losses or emissions outcomes.

Explanation: This question tests understanding of consequences of agricultural practices, specifically CAFOs. The stimulus describes confined livestock operations that concentrate manure, leading to waterway pollution and emissions when management is inadequate, varying by regulation and technology. Choice A accurately explains this consequence by stating pollution arises from concentrated manure exceeding local capacity for absorption and treatment, aligning with the brief's points. Choice D is a distractor that ignores scale, exaggerating CAFOs' impact to global desertification by removing all rainfall, which overstates local effects. Agricultural consequences questions require recognizing TRADEOFFS—most practices have both benefits and costs. Analyze at appropriate SCALE—some impacts are local (soil erosion), others regional (water depletion), others global (GHG emissions). Note consequences depend on CONTEXT—irrigation can cause salinization if poorly managed.

Question 4

1. Organic farming always outyields conventional agriculture while eliminating all environmental impacts, making tradeoffs unnecessary across diverse climates.
2. Organic systems can reduce chemical inputs and improve some soil outcomes, but lower yields may increase land pressure depending on context. (correct answer)
3. The described effects are mainly caused by irrigation canals, since salinization and aquifer decline are the defining outcomes of organic certification.
4. The most important consequence is only local aesthetic improvement, because organic practices cannot influence soils, biodiversity, or land demand.
5. Organic farming inevitably restores all ecosystems within a decade, regardless of crop choice, rotation design, pest pressure, or nearby land uses.

Explanation: This question tests understanding of consequences of agricultural practices, specifically organic farming. The stimulus evaluates organic systems that limit synthetics and use natural methods, yielding soil and biodiversity gains but potentially lower outputs requiring more land. Choice B accurately illustrates this consequence by pointing out reduced chemicals and soil improvements alongside possible land pressure from lower yields, depending on context as noted. Choice A functions as a distractor with only positive claims, asserting organic farming always outyields conventional methods without tradeoffs, ignoring yield variations. Agricultural consequences questions require recognizing TRADEOFFS—most practices have both benefits and costs. Analyze at appropriate SCALE—some impacts are local (soil erosion), others regional (water depletion), others global (GHG emissions). Note consequences depend on CONTEXT—irrigation can cause salinization if poorly managed.

Question 5

1. CAFOs primarily reduce pest outbreaks in crops by increasing genetic diversity, so nearby farms need fewer pesticides regardless of manure handling practices.
2. The key consequence is nutrient pollution from concentrated manure, which can degrade water quality and air quality, depending on storage and land-application controls. (correct answer)
3. CAFOs are purely harmful because they always contaminate every river in a region, even when waste is treated, monitored, and applied at agronomic rates.
4. The main impact occurs only inside the barns, so broader watershed effects are negligible and cannot extend beyond the facility boundary.
5. CAFO impacts are best explained by irrigation-driven salinization, since livestock confinement creates salt crusts through canal evaporation on surrounding cropland.

Explanation: This question tests understanding of consequences of agricultural practices, specifically CAFOs. The stimulus describes CAFOs as high-density livestock operations that efficiently produce meat but generate concentrated manure risking pollution. Choice B accurately identifies nutrient pollution from manure as the key consequence, degrading water and air quality depending on management. Choice C is a distractor that is deterministic, claiming CAFOs always contaminate every river even with treatment, ignoring mitigation possibilities. Agricultural consequences questions require recognizing TRADEOFFS—most practices have both benefits and costs. Analyze at appropriate SCALE—some impacts are local (soil erosion), others regional (water depletion), others global (GHG emissions).

Question 6

1. Monoculture can heighten pest and disease vulnerability because uniform host plants across large areas facilitate rapid spread, though effects vary with management and landscape diversity. (correct answer)
2. Monoculture always improves soil structure and eliminates fertilizer needs, so long‑term yields rise automatically without considering rotations or local nutrient balances.
3. Terracing increases pest vulnerability by creating flat steps that trap insects, so monoculture regions should replace terraces with steep slopes to reduce outbreaks.
4. The key consequence is only local price volatility in one village market, with no broader ecological implications for soils, pests, or regional food systems.
5. Monoculture inevitably causes total crop failure every season because genetic uniformity guarantees that one pest will always appear and destroy all fields.

Explanation: This question tests understanding of consequences of agricultural practices, specifically monoculture. The stimulus explains that monoculture involves planting a single uniform crop over large areas, which can simplify operations but increases pest and disease risks due to lack of diversity. Choice A correctly illustrates heightened vulnerability to pests and diseases, as uniform plants facilitate rapid spread, with effects varying by management. Choice B is a distractor that is only positive, claiming monoculture always improves soil and eliminates fertilizers, ignoring nutrient depletion risks. Agricultural consequences questions require recognizing TRADEOFFS—most practices have both benefits and costs. Note consequences depend on CONTEXT—irrigation can cause salinization if poorly managed.

Question 7

1. Green Revolution packages typically raise yields but can increase chemical runoff and water stress when inputs and irrigation intensify without adequate safeguards. (correct answer)
2. Green Revolution adoption always eliminates the need for irrigation and fertilizers because improved seeds produce maximum harvests in any soil and climate.
3. Terracing causes pesticide resistance by forcing farmers to plant the same crop on steps, so Green Revolution impacts are mainly from hillside construction.
4. The most direct result is only a household-level dietary shift, with no regional implications for water quality, soils, or agrochemical use patterns.
5. Green Revolution technologies inevitably collapse ecosystems everywhere, because any fertilizer use automatically produces irreversible dead zones in all rivers.

Explanation: This question tests understanding of consequences of agricultural practices, specifically Green Revolution tech. The stimulus describes how Green Revolution technologies like high-yielding seeds, fertilizers, pesticides, and irrigation boost yields but can lead to runoff, resistance, and water stress. Choice A accurately states that these packages raise yields but increase chemical runoff and water stress without safeguards. Choice E is a distractor that is deterministic, claiming technologies inevitably collapse ecosystems everywhere, ignoring variations in management. Agricultural consequences questions require recognizing TRADEOFFS—most practices have both benefits and costs. Note consequences depend on CONTEXT—irrigation can cause salinization if poorly managed.

Question 8

1. Monoculture can heighten pest and disease vulnerability due to genetic uniformity, sometimes increasing fungicide use and causing large-scale plantation losses. (correct answer)
2. Monoculture primarily creates salinized soils because banana exports require seawater irrigation, which deposits salt crystals on all tropical farmland.
3. The practice is entirely negative, so it always collapses immediately; no monoculture can persist long enough to produce export surpluses.
4. The main impact is global only; plantation disease cannot affect local ecosystems because pathogens do not alter pesticide decisions or land use.
5. Disease outbreaks are guaranteed in every monoculture each year, regardless of cultivar choice, quarantine, rotations, or integrated pest management.

Explanation: This question tests understanding of consequences of agricultural practices, specifically monoculture. The stimulus describes banana plantations with single cultivar uniformity creating vulnerability to fungal diseases requiring replanting or intensified chemical controls. Answer A correctly identifies that monoculture heightens pest and disease vulnerability due to genetic uniformity, sometimes increasing fungicide use and causing large-scale plantation losses. Answer B incorrectly claims monoculture creates salinized soils through seawater irrigation, which confuses monoculture with irrigation consequences. Agricultural consequences questions require recognizing TRADEOFFS—most practices have both benefits and costs. Note consequences depend on CONTEXT—irrigation can cause salinization if poorly managed.

Question 9

1. The central consequence is terrace maintenance labor, because groundwater pumping primarily increases the need to rebuild hillside walls after storms.
2. Irrigation can contribute to water depletion at regional basin scales when withdrawals exceed recharge, especially during drought and expanded irrigated acreage. (correct answer)
3. Irrigation is purely beneficial, so aquifers always recharge faster than pumping and wetlands inevitably expand wherever irrigation is introduced.
4. The effect is only on a single farm; pumping cannot reduce wetland baseflow because hydrologic connections never operate across landscapes.
5. Aquifer depletion is automatic and identical in every irrigated region, regardless of recharge rates, crop choice, governance, or irrigation technology.

Explanation: This question tests understanding of consequences of agricultural practices, specifically irrigation. The stimulus describes groundwater pumping for irrigated alfalfa causing declining water tables and reduced wetland baseflow during droughts. Answer B correctly identifies that irrigation can contribute to water depletion at regional basin scales when withdrawals exceed recharge, especially during drought and expanded irrigated acreage. Answer A incorrectly focuses on terrace maintenance labor, which is unrelated to groundwater pumping for irrigation. Analyze at appropriate SCALE—some impacts are local (soil erosion), others regional (water depletion), others global (GHG emissions). Agricultural consequences questions require recognizing TRADEOFFS—most practices have both benefits and costs.

Question 10

1. Monoculture reduces risk by guaranteeing stable prices worldwide, since global commodity markets do not fluctuate for agricultural products.
2. Dependence on a single crop concentrates biological and market exposure, so pests or price declines can affect most income at once. (correct answer)
3. Terracing causes export price shocks because hillside steps block trade routes, making monoculture an insignificant factor in livelihoods.
4. These effects occur only at the global scale; individual households cannot experience economic vulnerability from cropping decisions.
5. Any monoculture automatically collapses within one season everywhere, regardless of pest management, storage, credit, or insurance availability.

Explanation: This question tests understanding of consequences of agricultural practices, specifically monoculture and its economic vulnerability. The stimulus describes how replacing diverse food plots with single cash crops can increase income but also increases vulnerability to pests and price volatility. The correct answer (B) accurately explains why this occurs: dependence on a single crop concentrates biological and market exposure, so pests or price declines can affect most income at once. Answer A incorrectly claims monoculture reduces risk by guaranteeing stable prices, ignoring the reality of volatile global commodity markets and pest outbreaks. Note consequences depend on CONTEXT—monoculture's risks can be partially mitigated through insurance and cooperatives but not eliminated, showing how institutional factors modify but don't erase the inherent vulnerabilities of specialized production.

Question 11

1. Terracing can conserve soil by reducing runoff and erosion, but it is labor intensive and may fail without maintenance, increasing localized slope instability. (correct answer)
2. Terracing always causes regional water depletion by diverting rivers into canals, making salinization unavoidable across entire basins.
3. Terracing is purely harmful because it inevitably triggers landslides on every hillside, regardless of design, rainfall, or wall maintenance.
4. The main effect is global biodiversity increase, because terraces automatically create forests and eliminate all erosion in any climate zone.
5. Only national-level impacts matter; terracing cannot meaningfully change erosion or sedimentation at the field and watershed scales.

Explanation: This question tests understanding of consequences of agricultural practices, specifically terracing. The stimulus describes how terraces reduce erosion when maintained but require substantial labor and can fail without upkeep, potentially causing localized instability. Choice A accurately captures this dual nature: terracing conserves soil by reducing runoff/erosion but is labor-intensive and may increase slope instability if maintenance lapses. Choice C wrongly portrays terracing as purely harmful, ignoring its proven soil conservation benefits when properly maintained. Analyze at appropriate SCALE—some impacts are local (soil erosion), others regional (water depletion), others global (GHG emissions). Terracing exemplifies how agricultural solutions create new management requirements and potential failure points.

Question 12

1. Shortened fallow cycles can increase deforestation and reduce soil nutrient recovery, especially where repeated clearing outpaces regrowth. (correct answer)
2. Slash-and-burn permanently enriches soil everywhere by adding ash, eliminating the need for long fallows in all tropical settings.
3. Irrigation canals built for shifting cultivation cause salinization, making salt crusts the dominant driver of forest loss.
4. The primary impact is global sea-level rise, because small forest clearings directly expand ocean volume over decades.
5. Once shifting cultivation begins, deforestation is unavoidable and identical across regions, regardless of fallow length or land tenure.

Explanation: This question tests understanding of consequences of agricultural practices, specifically slash-and-burn cultivation and its environmental impacts. The stimulus describes how shortened fallow periods prevent forest regeneration and soil nutrient recovery, leading to expanded deforestation. The correct answer (A) accurately identifies this consequence: shortened fallow cycles increase deforestation and reduce soil nutrient recovery when repeated clearing outpaces regrowth. Answer B makes the deterministic error of claiming slash-and-burn permanently enriches soil everywhere, ignoring that ash nutrients are quickly depleted without adequate fallow periods. Note consequences depend on CONTEXT—slash-and-burn can be sustainable with long fallows but becomes destructive when population pressure shortens recovery time, showing how the same practice has different outcomes based on management intensity.

Question 13

1. Irrigation-driven salinization, because burning vegetation adds salts that accumulate in all soils regardless of rainfall or fallow length.
2. A nutrient pulse from ash followed by fertility decline when fallows are shortened, often increasing pressure for additional forest clearing. (correct answer)
3. Permanent soil improvement and continuous high yields, because burning always creates long-lasting humus and prevents erosion in every tropical setting.
4. Only plot-scale effects with no landscape change, since shifting cultivation cannot alter regional forest cover or habitat mosaics.
5. Terrace formation on steep slopes, because shifting cultivators typically build stone walls that stabilize hillsides and reduce runoff everywhere.

Explanation: This question tests understanding of consequences of agricultural practices, specifically slash-and-burn/shifting cultivation. The stimulus describes how burning releases nutrients from ash but fertility declines when fallow periods shorten, potentially driving more forest clearing. Choice B correctly identifies this sequence: initial nutrient pulse from ash, followed by declining fertility with shortened fallows, creating pressure for additional clearing. Choice C wrongly claims burning creates permanent improvement, ignoring that nutrients from ash are quickly depleted without adequate fallow regeneration. Agricultural consequences questions require recognizing TRADEOFFS—most practices have both benefits and costs. Shifting cultivation can be sustainable with long fallows but becomes destructive when population pressure shortens regeneration periods.

Question 14

1. The primary consequence is permanent soil enrichment, because ash nutrients accumulate year after year regardless of leaching or fallow length.
2. The key consequence is salinization from standing irrigation water, since burning vegetation typically increases dissolved salts in canal networks.
3. Where fallow periods shorten, slash-and-burn can accelerate deforestation and soil nutrient decline, with outcomes shaped by local conditions. (correct answer)
4. The main effect is only global-scale warming, because smallholder burning dominates world greenhouse emissions more than all industry combined.
5. Deforestation and erosion occur everywhere and immediately, because slash-and-burn always destroys soils regardless of rainfall, slope, or fallow management.

Explanation: This question tests understanding of consequences of agricultural practices, specifically slash-and-burn. The stimulus reviews slash-and-burn where burning provides temporary nutrients, but short fallows under land scarcity lead to erosion, nutrient decline, and forest fragmentation. Choice C accurately identifies this consequence by noting accelerated deforestation and soil decline with shortened fallows, shaped by local conditions as emphasized. Choice D serves as a distractor that ignores scale, claiming smallholder burning dominates global warming more than industry, which exaggerates its worldwide impact. Agricultural consequences questions require recognizing TRADEOFFS—most practices have both benefits and costs. Analyze at appropriate SCALE—some impacts are local (soil erosion), others regional (water depletion), others global (GHG emissions). Note consequences depend on CONTEXT—irrigation can cause salinization if poorly managed.

Question 15

1. Shortened fallow reduces biomass recovery and nutrient cycling, so soils lose fertility faster and additional forest clearing may increase to maintain production. (correct answer)
2. Irrigation canals raise soil salinity in shifting cultivation plots, so farmers burn forests mainly to flush salts from the root zone.
3. Slash-and-burn is purely beneficial because ash permanently fertilizes soils, making repeated cultivation sustainable everywhere without any need for fallow.
4. The main effect is global atmospheric change only, since shifting cultivation has no meaningful local impacts on soils or surrounding forests.
5. Deforestation always accelerates regardless of fallow length, because shifting cultivators inevitably clear new forest annually even when yields remain stable.

Explanation: This question tests understanding of consequences of agricultural practices, specifically slash-and-burn. The stimulus details how slash-and-burn releases nutrients through burning but requires fallow periods for soil recovery, and shortened fallows lead to declining fertility and more forest clearing. Choice A best explains that shortened fallows reduce biomass recovery and nutrient cycling, causing faster soil fertility loss and increased clearing. Choice C is a distractor that is only positive, stating slash-and-burn is purely beneficial with permanent fertilization, ignoring the need for fallow. Agricultural consequences questions require recognizing TRADEOFFS—most practices have both benefits and costs. Analyze at appropriate SCALE—some impacts are local (soil erosion), others regional (water depletion), others global (GHG emissions).

Question 16

1. Irrigation can deplete surface water and alter river ecosystems, though efficiency improvements may reduce impacts depending on adoption and governance. (correct answer)
2. Irrigation is always environmentally neutral because diverted water returns instantly to rivers unchanged, making drought shortages impossible.
3. The described impacts are mainly due to monoculture, since planting one crop automatically reduces river flow even without diversions.
4. The most important consequence is global deforestation, because canal construction requires clearing entire continental forests regardless of location.
5. River depletion inevitably occurs in every irrigated basin, because technology and institutions cannot influence water savings or allocation outcomes.

Explanation: This question tests understanding of consequences of agricultural practices, specifically irrigation. The stimulus assesses river diversions for irrigation that reduce flows, warm waters, and affect habitats, with downstream shortages during droughts, mitigable by efficiency but varying by governance. Choice A accurately illustrates this consequence by highlighting surface water depletion and ecosystem changes, with potential reductions through improvements depending on adoption. Choice C is a distractor attributing the wrong practice, blaming monoculture for flow reductions without diversions, which misidentifies the cause. Agricultural consequences questions require recognizing TRADEOFFS—most practices have both benefits and costs. Analyze at appropriate SCALE—some impacts are local (soil erosion), others regional (water depletion), others global (GHG emissions). Note consequences depend on CONTEXT—irrigation can cause salinization if poorly managed.

Question 17

1. Terracing reduces erosion by slowing runoff on steep slopes, but it can be labor-intensive and vulnerable to wall failure in heavy storms. (correct answer)
2. Terracing primarily causes salinization, because standing water on steps always concentrates salts even in humid mountains with ample drainage.
3. Terracing is purely harmful since it inevitably triggers landslides everywhere, making slope agriculture impossible regardless of construction quality.
4. The main consequence is global deforestation, because terraces require clearing entire mountain ranges rather than modifying existing cultivated hillsides.
5. Terracing results from shifting cultivation, so its key effect is shortening fallow cycles and accelerating forest loss on tropical frontiers.

Explanation: This question tests understanding of consequences of agricultural practices, specifically terracing. The stimulus explains terracing on steep slopes to reduce erosion and retain moisture, but notes high labor demands and risks of wall failure causing landslides during storms. Choice A accurately identifies this result by stating terracing slows runoff and erosion while being labor-intensive and prone to failure in heavy rains, capturing the case study's balance. Choice B acts as a distractor by attributing the wrong practice, claiming terracing primarily causes salinization from standing water, which misapplies irrigation-related issues. Agricultural consequences questions require recognizing TRADEOFFS—most practices have both benefits and costs. Analyze at appropriate SCALE—some impacts are local (soil erosion), others regional (water depletion), others global (GHG emissions). Note consequences depend on CONTEXT—irrigation can cause salinization if poorly managed.

Question 18

1. The primary consequence is improved water quality, because repeated burning always sterilizes soils and prevents sediment from entering streams.
2. The key consequence is salinization from canal seepage, since shifting cultivators depend on permanent irrigation networks that raise groundwater tables.
3. Shortened fallow shifting cultivation can increase deforestation and erosion, raising stream sediment loads when regrowth is insufficient to stabilize soils. (correct answer)
4. The effect is only at the household plot scale; watershed sediment loads cannot change because small clearings never aggregate hydrologically.
5. Deforestation and erosion occur automatically in every shifting cultivation system, even with long fallows, low population density, and careful slope practices.

Explanation: This question tests understanding of consequences of agricultural practices, specifically slash-and-burn/shifting cultivation. The stimulus compares long-fallow systems maintaining mosaic landscapes with shortened cycles causing continuous clearing and higher stream sediment loads. Answer C correctly identifies that shortened fallow shifting cultivation increases deforestation and erosion, raising stream sediment loads when regrowth is insufficient to stabilize soils. Answer B incorrectly focuses on salinization from canal seepage, which is an irrigation consequence, not a shifting cultivation consequence. Analyze at appropriate SCALE—some impacts are local (soil erosion), others regional (water depletion), others global (GHG emissions). Agricultural consequences questions require recognizing TRADEOFFS—most practices have both benefits and costs.

Question 19

1. Terracing can reduce erosion by slowing water flow and trapping soil, but it often demands high labor inputs for building and maintaining retaining structures. (correct answer)
2. Terracing automatically causes widespread salinization because leveling slopes forces salt to rise to the surface, regardless of rainfall or drainage.
3. The main result is mechanized efficiency that eliminates labor needs entirely, since terraces are designed primarily for large combine harvesters.
4. Terracing is identical to slash-and-burn, so its direct result is rapid deforestation driven by repeated burning and shortened fallow periods.
5. Any terrace system inevitably prevents all landslides and wall failures, because engineered slopes cannot collapse under extreme rainfall.

Explanation: This question tests understanding of consequences of agricultural practices, specifically terracing. The stimulus describes stone and earthen terraces that slow runoff and capture sediment but require substantial labor for construction and maintenance. Answer A correctly identifies that terracing reduces erosion by slowing water flow and trapping soil, while demanding high labor inputs for building and maintaining structures. Answer B incorrectly claims terracing causes salinization by forcing salt to rise, which confuses terracing with irrigation consequences. Agricultural consequences questions require recognizing TRADEOFFS—most practices have both benefits and costs. Analyze at appropriate SCALE—some impacts are local (soil erosion), others regional (water depletion), others global (GHG emissions).

Question 20

1. Terracing typically reduces soil erosion by slowing runoff on steep slopes, but it can be labor-intensive to build and maintain. (correct answer)
2. Terracing always eliminates erosion permanently, so maintenance is unnecessary once the first stone wall is constructed.
3. Terracing primarily causes salinization because standing water in paddies concentrates salts, regardless of climate or drainage.
4. The main outcome is global desert expansion, because terrace construction directly increases planetary albedo and shifts monsoon systems.
5. Terracing affects only household gardens and cannot influence watershed erosion patterns at any larger, landscape scale.

Explanation: This question tests understanding of consequences of agricultural practices, specifically terracing and its effects on erosion control. The stimulus describes how terraces slow runoff and reduce erosion on steep slopes but require significant labor for construction and maintenance. The correct answer (A) accurately identifies this outcome: terracing typically reduces soil erosion by slowing runoff on steep slopes, though it is labor-intensive to build and maintain. Answer B makes the deterministic error of claiming terracing always eliminates erosion permanently without maintenance, ignoring that collapsed terraces can actually concentrate water flow and increase erosion. Analyze at appropriate SCALE—terracing affects both field-level erosion control and watershed-wide sediment flows, demonstrating how agricultural practices have impacts at multiple spatial scales.