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TASC Agricultural Systems study materials
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TASC Agricultural Systems practice questions

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Question 1Agricultural Systems

Which soil particle size fraction generally holds the most plant-available water and nutrients due to its high surface area and negative charge?

  1. Clay Correct answer.
  2. Gravel
  3. Coarse silt
  4. Sand

Explanation

Clay particles are the smallest soil fraction and carry a large surface area with net negative charge, which allows them to retain water and exchangeable cations. This high retention makes clay the main contributor to a soil's nutrient and water-holding capacity.

Question 2Agricultural Systems

A crop rotation that alternates a legume with a cereal is mainly used to supply which nutrient through biological fixation?

  1. Potassium
  2. Nitrogen Correct answer.
  3. Phosphorus
  4. Sulfur

Explanation

Legumes form symbiotic associations with rhizobia bacteria that convert atmospheric nitrogen into forms the plant can use. When legume residues decompose, that fixed nitrogen becomes available to the following cereal crop.

Question 3Agricultural Systems

Which irrigation method typically delivers water most efficiently to the root zone by minimizing evaporation and runoff?

  1. Drip irrigation Correct answer.
  2. Sprinkler irrigation
  3. Furrow irrigation
  4. Flood irrigation

Explanation

Drip irrigation applies water slowly and directly to the root zone through emitters, which limits evaporation, deep percolation, and runoff. This targeted delivery generally gives the highest application efficiency among common surface and overhead methods.

Question 4Agricultural Systems

In a livestock operation, which term describes the number of animals an area of pasture can support over a grazing season without degrading the resource?

  1. Stocking rate
  2. Grazing pressure
  3. Carrying capacity Correct answer.
  4. Forage yield

Explanation

Carrying capacity is the maximum animal load a pasture can sustain over a defined period without long-term damage to the forage and soil resource. Stocking rate is the actual number of animals placed on the land, which may be above or below that capacity.

Question 5Agricultural Systems

Which practice most directly reduces soil erosion on a steep cultivated field?

  1. Plowing the field before winter
  2. Removing crop residue after harvest
  3. Establishing contour strips of cover vegetation Correct answer.
  4. Planting rows up and down the slope

Explanation

Contour strips of cover vegetation slow surface water flow and trap sediment, which reduces erosion on sloping land. Aligning strips with the contour interrupts the downhill path of water and protects the soil between strips.

Question 6Agricultural Systems

Which macronutrient is most closely associated with promoting root development and early plant establishment?

  1. Chlorine
  2. Calcium
  3. Phosphorus Correct answer.
  4. Nitrogen

Explanation

Phosphorus supports root growth, energy transfer, and early seedling establishment, which is why it is often placed near the seed at planting. Nitrogen mainly drives vegetative growth, while calcium and chlorine serve other structural and osmotic roles.

Question 7Agricultural Systems

Which pest management approach relies on introducing a natural enemy such as a predatory insect to control a pest population?

  1. Chemical control
  2. Cultural control
  3. Mechanical control
  4. Biological control Correct answer.

Explanation

Biological control uses living organisms, including predators, parasitoids, and pathogens, to suppress pest populations. This approach harnesses natural ecological relationships rather than synthetic chemicals or physical barriers.

Question 8Agricultural Systems

Which factor is the primary reason for crop rotation's effectiveness in breaking soil-borne disease cycles?

  1. It increases soil compaction
  2. It raises soil pH consistently
  3. It eliminates all soil moisture
  4. It changes the host plant available to pathogens Correct answer.

Explanation

Many soil-borne pathogens are host-specific and decline when a non-host crop occupies the field. Rotating to a different crop starves these pathogens of their preferred host and interrupts their life cycle.

Question 9Agricultural Systems

A farmer wants to reduce nitrate leaching into groundwater after applying nitrogen fertilizer. Which timing strategy best limits leaching losses?

  1. Apply nitrogen in split applications matched to crop uptake Correct answer.
  2. Apply all nitrogen in late fall before winter rains
  3. Apply a single large dose at planting regardless of crop stage
  4. Apply nitrogen to bare soil just before heavy rainfall

Explanation

Split applications synchronize nitrogen supply with periods of rapid crop uptake, so less nitrate remains in the soil when drainage occurs. Matching application timing to demand reduces the pool of mobile nitrate vulnerable to leaching.

Question 10Agricultural Systems

A soil test reports a cation exchange capacity (CEC) of 5 cmol/kg, which is low. What does this most likely imply for management?

  1. The soil has limited capacity to retain applied cations and may need frequent small applications Correct answer.
  2. The soil can hold large reserves of exchangeable nutrients
  3. The soil pH cannot be adjusted with lime
  4. The soil is highly saline and unsuitable for crops

Explanation

Low CEC means fewer negatively charged exchange sites, so the soil retains fewer cations such as potassium, calcium, and magnesium. Such soils are prone to nutrient leaching and generally benefit from more frequent, smaller fertilizer applications.

Question 11Agricultural Systems

In a crop rotation, a farmer places corn after a legume cover crop that was terminated and left on the soil surface. Which benefit is most directly expected?

  1. Immediate reduction of soil pH
  2. Elimination of the need for any phosphorus
  3. Complete control of all weed species
  4. Increased nitrogen availability from decomposing legume residue Correct answer.

Explanation

Legume residue has a relatively low carbon-to-nitrogen ratio, so it decomposes quickly and releases nitrogen for the following crop. This mineralization can reduce the amount of synthetic nitrogen needed by the corn.

Question 12Agricultural Systems

Which grazing strategy is most likely to improve uniformity of pasture utilization and reduce overgrazing near water sources?

  1. Season-long set stocking
  2. Continuous grazing with a fixed herd
  3. Grazing only during the wettest months
  4. Rotational grazing with frequent paddock moves Correct answer.

Explanation

Rotational grazing with frequent moves limits the time animals spend in any one area, which reduces selective overgrazing and distributes manure more evenly. Shorter residence periods also give grazed plants time to recover before being re-grazed.

Question 13Agricultural Systems

A producer notices that a pesticide that worked previously now controls the target insect poorly. Which explanation best fits an evolved resistance scenario?

  1. The pest population has been selected for individuals that survive the treatment Correct answer.
  2. The crop has become allergic to the pesticide
  3. The pesticide container lost potency during storage
  4. The pest has learned to avoid the pesticide by observation

Explanation

Repeated exposure to a pesticide selects for individuals with traits that let them survive and reproduce, so the population shifts toward resistance over generations. This is an evolutionary process driven by selection pressure, not a change in the product itself.

Question 14Agricultural Systems

Which practice best reduces the risk of pesticide runoff into nearby surface water?

  1. Spraying to the edge of a waterway with no buffer
  2. Applying pesticide on saturated soil
  3. Applying pesticide just before a forecast heavy rain
  4. Maintaining a vegetated buffer strip between the field and the water body Correct answer.

Explanation

A vegetated buffer strip slows runoff and traps sediment and pesticide before it reaches surface water. Buffers are most effective when combined with appropriate application timing and rates.

Question 15Agricultural Systems

Which statement correctly distinguishes tillage from no-till regarding soil organic matter?

  1. Tillage increases organic matter by burying residue deeper
  2. Tillage generally accelerates organic matter loss by increasing aeration and microbial breakdown Correct answer.
  3. No-till reduces organic matter by preventing residue contact with soil
  4. No-till always eliminates organic matter decomposition

Explanation

Tillage aerates the soil and mixes residue into the profile, which stimulates microbial activity and speeds the oxidation of organic matter. No-till tends to conserve organic matter by reducing disturbance, though decomposition still occurs.

Question 16Agricultural Systems

A dairy producer wants to reduce phosphorus excretion in manure. Which feeding change is most directly effective?

  1. Increasing forage moisture content
  2. Increasing dietary phosphorus supplement
  3. Adding more salt to the ration
  4. Feeding according to animal requirement with reduced excess phosphorus Correct answer.

Explanation

Phosphorus excreted in manure is largely the portion not used by the animal, so matching dietary phosphorus to requirement reduces excess. Precision feeding lowers both feed costs and the environmental load of manure phosphorus.

Question 17Agricultural Systems

Which of these best describes the principle of integrated pest management (IPM)?

  1. Applying the strongest pesticide at the first sign of any insect
  2. Combining monitoring, thresholds, and multiple control tactics Correct answer.
  3. Eliminating all insects from the field regardless of damage
  4. Relying solely on genetically modified crops

Explanation

IPM combines scouting, economic thresholds, and a mix of biological, cultural, mechanical, and chemical tactics to manage pests economically and with minimal harm. Treatments are justified by measured pest pressure rather than by calendar or by the mere presence of pests.

Question 18Agricultural Systems

Which soil property most directly determines how quickly water infiltrates at the surface?

  1. Soil temperature in winter
  2. Soil texture and structure Correct answer.
  3. Soil color
  4. Organic matter color

Explanation

Infiltration depends on pore size and continuity, which are governed by texture and structure. Well-aggregated soils with larger pores admit water faster than compacted or fine-textured soils.

Question 19Agricultural Systems

A farmer uses a cover crop of cereal rye before planting soybeans. Which management concern is most relevant?

  1. Rye will increase soil erosion
  2. Rye will eliminate all soil moisture
  3. Rye residue may tie up nitrogen and delay soybean establishment if terminated too late Correct answer.
  4. Rye will add large amounts of nitrogen through fixation

Explanation

Cereal rye has a high carbon-to-nitrogen ratio, so its residue can immobilize nitrogen as microbes break it down. Late termination can also leave a thick mat that interferes with soybean planting and early growth.

Question 20Agricultural Systems

Which measure best indicates whether an irrigation schedule is supplying the right amount of water to a crop?

  1. Measuring soil moisture depletion within the root zone Correct answer.
  2. Estimating water use from the size of the field only
  3. Checking the color of the irrigation equipment
  4. Counting the number of irrigation events per week

Explanation

Monitoring soil moisture depletion in the root zone shows whether available water is being replenished in step with crop use. Scheduling based on measured depletion avoids both under-irrigation and excess leaching.

Question 21Agricultural Systems

Which statement best explains why legume-based pastures can sustain grazing without frequent nitrogen fertilizer?

  1. Legumes absorb nitrogen directly from soil air through leaves
  2. Legumes release nitrogen fixed by rhizobia as roots and nodules decay Correct answer.
  3. Legumes prevent nitrogen from leaving the soil
  4. Legumes convert phosphorus into nitrogen

Explanation

Rhizobia in legume root nodules fix atmospheric nitrogen, and when roots and nodules senesce, that nitrogen is released into the soil for the pasture. This internal cycling reduces the need for purchased nitrogen fertilizer.

Question 22Agricultural Systems

A field has a long history of the same crop and shows declining yields despite adequate fertilizer. Which diagnosis is most consistent with a build-up of a host-specific soil pathogen?

  1. Nutrient deficiency caused by low fertilizer rates
  2. Yield decline that improves when the crop is rotated to a non-host Correct answer.
  3. Yield decline caused by too much rainfall only
  4. Yield decline caused by high soil organic matter

Explanation

If yields recover when a non-host crop is grown, the cause is likely a pathogen that depends on the continuous host. Continuous cropping allows host-specific pathogens to accumulate to damaging levels, which rotation interrupts.

Question 23Agricultural Systems

In nutrient management planning, which approach best balances economic return with environmental protection?

  1. Ignoring manure nutrients because they are considered free
  2. Basing application rates on yield goals, soil tests, and realistic credit for legumes and manure Correct answer.
  3. Applying nitrogen at a flat rate to every field regardless of soil test
  4. Applying the maximum legal rate to guarantee high yields

Explanation

A sound plan credits all nutrient sources, including legumes and manure, and matches application to realistic yield goals and soil test levels. This avoids over-application that wastes money and increases losses to water and air.

Question 24Agricultural Systems

Which combination of practices most effectively builds soil aggregate stability over several seasons?

  1. Annual deep plowing and bare fallow
  2. Reduced tillage, continuous living roots, and organic amendments Correct answer.
  3. Frequent intensive tillage and residue removal
  4. Flood irrigation with no crop cover

Explanation

Aggregate stability develops when soil organic matter and root and microbial activity bind particles into stable units. Reduced disturbance, continuous roots, and organic inputs promote that binding over time.

Question 25Agricultural Systems

A grower must choose between two fields for a nitrogen-demanding crop. Field A has 3 percent organic matter and Field B has 1 percent organic matter, with similar texture and management. Which reasoning is most defensible?

  1. Field A likely supplies more mineralizable nitrogen and may need less fertilizer Correct answer.
  2. Organic matter content has no effect on nitrogen supply
  3. Field B will mineralize more nitrogen because it has less organic matter
  4. Field A will leach more nitrogen because organic matter repels water

Explanation

Higher organic matter contains more organic nitrogen that microbes mineralize into plant-available forms during the season. All else equal, Field A can be expected to contribute more nitrogen, allowing a reduced fertilizer rate.

Question 26Agricultural Systems

Which soil particle size class holds the most plant-available water and nutrients due to its high surface area?

  1. Gravel
  2. Clay Correct answer.
  3. Sand
  4. Silt

Explanation

Clay particles are the smallest soil separates and have by far the greatest surface area per unit mass, which lets them retain water and adsorb nutrient cations. Silt has intermediate surface area, and sand and gravel hold little water or nutrients. This high surface area is why clay-rich soils buffer nutrients strongly.

Question 27Agricultural Systems

Which soil organism group is most responsible for decomposing fresh organic residues and recycling nutrients in the soil food web?

  1. Bacteria and fungi Correct answer.
  2. Earthworms
  3. Moles
  4. Nematodes

Explanation

Bacteria and fungi are the primary decomposers that break down organic residues and release nutrients in plant-available forms. Earthworms and other fauna assist by fragmenting residue and mixing soil, but the microbial community performs the bulk of decomposition. Without microbes, residue would accumulate and nutrients would remain locked up.

Question 28Agricultural Systems

Which term describes the process by which water moves downward through soil pores under gravity?

  1. Capillary rise
  2. Infiltration
  3. Evapotranspiration
  4. Percolation Correct answer.

Explanation

Percolation is the downward movement of water through the soil profile after it has entered the surface. Infiltration is the entry of water across the soil surface, which precedes percolation. Capillary rise moves water upward, and evapotranspiration describes water loss to the atmosphere.

Question 29Agricultural Systems

Which plant family is associated with the ability to fix atmospheric nitrogen through a symbiotic relationship with rhizobia?

  1. Poaceae (grasses)
  2. Solanaceae (nightshades)
  3. Brassicaceae (mustards)
  4. Fabaceae (legumes) Correct answer.

Explanation

Legumes in the Fabaceae family form nodules where rhizobia convert atmospheric nitrogen into forms the plant can use. Grasses, mustards, and nightshades do not form this nitrogen-fixing symbiosis. This is why legumes are valued in rotations and pastures.

Question 30Agricultural Systems

Which term refers to the practice of growing two or more crops in the same field at the same time?

  1. Fallow
  2. Monoculture
  3. Intercropping Correct answer.
  4. Relay planting

Explanation

Intercropping is growing two or more crops together in the same field during the same season. Monoculture is the opposite, using a single crop. Fallow means leaving land uncropped, and relay planting involves overlapping life cycles rather than simultaneous full-season coexistence.

Question 31Agricultural Systems

Which form of nitrogen is most readily taken up by most crop plants from the soil solution?

  1. Nitrate Correct answer.
  2. Lignin-bound nitrogen
  3. Protein-bound nitrogen
  4. Elemental nitrogen gas

Explanation

Plants absorb nitrogen mainly as nitrate and ammonium from the soil solution. Elemental nitrogen gas is unavailable to plants without fixation, and protein- or lignin-bound nitrogen must first be mineralized by microbes. Nitrate is the most mobile and commonly absorbed form in aerated soils.

Question 32Agricultural Systems

Which irrigation method delivers water directly to the root zone through small emitters at low flow rates?

  1. Drip irrigation Correct answer.
  2. Sprinkler irrigation
  3. Flood irrigation
  4. Furrow irrigation

Explanation

Drip irrigation uses emitters to apply small amounts of water near the root zone, which reduces evaporation and runoff losses. Furrow and flood irrigation rely on gravity flow across the field, and sprinklers apply water through the air. Drip systems are valued where water efficiency and precise placement matter.

Question 33Agricultural Systems

Which animal nutrient is most often the limiting factor for forage digestibility in mature, stemmy grass hay?

  1. Salt
  2. Energy Correct answer.
  3. Selenium
  4. Calcium

Explanation

As grasses mature and become stemmy, fiber and lignin increase while digestible energy declines, making energy the primary limitation. Minerals such as calcium and selenium are important but are not the main reason mature hay supports poor performance. Livestock fed stemmy hay typically need supplemental energy to meet production needs.

Question 34Agricultural Systems

A grower applies manure to a field in autumn and wants to reduce nitrogen loss before the next spring crop. Which practice best limits nitrogen loss?

  1. Incorporating manure promptly and planting a cover crop Correct answer.
  2. Applying manure to frozen ground in winter
  3. Leaving manure on the surface without incorporation
  4. Spreading manure on a steep slope near a stream

Explanation

Prompt incorporation reduces ammonia volatilization and places nutrients where roots and microbes can capture them. A cover crop then takes up residual nitrogen and holds it through winter, reducing leaching. Leaving manure on the surface or applying it to frozen or sloping ground increases loss and runoff risk.

Question 35Agricultural Systems

A soil test shows a pH of 5.2 for a field intended for alfalfa, which prefers near-neutral pH. Which amendment is most appropriate?

  1. Ammonium sulfate
  2. Elemental sulfur
  3. Gypsum
  4. Agricultural lime Correct answer.

Explanation

Agricultural lime raises soil pH by neutralizing acidity and supplying calcium. Elemental sulfur and ammonium sulfate acidify soil further, and gypsum adds calcium without changing pH. Alfalfa performs poorly in strongly acid soil, so liming is the standard correction.

Question 36Agricultural Systems

A farmer wants to reduce soil erosion on a sloping field planted to a row crop. Which practice most directly slows water movement across the slope?

  1. Increasing tillage passes
  2. Installing contour strips of grass Correct answer.
  3. Planting rows up and down the slope
  4. Removing crop residue after harvest

Explanation

Contour strips of grass follow the slope's elevation and slow runoff, giving water time to infiltrate. Rows oriented up and down the slope channel water downhill and accelerate erosion. More tillage and residue removal both leave soil more exposed to detachment and loss.

Question 37Agricultural Systems

A producer wants to reduce heat stress in a grazing herd during summer. Which management action is most effective?

  1. Feeding extra hay in the afternoon
  2. Increasing stocking density in open pasture
  3. Providing shade and ensuring access to cool water Correct answer.
  4. Grazing only during the hottest midday hours

Explanation

Shade and abundant cool drinking water help animals dissipate heat and maintain intake during hot weather. Grazing during peak heat and crowding animals in open pasture increase heat load. Extra hay does not address the underlying heat stress.

Question 38Agricultural Systems

A grower observes yellowing between the veins of older leaves in a crop, while new leaves remain green. Which nutrient deficiency is most consistent with this pattern?

  1. Calcium
  2. Iron
  3. Magnesium Correct answer.
  4. Boron

Explanation

Magnesium is mobile in plants, so deficiency symptoms appear first on older leaves as interveinal chlorosis. Iron and calcium are immobile, so their symptoms show on new growth. Boron deficiency also affects growing points rather than older leaves.

Question 39Agricultural Systems

A farmer wants to reduce weed pressure in a vegetable rotation without relying solely on herbicides. Which strategy best fits an integrated approach?

  1. Planting the same crop in the same bed each season
  2. Combining cultivation, mulching, and competitive crop varieties Correct answer.
  3. Eliminating all crop residue from the field
  4. Using the same herbicide every year

Explanation

Integrated weed management combines cultural, mechanical, and biological tactics so no single method is relied on exclusively. Repeated use of one herbicide selects for resistant weeds, and repeating the same crop favors adapted weed species. Removing residue also sacrifices suppression and soil benefits.

Question 40Agricultural Systems

A livestock operation must store manure over winter. Which design feature most reduces the risk of groundwater contamination?

  1. A storage structure with an impermeable liner and runoff collection Correct answer.
  2. A pile placed in a drainage channel
  3. An uncovered pile on sandy soil
  4. A storage area on a slope draining toward a well

Explanation

An impermeable liner prevents leachate from reaching groundwater, and runoff collection captures contaminated water for later use or treatment. Sandy soils transmit water rapidly, and placing storage in a drainageway or above a well increases contamination risk. Siting and containment together protect water resources.

Question 41Agricultural Systems

A rancher wants to estimate pasture carrying capacity before turning out cattle. Which information is most essential?

  1. The color of the pasture grasses
  2. The number of fence posts in the paddock
  3. Available forage mass and estimated animal intake Correct answer.
  4. The breed registry status of the herd

Explanation

Carrying capacity depends on how much forage is available and how much livestock will consume over a period. Forage mass is usually estimated by clipping or pasture measurement, then divided by intake to estimate animal days. Grass color, fence details, and registry status do not quantify feed supply.

Question 42Agricultural Systems

A farmer notices a white, powdery coating on the upper leaf surfaces of squash plants late in the season. Which disease is most likely?

  1. Powdery mildew Correct answer.
  2. Root rot
  3. Damping-off
  4. Bacterial wilt

Explanation

Powdery mildew produces white, powdery fungal growth on leaf surfaces and is favored by warm days and cool nights. Damping-off attacks seedlings at the soil line, root rot affects roots below ground, and bacterial wilt causes wilting rather than a powdery coating. Correct identification guides the choice of resistant varieties and fungicides.

Question 43Agricultural Systems

A grower wants to reduce the risk of nitrate leaching from a sandy field receiving nitrogen fertilizer. Which approach is most appropriate?

  1. Applying nitrogen to bare soil with no crop growing
  2. Applying nitrogen just before heavy rain
  3. Applying all nitrogen at planting in a single large dose
  4. Splitting applications and applying only what the crop needs Correct answer.

Explanation

Splitting nitrogen applications matches supply to crop uptake and reduces the amount of nitrate present when leaching rains occur. A single large dose leaves excess nitrate vulnerable to downward movement, especially in sandy soils. Applications before heavy rain or to bare soil increase the risk substantially.

Question 44Agricultural Systems

A farmer wants to compare two tillage systems for their effect on soil organic carbon over five years. Which measurement plan is most appropriate?

  1. Measuring only the crop yield in year five
  2. Sampling soil carbon at the start and end under identical depths and methods Correct answer.
  3. Measuring soil carbon once at the end of year five
  4. Recording the number of tillage passes each season

Explanation

Detecting change in soil carbon requires baseline and endpoint sampling with consistent depth, sampling method, and laboratory procedures. A single endpoint measurement cannot show change without a starting value. Yield and tillage pass counts do not directly measure soil carbon.

Question 45Agricultural Systems

A producer has a pasture with patchy grazing, where some areas are grazed short and others are left tall. Which change is most likely to improve uniformity?

  1. Grazing continuously year-round with no rest
  2. Using smaller paddocks with shorter grazing periods and longer rest Correct answer.
  3. Increasing paddock size and reducing animal numbers
  4. Removing water sources from the pasture

Explanation

Smaller paddocks with short graze periods and adequate rest concentrate animals so they graze more evenly and allow plants to recover. Larger paddocks and continuous grazing allow selective grazing and patchiness. Removing water makes distribution worse rather than better.

Question 46Agricultural Systems

A field has a history of the same crop and shows poor growth, stunted roots, and declining yield despite adequate fertilizer. Which diagnosis is most consistent with these symptoms?

  1. Drought stress
  2. Nitrogen deficiency from insufficient fertilizer
  3. Herbicide carryover from a previous unrelated crop
  4. Soil-borne pathogen buildup Correct answer.

Explanation

Repeated cropping of the same species allows soil-borne pathogens and pests adapted to that host to multiply, producing stunting and yield decline despite adequate nutrition. Nutrient deficiency is less likely when fertilizer is adequate, and drought or herbicide carryover would not specifically track a continuous cropping history. Rotation and resistant varieties are common management responses.

Question 47Agricultural Systems

A producer wants to reduce phosphorus loss from a field with high soil test phosphorus while maintaining crop yield. Which strategy is most appropriate?

  1. Applying phosphorus in winter on frozen ground
  2. Drawing down soil phosphorus by applying only replacement rates based on crop removal Correct answer.
  3. Applying phosphorus at the maximum recommended rate every year
  4. Increasing erosion by leaving the soil bare

Explanation

When soil test phosphorus is already high, applying only what the crop removes prevents further buildup while maintaining fertility. Maximum annual applications keep adding to the surplus, and winter applications on frozen ground increase runoff risk. Bare soil also increases erosion and particulate phosphorus loss.

Question 48Agricultural Systems

A farmer must choose between two fields for a nitrogen-demanding crop. Field A has 3 percent organic matter and a sandy loam texture; Field B has 3 percent organic matter and a silt loam texture. Which statement best explains the likely difference in nitrogen supply?

  1. Field B will generally mineralize and retain more nitrogen due to greater water-holding and microbial habitat Correct answer.
  2. Field A will mineralize more nitrogen because sand warms faster
  3. Field B will supply less nitrogen because silt holds nutrients too tightly
  4. Both fields will supply identical nitrogen because organic matter is equal

Explanation

Although organic matter percentages are equal, silt loam soils hold more water and provide better microbial habitat, supporting more consistent mineralization and less leaching loss. Sandy loam drains rapidly, so mineralized nitrate is more easily leached. Texture therefore modifies how much of the organic nitrogen becomes available to the crop.

Question 49Agricultural Systems

A producer wants to design a crop sequence that reduces both soil erosion and nitrogen leaching over winter. Which sequence best meets both goals?

  1. Continuous corn with residue removed after harvest
  2. Corn followed by a cereal rye cover crop terminated in spring Correct answer.
  3. Soybean followed by clean tillage in autumn
  4. Corn followed by bare fallow through winter

Explanation

A cereal rye cover crop establishes quickly after corn, covering the soil to reduce erosion and taking up residual nitrogen that would otherwise leach. Bare fallow, clean tillage, and residue removal all leave the soil exposed and nutrients vulnerable. Terminating rye in spring releases captured nitrogen for the following crop.

Question 50Agricultural Systems

A dairy producer wants to lower the risk of manure-borne pathogens reaching surface water. Which combination of practices is most effective?

  1. Applying manure at agronomic rates, incorporating it, and maintaining vegetated buffers Correct answer.
  2. Storing manure in an open pile beside a drainage ditch
  3. Applying manure to saturated soils before a forecast storm
  4. Spreading fresh manure near a stream and relying on rainfall to dilute it

Explanation

Applying manure at agronomic rates limits excess nutrients, incorporation reduces surface exposure, and vegetated buffers filter runoff before it reaches water. Spreading near streams, storing beside drainage ditches, or applying before storms all increase transport risk. Timing and setback distances are central to pathogen control.