Mixed Deck — All Agronomy Topics Flashcards
100 cards from real Agronomy practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 20 Mixed Deck — All Agronomy Topics flashcards as text
Which cover crop is most commonly used to add nitrogen back to the soil?
Answer: Hairy vetch
Hairy vetch is a legume that fixes atmospheric nitrogen through root nodule bacteria, making it a popular nitrogen-building cover crop.
What is the primary goal of marker-assisted selection (MAS) in plant breeding?
Answer: To use DNA markers linked to traits for faster, more accurate selection
MAS uses molecular markers associated with desired traits to select superior plants without waiting for phenotypic expression, speeding up breeding cycles.
What is leaching requirement in irrigated agriculture?
Answer: Additional irrigation water needed to flush excess salts below the root zone
Leaching requirement is the fraction of applied irrigation water that must pass through and below the root zone to prevent salt accumulation to damaging levels.
Which of the following best describes 'vernalization' in crop plants?
Answer: Exposure to cold temperatures required to trigger flowering
Vernalization is the induction of flowering by exposure to prolonged cold, a requirement for many winter cereals like winter wheat.
Which of the following is an illustration of an intercrop?
Answer: Moong
Intercropping is the practice of growing two or more crops simultaneously on the same field. Moong (green gram) is a common legume frequently intercropped with cereals like bajra (pearl millet) or maize. Legumes like moong are beneficial intercrops because they fix atmospheric nitrogen, enriching the soil and benefiting the companion crop.
Center pivot irrigation systems are designed to apply water in what pattern?
Answer: Circular pattern around a central pivot point
Center pivots rotate around a fixed central point, applying water in a circular pattern and covering large areas efficiently.
What is the primary environmental concern associated with excess nitrate leaching from agricultural soils?
Answer: Groundwater and surface water contamination causing hypoxia and health risks
Nitrate leaches readily through soil into groundwater and streams, contaminating drinking water and contributing to aquatic hypoxia (dead zones) in water bodies.
Open-pollinated varieties differ from hybrid varieties primarily because they do what?
Answer: Breed true from saved seed and maintain genetic consistency
Open-pollinated varieties are genetically stable populations that breed true when seed is saved and replanted, unlike hybrids which segregate in F2.
What does the term 'action threshold' mean in IPM decision-making?
Answer: The pest level at which management action should be taken to prevent economic damage
The action threshold is the pest population level that triggers a management response before economic damage occurs, allowing time for effective intervention.
Which corn growth stage is characterized by the silks emerging from the ear?
Answer: R1
R1 is the silking stage in corn, when silks emerge from the husks and are ready for pollination.
What is evapotranspiration (ET) used for in irrigation management?
Answer: Estimating crop water use to schedule irrigation timing and amounts
ET estimates the combined water loss from soil evaporation and plant transpiration, providing the basis for scheduling irrigation to replace crop water use.
Which crop is classified as a C3 plant?
Answer: Wheat (Triticum aestivum)
Wheat uses the C3 photosynthetic pathway, fixing CO₂ directly via RuBisCO without a prior carbon-concentration step.
Roundup Ready crops were engineered to be tolerant to which herbicide?
Answer: Glyphosate
Roundup Ready crops contain a modified EPSPS gene that confers tolerance to glyphosate (Roundup), allowing herbicide application over the top of crops.
Which practice helps reduce lodging in small grain crops such as wheat?
Answer: Applying plant growth regulators
Plant growth regulators (PGRs) shorten and strengthen straw internodes, reducing the risk of lodging in wheat and other small grains.
What is Integrated Pest Management (IPM)?
Answer: A strategy combining biological, cultural, mechanical, and chemical controls to minimize economic damage
IPM uses a combination of methods—biological, cultural, mechanical, and chemical—to manage pests economically while minimizing environmental impact.
Which practice is a core principle of regenerative agriculture that builds soil organic carbon?
Answer: Keeping soils covered and minimizing disturbance with cover crops and reduced tillage
Keeping soils covered with living roots or residue and minimizing tillage disturbance builds soil organic carbon and improves soil biological health.
What does the term 'base saturation' refer to in soil science?
Answer: Percentage of CEC occupied by base cations
Base saturation is the percentage of a soil's CEC occupied by basic cations such as Ca²⁺, Mg²⁺, K⁺, and Na⁺.
What does the term 'photoperiodism' refer to in crop production?
Answer: Plant response to relative lengths of day and night
Photoperiodism is a plant's physiological response to the ratio of light to dark periods, which controls flowering in many crops.
Which of the following is considered a legume cover crop used to improve soil nitrogen?
Answer: Hairy vetch
Hairy vetch (Vicia villosa) is a legume cover crop that fixes atmospheric nitrogen through its symbiotic relationship with Rhizobium bacteria.
Which micronutrient deficiency commonly appears as interveinal chlorosis on young leaves?
Answer: Iron
Iron deficiency causes interveinal chlorosis on young leaves because iron is immobile in plants.