CCA - Certified Crop Advisor Crop Management Systems Questions and Answers 1 — Questions and Answers
Question 1: A producer practicing no-till farming on a field with heavy residue cover is planting corn into cool, moist soils. Which of the following is the most significant potential benefit of using a starter fertilizer in a 2x2 band placement?
- Increased germination rates due to seed-placed nutrients.
- Reduced risk of soil compaction from fertilizer application equipment.
- Enhanced early-season vigor and nutrient uptake in unfavorable conditions. (Correct answer)
- Complete elimination of the need for in-season nitrogen applications.
Correct answer: Enhanced early-season vigor and nutrient uptake in unfavorable conditions.
In no-till systems with heavy residue, soils are often cooler and wetter in the spring, which can slow root development and reduce nutrient mineralization and availability. Placing a starter fertilizer 2 inches to the side and 2 inches below the seed (2x2 placement) provides a concentrated band of essential nutrients like nitrogen and phosphorus that are readily accessible to the seedling's developing root system. This promotes enhanced early-season growth and vigor, helping the crop overcome the stressful cool, wet conditions.
Question 2: Which of the following best defines the 'Economic Threshold' in an Integrated Pest Management (IPM) program?
- The pest population density at which the cost of control equals the value of the crop.
- The pest population density at which control measures should be initiated to prevent the population from reaching the Economic Injury Level. (Correct answer)
- The maximum pest population a crop can tolerate without any yield loss.
- The point where 100% pest mortality is achieved after a pesticide application.
Correct answer: The pest population density at which control measures should be initiated to prevent the population from reaching the Economic Injury Level.
The Economic Threshold (ET) is a key concept in IPM that acts as an action threshold. It is the pest density at which management action must be taken to prevent the pest population from increasing to the Economic Injury Level (EIL). The EIL is the point where the cost of control is equal to the value of the crop loss that would be prevented. By acting at the ET, producers can prevent economic losses.
Question 3: A primary benefit of implementing crop rotation is the disruption of pest life cycles. How is this achieved?
- By increasing the genetic diversity of the cash crop, making it more resistant to all pests.
- By introducing allelopathic crops that are toxic to all soil organisms.
- By creating a more favorable environment for a wide range of generalist predators.
- By removing the specific host plant a pest requires for survival and reproduction for a period of time. (Correct answer)
Correct answer: By removing the specific host plant a pest requires for survival and reproduction for a period of time.
Many insect pests and plant diseases are host-specific, meaning they rely on a particular crop or plant family to complete their life cycle. By rotating to a non-host crop, the food source and reproductive habitat for that specific pest are removed. This disrupts the pest's life cycle, leading to a decline in its population.
Question 4: When terminating a grass cover crop like cereal rye using a roller-crimper for maximum effectiveness in an organic system, at which growth stage should the operation be performed?
- Vegetative stage (tillering)
- Boot stage
- Anthesis (flowering/pollen shed) (Correct answer)
- Dough stage
Correct answer: Anthesis (flowering/pollen shed)
For mechanical termination with a roller-crimper to be most effective, grass cover crops like cereal rye should be rolled at anthesis (when the plant is flowering and shedding pollen). At this stage, the plant has committed its energy to reproduction, and crimping the stems effectively stops water and nutrient flow, leading to a successful kill without regrowth. Rolling at earlier vegetative stages often results in incomplete termination and regrowth.
Question 5: A farmer is transitioning a field from conventional tillage to a long-term no-till system. Which of the following is a key soil health benefit they can expect to see over time?
- A rapid decrease in soil pH requiring immediate lime application.
- Increased soil bulk density in the upper soil profile.
- An accumulation of soil organic matter and improved soil structure. (Correct answer)
- Reduced water infiltration rates due to surface crusting.
Correct answer: An accumulation of soil organic matter and improved soil structure.
No-till farming eliminates soil disturbance, allowing crop residues to remain on the surface. This leads to a gradual increase in soil organic matter as the residue decomposes. The lack of tillage also allows for the development of stable soil aggregates, macropores from root channels and earthworms, which improves soil structure, water infiltration, and overall soil health.
Question 6: A grower wants to use a cover crop to suppress weeds and reduce soil erosion, but needs to terminate it effectively before planting a cash crop. Which termination method is generally considered least effective when used alone and often requires a follow-up action to prevent regrowth?
- Application of a systemic herbicide like glyphosate.
- Tillage that incorporates the cover crop residue.
- Roller-crimping at the correct growth stage.
- Mowing the cover crop. (Correct answer)
Correct answer: Mowing the cover crop.
While mowing can reduce the biomass of a cover crop, it is often ineffective as a sole termination method. Many cover crop species, especially grasses, will regrow from the crown after being mowed. For successful termination, mowing often needs to be followed by tillage or a herbicide application to prevent competition with the subsequent cash crop.
CCA - Certified Crop Advisor Crop Management Systems Questions and Answers 1
A producer practicing no-till farming on a field with heavy residue cover is planting corn into cool, moist soils.
Which of the following is the most significant potential benefit of using a starter fertilizer in a 2x2 band placement?