Question 1

The R factor of the Universal soil-loss equation is concerned with _____.

Accepted Answer

The R factor in the Universal Soil Loss Equation (USLE) represents rainfall and runoff, which are climate-related factors influencing soil erosion.

Question 2

The revised universal soil-loss equation (RUSLE) differs from USLE in all ways but one of the following.

Accepted Answer

D

Question 3

Wind erosion accounts for about what percent of the total soil erosion losses in the United States?

Accepted Answer

D

Question 4

The universal soil-loss equation (USLE) suggests that soil erosion loss is a product of all but one of the following factors:

Accepted Answer

The USLE includes factors such as climate, slope length, slope steepness, and vegetative cover, but does not consider soil drainage as a factor in soil erosion loss.

Question 5

Which of the USDA land use capability classes (LUC) is most suitable for the production of row crops?

Accepted Answer

Class I lands are the most suitable for the production of row crops because they have the fewest limitations, requiring the least amount of management and conservation practices.

Question 6

Which of the following statements about soil erosion is not true?

Accepted Answer

The answer of Which of the following statements about soil...

Question 7

Which of the following statements is true?

Accepted Answer

The answer of Which of the following statements is true?
...

Question 8

In one field trial comparing no-till and conventional tillage, soil samples taken after 15 years without liming revealed that the pH of the upper 15 cm was lower on the no-till plot than on the conventional plot. Which of the following most likely accounts for this difference?

Accepted Answer

The answer of In one field trial comparing no-till and...

Question 9

The P factor in the Universal soil-loss equation is concerned with all but one of the following:

Accepted Answer

The P factor in the Universal soil-loss equation is concerned with precipitation and runoff, not contour tillage, strip-cropping, terraces, or vegetative covers. Soil erodibility is affected by factors such as soil texture, structure, and organic matter content.

Question 10

"Living" terraces involving rows of deep rooted grasses planted on the contour would be considered as contributing to which factor in the Universal soil-loss equation?

Accepted Answer

The "living" terraces, which involve planting rows of deep-rooted grasses on the contour, contribute to the P factor in the Universal Soil Loss Equation (USLE). The P factor represents the support practice factor, which includes practices that reduce the amount of erosion under specific conditions, such as contour farming, strip cropping, terracing, and cover crops.

Question 11

The U.S. Department of Agriculture has developed soil-loss tolerance limits (T values) for different soils. Which of the following is the highest T value assigned for most soils in this country (Mg/ha)?

Accepted Answer

The answer of The U.S. Department of Agriculture has developed...

Question 12

On which of the land use capability classes is suggested use restricted to non-production purposes, only wildlife and recreational purposes being appropriate?

Accepted Answer

Class VIII lands are those that are most severely limited, making them unsuitable for cultivation or any form of agricultural production. The suggested uses for these lands are restricted to non-production purposes, such as wildlife habitat and recreational activities, due to their limitations which may include factors like very steep slopes, poor soils, or other significant constraints.

Question 13

Wind erosion is generally not affected by _____.

Accepted Answer

Wind erosion is primarily driven by the force of wind and the size and weight of soil particles. Soil pH, on the other hand, does not significantly impact wind erosion.

Question 14

You have been asked to produce continuous corn on five different soils using both no-till and conventional management systems. Yields on the no-till and conventional-till systems are about the same on all but one of the soils. In which of the following suborders would the poor- performing soil most likely be classified?

Accepted Answer

Borolls are soils with a fragile structure that can easily be damaged by tillage. This can lead to compaction, reduced water infiltration, and reduced yield potential. Therefore, the poor-performing soil is most likely a Boroll because it did not perform well under conventional management, which involves tillage. The other suborders listed typically do not have issues with tillage or reduced yield potential from compaction.

Question 15

In explaining erosion processes to a friend, which of the following would you say about accelerated erosion?

Accepted Answer

Accelerated erosion is significantly influenced by the splash effect of raindrops on bare soil, which can dislodge soil particles and increase erosion rates. This contrasts with natural geological erosion processes, which are typically slower and less influenced by human activities.

Question 16

If you want to maximize the quantity of vegetative cover on soil which of the following tillage practices would you use?

Accepted Answer

No-tillage is a practice that leaves the soil undisturbed and retains the maximum amount of vegetative cover, which helps in preventing soil erosion and maintaining soil health.

Question 17

About what percentage of the total non-federal government owned rural lands is considered suitable for cultivation according to USDA land use capability classes (if appropriate management practices are employed)?

Accepted Answer

According to the USDA, approximately 55% of non-federal government owned rural lands are considered suitable for cultivation if appropriate management practices are employed.

Question 18

Conservation tillage systems are said to have all of the following advantages but one over conventional tillage systems

Accepted Answer

The answer of Conservation tillage systems are said to have...

Question 19

To be classified as a conservation tillage practice, a system must leave at least what portion of the soil surface covered with plant residues?

Accepted Answer

Conservation tillage practices aim to reduce soil erosion, improve soil health, and enhance plant growth. Leaving plant residues covering at least 30% of the soil surface is a key principle of effective conservation tillage. This helps to protect the soil from erosion, reduce water loss through evaporation, and promote organic matter buildup in the soil, which can improve fertility and structure.

Question 20

A soil has been managed using a no-till system for 10 years following many years of conventional tillage operations. Which of the following changes in surface soil properties would you expect due to the no-till management system?

Accepted Answer

No-till management system improves soil health and increases the organic matter content in the soil. This is because residues from the previous crops remain on the soil surface undisturbed, providing a food source for soil microbes and worms that break down the residues into organic matter. The increased organic matter content results in improved soil structure, water-holding capacity, and nutrient retention. The earthworm population would actually increase in a no-till system since the undisturbed soil environment provides a suitable habitat for them. Soil pH, aggregate stability, and bulk density are unlikely to be affected by the no-till management system.

Quiz 14: Soil Erosion and Its Control