Soil conservation and water management exam #2

Which of the following options is not considered a means of soil movement by wind erosion

Solution

Over time, land exposed to long term wind erosion may form which of the following conditions?

Desert pavement

Wind erosion is most common in dryland regions.

True

Rangeland is affected by wind erosion more than pasture.

True

Wind erosion carries away soil particles making the texture finer.

False

Of the three types of soil movement by wind, surface creep moves the largest particles but travels the shortest distance.

True

The term saltation or movement of soil by wind in short leaps was actually coined by the 1990's band House of Pain.

False

Soil particles smaller than 0.05mm are suspended by turbulent air currents during a wind erosion event.

True

Transport capacity is the amount of material a given wind can carry.

True

Wind velocity decreases closer to the surface.

True

Loss of topsoil from wind erosion will lead to less favorable growing conditions

True

Soil must be dry for wind erosion to occur.

True

IN 1992 NRCS estimated that soil loss from wind erosion impacted more than 116 million acres.

True

Surface creep accounts for 5 to 25 % of total movement during a wind erosion event.

True

From the following options, select the six characteristics of winds that cause wind erosion.

Gusts, friction velocity, Turbulence, Duration, Direction, Time of year

Keeping the soil covered is the most effective erosion control practice regardless of land use.

True

The vegetative cover factor for WEQ is always converted back to a small grain equivalent regardless of the crop.

True

Which of the following WEQ factors can be changed to reduce annual soil loss from wind erosion? Select all that apply.

K, L, I

Shelterbelts provide protection for crop fields from the effects of wind erosion. 

True

If tilling is required, the best practice would be to till as close to the time of planting as possible.

True

Which of the following options best describes the distance upwind that windbreaks and other barriers reduce wind velocity compared to their height?

twice the distance

Which of the following options best describes the distance downwind that windbreaks and other barriers reduce wind velocity compared to their height?

10 to 20 times the distance

Windbreaks provide protection for people and livestock from the effects of wind erosion.

True

Irrigation management is not important for wind erosion control.

False

The width of field factor for WEQ cannot exceed the longest possible measured distance across the field.

True

One of the best management practices for wind erosion control is orient rows parallel to prevailing winds.

False

WEQ or the Wind Erosion eQuation looks at a given period, usually a critical time of the year and doesn't make adjustments for changes in wind direction.

True

It can take 100-400 years to create 1 cm of topsoil.

True

The earliest modern reference to the word hydroponics was by W. F. Gericke in the 1920's.

True

A 10% increase in the soil carbon pool would equal how many years of human derived emissions?

30 years

Livestock production accounts for approximately how much of total greenhouse gas emissions?

7-18%

Which of the following climate types led to increases in soil carbon under all grazing intensities?

Moist/warm

1 acre foot of water equals 325,851 gallons

True

What is the average recharge rate for many areas in the aquifer?

1 inch/year

Approximately how much of the water used in irrigation for agriculture comes from the Ogallala aquifer?

~30%

Select all of the states below that the Ogallala aquifer extends under.

South Dakota, Wyoming, Kansas, Colorado, Oklahoma, New Mexico, Nebraska, Texas

The supply from the Ogallala aquifer has dropped by 9% since 1950.

True

The Ogallala aquifer formed millions of years ago from river sediment that originated with the erosion of the Rocky Mountains.

True

Which of the following options is not considered an input to the water cycle?

Transpiration

It is estimated that the irrigated acres of the Ogallala aquifer contribute how much money in crop sales annually?

$7 Billion

One of the success stories from the Ogallala region occurred in Kansas with the LEMA group in Sheridan county, where residents voluntarily reduced their pumping by how much over a 5 year period?

30%

How many gallons of water are contained in 1 acre foot of water?

325,851

The Ogallala aquifer extends beneath how many states?

8

Which of the following figures was responsible for the naming of the Ogallala aquifer in 1898?

N. H. Darton

Some areas of the Ogallala aquifer have dropped more than 1,000 feet.

False