Agronomy Exam 2

A good bulk desity for plant growth is

1.3-1.35 g/cm3

In 1846, the Fayette A horizon had about how much SOM?

10%

SOM Stands for

Soil Organic Matter

The two most common textural classes in Iowa’s A Horizons are

loam & silt loam

A sand textered soil will generally have

Clay has high CEC & AWHC

Silt has a high water holding capacity

Two examples of types of soil struction are

granular

block

The textural size that retains the most cations is

d. clay

Two crops domesticated by the Mesopotamians were

Wheat & barley

A crop domesticated by the chineese that are still important today are:

Soybeans

In Iowa growing 1 ton of corn grain takes at least _____ tons of plant available water

100

The U.S.dust bowl occurred in

1930’s

A century of cotton & tobacco farming in colonial Virginia resulted in about

40 cm of soil erosion

the fayette soil is found

In and out of eastern Iowa

Where did the fayette soil form under

disciduos forest

The horizon sequence of the Fayette soil is

A, E, BT, C

The E horizon pH of the fayette soil is generally around?

4.5

Our reaction for respiration is

C6H12O6 + 6O2 > 6CO2 +6H2O

Soil erosion is defined as

detachment & movement of the soil

the first dictator of the USDA-NRCS was

D. Hugh H. Bennet from Anson County, North Carolina

One of the goals of land use planning is

to protect current uses

The kinetic energy initiator of accelerate water erosion

rain drop impact

A soil with a moist weight of 100g and an oven-dry weight of 80g has

25% MC

A tensiometer measures the ____ status of soil water

Energy