SOIL AND WATER MANAGEMENT CCA INTERNATIONAL EXAM

If a field has an 11 foot change in elevation over a distance of 1000 feet, the slope is ___% 0.011 0.11 1.1 11

1.1

the bulk density of 100cm^3 of dry soil that weights 145g is ____ g/c,^3 4.5 1.45 0.7 2.45

1.45

irrigation is needed when the soil moisture deficit equals 6 inches. how long will it be before irrigation is needed if the avg daily ET is 0.5 inches and one 1 inch rainfall event occurs with no runoff? Initial soil moisture deficit is 2 inches.

10 days

If a septic system is being planned for a housing subdivision, a ____ order soil survey is needed. 1st 2nd 3rd 4th

1st

The area of a rectangular field is 1250 feet long and over 700 feet wide is _____acres. 10 20 40 67

20

what is the percent crop residue cover if the avg number of residue intersections at 20 at 6 inch increments over 50 feet? 10 15 20 40

20

A day when there is _______profitability of precipitation would be best for pesticide application to minimize pesticide losses in runoff. 20% 40% 60% 80%

20%

which of the following NO3- concentrations would be considered hazardous to an infant? 10mg/L 34mg/L 40mg/L 44mg/L

44mg/L

the maximum value for plant avaliable water is_______ greatest in soils with large pores smallest in soils with small pores the difference between field capacity and wilting point different in different climates

the difference between field capacity and wilting point

in order to increase soil organic matter levels, _________ must be markedly reduced or eliminated fertilization use of legumes weed control tillage

tillage

what standards are used to determine if a water body is impaired?

total maximum daily load

a _____ is specifically designed to improve ground water quality before ground water can move to a stream.

tree planting

maximum ET generally occurs_____.

when atmospheric demand peaks

nutrient enrichment of a surface water is termed ________.

eutrophication

maximum plant available water is _____minus_____

field capacity minus permanent wilting point

which kind of soil structure would be typical for a good seed bed? granular blocky platy massive

granular

poorly drained soils that are wet most of the year are often ______. grey red brown pink

grey

which of the following are most sensitive to saline water? cattle pigs salt tolerant plants humans

humans

the stable form of soil organic matter is called_______. pumice humus fulvic acid illite

humus

potassium fixation occurs when which of the following clays is present in soil? montmorillonite humite illite kaolinite

illite

which of the following can decrease bulk density? burning crop residue equipment wheel traffic incorporating compost tillage

incorporating compost

which of the following favors increased soil microbial activity? temperature increases from 35c to 50c temperaute decreases from 35c to 25c increase in soil water content from 20 to 40 % of water holding capacity decrease in soil water content from 30 to 10 % of water holding capacity

increase in soil water content from 20 to 40% water holding capacity

Which of the following is not an example of a contribution of soil organic matter to soil properties? increased molybdenum availability increased nitrogen availability increased CEC increased soil aeriation

increased molybdenum availability

soil microorganisms cause ________in soil structure when crop residues are added to soil. increases decreases minor changes no changes

increases

any factor that _____runoff and _____surface protection, increases erosion decreases, decreses increases, increases decreased, increases increases, decreases

increases, decreases

_____decreases odor and NH3 losses from biosolids

injection

which of the below is an example of sub-surface drainage ditch precision leaching interceptor drain grassed waterway

interceptor drain

Water moving horizontally in a soil is called ____________ flow.

lateral

sediments in runoff decrease _____in surface waters

light penetration

maintaining crop residues on the surface and ____ reduce surface compaction

light tillage

which of the following pollutants is in water is NOT generally attributed to agriculture? phosphorus nitrate pesticides mercury

mercury

which of the following clays contributes most to CEC if the same amount of each clay is present? montmorillonite hydroxyapatite illite kaolinite

montmorillonite

cations are held on the CEC by ______charges on clay and organic matter neutral gravitational positive negative

negative

soil organic matter is a source of ______ for crops iron nitrogen potassium calcium

nitrogen

what is the most important soil property that affects soil health? CEC AEC downward drainage organic matter

organic matter

in most situations, surface soil______will be lower after water erosion occurs CEC PH organic matter content clay content

organic matter content

Soil ________ has little effect on sulfate movement.

pH

Knowing the drainage class of soil is helpful when building a _______.

pond, wetland, road (all of the above)

which of the following increases soil water storage? runoff evapotranspiration precipitation deep percolation/recharge

precipitation

Rapid water movement downward in large pores after a rain is called __________.

preferential flow

which of the following is most important in carbon sequestration? proper irrigation landing leveling reducing tillage good fertility

reducing tillage

which of the following must exist for ET to occur? high temps relative humidity gradient wind sun spots

relative humidity gradient

maintaining surface residues on a soil will ____surface soil warming in the spring retard enhance not affect eliminate

retard

good structure in the subsoil improves___ germination root elongation water table development anaerobioses

root elongatoin

phosphorus is transported by ____from fields

runoff

If a soil has an EC of 0.6 siemens per meter and contains 20 percent sodium on the CEC, it is a ______ soil. a. saline b. sodic c. saline-sodic d. acid

saline-sodic

Which kind of erosion removes a thin layer of soil? a. splash b. sheet c. rill d. gully

sheet

what is the textural class of soil that is 10 percent clay and 35 percent sand? sandy loam sand silt loam loamy sand

silt loam

which of the following textural classes has the largest potential available water? silt loam sandy loam silty clay loam clay

silt loam

which of the following factors does not affect wind erosion? surface roughness vegetation slope length soil texture

slope length

The amount of soil that can be lost by erosion, while crop production is maintained economically for the long-term is _____________________. soil erosion potential soil loss tolerance soil economic threhold soil maximum erosion limit

soil loss tolerance

_____irrigation allows the most control to prevent runoff

sprinkler

which of the following irrigation systems is least labor intensive? sprinkler flood furrow drip

sprinkler

which of the following increases as a soils clay content increases? surface area bulk density pore size particle size

surface area

seedling emergence is hindered by

surface crusting

runoff decreases as _______increases

surface residue

which of the following has the greatest impact on infiltration? tile drains evapotranspiration surface soil texture runoff

surface soil texture

which of the following is a kind of wind erosion that forms dust storms? suspension saltation surface creep incursion

suspension

which of the following would be an acceptable conservation practice for a steep slope cord production wind breaks tillage perpendicular contours terracing

terracing

soil structure modifies the physical properties of soil_____ biota microclimate texture color

texture

A horizon that contains illuviated clay is the _____ horizon. O A B C

B

When organic materials decompose, most of the C ends up as microbial cells O2 CO2 humus

CO2

the irrigation method where water is applied at low volume is ______.

drip

When crop residues are removed from a field, soil ________ increases

erosion

ten ppm of NO3- (mw is 62) is ___ 10ppm 10 mg/l 0.16meq/L All of the above

all of the above

Which of the following is negatively charged? anion cation AEC hyperion

anion

Subsurface compaction from tillage usually starts __________.

at the depth of tillage

_____are raised soil areas to improve drainage

beds

Phosphorus transport from a field can be reduced by _______.

buffer strip

Well water contamination from surface water can be prevented by using a ______.

casing

Which of the soil textures listed below has the highest porosity and lowest bulk density? sandy loam silt loam loamy sand clay

clay

which of the following soil textures has the greatest o/o porosity? clay loam silt loam sand

clay

Tile drain spacing is smallest for a ______ soil.

clay loam

soil erosion potewntial is highest in which of the following? clean-till no-till mulch-till strip-till

clean till

in a typical row crop production system, most of the soil organic matter originates from _______. green manures earthworms crop residue organic waste

crop residue

which of the following organic materials would be expected to mineralize the most nitrogen? sawdust dairy manure wheat straw peat moss

dairy manure

Limited soil moisture generally ___________ nutrient uptake

decreases

excessive soil moisture generally _____nutrient uptake

decreases

Leaching is most impacted by

depth to restrictive layers