AGRONOMY 114 Exam 2 Page 1

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1. Drip irrigation is most likely found in what soil type?

a) silt loam

b) loamy sand

c) clay loam

d) loam

e) sandy clay loam

2. Nitrogen is a primary nutrient that is a common limiting factor

in plant growth. Plants use the majority of the nitrogen to

form what?

a) carbohydrates

b) proteins

c) lipids

d) fats

e) lignin

3. Which crop is likely produced by the synthetic variety method?

a) wheat

b) maize

c) red clover

d) rice

e) soybean

4. The types of structural units in a soil do not affect

a) soil pore size

b) soil permeability to water and air

c) soil texture

d) water infiltration rate

e) water holding capacity

5. Genetic segregation occurs

a) in the F1 population of a cross between inbred lines

b) in the F1 population of a cross between two wheat

varieties

c) among the offspring of a corn plant after 7 generations

of self pollination

d) among the F2 plants following a cross between two soybean

varieties

e) among plants of the BC7 population in a backcross after

selecting out the desired characteristic (such as rust

resistance)

AGRONOMY 114 Exam 2 A Page 2

6. The negative effects of inbreeding on genetic improvement of

crop plants is minimized or overcome by

a) selection and culling of plants

b) hybridization of inbreds when feasible

c) selecting parents from outside the closely related line of

the progeny

d) b and c

e) all of the above

7. Suppose a person using the same variety of seed on the same

land measured a yield variation over ten years of 70 bushels

per acre. The average yield of this ten-year period was 150

bushels per acre. Pick the formula that gives the correct

answer.

a) 150 - 70 = 80, due to genotype

b) 150 + 70 = 220, due to genotype

c) 150 / 70 = 2.14, due to phenotype

d) 150 * 70 = 10,500, due to environment

e) 150 - 70 = 80, due to phenotype

8. Generally speaking, seeds would germinate most slowly in soils with

a) low capillary water

b) little surface trash

c) low iron content

d) 25% air content

e) little salt content

9. Which is true about a potato planter?

a) seed placement 1-2" deep is critical

b) good seed-to-soil contact is essential

c) covering the seed requires a shallow disking after planting

d) seed pieces are covered by "hilling" the soil over the

planted row by covering disks

e) seed placement is random because of the lack of placement

control of broadcasting

10. If a bag of seed has 80% germination, 90% purity, 0.2 other

crop seed and 1% damage, and has a quoted price of 0.26 per

kilogram, what is the real cost of the pure live seed?

a) 28 cents per kilogram

b) 29 cents per kilogram

c) 30 cents per kilogram

d) 36 cents per kilogram

e) 38 cents per kilogram

11. Over 99% of the total water needs of a farm in Central U.S.

is related to crop production. Most of the water used by

crops is for

a) grain moisture

b) stalk moisture

c) root moisture

d) flower structures

e) evapotranspiration

AGRONOMY 114 Exam 2 A Page 3

12. Suppose 200 bushels of wheat graded No. 1, 400 bushels of wheat

graded No. 3, and 600 bushels of wheat graded No. 5. If these

lots were blended, then the average grade for the overall

amount would be marketed and sold as what grade?

a) 1

b) 2

c) 3

d) 4

e) 5

13. The Loess Hills in western Iowa are an important and unique

ecological feature in Iowa. The parent material of the Loess

Hills was transported to form what type of soil?

a) alluvial

b) lacustrine

c) glacial

d) eolian

e) residual

14. Nitrate contamination in fresh water streams in a given year

would probably be greatest in the watershed that contains the

greatest amount of

a) sandy soils, soybeans, conventional tillage

b) loam soils, corn production, conventional tillage

c) loam soils, wheat production, conventional tillage

d) sandy soils, alfalfa production, conventional tillage

e) silt loam soils, corn production, no-tillage

15. Your neighbor has some extra seed from six years ago that she

is willing to sell you at a greatly reduced price. You want

seed with high vigor and therefore ask your neighbor if you can

have some seed to test the seed vigor. Which test would you do?

a) physiological dormancy test

b) tetrazolium test

c) accelerated aging test

d) sodium hypochlorite test

e) mechanical damage drop test

16. Good seed-to-soil contact is needed primarily to supply the

seed with

a) air

b) moisture

c) oxygen

d) nutrients

e) germination hormones

17. If the test weight (lbs./bu.) requirements for soybeans were

56 for No.1, 54 for No.2, 52 for No.3, and 49 for No.4, what

would the grade be for a load of soybeans that had a test

weight of 48 lbs/bu?

a) No.1

b) No.2

c) No.3

d) No.4

e) sample grade

AGRONOMY 114 Exam 2 A Page 4

18. The commercial weight of oats is 32 lbs/bu. A farmer brought a

load of oats into the local elevator. The gross weight of the

truck and oats was 32,000 lbs. The empty weight of the truck

was 12,000 lbs. The test weight of the sampled oats were 40

lbs/bu. At a value of 2/bu for oats weighing over 38 lbs/bu

test weight, what was the value of oats in the truck?

a) $1000

b) $1053

c) $1250

d) $1600

e) $2200

19. The important thing to remember when dealing with cereal

endosperm genetic traits is that

a) the zygote is 2N

b) the endosperm has double fusion

c) two nuclei always come from the female parent

d) the pollen grain has 8 identical nuclei

e) segregation of alleles only occurs from the male genome

20. A farmer in the semi-arid region of eastern Nebraska uses

fertilizer and a combination of irrigation and natural rainfall

to raise a crop of maize on his sandy soil. It's mid summer and

the farmer notices the maize plants are wilting, but calculated

that the crop should have plenty of water. What could be a

likely cause?

a) salt accumulation near the plant roots

b) excess moisture

c) lack of oxygen near the roots

d) poor soil aeration

e) excess oxygen near the roots

21. A soil was found to have poor drainage because of an

impervious layer in the soil approximately 12 inches deep.

Which of the following most likely would improve drainage?

a) rotary tillage

b) subsoiling

c) sweep tillage

d) chisel-plow planting

e) till plant

22. Plants that reproduce sexually go through gametogenesis,

pollination and fertilization. During gametogenesis,

a) meiosis increases the number of chromosomes from haploid to

diploid

b) the male gametes are transferred to the female gametes

c) the male and female gametes are fused together

d) meiosis occurs, and haploid microspores and megaspores are

produced

e) there is triple fusion and the development of triploid

pollen cells

AGRONOMY 114 Exam 2 A Page 5

23. This conservation tillage system has been primarily used in

areas deficient in rainfall. This system forms a furrow on

non-plowed soil and plants seed in the furrow in one operation.

This system is called

a) lister-planting

b) strip-till planting

c) strip-rotary tillage

d) till-plant on ridged soil

e) no-till on non-ridged soil

24. Which crop should be planted at a depth of 1/4 inch below

the soil surface?

a) barley

b) popcorn

c) birdsfoot trefoil

d) wheat

e) rye

25. The tall grass prairies of Iowa helped form the state's

a) forest soils

b) alluvial soils

c) eolian soils

d) hygroscopic soils

e) mollisol soils

26. If F1 plants with the genotype YYTt are selfed, what proportion

of the plants will be high yielding and tall? (YY or Yy = high

yielding; yy = low yielding; TT or Tt = tall; tt = short)

a) 1/2

b) 1/4

c) 3/4

d) 3/8

e) 9/16

27. This tillage system is generally used to minimize soil erosion

while maximizing the amount of soil residue left on the soil

surface. In addition, this tillage system reduces compaction

and generally saves money by only requiring one pass. This

tillage system is called

a) clean tillage

b) full width tillage

c) conventional tillage

d) no-till

e) strip tillage

28. A young soil, as compared to a mature soil, would generally

have

a) less definite profile development

b) well developed surface drainage

c) a well defined B horizon

d) been developed under forest vegetation

e) hilly topography

AGRONOMY 114 Exam 2 A Page 6

29. Suppose a farmer was seeding Variety X at a recommended

planting rate of 24,000 plants per acre in 24" rows. The pure

live seed percentage of the variety being planted was 80%. The

planter should be dropping seeds in the row at what distance

apart from each other?

a) 0.4 feet

b) 0.8 feet

c) 1.1 feet

d) 1.4 feet

e) 1.7 feet

30. "Selfing" a pure line variety (genotype: TT) for 3 generations

would probably result in a

a) heterogenous population

b) slight increase in heterosis

c) slight decrease in male sterility

d) segregating population in the F3

e) population the same as what you started with

31. In the pedigree method of breeding self-pollinated species

a) no hybridization occurs

b) only pedigreed plant introductions are used

c) inbred lines are crossed to produce F1 hybrid varieties

d) pure lines are released as cultivars

e) no selection is made until the F4 generation or later

32. The crop in Iowa most responsible for increased soil erosion in

the past 50 years due to increased production is

a) corn (Zea mays)

b) oats

c) alfalfa

d) soybeans

e) sunflowers

33. A farmer has planted his crop; but after a recent rainfall, the

soil has crusted. Which implement should the farmer use to

break the crust before the entire crop has emerged?

a) field cultivator

b) rotary hoe

c) lister

d) disk harrow

e) subsoiler

34. The best chance of crossing traits of wheat with grain sorghum is

a) the pedigree method

b) the bulk method

c) the synthetic variety method

d) the backcross method

e) genetic engineering

35. The ability of soil to hold water is mainly a function of

a) the amount of sand in the soil

b) percent slope

c) capillary pore space

d) gravitational pore space

e) crop grown

AGRONOMY 114 Exam 2 A Page 7

36. The term that has been established in grading standards to

distinguish groups, varieties, or types within a crop that

differ in suitability and/or utilization is

a) grade

b) dockage

c) analytical determination

d) class

e) test weight

37. Companies that sell some forage legume seeds send the seed

through a scarification process. Why does the company do this?

a) to help immature seed embryos to mature quicker

b) to apply a seed coating to improve injury resistance

c) to reduce seed coat permeability

d) to apply a seed coating

e) to balance the seed hormones that can prevent germination

38. What is soil texture?

a) a measure of particle strength

b) a description of the arrangement of individual soil

particles

c) the classification of soil aggregates by shape

d) a soil characteristic not related to permeability

e) the relative proportion of sand, silt, and clay in the soil

39. In which of the following crops would you expect more

"hard seed" being present in the seed lot?

a) alfalfa

b) sorghum

c) corn

d) soybeans

e) oats

40. The product of organic matter decomposition which helps to

reduce nutrient leaching from the soil is(are):

a) granular particles

b) potassium

c) humus

d) inorganic compounds

e) bacteria

41. Nitrogen fixing bacteria found on alfalfa roots generally do

best on a soil pH of

a) 2-4

b) 5-7

c) 6-8

d) 9-11

e) 13-15

AGRONOMY 114 Exam 2 A Page 8

42. Your aunt and uncle bought a farm in western Nebraska, and plan

to grow corn (maize). Because this area generally has an

insufficient amount of rainfall to grow maize, they will need

to irrigate and maximize the water-use efficiency of their

crop. Which of the following combinations should have the

greatest water-use efficiency?

a) wide row spacing and low populations

b) narrow row spacing and high populations

c) wide rows spacing and high populations

d) narrow row spacing and low populations

e) wide row spacing and medium populations

43. Primary tillage includes

a) rough working of soil to incorporate past crop residue

and/or incorporate fertilizers

b) final preparation of soil as a seedbed

c) all the practices utilized in a no-till system

d) leveling and firming of the soil

e) shallow working of the soil

44. One of the limiting factors in achieving adequate emergence

of summer annual crops from an earlier than normal planting

date is

a) carbon dioxide

b) nitrogen

c) phosphorus

d) temperature

e) day length

45. To be able to legally sell oats seed for planting purposes

the following is a requirement

a) the seed must not contain troublesome weed seed

b) the seed must be tested for germination within the last 2

years

c) the seed must be certified

d) germination percentage, if not known, must be listed as 0%

e) no primary noxious weed seed can be present

46. The quickest method to produce a new self-pollinating variety

of oats would be the

a) pedigreed method

b) F1 hybrid method

c) bulk method

d) synthetic variety method

e) single-seed descent method

47. Low pH

a) indicates an acid soil

b) indicates an alkaline soil

c) soils are common under arid conditions

d) soils are infertile

e) indicates a low hydrogen ion concentration

AGRONOMY 114 Exam 2 A Page 9

48. The moisture content of the soil after a thorough wetting

and the subsequent draining away of gravitational water is

properly known as

a) the saturated condition

b) the wilting point

c) gravitational point

d) field capacity

e) the wilting range

49. In his 1731 book, "New Horse-Houghing Husbandry", Englishman

Jethro Tull stated that plants take up minute soil particles

for nutrition. Therefore, he reasoned, the more finely the

soil is divided (pulverized), the more particles will be

absorbed by roots and the better crop plants will produce.

This single book established a philosophy of secondary

tillage in Northern Europe that has been very influential

there, as well as in the United States, to this day. This

belief led to practices that

a) minimized the importance of proper seedbed preparation

b) markedly increased the erodibility of cropland

c) delayed the acceptance of farm mechanization

d) have had no effect on modern agriculture

e) are now completely abandoned

50. Irrigation frequency would increase for which condition?

a) heavier soil compared to a sandier soil

b) a deeper rooted crop compared to a shallower rooted crop

c) a crop of LAI = 3 compared to one at LAI = 4

d) an area that has an average vapor pressure deficit of 5

compared to 15

e) a soil with greater amounts of salt present than an

identical soil with lower salt content

AGRONOMY 114 Exam 2

(Answers may not be 100% correct; check with instructor if questionable)

Item Answer

1 B

2 2

3 3

4 3

5 4

6 5

7 1

8 1

9 4

10 4

11 5

12 2

13 4

14 2

15 3

16 2

17 5

18 3

19 3

20 1

21 2

22 4

23 1

24 3

25 5

26 3

27 4

28 1

29 2

30 5

31 4

32 4

33 2

34 5

35 3

36 4

37 3

38 5

39 1

40 3

41 3

42 2

43 1

44 4

45 5

46 5

47 1

48 4

49 2

50 5