Final Exam - Spring 2008

Agry 365T

Final Exam - Spring 2008

Name ______

Lab Day & Hour ______

TOTAL (100 pts) ______Lab Instructor ______

SHORT ANSWER QUESTIONS

1) Complete the list of nutrients for plant growth (correctly spelled) and give their chemically available form for uptake - Do not list C, H, O. (6points)

Nutrient (correctly spelled) Correct Form and Valance Category

1. ______Primary

2.______Primary

3.______Primary

4. Calcium Ca++ Secondary

5.______Secondary

6.______Secondary

7. Zinc Zn++ Micronutrient

8.______Micronutrient

9.______Micronutrient

10.______Micronutrient

11.______Micronutrient

12.______Micronutrient

13.______Micronutrient

14______Micronutrient

2)If calcitic and dolomitic limestone were each of equal purity and fineness, which would have the greater neutralizing value? Justify your answer. (1point)

3)A. Examine the four soils on display and indicate which soil is most likely high in:

Kaolinite and Hydrous Oxides ______(1 point)

B. Which of the four soils is a well drained prairie soil? ______(1 point)

4) A. Calculate the Relative Neutralizing Value (R.N.V.) of the limestone sample which has
a Neutralizing Value of 95% and has this sieve analysis: (2 points)

Amount remaining on an 8 mesh sieve = 10 %

Amount passing an 8 mesh sieve but not passing a 60 mesh sieve = 30 %

Amount passing a 60 mesh sieve = 60%

B. What would be the Neutralizing Value (Calcium Carbonate Equivalent) of a
liming material that was found to neutralize 18 meq. of acid per gram of material.
(Remember, the Milliequivalent Weight of CaCO3is 0.05 g) (1 point)

5) Explain the proper way to collect a “good” composite soil sample on an established
golf course – be complete with your answer. (3 points)

6) If I use a soil sample grid of 300 feet by 300 feet, what is the grid size in acres?
(1 acre = 43, 560 sq. ft.) (1 point)

7) List one physiological role or function in the plant for each of these essential nutrients.

(4 points)

Magnesium

Phosphorus

Potassium

Nitrogen

8) Explain how you can have two soils on a soil test report, each having a pH of 5.2 and one
soil having a lime recommendation of 4 tons per acre and the other having a lime
recommendation of only 1 ton per acre. Both are being limed to a pH of 6.5. (2 points)

9) Define or explain the following terms. (3 points)

Liebig’s Law of the Minimum

Symplastic Transport

Morrill Act

10). Based on the following information:

Assume a Kentucky Bluegrass golf course rough produces 90 lbs of above ground dry matter per 1000 square feet per year and that the plants use 60,000 pounds of water per 1000 ft2 to produce this dry matter.
Assume root volume is 3.0 % of soil volume to a depth of 4 inches
Assume total amount of N taken up by the Kentucky Bluegrass per 1000 ft2is 3.0 lbs.

Nutrient concentrations in soil solution and total available nutrients in top 4 inches.

Total available

NutrientSoil solution concentrationin top 4 inches

mg L-1(ppm) lb/1000 ft2

N 20 4.0

Calculate how many lbs of N per 1000 ft2 would reach the roots of the turf plants via the following mechanisms: Show all work!!! If you have trouble calculating these values, be sure to at least give the correct equation.

Root Interception: (1 point)

Mass Flow: (1 point)

Diffusion: (1 point)

11) If an acre of soil requires 3,000 pounds of pure calcium carbonate to raise its pH from 5 to 6, approximately how many pounds of sulfur would it require to lower the pH from 6 to 5 (Formula weight: CaCO3 = 100 g, S = 32 g). (2 points)

12) Define a sodic soil and indicate a likely pH for this soil. (2 points)

13). A. Define denitrification and indicate the conditions which favor its occurrence: soil moisture content, aerobic or anaerobic conditions, heterotrophic or autotrophic bacteria, soil pH, and the form of nitrogen that needs to be present to begin the process.
(3 points)

B. Discuss the conditions (pH, soil temperature, wind speed, etc) which favor loss of
nitrogen from soil due to N volatilization as NH3. Which fertilizer material
surface applied would result in the greatest N volatilization (excluding anhydrous
ammonia)? (2 points)

14) Fill in the information requested in each box: 1 and 2 are soil organisms

3 is a nitrogen transformation/process

4 and 5 are chemical forms of Nitrogen

15) Discuss mineralization and immobilization of nitrogen in soils. Define each term and indicate how the C/N ratio of added residues influences these reactions. (4 points)

16)Given the following information:

Soil A has a pH of 5.8 and a Buffer pH of 6.8

Soil B has a pH of 5.8 and a Buffer pH of 6.4

Which soil has the greater lime requirement?(1 point)

Which soil has the greater CEC?(1 point)

17)Explain how the following are important to soil fertility:

(2 points)

a) Apatite

b) Feldspars, Muscovite, and Biotite

18) For each of the micronutrients listed, give the information requested. (9 points)

Potential Soil Conditions Where List the Most List one

Deficiency Might Occur Susceptible Fertilizer Source

(2 conditions for each nutrient) Crop found in Indiana for each Nutrient

Iron

Manganese

Boron

19) On the graph below, diagram the Build-up, Maintenance, and Drawdown portions of the Build-up and Maintenance philosophy of making fertilizer recommendations (Tri-State Fertilizer Recommendation Manual). Include in your diagram the shape of the curve(3 connected straight lines) and the three different regions of the diagram with appropriate labels: Build up, Maintenance, and Drawdown. Also, label the critical level. (4 points)

20) Discuss the factors you must consider before taking tissues samples for plant analysis and indicate the best way to take these samples and send them to a lab for analyses. Also, discuss the importance of using plant analysis as part of a nutrient management plan. (2 points)

21) Explain the origin of the numbers 2.0 and 0.5 in the following equation used for estimating CEC in Midwestern soils: (2 points)

CEC = (2.0 X % OM) + (0.5 X % clay)

22) How much would it cost per year to fertilize 18 golf greens if you were annually applying 4 lbs of N per 1000 ft2assuming each green averaged 6,000 sq. ft. and you were using a 22-4-8 that sells for $40.00 per 50 lb bag. You can not buy a partial bag of fertilizer! (4 points)

23) On cool season grasses in Indiana, when should the majority of N on turf be applied – Spring, Summer, Fall? WHY? (At least two reasons) (2 points)

24) Discuss the two different mechanisms by which IBDU and ureaformfertilizers release nitrogen. Be specific, include information on howtheir physical, chemical, and/or biological release mechanisms work! (2 points)

25) Discuss what is meant by phosphorus fixation. Be complete! In addition, list two extractants that are used to measure “ available” soil phosphorus and under which soil pH conditions each works most effectively. (4 points)

26) Discuss what is meant by potassium fixation. Be complete! In addition, list one extractant that you used to measure “available” potassium and indicte how this extractant works to measure “available” potassium. (4 points)

27) Attached to the last page of your exam is a soil test report that was obtained from an area that one of your classmates had analyzed this semester. I have removed some of the data that was supplied by A&L Great Lakes Labs. Using this report, provide me with the following information:

A. What is the CEC of this soil? (2 points)

B. What is the % base saturation of this soil? (1 point)

C. Based on the % base saturation of this soil, what would you estimate is the pH?
(1 point)

D. What would you assume the texture of the soil is considering the % organic matter listed
in the report and the CEC you calculated? (1 point)

E. Based on the Buffer pH or this soil you need to add lime. If calcitic lime is your
cheapestsource of lime, is there a need to find a source of dolomitic lime to use instead
of calcitic lime based on the magnesium level of your soil? (1 point)

F. Is P or K most likely to be deficient if you were to grow either turf or corn on this soil?
(1 point)

Multiple Choice

Select the best answer to each multiple choice question. (1 points each- total 10 points).

____1. A soil with a hydrogen ion concentration of 0.000005 N has a pH of

A. 7.00Hint: log 4 = .60

B. 6.00log 5 = .70

C. 5.30log 6 = .78

D. 5.15log 7 = .85

E. 5.00

____2.The parent material (C horizon) of a glacial till derived soil in Indiana contains mostly calcareous till (Ca saturated exchange sites and free CaCO3), what is the pH of this material.

A. 9.2 B. 8.2 C. 7.2 D. 6.2 E. 5.2

____ 3. A soybean plant interveinal chlorosis on its upper leaves and the soil pH is 7.2

would most likely have a deficiency of

A. Phosphorus B. Potassium C. Magnesium D. Manganese

_____4. This 6-24-12 fertilizer has its potassium (most likely) in what chemical form:

A. CaHPO4

B. KC1

C. potassium hydrogen phthalate

D. K2O

E. P2O5

_____5. The availability of Fe, Mn, Zn, and Cu increases as soil pH

increases
decreases
exceeds 8.3

_____6. The ratio for N:P2O5:K2O in turfgrass clippings is approximately:

A) 6:14 B) 8:1:3 C) 4:1:7 D) 4:1:3 E) 5:7:3

____ 7. Which of these nutrients might become chelated in an organic soil and become less
available to plants thus resulting in a deficiency?

A. Mo

B. B

C. Cu

D. Cl

E. All of these

_____ 8. Which of these nutrients commonly applied to turf is on the “target” list by some states for removing it from fertilizers used on home lawns, if soil tests do not confirm a need for the nutrient.

A. NitrogenB. PhosphorusC. PotassiumD. Iron E. Boron

_____9.How many pounds of N would be supplied from 11-52-0 if it was used to supply 90 lb P2O5/A

A. 5 lb B. 19 lb C. 31 lb D. 90 lb E. 818 lb

____ 10. This question is worth 1 BONUS POINT!!! (+1 point)

So, relax.
Congratulations on finishing the exam.
Forget about coursework.
Begin planning for a wonderful summer.
And if you are graduating – stay in touch and have a wonderful life!!!

I have enjoyed having you in class this semester. If you ever have any questions related to soil fertility and turf management, I am always ready and willing to assist you.

Have a fantastic summer !!!