Be sure to show all calculations so that you can receive partial credit for your work!

Transcription

1 Agronomy 365T Exam 3 Spring 2007 Exam Score: Name TA Lab Hour Be sure to show all calculations so that you can receive partial credit for your work! 1) List 8 of the plant essential miconutrients for plant growth. Provide the complete name of the element and one form taken up by plants. List one fertilizer source for four of them. Spelling and charge count! (10 points) Form taken up by plant Essential Micronutrient including valence List Fertilizer Source ) What nutrient deficiencies are shown in the pictures projected. (3 points) a) b) c) 3) Define and explain the following terms as they relate to soil fertility: (6 points) Polyphosphate Fertilizer Ureaform WIN

2 2 4) The primary function in the plant of each of these nutrients is (2 points) Nutrient Phosphorus Potassium Primary Function in the Plant 5) CEC Calculations - Use the following data for problems a through f. (7 points) Soil Test Report ph Lime OM P K Mg Ca CEC % B.S. Index (%) ( ppm ) (cmol c /kg) (%)? ?? a) Calculate the CEC of this soil. (Exch. Acidity = 3.6 cmolc/kg) b) Calculate the % Base Saturation of this soil. c) What is the estimated ph of this soil? d) If you were growing turf (or wheat), would P or K be the more limiting nutrient based on the soil test above? e) In reviewing this soil test which nutrient or nutrients seem out of line with ideal results? Indicate of the nutrient(s) you selected are high (H) or low (L) - [circle appropriate term]. H or L H or L f) Since one of these nutrients listed on the soil test is HIGH, which micronutrient might be found deficient? H or L

3 6) Discuss the mechanism(s) by which IBDU, ureaform, and sulfur coated urea fertilizers differ in their mechanism of releasing nitrogen over time. Be specific, include information on the way these materials are manufactured. (6 points) 3 7) Phosphorus in Soils A. Label the four arrows shown on the diagram in Part B: (4 points) B. Explain the chemistry of soil phosphorus in a Mollisol (from Indiana) for Boxes A and C shown below. List the forms of phosphorus found in each box, the relative amounts found in soil, and briefly explain how the four numbered processes affect availability of phosphorus to plants. Also, write the predominate available forms (Box B) of phosphorus (including valence) taken up by plants at ph 4.5 and at ph 7.5 (6 points) Organic Unavailable P (Box A) 1 2 Inorganic Available P (Box B) 3 4 Inorganic Unavailable P (Box C) C. What is the name of the mineral that is mined in Florida and is often refered to as rock phosphate and is the raw material for manufacturing phosphorus fertilizers? (2 points)

4 4 8) Briefly explain or diagram slowly available or fixed K and exchangeable K and explain how they are accessible to plants. Explain how potassium in fertilizers can be fixed when added to soil. Which types of soils have the most fixing potential? (5 points) 9) List two minerals that naturally provide potassium in soils through the process of weathering? (2 points) 10) For each of the micronutrients listed, give the information requested. (9 points) Potential Soil Conditions Where List the Most Deficiency Might Occur Susceptible (2 conditions for each nutrient) Crop_Found in Indiana Zinc Manganese Molybdenum

5 5 11) You suspect a nutrient deficiency in the crop/turf that you are growing. State the best practices in obtaining a plant sample. Also indicate the approximate cost to have the sample analyzed if you are sending it to a private lab that does not receive a state subsidy. (4 points) 12) List two reasons organic foods are gaining popularity in the U.S. (2 points) ) You have just landed your first job as the head superintendent at the Emmert Palms Country Club. On your first day a salesman stops and claims that you need to purchase his newest complete micronutrient fertilizer to aid in greening-up your turf since it appears slightly yellow. Before buying this product you should.. (2 points) 14) What micronutrient is MOST commonly deficient in turfgrasses? (2 points) 15) Briefly explain how each of these fertilizer materials is manufactured. Include the starting material(s) and the general process that produces the fertilizer. State which of the two processes involves the use of a pipe reactor and produceses a polyphosphate material. (4 points) A B Multiple Choice Questions (2 point each) Record the best answer to each on the line provided.

6 6 1. If a fertilizer label reads , it contains: (Read the answers carefully!) A. 8% soluble N B. 32% available P 2 O 5 C. 16% soluble K D. All of the above 2. If your lawn covered 30,000 ft 2 and you wanted to apply 0.75 lbs of N per 1000 ft 2, how many 50 lb bags of must you buy: A. 1 bag B. 2 bags C. 3 bags D. 4 bags 3. How many pounds of N would be supplied from if it was used to supply 90 lb P 2 O 5 /A A. 35 lb B. 45 lb C. 75 lb D. 130 lb E. 180 lb fertilizer would most likely have its source of phosphorus in which chemical form: A. P 2 O 5 B. Dicalcium Phosphate C. KCl D. K 2 O 5. The availability of Mo increases as soil ph A. increases. B. decreases. C. drops below The ratio for N:P 2 O 5 :K 2 O in turfgrass clippings is approximately: A) 6:14 B) 6:1:5 C) 4:1:7 D) 8:1:3 E) 4:1:3 7. Of the three major fertilizer nutrients, which two are most likely to cause salt injury to turf or cause salt injury when using starter fertilizer on corn? A. nitrogen and potassium

7 B. phosphorus and potassium C. nitrogen and calcium D. nitrogen and phosphorus 7 8. Most of the potassium and phosphorus reaching plant roots gets to the roots by: A. root interception. B. mass flow. C. diffusion. D. complimentary ion carriers. 9. Which of the three soils on display would most likely fix the most phosphorus and would have little potential to fix potassium? A. Soil A B. Soil B C. Soil C 10. A tissue analysis for turf was found to contain 3.6% N, 0.38% P, 0.62% K, and 200 ppm Fe. Which element is most likely hindering growth? A. N B. P C. K D. Fe 11. Which extractant for soil phosphorus would give you the best results if you were analyzing a soil from the Midwest with a ph of 6.5? A. Bray P1 B. Morgan C. Olsen D. Walker s Special Extractant Which nutrient is of great concern related to pollution, impacts lake eutrification, and is restricted in use for lawns in some states (e.g. Minnesota): A) N B) P C) K D) Fe E) Mg Bonus: A. Which two micronutrients availability are most influenced by oxidation-reduction reactions (fluctuating anaerobic and aerobic soil conditions) - 1 point B. For established cool season turf, most nitrogen should be applied when? - 1 point