One method is shown in the diagram for question 13
and is called __?__ which is important for the nutrient ____?____ Soil Science WEB Exam 13 Fall 2007 Dept. of Soil, Water and Climate
Directions 1. There is ONE BEST answer per question. 2. Place your answers on answer sheet, you only need to turn in the answers.
Name
1.________ 2._______ 3._________ 4._______ 5.______ 6._______ 7._________ 8._______
9.______ 10._______ 11. _________ 12.________ 13.______ 14.________ 15._________
Total=_ _______
_______________Fertilzers & Fertility_____________________
15 Questions
1. If you add nitrogen fertilizer as the NH4+ ion to a warm soil at field capacity, it will most likely __?___.
a) Leach from the root zone or be immobilized by plants
b) Undergo nitrification and be converted to nitrate
c) Become denitrified
d) Be used by microorganisms in the decomposition of SOM.
2. If a soil has a build up of NO3- in amounts that are more than the plant can use, the fate of this ion will most likely be ___?____
a) converted to nitrate
b) transformed into nitrogen gas
c) to increase nodule formation and thus increase uptake by plants.
d) to leach from the root zone if soil water additions increase.
3. What is the elemental analysis for the 18 - 3 - 6 fertilizer?
a) 18 - 18 - 6 --b) 18 - 2.6 - 5 --c) 18 - 1.3 - 5 --d) 16 -5 - 1
4. If you use Hardware Hank lawn care fertilizer ( Grade of 24 - 0 - 9) and apply "two" 30 lb. bags to your lawn. You have put on how much nitrogen?
a) 0.9 lbs b) 7.4 lbs c) 10.8 lbs d) 14.4 lbs
5. For the situation in question 4, what is the amount of elemental potassium that you have applied?
a) 1.3 lbs-- b) 2.3 lbs-- c) 4.5 lbs --d) 5.4 lbs
6. The recommend amount of K 20 to apply to your flower garden is 0.6 lbs for your mums. What is the amount of Swift Garden fertilizer (14 -18 -12) that you would need to apply?
a) 4 lbs --b) 5 lbs-- c) 6 lbs --d) 7 lbs
7. Synthetic nitrogen fertilizers (made from atmospheric N2 gas and Methane gas (CH4) have an advantage over organic nitrogen fertilizers because:__?___
a) the nitrogen is more readily (quickly) available to plants when compared
to organic fertilizer that must have decomposition by heterotrophic bacteria,
before the nitrogen becomes available to plants.
b) the rhizobium bacteria rapidly convert the ammonia N to nitrate;
c) the organic nitrogen in synthetic fertilizers are healthier for the plants
since they would not contain any bad carbon sources (ie pollutants).
d) synthetic fertilizers are generally less concentrated and thus will be less
harmful to the environment.
8. The type of nitrogen that is readily taken up by plant roots is __?__.
a) NH4+ & NO3-
b) NO2- & NO3-
c) NH4+ & NO2-
d) NO3- & NH3
9. The best way to prevent soil nitrogen from becoming a pollutant to a nearby water body for a highly productive corn field would be to __?__.
a) maintain high CEC levels in the soil to absorb all the excess N
b) keep soil pH levels near 6.5 and SOM levels low (<2%).
c) keep nitrogen levels at a minimum to maintain plant growth and add more N as needed rather then to add all of the nitrogen for the full growing season at one time.
d) maintain a high level of soil organic matter that will gradually supply all of the nitrogen the plant needs.
10. A soil is tested and is found to be very low in phosphorus. This is most likely because _____?_______.
a) the soil is from western Minnesota and was developed in Des Moines Lobe till.
b) the pH of the soil is near 7 and the soil texture is loamy sand.
c) the soil is high in organic matter and the dominant clay mineral is smectite.
d) the soil has been mainly used for turf and a complete fertilizer had been added for the past 20 years that was high in urea nitrogen.
11. A soil that tests low for phosphorus will have ___?__ ppm of P while a soil that tests low for potassium will have ____?__ ppm of K.
a) 80 ........... 10
b) 40 ............4
c) 6...........60
d) 10..........100
12. In the UM Soil Testing Laboratory, the video indicated the pH of the soil sample is tested by _____?____ .
a) pH papers;
b) indicator dye
c) glass and reference electrode with a pH meter on a 1:1 suspension soil water
suspension
d) determining the electrical conductivity with a dip cell and Solu Bridge of a
1:1 suspension (10 gram scoops of soil and 30 milliliters of deionized) which
has been shaken for 30 minutes.
13. The need for nutrients to come in contact with a root is important for
nutrient uptake. One method is shown in the diagram for question 13
and is called __?__ which is important for the nutrient ____?____
a) diffusion - P ; b) root extension - Ca; c) mass flow - N ; d) equilibrium - K
14. It is very important to know ___?_____ when using a soil test for nitrogen (for soil nitrates) to make recommendations for a crop
a. the amount of nitrogen consumed by the previous crop;
b. the amount of rainfall between when the soil was tested and when the
fertilizer is to be applied;
c. the quantity of nitrosomonas and nitrobacter in the soil for nitrification;
d. amount of N credit from a previous application of manure.
15. Sustainable agriculture is ... "__?__".
a) resource-conserving, socially supportive, commercially competitive, and environmentally sound; b) consumer friendly, easy to do and socially acceptable; c) the same thing as 'Organic Farming'; d) using precision agriculture to accurately determine nutrient needs so pollution is avoided.
