Final Exam 2001    

Final Exam
Spring 2001
SOIL 4213/BIOEN 4213



1.      What are two variables that affect the profitability of precision agriculture? (Frannie Rogers)

Crop Value, Crop Yield, Costs

2.      Is GIS improving and will it continue to improve? Explain. (Amy Overturf)

Yes, Opinion basis

3.      Does the organic matter sensor operate at a higher or lower wavelength than NDVI? (Kent Martin)


4.      What is the main goal of organizations like INIFAP and CIMMYT for developing countries? (Cesar Galaviz) 

Develop technology that is readily accessible to any user in the agricultural sector, and assist them with the appropriate methodology

5.      A CNMP is a ______________? (Michael Franklin)

a.      Variable rate air seeder

b.      Continuous nitrogen monitoring platform

c.      Process to monitor carbon, nitrogen, magnesium, and phosphorous soil levels

d.      Comprehensive nutrient management plan

6.   What are two parameters that are monitored, or remotely sensed, for wetland  and/or water quality? (Rodney Farris)

water storage capability,  -size of wetlands,  -water flow or fluctuations,  -extent of water spread and its seasonal variation,  -vegetation,  -water quality parameters,  -turbidity levels,        -eutrophication,         -siltation/sediment concentration,           -chlorophyll , concentration/algal parameters,       -herbicides,    -bioaccumulation of metals,   -wetland wildlife

7.      What does V-MOS stand for when dealing with turf? (Phillip Fisher)


a.      Virus Monitoring Optical Station

b.      Variable Maintaining Optical Sensing

c.      Viable Measuring Organism Sensor

d.      Vehicle Mounted Optical Sensing

8.      The OSU sensor used for precision management in turf has its own integrated light source for sensing.  True/False  (Phillip Fisher)

9.      Give two disadvantages of precision agriculture. (Roger Teal)

Very expensive, very time consuming, not easy to use

10. What is the most practical system in use for variable rate application of fertilizer? (Roger Teal)

Management zoning

11. What is the difference between green and red NDVI in relation to determining  

crop health? (Shambel Moges)   

Red NDVI is becoming less responsive as the amount of chlorophyll concentration is becoming higher (late crop growth stages).  Whereas the green NDVI is responsive for a wide range of chlorophyll concentration and can probably be used at later growth stage prediction of crop condition

12. Circle the answer below that corresponds to a critical factor(s) that will drastically affect the future concerning the issue of GMO’s (Genetically Modified Organisms). (Michael Roberts)

a.      Future research

b.      Public acceptability

c.      Foreign trade potential

d.      All of the above

  1. Which of the following are potential advantages of utilizing precision weed control? (Caleb Stone)
    1. reduced herbicide costs
    2. reduced herbicides in the environment
    3. increased herbicide efficacy
    4. A&B
    5. All of the above
  1. When sensing aphid-induced stress in wheat, why is it important to monitor climatic variables as well as changes in NDVI? (Victor Slowik) Because there are other sources of variability besides aphids, we want to keep track of other parameters that help explain variability in wheat
  1. When using precision agriculture, which method is better for gathering data? (Chris Sechrest)
    1. Map based methods
    2. Sensor Based Methods
    3. Depends on situation

  1. On a Case-Tyler spray rig, they use an AIM system for GPS tracking and data collection.  What does AIM stand for? (Dustin Simmons)

Agriculture Information Management System

  1. What does a riparian buffer protect against? (Galen Wilson)
    1. Protect the environment from pesticides
    2. Protect the stream bank from erosion
    3. Protect fields against erosion
    4. Protect wooded areas against deforestation
  1. What does NDVI stand for and how is it calculated? (Seyed Rabet)

Normalized Difference Vegetative Index = (NIR-red)/(NIR+red)

  1. Variable rate seeding is a production practice currently being used by most Oklahoma farmers. True or False. (Matthew Steinert)
  1. What is the current NUE of cereal grain? (Paul Hodgen)
    1. 50%
    2. 33%
    3. 45%
    4. 100%
  1. What is GIS? In what way does farm GIS software allow us to design? (Jagadeesh Mosali)

A Geographic Information System (GIS) consists of data and software designed for spatial analysis.  In the case of precision agriculture, the farm GIS software has tools designed to allow the display of crop yield data and factors which may affect crop yield.

  1. What remote sensing techniques can be used by precision irrigation? (Zhiming Yang)

(1) Imaged—based remote sensing, satellite, aircraft

(2) Radar, synthetic aperture radar

(3) Field-based remote sensing, infrared thermometer

  1. What is the heart of precision irrigation, what does it tell us? (Xiaoxue Li)

  1. What is the response index (RI)?  How is the in-season response index calculated when based on spatial variability (RIsv) using NDVI? (Xiaoxue Li)

RISV= Estimate of RI (spatial variability), using the average NDVI value from a random sensor sample (100 m in length) collected in a farmers field + 1 standard deviation, divided by the average NDVI value minus 1 standard deviation.

  1. Spatial data needed for a comprehensive watershed based Phosphorous Risk Index does not include: (Jason Warren)


    1. Soil phosphorous content
    2. Landscape position
    3. Soil nitrogen content
    4. Maximum daily load for water body

  1. Describe the trend of NDVI values of wheat crop in the duration of a season. (Danielle Williams)

Low after planting, rise up to maximum, and then decline again with senescence

  1. Define and Discuss VRT. (Yan Tang)

VRT is variable-rate-technology, equipment to carry out VRA. One management approach for addressing the within-field, spatial variability. VRA=spatial variability including seed, fertilizer and pesticide

  1. Provide two reasons why a producer should be concerned about non point source pollution (Ron Tejral)

sustainability, legal/regulatory action, significant npsp indicates possible overapplication of inputs, significant npsp indicates need for improved conservation practices

  1. If phosphorus is considered to be nonmobile, why is it a significant problem in the form of non point source pollution? (Ron Tejral)

soil erosion


Answer & circle all that apply

1.  Recalling our discussion on the Green Revolution, in what year did the India-Pakistan war take place, the same year that Dr. Borlaug made private contracts for seed production in this volatile region?

Year:  1966

2.  CV’s were found to be useful for

a. comparing experimental variation of trials containing variables with common units

b. comparing the variability in seed trials with soil contamination

c. determining stock prices when market fluctuations were high

3.  When smaller plot sizes were used (study of <300 experiments), the CV’s from these experiments were found to be smaller (e.g., variety trials versus fertilizer trials)

True  or   False

4.  The Coefficient of variation is

            a.  a Relative measure of variation

b. (standard deviation/mean)*100 = (s/x)*100

c. (square root of the variance/mean)*100  =   √s2/x, where MSE = s2

d.  Index of the reliability of the experiment (Gomez & Gomez)

e. Used to describe the amount of variation in a population (Cochran)

f.  Used to evaluate results from different experiments involving the same units of measure (Steel et al)

5.  Field Element Size (FES) should theoretically identify (circle all that apply)

a. The smallest resolution where cause and effect relationships can be identified

b. The precise resolution where variances between paired samples of the same size (area) become unrelated and where heterogeneity can be recognized

c. The resolution where misapplication could pose a risk to the environment

d. The treated resolution where net economic return is achieved.

e. The resolution where differences in yield potential may exist

6.  For the sufficiency concept, which of the following are true (circle all that apply).

a. Levels of available nutrients range in a group of soils from insufficient to sufficient for optimum plant growth

b. Amounts of nutrients removed by suitable extractants will be inversely proportional to yield increases from added nutrients

c. Calibrations have been made for changing the levels of available nutrients in the soil by adding fertilizer

True or False

T          F                INSEY =    In Season Estimated Yield = NDVI (Feekes 4 to 6)/days from planting to sensing (days with GDD>0) = YP0

T          F                GDD=Growing Degree Days = (Tmin + Tmax)/2 – 4.4°C

T          F                RINDVI = NDVI from plots receiving adequate but not excessive preplant N, divided by NDVI from plots where no preplant N was applied

T          F                RIHARVEST   = Maximum observed grain yield (treatment average with N fertilizer) divided by observed yield from plots where no N was applied either preplant or topdress

T          F                RISV= Estimate of RI (spatial variability), using the average NDVI value from a random sensor sample (100 m in length) collected in a farmers field + 1 standard deviation, divided by the average NDVI value minus 1 standard deviation.

T          F                YPMAX = Maximum obtainable yield level for a specific environment determined by the farmer, or previously defined as a biological maximum by research agronomists for that crop, and for that region

T          F                YP0 = Predicted or potential yield based on growing conditions up to the time of sensing, that can be achieved with no additional (topdress) N fertilization

T          F                YPN = Predicted or potential yield that can be achieved with additional (topdress) N fertilization based on the in-season response index (RINDVI)

                              YPN= (YP0)/ (1/RINDVI)

7.  From the diagram below, please indicate what is entailed in steps 1, 2, 3, and 4.












1) Sketch and label a semivariogram.

2)  Which of the following satellites has a panchromatic resolution of 1 m and a multispectral resolution of 4 m?

a)     Landsat 7

b)     Landsat 5

c)      SPOT

d)     IKONIS

e)     IRS-LISS 3

3)     Interpolation methods such as Kriging work best with

a)     Rich data sets

b)     Data sets with only a few missing points

c)      Widely spaced data

d)     Data from transects

4)     Which of the following devices are not used on a combine yield monitors?

a)     Ground speed sensor

b)     Grain Moisture sensor

c)      Cylinder speed sensor

d)     Clean grain elevator speed sensor

e)     Grain impact force sensor

f)        Header Height sensor

5)     A nanometer is:

a)     1012 m

b)     109 m

c)      106 m

d)     103 m

e)     1 m

f)        10-3 m

g)     10-6 m

h)      10-9 m

i)        10-12 m

6)     Tulsa is located on which UTM zone

a)     12

b)     13

c)      14

d)     15

e)     16

7)     Grain moisture sensors generally use ____ to measure moisture.

a)     Capacitance

b)     Resistance

c)      Mass

d)     Voltage

e)     Inductance

f)        Gamma ray attenuation

Dr. Marvin Stone

8. Irradiance is a measure of the ratio of incident radiation to reflected radiation. (True or False)

9. A farmer has asked you for your opinion regarding his purchase of a "light meter" for measuring performance of corn plants.  The meter is described in the catalog as a "photometer".  He has a red filter he is going to put over the "photoeye" and is planning to point this meter at the plants at an early stage of growth and expects this measurement to tell him how much red light the plants are absorbing.

a) What does a photometer measure? irradiance

b) What major factor will be a problem with measurements made this way? Because irradiance is measured and not reflectance, compensation for changing light conditions is not included, thus no possible ‘calibration’ of repeatable data.

10.  A field mapping program is designed to run on a laptop and uses GPS input. The program says that it requires a GPS unit with NMEA 0183 formatted data, and uses the GGA sentence.  You have a differentially corrected GPS unit available which says it will provide the GGA sentence. Will the GGA sentence transmit differentially corrected data?


11.) In the column “Match” place the letter of the “Question” that matches the Answer.



Match, e.g., 4)

1)       Distance at which two measurements are no longer related



2)       Distance over which measurements vary randomly



3)       Interpolation method where unknown values are calculated from adjacent measurements



4)       550 nm




5)       950 nm



6)       450 nm



7)       1,500 nm



8)       Hyperspectral measurements

Ground Control Points


9)       Common GIS data format for digital images



10)   Common GIS data format for shapes



11)   Spatial reference system with distances measured in meters



12)   Angular distance measured from the Prime meridian

Major Water Band


13)   Angular distance measured from the equator

Many Bands


14)   Ratio of incident and reflected light

Minor Water Band


15)   Light emitted or reflected from an object

Nearest Neighbor


16)   The process of matching a pixel on a digital image to a spatial location



17)   The process of aligning bands of a digital image



18)   When digital images are resampled, specific pixels are matched to …?



19)   Distance in meter from the equator



20)   Distance from the west side of a UTM zone



21)   Russian satellite navigation system



22)   The beacon differential system is operated by…



23)   Devices usually used to actuate sprayer valves



24)   Sprayer application rates are usually changed by varying…



25)   Application rate of dry fertilizer applicators are generally changed by adjusting ____ opening



26)   A measure of the distribution around the average

Standard Deviation



U.S. Coast Guard