Using Aerial Imageryto Aid Site-Specific
Management of Fields
report to the Potash and Phosphate Institute
Jennifer Wells and Craig Kvien for the
Precision Agriculture TeamUniversity of Georgia -- NESPAL
February 2002
Using aerial imagery to aid in selecting fields for variable rate
management of inputs
“Good”, “medium”, and “poor” growth areas within each peanut field were selected
• Deep core soil samples and divided into A and B horizons
• Soil texture, organic matter content, pH, calcium, potassium, magnesium, manganese, phosphorus, and zinc measured
• Cation exchange capacity estimated
Variability in Surface Texture
Field: B-06
Poor GrowthYield: 2257 lbs/A
Medium GrowthYield: 3610 lbs/A
Good GrowthYield: 4013 lbs/A
83%sand 11%clay 66%sand 27%clay69%sand 19%clay
Variability in Subsoil Texture
Field: B-06
Poor GrowthYield: 2257 lbs/A
Medium GrowthYield: 3610 lbs/A
Good GrowthYield: 4013 lbs/A
82%sand14%clay 52%sand 42%clay78%sand 17%clay
Variability in Organic Matter
Field: B-06
Poor GrowthYield: 2257 lbs/A
Medium GrowthYield: 3610 lbs/A
Good GrowthYield: 4013 lbs/A
1.1% 2.7%3.8%
Variability in Phosphorus in Surface Horizon
Field: Thaggard7
Poor GrowthYield: 3177 lbs/A
Medium GrowthYield: 3866 lbs/A
Good GrowthYield: 4716 lbs/A
221 lbs P/A118 lbs P/A
278 lbs P/A
Variability in Phosphorus in Subsoil
Field: Groover
Poor Growth 2
Medium Growth
Good Growth8 lbs P/A
Yield: 4554 lbs/A
33 lbs P/AYield: 4063 lbs/A
5 lbs P/AYield: 4383 lbs/A
Poor Growth 121 lbs P/AYield: 3021 lbs/A
Variability in Potassium in Surface Horizon
Field: Butler
Poor GrowthYield: 3844 lbs/AMedium Growth
Yield: 4985 lbs/A Good GrowthYield: 3524 lbs/A
72 lbs K/A 185 lbs K/A56 lbs K/A
Variability in Potassium in Subsoil
Field: Thaggard8
Poor GrowthYield: 2155 lbs/A
Medium GrowthYield: 4579 lbs/A
Good GrowthYield: 4606 lbs/A
116 lbs K/A 40 lbs K/A138 lbs K/A
Variability in Calcium in Surface
Field: Groover
Poor Growth 2Yield: 4063 lbs/A
Medium GrowthYield: 4383 lbs/A
Good GrowthYield: 4554 lbs/A1088 lbs Ca/A
267 lbs Ca/A
800 lbs Ca/A
Poor Growth 1Yield: 3021 lbs/A
392 lbs Ca/A
Variability in Calcium in Subsoil
Field: Butler
Poor Growth2Yield: 3844 lbs/AMedium Growth
Yield: 4985 lbs/A Good GrowthYield: 3524 lbs/A
294 lbs Ca/A624 lbs Ca/A180 lbs Ca/A
Poor Growth1Yield: 3987 lbs/A
162 lbs Ca/A
Variability in CEC in Surface
Field: Groover
Poor Growth 2Yield: 4063 lbs/A
Medium GrowthYield: 4383 lbs/A
Good GrowthYield: 4554 lbs/A4.0 meq/100g
1.1 meq/100g
2.9 meq/100g
Poor Growth 1Yield: 3021 lbs/A
1.6 meq/100g
Variability in pH at Surface
Field: Crossroads
Medium GrowthYield: 4110 lbs/A
Good GrowthYield: 3979 lbs/A
pH 5.9pH 6.0
Poor GrowthYield: 2492 lbs/A
pH 6.8
Variability in pH in Subsoil
Field: Thaggard7
Poor GrowthYield: 3177 lbs/A
Medium GrowthYield: 3866 lbs/A
Good GrowthYield: 4716 lbs/A
pH 5.0pH 5.5
pH 5.0
• We found large differences in soil properties among the sixteen fields.
• The reasons for differences varied both within and between fields, and no single reason was common among all of the fields.
• Site-specific agriculture embraces the concept of variability within a field, thus it is no surprise that the reasons for variability between fields also varied.
• This brief report contains a small sub-set of data now being analyzed as part of Jennifer Wells’ MS thesis project. For more information:
• Craig Kvien ([email protected])
• Jennifer Wells ([email protected]).