Ken Coles M.Sc. P.Ag.

Sorting Through the LayersOf Precision Agriculture

Farmer Smarter Conference Lethbridge, AB, December 4, 2013

7. Satellite-based NDVI imagery

1.Producer knowledge

2. Aerial Imagery/Orthophotos

3.Soil Apparent Electrical Conductivity (ECa) Mapping Sensors

4. Digital Elevation Models (DEMs)

5. Yield Maps

6. Aerial Imagery from UAV –based Sensors

8. Ground-based vegetation sensors (greenseeker)

9. Grid soil sampling

Understanding Soil Variability for Effective Zone Management in Precision Agriculture – an evaluation of sensor based soil mapping tools.

• Multidisciplinary team of experts in precision agriculture, agronomy, soils, GIS, spatial statistics, remote sensing, salinity, economics

• Data collection: all layers, EC twice per sensor, field scale replicated response trials

• Evaluate multiple zones after the fact using field trial, conventional and spatial stats.

0 5 10 15 20 25 30 35 40 450

102030405060708090

100

f(x) = 0.329279990564237 x + 39.5336349542337R² = 0.0841116963590952

f(x) = NaN x + NaNR² = 0 All Fields Depth Weighted Silt (Outliers

Removed)

Silt ShallowLinear (Silt Shallow)Silt DeepLinear (Silt Deep)

Depth Weighted Silt Content %

EM 3

8 Re

adin

g

20 30 40 50 60 70 80 900

10

20

30

40

50

60

70

80

90

100

f(x) = − 0.118824078581209 x + 54.256233892652R² = 0.0231609874626114

f(x) = NaN x + NaNR² = 0 All Fields Depth Weighted Sand (Outliers

Removed)

Sand ShallowLinear (Sand Shallow)Sand DeepLinear (Sand Deep)

Depth Weighted Sand Content %

EM 3

8 Re

adin

g0 5 10 15 20 25 30 35 40 45 50

0102030405060708090

100

f(x) = − 0.231593042873098 x + 50.9831761212472R² = 0.0209438293250105

f(x) = NaN x + NaNR² = 0 All Fields Depth Weighted Clay (Outliers

Removed)

Clay ShallowLinear (Clay Shallow)Clay DeepLinear (Clay Deep)

Depth Weighted Clay Content %

EM 3

8 Re

adin

g

Variable Rates:

Nitrogen (lbs/ac): 0, 30, 60, 90, 120

Seeding Rates (seed/m2): 250 , 350

0 30 60 90 12020

22

24

26

28

30

32

34

36

38

40

42

44

46

48

50

38

31

43

4544

36 35

39

43

48

Hand Sampled Wheat Yield (bu/ac) Field Scale Replicated Trial Mossleigh, AB 2013

250 seeds/m2Seed Rate

bu/a

c

RTK > RTX > SF2=OmnistarHP > Ominstar XP=SF1 > Glonass > WAAS

Lessons:

• Trying to do anything with Ag GPS beyond auto-steer is like herding cats!

• Calibration is critical

• Accurate GPS is important for minimizing error

• Constant and reasonable speeds are required

• Soil moisture important, frost free window is small

• Veris more costly & slower but can add OM and pH sensor

• The devils in the detail!

Ken Coles M.Sc., B.Sc., P.Ag.General ManagerFarming Smarter #100 5401 – 1st Ave. SouthLethbridge, AB T1J 4V6ken@farmingsmarter.comwww.farmingsmarter.comtwitter: @killerkencolesoffice: 403-381-5118cell: 403-317-0757