Soil moisture data analysis is often straightforward, but it can leave you scratching your head with more questions than answers. There's no substitute for a little experience when looking at surprising soil moisture behavior. METER soil scientist, Dr. Colin Campbell has spent nearly 20 years looking at problematic and surprising soil moisture data. In this 30-minute webinar, he discusses what to expect in different soil, environmental, and site situations and how to interpret that data effectively.

2. HOW TO INTERPRET
SOIL MOISTURE DATA
DISCOVERING THE MEANING
BEHIND THE TRACES
Colin Campbell
METER Group, Inc. USA

3. Date
Mar May Jul Sep Nov
VWC
0.0
0.1
0.2
0.3
0.4
0.5
EXPECT THE UNEXPECTED
Soil Type Crop Type
Sand/Clay -
layered
Semi-arid
grassland

4. SOIL MOISTURE CASE STUDIES
• Soil types
• Loamy sand
• Clay loam
• Infiltration
• Saturation and flooding
• Cracking
• Soil freezing
• Spatial variability
• Temperature effects
• Diurnal patterns due to
hydraulic redistribution
• Broken sensor
• Installation problems

5. SOIL TYPE EFFECTS
LOAMY SAND

6. SOIL TYPE EFFECTS
WET CONDITIONS Soil Type Crop Type
Loamy sand Turf grass
Water potential
Water content
15 cm
6 cm
30 cm
15 cm
6 cm

7. SOIL TYPE EFFECTS
WET CONDITIONS
15 cm
15 cm
6 cm
6 cm
30 cm
Soil Type Crop Type
Loamy sand Turf grass

8. SOIL TYPE EFFECTS
OPTIMAL CONDITIONS
15 cm
15 cm
6cm
6cm
30 cm
Soil Type Crop Type
Loamy sand Turf grass

9. SOIL TYPE EFFECTS
DROUGHT CONDITIONS
15 cm
15 cm
6cm
6cm
30 cm
Soil Type Crop Type
Loamy sand Turf grass

10. SOIL TYPE EFFECTS
CLAY LOAM

11. SOIL TYPE EFFECTS
WELL IRRIGATED Soil Type Crop Type
Clay loam Seed potatoes

12. SOIL TYPE EFFECTS
WELL IRRIGATED
Matric potential
-5 to -100 kPa Plant Optimal
-100 to – 1500 kPa Stress
< -1500 kPa Permanent Wilt
Soil Type Crop Type
Clay loam Seed potatoes

13. INFILTRATION
SANDY LOAM

14. DESERT SANDY LOAM SOIL
FALL 2019 Soil Type Crop Type
Sandy loam Desert invasive species
Data from ZENTRA Cloud software

15. DESERT SANDY LOAM SOIL
SUMMER 2019 Soil Type Crop Type
Sandy loam Desert invasive species
Data from ZENTRA Cloud software

16. SOIL MOISTURE INDICATORS OF
FLOODING
SILT LOAM

17. FLOODING FROM SATURATED
SOIL

18. FLOODING FROM SATURATED
SOIL

19. FLOODING
PRECIPITATION
Data from ZENTRA Cloud software

20. FLOODING
WATER CONTENT Soil Type Crop Type
Silt loam Bare soil surface
Data from ZENTRA Cloud software

21. FLOODING
PRECIPITATION
Data from ZENTRA Cloud software

22. Water depth, bank of Missouri Flat Creek
FLOODING
STREAM HEIGHT (HYDROS 22)
Data from ZENTRA Cloud software

23. CRACKING
SHIPS CLAY
(high shrink swell)

24. SOIL CRACKING
Soil Type Crop Type
Clay Native grass
Data from ZENTRA Cloud software

25. FREEZING
SANDY LOAM

26. FREEZING
WINTER 2019-2020 Soil Type Crop Type
Sandy loam Invasive species
(dead)
Data from ZENTRA Cloud software

27. FREEZING
WINTER 2019-2020 Soil Type Crop Type
Sandy loam Invasive species
(dead)
Data from ZENTRA Cloud software

28. FREEZING
WINTER 2019-2020 Soil Type Crop Type
Sandy loam Invasive species
(dead)
Data from ZENTRA Cloud software

29. FREEZING
2019-2020
No rain gauge
Soil Type Crop Type
Sandy loam Invasive species
Data from ZENTRA Cloud software

30. SPATIAL VARIABILITY
CLAY LOAM

31. SPATIAL VARIABILITY
WATER CONTENT Soil Type Crop Type
Clay loam Seed potatoes
Data from ZENTRA Cloud software

32. SPATIAL VARIABILITY
WATER POTENTIAL Soil Type Crop Type
Clay loam Seed potatoes
Data from ZENTRA Cloud software

33. TEMPERATURE SENSITIVITY
SANDY LOAM

34. TEMPERATURE SENSITIVITY
SUMMER 2019
0.0003 m3 m-3 /oC
Soil Type Crop Type
Sandy loam Invasive species
Data from ZENTRA Cloud software

35. HYDRAULIC REDISTRIBUTION
CLAY LOAM

36. HYDRAULIC REDISTRIBUTION
Soil Type Crop Type
Clay loam Irrigated wheat
Data from ZENTRA Cloud software

37. HYDRAULIC REDISTRIBUTION
15 CM Soil Type Crop Type
Clay loam Irrigated wheat
Data from ZENTRA Cloud software

38. HYDRAULIC REDISTRIBUTION
45 CM Soil Type Crop Type
Clay loam Irrigated wheat
Data from ZENTRA Cloud software

39. HYDRAULIC REDISTRIBUTION
65 CM Soil Type Crop Type
Clay loam Irrigated wheat
Data from ZENTRA Cloud software

40. CLAY LOAM SOIL (POTATOES)
65 CM TEMPERATURE Soil Type Crop Type
Clay loam Irrigated wheat
Data from ZENTRA Cloud software

41. FAILED SENSOR
SILTY CLAY LOAM

42. FAILED SENSOR
Soil Type Crop Type
Silty clay
loam
Unknown
Data from ZENTRA Cloud software

43. INSTALLATION PROBLEMS
SILT LOAM

44. INSTALLATION ISSUES
Soil Type Crop Type
Silt loam Bare soil surface

45. SUMMARY
Many things to discover about soil moisture in the field
Expect to find the unexpected
Soil moisture data behaves much differently in coarse vs fine soils
A soils ability to take up and store water can stop water infiltration or cause soils to flood
Some soils (typically clays) can cause cracks to form around the sensor and impact results
Freezing causes soil water to disappear to the sensor and results in strange behavior
Soil water content has a high spatial variability
Diurnal patterns in data can be caused by temperature fluctuations or by root water uptake
and redistribution
Problems arise from poorly installed sensors as well as those that fail electrically

46. FINAL NOTES
ZENTRA System is key to interpreting soil moisture
• Near real-time data
• Simple and fast visualization
• Alerts and critical ranges
• Shared data with collaborators
• Learn more: metergroup.com/zentra-cloud
Support
• METER scientists are here for you
• support.environment@metergroup.com

47. QUESTIONS?