2. Precision Farming Using Veris Technologies for Texture Mapping
Bobby Grisso, Virginia Tech
Using Veris for Texture Mapping
Precision Farming Using Veris Technologies for Texture Mapping
Bobby Grisso Virginia Tech Biological Systems Engineering
Mid-AltanticCrop Managment

3. Resources: http://pubs. ext. vt
Precision Farming - A Comprehensive Approach Precision Farming Tools: GPS Navigation Precision Farming Tools: Yield Monitor Precision Farming Tools: Global Positioning System-GPS Precision Farming Tools: Variable-Rate Application Precision Farming Tools: Soil Electrical Conductivity Investing in GPS Guidance Systems? Interpreting Yield Maps - "I gotta yield map - now what?“ Virginia Geospatial Extension Program

4. The Influence of Precision Agriculture!
Bobby Grisso, Virginia Tech
Using Veris for Texture Mapping
The Influence of Precision Agriculture!
Mid-AltanticCrop Managment

5. Precision Agriculture: Systems Approach
Using Veris for Texture Mapping
Precision Agriculture: Systems Approach
Right source Right rate Right time Right place
Mid-AltanticCrop Managment 2

6. Precision Technology Use
Bobby Grisso, Virginia Tech
Using Veris for Texture Mapping
Precision Technology Use
Mid-AltanticCrop Managment

7. Precision Agriculture
Bobby Grisso, Virginia Tech
Using Veris for Texture Mapping
Precision Agriculture
Precise information on agronomic factors.
Precise selection and placement of crop inputs.
Precise position and travel information.
Precision agriculture has been practiced in many forms over the years.
Farmers have learned to rely on precise information about agronomic factors such as soil type, fertility and acidity.
Likewise, calibration of planters and chemical application equipment has provided the ability to achieve precise selection and placement of crop inputs.
The next phase of precision agriculture will allow us to go farther by combining precise information about each section of the field and apply precisely the amount of crop inputs needed in that part of the field.
Precision position and travel information available on the go in the field will be necessary to achieve this level of performance.
Mid-AltanticCrop Managment 3

8. Bobby Grisso, Virginia Tech
Using Veris for Texture Mapping
GPS Systems
Mid-AltanticCrop Managment

9. Mapping EC with Veris
Soil electrical conductivity (EC) is a measurement that correlates with soil properties that affect crop productivity, including soil texture, cation exchange capacity (CEC), drainage conditions, organic matter level, salinity, and subsoil characteristics.

10. EC Measurement in Soil
Electrical conductivity (EC) is the ability of a material to transmit (conduct) an electrical current and is commonly expressed in units of milliSiemens per meter (mS/m). Soil EC measurements may also be reported in units of deciSiemens per meter (dS/m), which is equal to the reading in mS/m divided by 100.

11. Example:
(see circle)
15% sand
15% clay
70% silt
The Textural Triangle

12. Cation Exchange Capacity
Measured in hundredths of moles (cmol) of charge (cmol+) per kilogram (kg) dry soil
Units of expression are cmol+/Kg
CEC’s usually range from <5 to around 30 cmol+ for natural soils
This is the same unit as meq/100 g, just gyrated around to fit the international system of units (SI). Many labs and books still report CEC as meq/100 g

13. Plant roots use cation exchange to assist in nutrient uptake from the soil—
(a) Soil moisture surrounding the roots
(b) Absorption of soil mineral nutrients by cation exchange

14. Absorption and leaching of soil nutrients in the soil solution

15. Cation exchange on soil particles— effects of soil pH

16. Veris Technologies Electrical Conductivity is Highly Correlated with
Organic Matter
Moisture Content
Soil Texture
Compacted Zones
Existing Soil Moisture
Salts
Good Nematode Correlation

17. EC Measure - Veris

18. Bobby Grisso, Virginia Tech
Using Veris for Texture Mapping
EC Measure - Veris
Mid-AltanticCrop Managment

19. Veris machine – note water tank

20. Sensor for Turf Management
Using Veris for Texture Mapping
Sensor for Turf Management
Mid-AltanticCrop Managment

21. Soils are 3-dimensional

22. 3-D
Landscape model 1 2 3 4 5 6
2-D
Soil map

23. Mapping EC with Veris
Soil EC maps often visually correspond to patterns on yield maps and can help explain yield variation

24. Yield Map – Why?

25. What does EC Look like?

26. Aerial Photo
and Soil Map

27. Overlay the Soils Map

28. Mapping EC with Veris
Other uses of soil EC maps, including developing management zones, guiding directed soil sampling, assigning variable rates of crop inputs, fine tuning NRCS soil maps, improving the placement and interpretation of on-farm tests, salinity diagnosis, and planning drainage remediation

29. Surface to Soil Map Boundaries

30. Subsurface to Soil Map Boundaries

31. Match with Aerial photos

32. Normalize data - Moisture
Bobby Grisso, Virginia Tech
Using Veris for Texture Mapping
Normalize data - Moisture
Mid-AltanticCrop Managment

33. Tips for collecting soil EC data
Take EC measurements when the soil is neither excessively moist nor very dry. Good soil-coulter contact is required for direct contact sensors.
Best mapping conditions are found following harvest in smooth, untilled fields or prior to planting in prepared fields. In a corn-soybean rotation, conditions following soybean harvest may be most favorable since the soybean residue is less. Otherwise, firm but non-compacted soil and a smooth field surface are preferred for soil EC measurement.
Avoid metal interferences with EM (non-contact) sensors by keeping a distance of about 4 to 5 feet between the sensor and any metal object. This can be accomplished with careful placement of the sensor beneath a high-clearance vehicle or on a custom- made cart constructed of nonmetallic materials.
Conduct soil EC mapping when soils are not frozen.
Collect data on measurement pass spacing no greater than about 60 feet. Experience shows that 40 to 60-foot passes provides a map that adequately identifies the spatial patterns of a field. Such a pass may represent half to a full spray-boom width or a multiple of the planter or combine width, and consequently the smallest area most growers will variably manage.
To add value to your soil EC maps, it is important to take a deep soil sample or compaction measurement at a few points in each field. Soil physical characteristics and moisture measurements will aid in interpreting what is causing soil EC variations. The sampling should be done at the same time as soil EC data are collected.

34. Good soil-coulter contact

35. Stay out of the mud

36. Uses of EC Maps

37. Precision Agriculture: Systems Approach
Using Veris for Texture Mapping
Precision Agriculture: Systems Approach
Mid-AltanticCrop Managment 2

38. Application Decisions?
Bobby Grisso, Virginia Tech
Using Veris for Texture Mapping
Application Decisions?
You may not be able to take advantage of all the technology that we have today in spraying, but as an applicator you should be knowledgeable about the choices. Making sound application decisions, whether you do it yourself or hire it done, is the only way to be reasonably sure that you are doing your best to maximize profits and protect the environment. Keep abreast of changes and adapt those practices that seem best for you.
Mid-AltanticCrop Managment

39. GPS current issues