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

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

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

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

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

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

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

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.

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.

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

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

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

Absorption and leaching of soil nutrients in the soil solution

Cation exchange on soil particles— effects of soil pH

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

EC Measure - Veris

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

Veris machine – note water tank

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

Soils are 3-dimensional

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

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

Yield Map – Why?

What does EC Look like?

Aerial Photo and Soil Map

Overlay the Soils Map

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

Surface to Soil Map Boundaries

Subsurface to Soil Map Boundaries

Match with Aerial photos

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

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.

Good soil-coulter contact

Stay out of the mud

Uses of EC Maps

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

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

GPS current issues