What is Precision Agriculture?

John K. Schueller

Agricultural and Horticultural Production

Inputs

Fertilizer, Pesticides, Labor, etc.

Outputs

Quantity, Quality

Complications to Simple Input--Output

• Stochastic (Random) – Weather

• Temporal (Time) – Season Progression

• Spatial (Location) – Spatial Variability

Managing According to Spatial Variability

• Many Names– Site Specific Crop Management– Spatially-Variable Crop Production

Managing According to Spatial Variability

• Many Names– Site Specific Crop Management– Spatially-Variable Crop Production

John Deere --- “Precision Farming”

=> Precision Agriculture

Citrus Antecedent – Agronomic Crops

• Yield and Soil Mapping• Variable Rate Applications

• mid-1980’s: Development and Experimentation• 1990’s: Commercial Products, Millions of Acres

Citrus Antecedent – Animal Agriculture

• Individual Production Records• Individual Breeding, Feeding, and Culling

Citrus Synthesis

Plant:

Like Agronomic

Multiyear and Individual Production Unit:

Like Animal

Precision Agriculture is NOT Technology

It is a Management Philosophy to

Respond to Spatial Variability.

Precision Agriculture is NOT Technology

It is a Management Philosophy to

Respond to Spatial Variability.

But Technology Makes It Possible

Precision Agriculture Steps:

1. Determine Variability

2. Determine Cause

3. Determine Possible Actions

4. Determine Economics of Actions

5. Implement Profitable Actions

REPEAT

Measuring Variability

Techniques

Manual

During Field Operations

Remote Sensing

QuickBird 2.4 meter satellite image, draped over DEM

ACIR photography, 0.17-meter scanned (close-up). Note Geolocation target (circled in yellow).

Measuring Variability

Techniques

Manual

During Field Operations

Remote Sensing

Variability of …

Soils (type, fertility, …)

Trees (size, vigor, yield, quality, …)

Pests (weeds, insects, disease, …)

Strategic Responses to Variability

• Grove and Block Boundaries

• Landforming and Layout

• Irrigation Layout

• Rootstock and Scion

• Resetting and Abandonment

Permanent, One-Time Costs

Often Lower Technology

Tactical Responses to Variability

• Variable-Rate Fertilizer and Pesticides

• Spatially-Variable Irrigation

• Spatial Harvest and Marketing

Good Technology and Management Needed

Line of sight radio-modem

The sensor network allows creating surface graphs showing the spatial and temporal variation in soil water matric potential (soil moisture).

Differences of water mobility in soil can be observed and can help on better adjusting the site-specific irrigation control.

Lessons Learned in Agronomic

• Uniform Production is NOT the Goal– Often Cut Fertilizer Where Poor Yields

• Water is Most Important• Technology Must Fit Operations• Economic Potential Must Be Present

Lessons Learned in Agronomic

• Uniform Production is NOT the Goal– Often Cut Fertilizer Where Poor Yields

• Water is Most Important

• Technology Must Fit Operations

• Economic Potential Must Be Present

– Risk Reduction– Environmental Demands

What is Precision Agriculture?

• Philosophy of Handling Spatial Variability• Tradition Technologies

– Variability Mapping– Variable Inputs

• Related Technologies– Labor Management– Remote Sensing– Robotics– Traceability