Global Positioning System

The Global Positioning System or GPS is a network of satellites controlled by the Department of Defense that are designed to help determine a radio receiver’s position in latitude, longitude, and altitude.  GPS is only one of many technologies used in Precision Farming.
 
The GPS system became fully operation in 1995 and was originally designed to serve the military.  Currently, the GPS system is being used extensively by people in all aspects of business and recreation.   This service is free of charge and available to everyone.  The system contains 24 satellites and four of these are always accessible at any given time.

It is these satellites that farmers are using to keep more accurate readings.  With a GPS receiver, a farmer can receive a signal from these satellites that helps him pinpoint his exact location.  If he is recording data such as moisture, yield, soil fertility, pest & weed problems or elevation, this data is stored with a reference to its location.  GPS allows us to reference data to a location and in then return to that same location within a meter of accuracy.   This takes us to the aspects of Precision Farming.

Precision Farming

Precision Farming may seem like a new idea, and in some ways it is new.  But the idea of treating small areas individually is not new.   Indians were among the first to realize that soil and yields vary across a field or area.  By watching their crops grow, they could identify where the “good” producing areas were.  The also used food and fish scraps to “fertilize” the areas where they had planted or would plant their crops.  The planted and fertilized each seed by hand.  The goal of farmers today is to manage their plots of land in smaller units as well.  The biggest difference is the level of technology being used today.

Precision Farming is managing one or more crop production inputs-fertilizer, lime, herbicide, insecticide, seed, etc.-on a site-specific basis to reduce waste, increase profits, and maintaining the quality of the environment.  An input is something a farmer adds to a field to produce an output or crop.  Inputs include fertilizers, lime and micro-nutrients spread on the ground before planting or pre-emergence, seed and pesticides put in the ground in the spring, and fertilizer, insecticide and herbicide applied after the crop is growing or post-emergence.

The management of these inputs takes place during the cycle of precision farming.  The following are descriptions of the six steps.

Harvesting

The first step is to harvest the crop using a combine equipped with a yield monitor.  This yield monitoring system contains a GPS receiver.  The monitor records data such as instantaneous yield, moisture, speed, average yield (bushels/acre), elevation and much more.  The GPS receiver gives that data a specific on-the-go location.

Data Analysis

This step involves using a computer and a crop specialist to determine what the data that is collected means, what actions should be taken and what maps should be generated.  Maps can be created because the receiver referenced the data to a Latitude/Longitude location.  These maps show us what is happening in a field and can show data such as soil fertility, yield, moisture, elevation and many more.  The computer can also generate a recommendation map based on data collected.  This shows the farmer where he needs additional or less inputs.

Soil Sampling

Using the GPS receiver, a boundary of a field is created.  The field is then divided into grids.  These are usually 1-5 acres.  A soil sample is drawn from within each grid and data is analyzed on a site-specific bases.  Data collected in this step includes pH, K, P, organic matter, moisture, micronutrients, CEC, etc.

Variable Rate Application

A recommendation is made based on the soil sample data.  For example, a lime recommendation map can be made based on the pH map created from the soil sample data.  This information is loaded into a computer on a variable rate spreader truck and nutrients are applied according to the recommendation.  The computer uses GPS and the referenced data to apply the right amount of input on the correct location.  After this step the seed is planted.

Crop Scouting

A crop scout can use a backpack GPS unit to locate and reference locations in the field where pests and weeds are a problem.  This must be done after the crop is growing in the field.  Recommendation maps can also be created using this referenced data.

Variable Rate Herbicide Application

Based on the recommendation map created as a result of crop scouting, a sprayer truck can apply the adequate rates of insecticide and pesticide to different areas of the field.  Using the reference made by the GPS receiver, the right amount of chemicals go in the right place.

This brings us back to the harvest step and the cycle continues again.  Farmers hope that by managing their inputs on a site specific basis, they will be able to farm more efficiently and effectively.

Benefits of Precision Agriculture

Reduce Waste

Using precision farming practices, farmers can reduce the amount of unneeded chemicals that are applied due to operator error, inaccurate data and over application.  Farmers are using the information they record using GPS monitors and other equipment to make better management decisions.   This will reduce waste in the future.

Increase Profits

By more accurately treating their fields, farmers are able to produce more grain and livestock for sale.  As precision agriculture equipment becomes more affordable, farmers will see an increase in profits.  This will be a result of reduced waste and increase in yield.

Increased Environmental Quality

If farmers can reduce the amount of chemicals applied by only applying them on the areas that need it, contamination possibilities will decrease.  Less chemical applied means there is less chance of run-off into neighboring streams or pond.

Raised Awareness

Farmers are learning through the analysis of their data how to better manage their cropland.  They are realizing that using buffer strips and CRP land may actually raise their profit potential.  They are also seeing more clearly the relationship between management and success.