Precision Farming with Today's Technologies

By Josh Thompson, Little Assawoman Bay Watershed Coordinator

Modern farm tractor cabs are highly complex workplaces.

New farming methods over the last decade are rapidly gaining supporters as technology advances.   Precision farming is a management strategy that benefits both the farmer and the environment through advanced information technologies.  A combination of detailed soil analysis and mapping, satellite technology, equipment capable of changing application and seeding rates on-the-go, and several other high technology tools allow site-specific farming practices that improve the farmer's bottom line.  In previous generations, land was managed at the individual field level.  Today's farmers can manage on a much smaller scale within a field depending on variations in soil characteristics, topography, drainage, nutrient residues, and other factors.  This reduces application of excess fertilizers, herbicides, and other chemicals, minimizing the farmer's cost and potential runoff problems.  Precision farming is practiced to varying degrees, depending on the individual needs and resources of each farm.  There are several major components that are essential for optimizing the benefits of this system.

The advent of global information system (GIS) software has allowed farmers to store data (soil type, nutrient levels, etc) in layers and assign that information to a field location.  These data layers can then be overlaid with information from past years or other data layers to analyze a field and develop management strategies.

One of the newest advances in precision farming, variable rate technology, refers to a system of computer controllers and associated hardware that is capable of varying the output of chemicals as the equipment moves across the field.  This technology is also applied to planters and drills, which can vary seeding rates depending on soil characteristics.  Variable rate technology relies on a controller that utilizes an application map along with the GPS unit to accurately manage the equipment.

Global Positioning Systems (GPS) are vital to the precision farming system.  The use of the 24 GPS satellites allows the farmer to pinpoint equipment location in the field to take advantage of site-specific data.  As a tractor moves across the field, the GPS relays the position to the various other components of the system.  This is essential to the accuracy of the yield mapping, creation of soil maps, and using the information to manage the variable rate equipment as it moves across the field.

An example of variable rate technology at work can be seen in precision fertilizer application.  Soil tests and sensors have been utilized to create a GIS map of a particular field, including layers of soil characteristics.  As the equipment moves through the field, its position is relayed from the GPS to the GIS, which is linked to the computer controller.  The controller then uses this information, along with predetermined yield goals, to manipulate the machinery to apply the necessary fertilizer to that spot.  The benefit of this is reduced fertilizer cost and higher yield.  Because the fertilizer being applied is utilized by the plant, the amount of excess nutrients in the soil that can move to the water is greatly decreased.

Yield monitors assess the productivity and “yield variability” of a field and find problems areas within the field.  These instruments measure the crop yield (bushels/acre), weight, and moisture content as it is being harvested.  This data is displayed in the combine cab, and at the same time works in conjunction with the GPS unit to create a map of the field using different colors to display yield ranges.  These maps are used to pinpoint sources of yield variability, aiding in developing strategies to address those problems.  The combined mapping systems are also used to identify areas of suitability for various best management practices (BMPs).  Farmers can also use the information to decide if it might be economically beneficial to convert certain low yield areas to Conservation Reserve Enhancement Program (CREP) tracts, artificial wetlands, or other appropriate uses.

As more farmers delve into the technological world of precision farming, even more advances are on the horizon, promising higher efficiency and more economic and environmental benefits.  On-the-go sensors that detect nitrogen levels in plants, plant disease levels, insect levels, and soil characteristics are now on the market and being utilized around the country.  Automated guidance systems are already being sold that operate equipment with minimal support from a driver.  The sky seems to be the limit as the agricultural community embraces what could be one of the most efficient BMPs available.