Dakota Farmer
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Zeroing in on Zones

                 
Kobe Bryant, a star power forward for the L.A. Lakers, was "in the zone" when he hit nine straight three point jump shots in a professional basketball game this season -- a record that some say may never be broken.
You could say Neil and Patty Power, Langdon, N.D., are in the zone, too.  The couple are hitting a string of higher wheat yields.

"We've increased our farm yield average by 5 bushels per acre," Neil says.

The Powers practice "zone management."  It's a precision farming method that involves breaking fields into several different areas, or zones, with similar productivity potential and managing them differently using variable-rate application technology.

The Powers--who also sell precision farming services to farmers and dealers -- identify crop management zones in their fields by using soil tests; remote sensing data; and topography, soil, yield and electrical conductivity maps.

Often, they can create several different management zones in an 80- or 160-acre field.  One zone may have high yield potential in years without excess moisture.  Another may have extremely low yield potential due to the soil type, salt content of the soil, erosion or other factors.  These zones need different amounts of other fertilizer and crop inputs to reach the soil's yield potential.

Fifty years ago, the Powers' grandparents probably squared off such zones and farmed them as individual fields.  But today, it would be impractical and uneconomical for the Powers to make separate passes to fertilize, seed spray and combine each zone.  Besides, true zones have irregular boundaries.  They are not neat, precise rectangles.  Instead, they follow soil types, drainage patterns and other land features.

Rather than treating all the productivity zones in teh same field the same way, the Powers use variable-rate application equipment to automatically apply different rates of fertilizer and other inputs to different zones as they work the field.    

REDUCING COSTS
The Powers first tried precision farming technology in 1999 and say immediate results in a field that they split.  But the technology was costly.  In the Corn Belt and Red River Valley, farmers were spending as much as $20 per acre to grid soil test.  Grid soil testing involved dividing fields into 2.5 acre squares and testing the soil in each square.  The results gave them a map that they could program in a variable-rate fertilizer spreader.  Some farmers used combine yield monitor maps to identify zones.
But neither method was economical or practical for the Powers.  Their soil types -- a major factor in productivity -- varied tremendously.  For example, in one 2.5 grid Neil found five soil types.  One soil sample from that grid would not represent the fertility of all the soils in the grid.  NDSU research indicates that in some areas in North Dakota you would have to sample each half acre to get an accurate grid soil test map.

Also, yield maps weren't reliable.  Like many small-grain growers who have a narrow harvest window, the Powers hire custom harvesters.  Some custom combines don't have the equipment to create yield maps.

And finally, spending an extra $20 per acre on grid soil testing to grow wheat just didn't pencil out.  Varying fertilizer rates didn't increase yields sufficiently to cover the costs and produce an extra profit.

But through zone management, the Powers cut the costs of precision farming to less that $5 per acre.

They build zones from the ground up.  They start with soul maps and add layers of other information.  They map the electrical conductivity of fields to more accurately define soil types.  They use topography, remote sensing and yield maps when they are available.  They soil test based on teh productivity zones they identify.  Soil testing by zones cost less than soil testing grids.  The Powers pull 10 to 12 soil cores from a zone, mix them together and have the sample analyzed.  In a 160-acre field, they may have four zones represented by four soil samples.  If they were sampling the same field in a 2.5-acre grids, they would pay for analysis of 60 to 70 samples.
 
ZONES PAY OFF
Zone management has paid dividends in several ways, according to Neil.  It has:
Increased yields.  The farm's wheat yield average is now 5 bushels per acre higher than prior to 1999, when they started precision farming
Evened out crop development.  Because proper fertility makes plants in all parts of the field grow more uniformly, it is easier to properly time herbicide and fungicide applications.  As a result, the Powers improved weed, leaf disease and head scab control.  They also have been able to switch from swathing to straight cutting small grains because fields ripen more evenly.
Reduce the risk associated with new crops.  They have been able to more accurately identify zones that will support soybeans, flax and specialty crops.
Led to better variety selection, input choices and tillage decisions through the analysis of strip trials.  On- farm tests conducted in the same management zone are more meaningful than tests that cut across several different zones.
Created a new business opportunity.  The Powers are helping other farmers learn how to create management zones and use precision farming technology.  In 2001, they started TotalCrop Farming Systems.  They and a staff agronomist provide a full range of conventional and precision farming agronomic services.  They also manage precision farming data for clients and sell precision farming equipment.
"Zone management has really made a difference on our farm," Neil says.  "It is an economical, practical way that we can use precision farming technology."

For more information, contact the Power's at 701-462-8307.