Dry land cropping system of winter wheat after chemical fallow.
This is the first year of variable-rate application of fertilizer. Received six inches of precipitation in June and received no moisture during the hot summer.
With variable-rate fertilization application:
Producer developed three zones.
It cost $6.00 per acre to get the satellite imagery to develop those zones; $50.00 per zone to design the zone; $150 per zone to install the zone
It cost $4.00 per acre to apply the fertilizer which is $.50 per acre more than the uniform rate of fertilizer application.
The variable rate of fertilizer varied between 122 and 193 pounds per acre with an average of 154 pounds of 46-0-0 at a cost of $300 per ton. There were some problems with the spreading of the fertilizer.
a. 80 pounds of 11-52-0 were applied through the drill.
b. A 60-bushel yield goal was used at a rate of 2.6 pounds of nitrogen per bushel.
c. The total volume of fertilizer applied on the field was about the same as the uniform rate of fertilizer application used in previous years.
The yields on hill tops seemed better.
The producer has custom harvesters and they do not have yield monitors.
Average yields were 65 bushels whether the field had fertilizer variable-rate applied or uniformly applied.
Producer does not plan on variable-rate applying fertilizer in the future.
Cost of zone mapping of $6.00 per acre.
Cost of design and installation of $300 for the zones.
$.50 per acre increased cost of variable-rate application of fertilizer.