University of Idaho Extension
specialists say the rising cost of nitrogen fertilizer should lead
growers to closely examine their crops’ actual needs.
“When nitrogen prices are cheap, growers apply a little extra
fertilizer as inexpensive insurance,” says Jason Ellsworth,
UI Extension soil fertility specialist at Twin Falls.
Rising natural gas prices this winter led major fertilizer plants
to raise prices or in some cases to stop production.
Bryan Hopkins, UI Extension potato cropping specialist at Idaho Falls,
Ellsworth and Paul Patterson, UI Extension agricultural economist
at Idaho Falls, teamed up to produce a guide, “Skyrocketing
Nitrogen Prices and Potato Production.”
It is designed to help farmers find ways to produce a quality crop
despite rising costs.
The key is accurately accounting for all nitrogen that is available
to the crop and providing an optimum, but not excessive, supply of
fertilizer.
1 - The first Step growers
can take is to adequately inventory the residual nitrogen present
in their fields. Several samples from a field, particularly when soil
types differ, can improve the accuracy of the final result.
2 - The next step call for
detemining an appropriate base rate - the right amount of fertilizer
for the crop.
3 - In addition, growers should
account for all nitrogen applications to the crop, ranging from nitrogen
used as a carrier in pesticide applications and manure or residues
from a previous crop. A previous legume crop such as alfalfa or beans
also can increase nitrogen levels in the soil by as much as 80 pounds
per acre.
4 - Irrigation management is
an essential part of the production equation. Too much water can leach
nitrogen below the root zone, or it can wash it down stream.
Replacing worn sprinkler nozzles or other equipment can ensure more
consistent irrigation and reduce waste of water and fertilizer
.
5 - The UI Extension specialists
recommend buying enough nitrogen fertilizer to ensure potatoes receive
the optimal amount - but no more. The economic optimum will vary based
on the price of potatoes, the price of nitrogen and the increase in
production when additional nitrogen is added.
For mor detail, consult the specialists’
guide on the internet at
http://www.ag.uidaho.edu/aers/PDF/AEES/AEES_03-04.pdf
