Cool-Season Grasses

appear to have a greater growth boost with swine effluent application, the
cool-season grasses have marketing advantages that make it a more viable
economic option for producers in the Oklahoma Panhandle and Southern Plains.

Park recently
had the results of his study published in the Journal of American Society of
Farm Manager and Rural Appraisal. The study was funded by a U.S. Department of
Agriculture grant for “Comprehensive Animal Waste Systems in Semiarid
Ecosystems.” Cooperators in the study were Dr. Jeffrey Vitale and Dr. Jeffory
Hattey, both with Oklahoma
State University.

The study
evaluated the risk and economics of intensive forage production systems under
four alternative types of forage and two alternative nitrogen sources, he says.
The results will help farmers make better informed production decisions.

The study
compared two cool-season grasses – orchard grass and wheatgrass – with two
warm-season grasses – Bermuda grass and buffalo grass, he says. The two
nitrogen sources used to fertilize the crop were urea or swine effluent.

Park says their
model showed that intensified production of cool-season grasses with the
application of fertilizer appeared to be the more economically viable option
for producers in the Southern Plains.

This, in part,
was due to seasonal constraints on forage production that drive up prices of
cool-season grasses, he says, providing better marketing opportunities than
warm-season grasses.

When combined
with lower production costs and more stable yields, cool-season grasses have
higher returns and less risk than warm-season grasses, which often have
negative returns, Park says.

The average
economic return of the cool-season grasses was $274.17 per acre, which was
considerably higher than the warm-season grasses average return of $36.64 per
acre, he says.

“This is an
interesting result, since the dry matter yields of warm-season grasses were
found to be significantly higher in the field trials than those of the cool-season
grasses,” Park says.

The difference
between yield and economic performance can be explained by both the higher
market prices and lower variable costs of the cool-season grasses that
compensated for the lower yields, he says.

When it came to
the comparison of swine effluent and urea, Park says the swine effluent
generated significantly greater returns when applied on the warm-season grasses
but provided no growth advantage over urea on the cool-season grasses.

All the grasses
respond to higher fertilizer levels, he says. However, the economic model
showed urea applications beyond 150 pounds per acre would never be economically
efficient due to declining product value at a higher rate.

For swine
effluent however, the economic model suggests that higher fertilizer levels
could generate higher returns since the marginal-value product has not yet
decreased, Park says.

At such higher
fertilizer levels, it is possible that swine effluent could result in
significantly higher dry matter yields than urea, he says.

Based on average
economic returns, the economic model was not able to provide a single best
alternative, but it was able to conclude that cool-season grasses perform
better than warm-season grasses, Park says.

Four
alternatives from the cool-season grasses emerge as generating the highest
economic return. These include orchard grass applied with 450 pounds per acre
of swine effluent, orchard grass applied with 50 pounds of urea, wheatgrass
applied with 450 pounds of swine effluent and wheatgrass applied with 50 pounds
of urea.

While there were
slight differences in economic returns between them, ranging between $297.19
and $305.03 per acre, the differences were not significant, Park says.

The performance
ranking of each forage species was, however, dependent on the decision maker’s
attitude toward risk, Park says. Urea was found to have less risk than swine
effluent and would be the preferred choice for even modestly risk-averse
producers.

Future research
will be required to explore different types of warm- and cool-season forages to
identify a wider range of options for producers, he said.

 “This should include investigating other types
of management options including herbicides, integration into crop rotations and
other types of animal manure, particularly beef,” Park says. “This could also
provide solutions to producers from a wider range of farming systems beyond the
Oklahoma Panhandle and Southern Plains.”