Not too late to beat high fall nitrogen costs
There is a way to beat high nitrogen fertilizer
costs for pastures when it comes to putting pounds on calves.
This is according to a four-year study comparing
different pasture management systems with cows and calves by the Texas
Agricultural Experiment Station. Based on average daily gain of calves,
the study found that adding a cool-season clover to a warm-season
perennial grass was more profitable than applying high amounts of
nitrogen.
“Adding a cool-season clover to a warm-season
perennial grass was more profitable than the high- and no-input systems
because the clover extended the grazing season, had higher nutritive
value, and provided summer weed control in addition to adding N
(nitrogen) to the pasture system,” wrote Dr. Gerald Evers, experiment
station researcher, in his formal report.
Evers compared three systems: A high-input
system on dallis grass pastures using 150 pounds of nitrogen per acre
and herbicides for weed control; a medium-input dallis grass system
where winter clover was over-seeded into a stand of warm-season grass
pasture; a no-input pasture system, using no nitrogen, no herbicide and
no clover.
Evers, who is now based at the Texas A&M
University agricultural research and extension center at Overton, TX,
originally conducted the study at a site near Angleton, TX, in the
1980s. At that time, however, nitrogen fertilizer was relatively cheap,
he said. And other than summer weed control, the economic benefits to
using cool-season clovers were not clear.
With nitrogen costs topping 55 cents per pound
in 2007, that situation has changed, Evers said. Average daily gains for
the calves were 1.57, 1.82 and 1.66 pounds per day for the high-,
medium- and no-input systems.
“Using 2007 costs for pasture and animal inputs,
production costs per pound of calf gain were $1.12, $0.58, and $0.81 for
the high-, medium- and no-input pasture systems respectively,” Evers
wrote. Additionally, using clover in the medium input system proved “as
effective as applying herbicide in April for controlling summer weeds”
in the high-input system, he said.
“Average daily gain for the cows on the
clover-grass system was even higher, being twice that of the other two
grass-only systems because of the longer grazing season and higher
nutritive value of the clover,” explained Evers.
The original study was using dallis grass and
white clover, both of which are well adapted to the upper Texas Gulf
Coast region. The system is just as applicable to more northern regions
of Texas, though different grasses and legumes would need be used, he
said.
North of Interstate 10, soils are sandier and
better drained. Bahia grass and Bermuda grass are better adapted to
these areas than dallis grass or white clover, he said. As for the
clover component, arrowleaf, crimson and ball clovers are better
adapted.
“Instead of only planting pure clover, I would
mix annual ryegrass with that clover,” Evers said. “If you mix rye grass
with the clover, you don’t worry about bloat. In that (Angelton) study,
we had to feed bloat guard blocks for six weeks when most available
forage out there was white clover, so you could eliminate that expense
of having to buy bloat guard blocks by just putting annual rye grass
with the clover.
“By adding clover, we started grazing five weeks
earlier than if we didn’t have clover, so that helped us by about $60
per cow,” Evers said. “So if you add ryegrass to the clover, we could
even start grazing another four to five weeks earlier than when we
started grazing clover, and that would give you another $50-$60 in
winter feed cost savings per cow.”
The one issue many east Texas producers must
attend to before they rush into over-seeding clover this fall is soil
acidity, Evers cautioned. Raising soil pH by liming takes four to six
months. Unamended east Texas soils often have a soil pH of 5.5 or lower.
“You like to see the pH at six or higher, but
now, here we are the early part of August,” he said. “If they do a soil
test and the pH is 5.5, they could put on two tons of lime and raise the
pH some by fall. It might not reach a pH of six in two to three months,
but it would be closer to six than 5.5.”
Though producers might not see optimum clover
production until spring, they could still get could results. “The only
thing you worry about if the soil is real acid in the fall when you
plant is you may not get a good stand of clover,” he said.
Since 1970, Evers has worked on forage
production problems throughout the eastern half of Texas. He is the
primary author or co-author of papers presented at the International
Grassland Congress in Kentucky, France, New Zealand, Canada, and Brazil,
and the International Herbage Seed Conference in Oregon, East Germany,
Italy and Australia.
Read more








