|
The
cost of fertilizer, especially nitrogen fertilizer, has sharply
increased recently because fertilizer production and transport are
linked to energy costs. This is a serious development for
forage/livestock producers, because fertilizer usually accounts for 40
percent or more of the cost of producing forage, with nitrogen
fertilizer alone often accounting for 20 to 40 percent of the cost of
producing grass forages. Here are some ideas regarding possible ways to
minimize fertilizer expenses.
Soil
Testing– Applying
fertilizer without having taken a soil test amounts to guessing how much
fertilizer is needed. Applying too much fertilizer is a waste of money;
applying too little will result in less-than-optimum forage production.
It is also important to follow liming recommendations on soil tests,
because fertilizer nutrients are less available when the soil pH is low.
Use
Legumes– In
many situations the single most beneficial technique for lowering
nitrogen fertilizer costs is to grow forage legumes, usually with
grasses. In association with Rhizobium bacteria, clovers and
other legumes obtain nitrogen from the atmosphere and "fix" it
in small nodules (knots) that form on the legume roots. The amount of
nitrogen fixed varies due to several factors, but the ranges of nitrogen
fixed in terms of pounds of N per acre per year by a good stand of (for
example) an annual legume, by white clover, or by red clover is usually
50 to 150, 75 to 150, and 75 to 200, respectively. This means that if
100 pounds of N per acre are fixed and nitrogen is selling for $0.45 per
pound, $45 worth of nitrogen per acre was added per acre.
In
addition to providing biological nitrogen, a legume/grass mixture may
produce more dry matter per acre than grass alone, particularly as
compared to grass receiving little or no nitrogen fertilizer. The
distribution of forage growth in pastures may also be more favorable,
thus helping reduce stored feed needs. However, the single most valuable
advantage forage legumes offer is better forage quality on average than
grasses, which usually sharply increases animal gains and may enhance
livestock reproductive rates.
Use
Organic Materials– Another
strategy is to use organic materials such as manure or by-products from
animal industries or various commercial processes as a source of
fertilizer nutrients. In particular, broiler litter is commonly spread
on pastures in Alabama, but other organic wastes are increasingly being
used in this manner as well. At current prices, the nutrients in a ton
of broiler litter are worth around $45 to $55.
The
feasibility of using organic waste materials depends on two factors.
First, is the value of the nutrients in the material high enough to
justify the cost of obtaining and applying it? To answer this question
requires knowing the level of nutrients in the material as well as how
much will actually become available to plants. The second factor is
whether the material contains any pathogens, heavy metals, or other
undesirable components that could be harmful to animals, humans, or to
the soil. If neither of these factors is a problem, then using a waste
material as a soil amendment may be quite justifiable.
Urea
As A Nitrogen Source– Urea
is usually less expensive than other sources of nitrogen, but it is also
more volatile and more likely to be lost during warm weather. However,
applying urea during warm weather may be justifiable in many situations
if it is substantially cheaper than other nitrogen sources. The
potential losses of urea by volatilization during warm weather can be
significant, but in recent research by Auburn University scientists,
losses in pasture situations were rarely greater than 10 to 20%. Losses
are lower when there is little pasture growth present and/or if the soil
pH is less than 7.0. Liquid nitrogen is usually a mixture of urea and
ammonium nitrate, but only the urea component is vulnerable to
volatilization loss.
Prioritize
Fertilizer Application– Not
every acre of pasture is equal, because some areas have a much higher
yield potential than others. For example, a rich, deep, and relatively
level bottomland pasture may be much more productive than an eroded,
thin hillside. The reasons are that on the hillside water runs off
quickly, the soil may not hold nutrients well, and roots may only have a
few inches of good soil in which to grow. In the bottom there will
probably be better moisture and nutrient availability during most of the
growing season and roots can penetrate deeply. The point is that the
first priority should be on providing nutrients in areas that have the
potential to be most productive.
Timing
Of Fertilizer Applications–
If funds to invest in fertilizer are limited, it makes sense to time the
applications so that extra pasture forage will be produced when it is
most needed. For example, on a farm in north Alabama that is not heavily
stocked, there may be excess forage available in spring. In such a
situation, money spent for fertilizer applied in autumn would result in
more valuable forage production by stimulating autumn grazing or for
stockpiling fescue forage to help reduce hay requirements.
Grazing
Management– Utilization
of pasture forage is greatly affected by grazing method. In fact,
research has shown that in many poorly managed continuous grazing
situations,
less than half the forage produced in a pasture ends |
