by the same operator round bales can vary 30% or more
in weight. The only thing consistent about round bales is
the width of the bale.
One additional option is to make your own set of
scales using the hydraulics of a tractor loader or threepoint hitch. A full explanation of how to accomplish
this is not possible in this article but the following link
is to a West Virginia University Extension webpage
that provides an explanation of what you would need
to know (http://www.wvu.edu/~agexten/forglvst/Using
Hydraulics as a Scale on the Farm.pdf). This informative
paper, “Forage Management: Using Hydraulics as a
Scale on the Farm,” by Craig W. Yohn, Dr. Edward
B. Rayburn and Dr. Dana Porter discusses the basic
principle, calibration, applications and accuracy of such
a system. Also of considerable interest in this fact sheet
is documentation of the variance in bale weights. Two
bales from the same 4’ x 5’ round baler varied in weight
by 449 lbs. Even more interesting is that consultants
guessed them to be about 42 lbs different and they
guessed the heavier bale to be the lightest. It appears
that guessing the weight of round bales is a true guessing
game.
An apt question at this point is, “When should I weigh
my hay?” You might be tempted to weigh your hay at
harvest time when you’re already loading, unloading and
transporting it. But if you want a more consistent way
of determining your yield, wait a couple months. The
moisture content of the hay decreases during storage.
Most dry hay is baled at less than 20-25% moisture and
will generally stabilize at about 12% after a couple of
months. Hay baled at more than 25% moisture will
likely mold and considerable loss of quality is expected.
As hay loses moisture content and stabilizes at about
12% some dry matter content is also lost, but as you bale
very dry hay you will experience a greater in-field loss,
so it is a trade off. Generally speaking, hay baled at 15
to 18% moisture will result in maximum overall nutrient
yield. (Dennis R. Buckmaster, Indoor Hay Storage: Dry
Matter Loss and Quality Changes. http://pubs.cas.psu.
edu/freepubs/pdfs/i102.pdf)
Once you have determined your hay yields, you can
begin planning for future fertilizer applications to ensure
a respectable yield for next year and the years to come.
The best way to know the fertilizer nutrient content
of your hay is to sample your hay and obtain a forage
analysis. In the absence of an analysis the following
table gives an idea of how much fertilizer nutrient
content you are removing in your hay crop.
Hay Type
Fertilizer Nutrient Content
Pounds/ton at 90% dry matter
N
P2O5
K2O
CaCO3 MgCO3
Hay, grass
Hay, mixed, mostly grass
Hay, mixed, mostly legume
Hay, legume
Hay, small grain
Straw
30
35
48
56
26
17
9
9
11
10 (