It should be noted that figures above are approximate
only and that actual dimensions of bales can vary considerably
from the expected, due to variations in dry-matter content of
the grass being baled and the pressure that balers can exert.
A more accurate figure can be obtained by measuring the actual circumference
of 20 bales which are representative of the bales in the field and
obtaining the average diameter.
Note that a 6" increase in diameter on a bale increases the
circumference of the bale by 0.479m, nearly half a metre! This
will reduce the number of bales covered per roll by as much as
25 (assuming a 4ft bale with 2 layers applied). A similar exercise
needs to be performed with the length of net being applied. Whilst
it may be considered that exactly 2 layers of net are being applied,
one extra metre of net applied to each bale would reduce the number
of bales per roll by as many as 39 bales.
to the Netwrap page