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Forage & Nutrition
Guide 2018
Fertiliser: it must be spread
Beef, dairy and sheep enterprises use grass as their primary source of
nutrition. The cost, yield, quality and efficient utilisation of grass are all
critical to profitability. Fertiliser is a hugely important and expensive input
that impacts on yield, quality and production costs
Uneven spreading is not uncommon. Grass or crop yield is
impacted long before any visual striping is seen. On a 50 hectare
(ha) dairy farm, the annual fertiliser bill averages in excess of
16,000 or in a lifetime of 10 years, a simple spreader may
spread 160,000 of fertiliser producing 4,500 tonnes of grass
dry matter (DM) and underpinning a farm output of 1.7m (milk
and livestock sales). This puts the purchase price of the spreader
in context considering the impact it may have over its working
life. If poor/uneven fertiliser spreading caused a 5 per cent loss
in production over its lifetime, that could reduce farm output
by 85,000. To avoid losses associated with fertiliser spreading,
there are three critical factors which must be considered:
The correct choice of machine for the fertiliser being used
at the chosen bout width;
The use of fertiliser with good physical quality
characteristics; and
Correct setting of the machine for fertiliser and bout width
and proper maintenance.
Like many machinery operations, the farmers have the choice
of doing the job with their own machinery or using a contractor
either an independent contractor or a contractor supplied by
the merchant. While choice of spreader, the selection of quality
fertiliser and the setting of the spreader are clearly within
the farmers' control in the case of their own machine, who's
responsibility is it in the case of a contractor's machine?
With contract spreading, there are potentially three parties who
have an interest in good spreading:
The fertiliser merchant (if selling a bulk product with
spreading supplied);
The spreading contractor; and
The farmer.
It is clear that, as the buyer of the service, it is up to the farmer
to set the standards required in terms of spreading. A quality
service is essential and must be sought. It is not adequate to
simply purchase the cheapest product, `as spread', as there is a
risk that:
The physical quality of the fertiliser is compromised
(smaller size particles, more dust, mismatched blend
components) to save money; and
The spreading service is compromised where the emphasis
is on getting fertiliser out as quickly and cheaply as
possible without attention to spreading that product
Figure 1: Basic (shaded area) and overlapped (line) spread pattern at 18m good pattern.
0 5 10 14 19 24 29 34 38
Lateral distance (m)
Application rat
e (%)
Author: Dermot Forristal
Teagasc, Oak Park