26 February 2013
Dairy farmers have cost effective “friend in N”
With high demand in dry areas edging up the price of supplementary feed, dairy farmers wanting to maintain production
into late autumn have got an increasingly cost effective “friend in N”, says Ballance Science Extension Manager Aaron
Stafford.
“As a feed source home grown pasture remains your best bang for buck and with supplementary feed prices now averaging
$50 a tonne more, farms that are not battling the dry conditions will find N an even more competitive tool for extending
autumn lactation and maintaining herd condition.”
Aaron says products like SustaiN Green, which reduces ammonia volatilisation, offer farmers more flexibility to apply
nitrogen when it’s needed most or when it suits them better, even if the weather or soil conditions often experienced
during autumn are not optimal.
He says the product also stacks up well when it comes to farm budgets by minimising nitrogen losses so farmers can get
the most out of their fertiliser investment.
“Taking an average autumn N response of seven kilograms of extra pasture dry matter for every kilogram of N applied, and
including $120 per tonne for application and cartage, using SustaiN Green to grow additional pasture means each kilogram
of additional dry matter grown costs about 29 cents. A PKE, at 90% dry matter comes in at 35 cents a kilo when the
average spot price is $300 a tonne and as these prices rise, N becomes even more competitive.”
Mr Stafford says other alternative supplementary feeds such as maize or cereal silage present a similar picture, usually
costing 30-40 cents/kg DM. In addition, without use of a feedpad, high wastage and pasture damage can further reduce the
economics of these alternative options.
“With autumn applied N, it is important to get this on earlier rather than later to ensure soil temperature does not
limit the size or timeliness of the N response, but as all farmers know, you need to watch the weather if using standard
urea. Without rainfall within 24 hours of application ammonia volatilisation losses from standard urea can be
significant, in excess of 10-15% of the N applied.”
Ballance-funded studies by AgResearch scientists show that in pastoral conditions, using SustaiN Green instead of urea
will result in an average 50% reduction in volatilisation losses. This is in agreement with results from international
research.
Other research also supports autumn pasture as a cost effective choice for maintaining herd condition ahead of calving.
“A cow body condition score of 5 at calving should be targeted to maximise milk production, and there are many feed
options to achieve this,” says Mr Stafford.
“However, research by DairyNZ has shown that with the exception of high-energy concentrate supplementary feeds, there is
little difference between autumn pasture and cereal silage, grain or PKE for increasing rate of gain in cow body
condition score leading up to calving, especially when wastage of the later options is taken into account.”
ENDS