Editorial: Credit is due
OPINION: It's official! New Zealand dairy farmers have the world’s lowest carbon footprint – at nearly half the emissions of other international producers.
“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.”
Stafford says products such as Ballance’s 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 in farm budgets by minimising nitrogen losses so farmers can get the most out of their fertiliser spend.
“Taking an average autumn N response of 7kg extra pasture DM/kg N applied, and including $120 per tonne for application and cartage, using SustaiN Green to grow additional pasture means each additional kgDM grown costs about 29 cents. Whereas PKE, at 90% DM, comes in at 35 cents/kg when the average spot price is $300 a tonne, and as these prices rise N becomes even more competitive.”
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 feed pad, 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, the company says.
“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 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,” he says.
