Speaker, Dawn Dalley, is a senior research scientist with DairyNZ and has a background as a scientist in the dairy industry in Australia. Her team’s focus is on methods to reduce nitrogen losses by 30 per cent on the farm.
Graeme and Louise Paul, with their children, Stephanie, Bayley and Darcy, hosted the 230 people who attended the Muster. Their co-farm hosts were their sharefarmers, Simon Reid and Belinda Egan, of Jackiah Jerseys.
Dawn told the gathering that in New Zealand, a raft of legislation around water quality, resource management and environmental standards has been reflected in milk company supply and bank lending conditions placed upon farmers.
A key focus is on reducing the risk of nitrates leaching from the soil, measuring the effect of fertiliser inputs and from animals urinating on pasture.
“The focus of research is to identify the link between farm practice and the risks for environmental outcomes, against profitability,” Dawn said.
She leads a 740-cow multi-year farm systems research project comparing actions and outcomes to reduce on-farm nitrogen inputs by at least 30 per cent.
Part of the research is to quantify the surplus of nitrogen, compared with nitrogen leaching.
“Generally, nitrogen surplus increases with increasing farm intensity,” Dawn said.
“But there is a large variation between farms, and different farming systems.”
Beginning data at the Northland Agricultural Research Farm identified at a stocking rate of 3.1 Friesians/hectare, production needed to be 190kg/N/ha using kikuyu and rye-grass pastures, and 700kg dry matter/cow of imported feed.
Nitrogen loss can be mitigated against reduced nitrogen inputs, by growing pasture species that are efficient users of nitrogen.
Then high production cows at a lower stocking rate, creates more pasture for each cow.
Then over-wintering activities that reduce pasture use can also lower nitrogen use.
One option is to breed a cow with more efficient utilisation of urine. This can also be enhanced with inhibitors added to her diet to reduce the nitrogen in the urine.
Dawn said seaweed and fodder beet were two of the inhibitors being researched, to reduce urinary nitrogen excretion.
“Plantain is also being researched, because low plantain consumption affects a cow’s urine output, and leads to significant reduction in nitrogen concentration in the cow’s urine,” Dawn said.
“These inhibitors lead to significant reduction in nitrate leaching from the urine.”
Dealing with regulation
Constructing wetlands, fencing and revegetating waterways, are all initiatives designed to improve water quality, mitigate nitrogen loss, and can be implemented on the farm to demonstrate environmental capital.
Dawn Dalley, of DairyNZ, said while change was inevitable, and the future of regulation could appear heavy handed, there have been positive outcomes from research in New Zealand.
“In the last 15 years, this tension between farm profit, environmental footprint, animal welfare and customer expectations, has driven research in New Zealand,” Dawn said.
The Resource Management Act, government commitments to the Paris Agreement, milk company supply conditions and bank lending conditions were among the stakeholders to support improved environmental standards on farms.
Effluent collection and management on-farm had improved.
Buffer areas — called Critical Source Areas — near water on farms were constructed with minimum setbacks and livestock exclusion areas, fulfilling the requirement for improved water quality.
Troughs provided in each paddock also kept cows drinking quality water and out of waterways.
With growing climate variability, farmers also needed contingency plans for dealing with the outcomes of adverse weather events.
One of the highest risk factors affected by adverse weather events, was effluent ponds filling and/or spilling during heavy rainfall.
Dawn said Australian farmers would be facing similar pressures to provide evidence they were protecting water quality, reducing nitrogen used and leaching, and housing their cows in comfort.
Can haylage help pasture?
A research project in New Zealand is identifying how effective ‘haylage’ is at generating pasture.
It is an adaptation of a United States project, and includes using freestall barns and feedpads.
Dawn Dalley, from DairyNZ, said one of the key consumer concerns was a public perception that cows lived in mud.
This had onflow environmental impacts, including structural damage to the soil and nutrient losses.
Farmers were expected to identify ways to reduce or prevent nitrogen losses from pasture, and use environmental accounting for other inputs.
A key focus in New Zealand was over-wintering for pastures and animals.
Dawn said using haylage, in North Island conditions, as bedding and food for cows, had shown positive results in growing pasture without cultivation or other inputs.
“Hay feeders aren’t used in this scenario,” Dawn said.
Hay bales are set out in a grid formation at about 30 bales/hectare. The bales are rolled out and cattle eat it and lay on it.
Dawn said this practice had led to natural pasture regeneration on the farm.
“There’s about 30 per cent wastage,” she said.
“This regenerates into pasture, because cattle lay on it and it becomes part of the soil structure.
“Therefore, farmers need to make sure they are harvesting or buying in good quality silage or haylage, because seed germination means it will regenerate into their own soil.”
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