The national average nitrogen leaching loss in 2015-16 was 39kg/ha a year — the same as the year before.
N-loss calculations in Canterbury and Otago (64 and 39 respectively) revealed higher figures than the rolling average of the two previous years of accord measurements (50 and 33).
This was because irrigation effects were included for the first time after a change in the Overseer computer model used to generate the leaching loss numbers.
Nitrogen losses were generally higher through stony soils under irrigation, DairyNZ sustainability team leader Theresa Wilson said.
Because Overseer generated rolling averages, improvements in N-loss numbers from changed farming practices such as the targeted use of nitrogen fertilisers or irrigation applications would take years to show up, she said.
The third year report was released by DairyNZ and seven dairy companies, including Oceania for the first time.
The audited report highlighted the progress against commitments and targets by 11,400 farms in key environmental areas.
The scope of the accord did not cover run-offs, only dairy platforms.
Dairy cattle were now excluded from 92.7% of waterways on farms and 99.4% of regular stock crossing points now have bridges or culverts.
Waterways were classified as greater than 1m in width and deeper than 30cm.
Nearly 6000 dairy farms had installed water meters and 9500, or 83%, had nutrient budgets that generated nitrogen information for farmers.
The rate of significant non-compliance for effluent systems dropped to 5.2% nationally, although Northland remained significantly higher.
Rate of progress on riparian planting plans for farms with waterways was also disappointing, being only 27% at the end of the latest audit period, versus a 50% target.
DairyNZ, in partnership with regional councils, had produced 13 tailored riparian planting guides.
Exclusion of dairy stock from significant wetlands was also lagging well behind the SD:WA target.
“This is one area where the nature of the obligation is problematic due to the variability of regional council regulations and an increasing national as well as regional interest,” the report said.
DairyNZ chief executive Tim Mackle said the year three report showed encouraging progress although there was still some work to do.
He thought it was the biggest mobilisation on behalf of the environment anywhere in New Zealand and that the average spend on farm was $90,000.
Total expenditure in recent years had exceeded $1 billion, of which about 70% was spent on effluent systems.
Greatly reduced non-compliance numbers showed that effluent systems were now more efficient, safer in the environment, and saving nutrients for land application.
All dairy companies now had effluent system assessments for all farms, several companies doing every farm every year.
All regions now had access to accredited effluent system designers among 22 companies offering services.
The report said water use measurement on over 100 farms had revealed 26% of Waikato water use was actually losses through long-term slow leaks or short-term high volume leaks.
In the three years of the SD:WA, there had been 253 conversions to dairy farms, with 78 in the 2015-16 season.
All conversions had to comply with environmental standards before milk supply began.
Primary Industries Minister Nathan Guy said the progress achieved in what was a short time was cause for celebration.
No longer were dairy farmers copping all the blame for water quality issues, he said.
“It’s also about urbanisation so we are all in this together. It is pointless playing the blame game.”
Consumers were now actually inside the farm gate because of technology and smart phones and the societal pressure on agriculture to do more came from both domestic and international customers.
