Unchanged nitrogen loss from dairy farms highlights long-term challenge to NZ waterways

The dairy industry's year-three report on its commitment to mitigating the environmental impact of farming shows it has achieved six of 13 goals that were set out in 2013 but hasn't yet made a dent in nitrogen loss, underlining the long-term nature of the task of improving waterways.

Nitrogen leaching in the 2015/16 year was a national average 39 kilograms of nitrogen per hectare per year, unchanged from the previous year. Of the 13 regions surveyed using the Overseer computer modelling system, seven actually had an increase in nutrient loss, the worst being Canterbury, which climbed to 64 kg/N/ha/year from a 50 kg N/ha/year rolling average for 2013/14 and 2014/15. Otago has the second-worst deterioration, with an increase to 39 kg N/ha/year from 33 kg N/ha/year.

That particular data has to be taken with a grain of salt because both Canterbury and Otago regions provided more irrigation data for the latest survey, which bumped up their nitrogen loss measure, while a more sophisticated version of Overseer was employed and there were likely changes on individual farms. A total of 9,516 farms nationwide were sampled for the 2015/16 season.

"Nitrogen loss will take longer and in some cases it's going to get worse before it gets better," DairyNZ acting chair Alister Body said after a briefing in Wellington for the release of the report. He said the lack of improvement in nitrogen loss reflected changes to Overseer which masked what he believed had been "real progress".

Of the 13 goals, only two of the six goals achieved related to the latest season - riparian guidelines were completed for all regions by May 31, 2016, and for the 2015/16 season, all new dairy conversions complied with environmental standards before milk supply commenced.

Of the others, four goals missed their deadlines; 100 percent stock exclusion of all wetlands identified by a regional council as at May 31, 2012 by May 31, 2014, was marked as still in progress; A target for 50 percent of dairy farms with waterways to have a riparian management plan by May 31, 2016, was missed, with only 27 percent reached; A deadline of having nutrient management data collected from 100 percent of farms by May 31, 2015, was missed, with 83 percent of farms reached; A target of nitrogen loss and nitrogen conversion efficiency performance information reported back to 85 percent of dairy farms by Nov. 30, 2014, was missed, with 83 percent achieved.

Dairy farmers have been on the defensive because of campaigns from environmental groups and as well as taking positive steps such as fencing off and planting waterways. The sector's lobby groups and biggest participant, Fonterra Cooperative Group, have gone on the offensive - pointing to dirty urban waterways and the role of city folk on one hand, while making efforts to reconnect with those same people on the basis that they've lost contact with the reality of farming.

"Dairy farmers are certainly feeling pressure from public opinion," Body said. That's why they're keen now to "tell their story. I don't think we've been very good at that in the past."

Minister for Primary Industries Nathan Guy was on hand to help the cause at today's briefing, saying the "fantastic numbers" in the report meant it was "a day about celebration".

He praised the voluntary efforts of farmers including 26,197 kilometres of new fencing since the Sustainable Dairying: Water Accord was announced while adding that urbanisation and industrial waste was part of the problem and it was "pointless to play the blame game."

DairyNZ chief executive Tim Mackle was asked by Federated Farmers president William Rolleston if he agreed with "greenie groups" that New Zealand actually needed to reduce the national dairy herd. He replied: "I'm an optimist. I believe we can have our cake and eat it. I believe that science can offer us solutions". The nation shouldn't rush to a conclusion that there were too many dairy cows.

His acting chair, Body, added that "fewer animals and greater protection for the environment is the better way", while Guy said it wasn't a question of a moratorium of dairy cows but a catchment by catchment issue.

(BusinessDesk)