The increasing profitability of dairy farming has led to a rush for ‘white gold’, with swathes of land converted to dairy farms in recent years, the Science Media Centre says in a press release which spotlights the latest report from the Parliamentary Commissioner for the Environment.
But there is hidden cost to the dairy boom.
The commissioner, Jan Wright, says increased dairying is negatively affecting the water quality of our lakes and rivers and we need to do something about it.
The Science Media Centre says:
Yesterday the Commissioner released a new report titled Water quality in New Zealand: Land use and nutrient pollution, adding weight to the growing concern over freshwater quality in the face of changes to the farming landscape.
The document details how a shift from sheep and beef farming to dairying has led to increased leaching of nitrogen and phosphorus into streams and rivers, which in turn causes excessive growth of weeds and algae. Drawing on modelling of land use and nutrient run-off, the report also paints a grim picture of the future, predicting that leaching of nitrogen and phosphorus into waterways will continue to increase – even under “optimistic” assumptions.
“Unfortunately, if we continue to see large-scale conversion of land to more intensive uses, it is difficult to see how water quality will not continue to decline in the next few years.” The report concludes.
“I applaud the effort that is being put into environmental mitigation on dairy farms,”Dr Wright said in a media release. “Unfortunately, it is particularly difficult to control nitrogen. Nitrogen – in the form of nitrate – is so soluble that I think of it as the ‘elusive’ pollutant.
“I am pleased that fresh water policy is very much on the Government’s agenda with the recent release of a discussion paper on setting ‘bottom lines’ for water quality. I hope that this report will better inform both the general public and those who make decisions on their behalf.”
Experts contacted by the Science Media Centre were generally welcoming of the report.
David Hamilton, President, New Zealand Freshwater Sciences Society, commented:
“It is clear from the report that ‘business as usual’ will not get us over the line and that a step change and solution-focused approach are required, mostly in environmental management in the agricultural industry, to meet the National Policy Statement for Freshwater Management objectives.”
Assoc Prof Russell Death, Institute of Agriculture and Environment, Massey University, commented:
“Many of our waterways are already badly degraded, agriculture creates pollutants (nitrogen, phosphorous and sediment) and thus increasing agriculture even with the best mitigation practices (none of which are even close to perfect) will still result in more pollutants entering our waterways. More pollutants, lower water quality, it’s not rocket science.”