Editorial: Sense at last
OPINION: For the first time in many years, a commonsense approach is emerging to balance environmental issues with the need for the nation's primary producers to be able to operate effectively.
A new scientific article on the management of soil phosphorus makes fascinating reading, writes Dr Bert Quin, managing director of Quin Environmentals.
The article is entitled ‘A Global Perspective on Integrated Strategies to Manage Soil Phosphorus Status for Eutrophication Control Without Limiting Land Productivity’, published in Journal of Environmental Quality, July 2019.
It was co-written by 15 scientists from several countries, including Lucy Burkitt from Massey University, and Murray Hart, formerly a senior research scientist for Summit-Quinphos before moving to Australia.
Here are a few direct quotes from the article:
‘Phosphorus losses from agricultural soils are hard to mitigate because they occur in both dissolved and particulate form, and are transported from highly variable source area…. Managing soils and soil P status represents an important strategy for the mitigation of eutrophication’.
‘Modern agriculture has come to rely on maximising the availability of P in soils through [so-called] insurance application rates of highly soluble P fertilisers to build up soil P fertility and minimise risks to productivity. This makes it harder to manage resulting soil P losses’.
‘Legislation to help reduce (loss-inducing) threshold soil P test values has been generally slow to implement despite widespread eutrophication problems’.
‘Our analysis spanned three continents and catchments with different ago-hydrochemical functioning. The study areas were expected to represent variable run-off response, soil P response patterns and erosion vulnerability’.
‘All data sets showed a highly significant effect of soil P status on P runoff concentrations’.
‘Future sustainable P management within the food system must reconsider old philosophies that place undue emphasis on maintaining an artificially high level of P fertility dependent on inputs of highly soluble manufactured fertilisers towards new philosophies that concentrate on precision feeding of the crop not the soil’.
‘Our meta-analysis across three continents suggests agronomic optimum P concentrations need to be in the range of 10-20 Olsen P to match challenging eutrophication control targets being set for freshwaters (around the world)’.
In New Zealand, where all our soils are mildly acidic, we have the enormous advantage that we could maintain high pasture production levels without Olsen P levels needing to be pushed above 20, simply by avoiding the use of soluble P fertilisers such as superphosphate where sustained-release P fertilisers like reactive phosphate rock (RPR) will maintain at least as high production, with much less P run-off and leaching.
Dairy farmers, you need to figure this reality out for yourselves soon, before you are forced to destock. Unfortunately, vested interests in a small country like ours prevent the fair and open discussion of scientific knowledge.
• Dr Bert Quin is managing director of Quin Environmentals (NZ) Ltd.
Boutique Waikato cheese producer Meyer Cheese is investing in a new $3.5 million facility, designed to boost capacity and enhance the company's sustainability credentials.
OPINION: The Government's decision to rule out changes to Fringe Benefit Tax (FBT) that would cost every farmer thousands of dollars annually, is sensible.
Compensation assistance for farmers impacted by Mycoplama bovis is being wound up.
Selecting the reverse gear quicker than a lovestruck boyfriend who has met the in-laws for the first time, the Coalition Government has confirmed that the proposal to amend Fringe Benefit Tax (FBT) charged against farm utes has been canned.
Holstein Friesian excellence was front and centre at the 2025 Holstein Friesian NZ (HFNZ) Awards, held recently in Invercargill.
The work Fonterra has done with Ballance Agri-Nutrients Ltd, LIC and Ravensdown to save farmers time through better data connections has been recognised with a national award.
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