The lead article in The Press on the 22nd of October was headed Nitrate Risk to Infant Health, with a warning from Canterbury District Health Board medical officer Alistair Humphrey that, “a baby could die if nitrate levels are not more tightly controlled”.

The term “ticking time bomb” occurred three times in the article and although it was stated that the steady increase of nitrate in ground water levels in the Canterbury region was not solely the result of farming, there is little doubt that the increased use of nitrogen fertiliser is seen as the main culprit by most people.

Reducing the loss of nitrate nitrogen into groundwater is a necessity and pressure will continue to mount until steps are taken – it’s just a matter of how long it will take before fundamental changes are made.

It was not until 1995 that farmers in New Zealand began embracing the regular applications of nitrogen fertiliser, primarily urea from Kapuni, first manufactured in 1983 to use surplus energy from the Maui gas field.

The 10 year time frame between the introduction and regular widespread use of urea is a not unusual period for the uptake of any new product in a market place dominated by traditional and conservative thinking.

A significant amount of research had already been by undertaken by AgResearch on the use of urea for the production of out of season pasture growth, however no trial work was available for its long- term use, so the consequences of present practices are unknown, but becoming more evident every day.

Nitrogen fertiliser is expensive and although the cost may be put in the supplementary feed budget it is a real expense and with more pasture requiring replacement each year the profit generated from pasture is continuously being squeezed.

Although pests, dry weather, and new cultivars are often blamed for the lack of persistence of ‘permanent’ pastures the real problem nearly always lies with the physical structure of the soil.  Soils that have become compacted do not allow plant roots to penetrate more than a few centimetres and these areas are most affected by summer dry and pulling in autumn.

Rather than attempt a radical rethink of farming systems there is a small and inexpensive step that can be taken that will significantly reform every aspect of a farms operation.

The application of Golden Bay Dolomite rapidly improves physical soil structures. Tight compacted soils become more friable allowing plant roots to penetrate to a greater depth.


With more root mass plants have access to greater quantities of both moisture and nutrient.  More nitrogen is able to be intercepted before reaching groundwater allowing for a reduction in both the frequency and rate of applications.

Pastures that are already earmarked for replacement this autumn may only require renovation; however the most obvious effect is the improvement in every aspect of animal health and performance.

Animals on properties where dolomite is applied annually at 200 – 250kg/ha suffer fewer metabolic disorders in spring, have a lower incidence of mastitis and are more likely to hold to the first insemination.

Dolomite can be applied at any time and each tonne of dolomite reduces the liming requirement by a similar amount.  Dolomite from Golden Bay is one of those rare natural resources that have a wide range of benefits impacting positively on every aspect of intensive pastoral farming.

For more information contact Peter on 0800 436 566 (0800 4 Dolomite).

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