Expert view

Sophistication will give farming economic and environmental win-win

A line from Samuel Taylor Coleridge’s poem Rime of the Ancient Mariner befits New Zealand’s media this past month. It’s all about water contamination.

There has been a water contamination story in almost every newspaper, TV or radio bulletin, usually with farming blamed for some rivers having, as the English poet Samuel Taylor Coleridge put it, “nor any drop to drink”.

It follows the New Zealand government’s February 22 announcement that it wants 90% of lakes and rivers ‘swimmable’ by 2040. Currently 72% pass. Unsurprisingly, opposition parties and environmental groups panned the plan, saying the target is too low, and too distant.

They also slammed its shift in the definition of swimmable from 260 E coli per 100ml to 540/100ml. When they realised not all rivers were included in the swimmable target, and that the E coli goal need only be met 80% of the time, there was more outcry.

Cows and pugging around drainage waterway, Taieri Plains, near Dunedin, South Island, New Zealand

Cows and pugging around drainage waterway, Taieri Plains, near Dunedin, South Island, New Zealand. Photo credit: David Wall, Alamy Stock Photo

Wind back production

Most articles gave farmers’ representatives an opportunity to respond, but the overall impression the reader was left with was that intensive farming is to blame and, therefore, the solution was to wind back production.

Ironically, one of the plan’s requirements, namely to fence all waterways by 2030, could see a moderate intensification of farming in some extensively farmed uplands, as stock and fertiliser rates are increased to offset investment in fencing and stock water systems.

Needed: sophisticated farming systems

Meanwhile on lowland, where most farms are already deemed ‘intensive’, unwinding current productivity levels will be difficult, particularly for dairy, due to high debt and the need to service loans.

What is really needed is greater use of sophisticated farming systems to solve the environmental issues.

Tools, such as variable rate fertiliser and manure application and rotational cropping of dairy paddocks to remove excess phosphate and other nutrient build up, will help.

See also: Ways to reduce the risks of water pollution

Economic and environmental benefits

Smarter animal nutrition can also reduce nitrate excretion, with high starch feed crops such as maize, fodder beet or wholecrop cereal helping to balance cow diets in spring when pasture crude protein is excessive.

Such changes won’t sit well with some environmentalists, who will see them as further intensification. However, science suggests nutrient and coliform bacteria contamination of water could be cut and productivity maintained or even improved.

If costs can be kept in check, then an economic and environmental win-win is on the cards.