The Northern Advocate

Green ideas come with a cost

What farmers need to be green is wealth, argues Jacqueline Rowarth

- Dr Jacqueline Rowarth is a soil scientist and a farmer-elected director for DairyNZ and Ravensdown. The analysis and conclusion­s are her own.

The suggestion that New Zealand can move to cloverbase­d organic and regenerati­ve agricultur­e needs serious thought before any change is made.

All changes have implicatio­ns, and some are more serious than others.

In this case, what is being suggested affects the industry that underpins the export economy, meets over half the needs of domestic food consumers, and is caretaker for about half of New Zealand.

This last role is often forgotten when environmen­talists are bemoaning the state of the country — without farmers and growers, could the Department of Conservati­on (DoC) cope with what needed to be done?

The answer is unlikely to be in the affirmativ­e given that DoC has Landcorp (trading as Pa¯mu) managing high country station Molesworth, and has indicated that it has enough funding to protect only about 10 per cent of the native forests from possums. It is also losing the battle on wilding pines.

Could taxes be increased sufficient­ly to enable DoC to do more? Or rates? Few people heading for national or local politics have campaigned successful­ly on the basis of increasing levies on the public.

A signal on this was provided by the New Zealand Institute of Economics Research (NZIER) report on water quality published last year: “there are definite limits to what the public are prepared to pay”.

The general public was found to value river clarity (visibility) above flora and fauna, swimmabili­ty and a levy in that order.

Authors reported that people’s views might change if they had to pay an annual levy. They also reported some push back when it came to higher levies or taxes.

“While a majority of Wellington guests and high school teenagers were happy to pay an extra $50 per year to increase flora and fauna, 60 per cent of the general public were not.” (Note that whether the teenagers were prepared to pay the extra $50 themselves or expected their parents to pay it on the rates was not asked.)

Water visibility, the most valued factor in the research, is affected by sediment.

Keeping animals out of water helps reduce sediment; koi carp, which are common in the lower reaches of the Waikato, increase sediment.

Bare soil, whether from cropping, deforestat­ion, road constructi­on or building, creates potential for sediment in rain. Earthquake­s and mountain uplift cause slips which can result in sediment. Dumping water from dams can also increase erosion and sediment.

Keeping soil covered is recommende­d in organic farming and is already regarded as best practice by most Kiwi farmers and growers whether they are organic, regenerati­ve or convention­al in approach to food production.

The biggest factor in understand­ing the issues of water quality is the concept that rivers should be pristine. The reality is that all rivers change as they flow from source to sea.

Sir David Attenborou­gh has explained in various documentar­ies that “young rivers are by nature vigorous and dangerous: they flow fast and form rapids, thick with mud and sediment. They accumulate sand and gravel en route, and this erodes all but the hardest surroundin­g rocks”.

Sir David has reported that the Yellow River of China carries the most sediment of any river.

“By the time it has settled down and fallen over its last cascade, the water becomes tranquil and rich with nutrients from its banks.”

Nutrients in rivers are another problem for agricultur­e, and organic agricultur­e has been touted as the solution because it does not allow the use of synthetic fertiliser­s or other chemicals.

There is, however, no difference in leaching loss of nitrogen (nitrogen lost from the soil in rainfall) between nitrogen fixed by clover or applied as urea at the same rate.

This result was reaffirmed recently on the Canterbury Plains in research supported by the MPI Sustainabl­e Farming Fund.

For operations that aren’t based on pasture, the problem for organics becomes nutrient supply. In any food production system where material is harvested and removed, nutrients must be replaced for sustainabi­lity.

Most organic farms rely on manure which comes from housed, or partially housed, animals.

In New Zealand poultry, pig and goat manure is available in limited quantities. The feed for those animals might be grown on the farm or elsewhere but, wherever the feed is grown has been depleted by the removal of the nutrients in the feed.

In societies trying to be selfsuffic­ient, the recycling of human waste becomes important — more than simply composting.

There might be public push back on that, as well.

But the big issue for organics and regenerati­ve agricultur­e is yield, cost and price.

There is no guarantee that a change would benefit the economy, despite assurances that people would pay more for food if they understand the issues. A change is also unlikely to benefit the environmen­t in the way being promoted.

All changes have implicatio­ns, and some are more serious than others. In this case both the economy and the environmen­t are at stake.

The big issue for organics and regenerati­ve agricultur­e is yield, cost and price.

 ?? Photo / File ?? A dad takes a selfie with his son of a raging waterfall. People value clear water but that can be affected by heavy rain, usch as here, as much as fencing cattle away from the waterway.
Photo / File A dad takes a selfie with his son of a raging waterfall. People value clear water but that can be affected by heavy rain, usch as here, as much as fencing cattle away from the waterway.
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