Opinion: When it comes to changing to organic and regenerative agriculture, both the economy and the environment are at stake, writes Dr Jacqueline Rowarth.
The suggestion that New Zealand can move to clover-based 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 caretakers approximately 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 Pāmu) 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.
Listen to Jamie Mackay interview Dr Jacqueline Rowarth on The Country below:
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 as this was "a stated preference survey (i.e. what people think should happen) there is a distinct possibility that their 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 assists with sediment reduction; 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 the majority of New Zealand 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 the source to the 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 self-sufficient, 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.
• Dr Jacqueline Rowarth is a farmer-elected director for DairyNZ and Ravensdown. The analysis is from publicly available data and the comments are her own. email@example.com