NZ Farmer - Soil scientist's road map to clean green future

Graham Shepherd writes:
According to the Government, our agricultural industry and dairying in particular has been working for a long time on mitigating its impact on the environment.

Rather than seeing a positive return to the farmer on the levies they pay in this regard, the health of our lakes, rivers and streams is a continuing concern.

One wonders whether the right questions are being asked and addressed, and what return has the taxpayer received from the public-good science funding into environmental research.

Farmers could convert the volatile N and P in dairy effluent ponds to less leachable and less volatilisable organically bound forms and apply as a liquid folia spray.

Given the increasing environmental footprint from agriculture, one wonders how the various mitigating measures, including increasing fencing of waterways, reducing cow numbers, stock exclusion, developing rumen vaccines etc, is working for us.

While good riparian, including wetland, management has many environmental benefits, including reducing the amount of nutrients (P and N) and faecal pathogens (E.coli) entering the waterways, it needs to occur alongside other good management practices.

There are, however, many farms where riparian management would have little or no bearing. While almost all waterways wider than a metre on dairy farms have been fenced, I'm not aware of the ability of a fence to filter out nutrients in the passing groundwater. There are also many farms that have short-lived (ephemeral) streams that only carry water and therefore nutrients during the wet winter months, areas that you wouldn't fence off.

As mentioned in my April article in NZ Farmer, while having their place, the above measures have commonly been used as band-aids enabling the continuation of the root cause of the problem, namely the excessive application of fertilisers and in the wrong form.

We could reverse our negative environmental footprint by simply doing the following:

• Move to less soluble forms of fertiliser and fertilisers that because of their composition provide a quick and slow release of nutrients.

• Encourage the efficient uptake and utilisation of applied nutrients and nutrients already in the soil by activating the micro-life in the soil.

• Increase the clover cover and promoting the N-fixation capability of legumes by ensuring good soil structure, good drought resistance and water-use efficiency of the plant, and the presence of the key soil nutrients required to ensure good N-fixation.

• Promote the drawdown of the 78,000 tonnes of free N in the atmosphere above every hectare of land by promoting rather than suppressing the free-living and associative nitrogen-fixing bacteria and archaea.

• Ensure good grazing management and avoid overgrazing.

• Apply good nutrient budgeting and riparian management, fence off waterways.

• Convert the volatile N and P in dairy effluent ponds to less leachable and less volatilisable organically bound forms and apply as a liquid folia spray.

While the urban area has correctly been identified as having quite an impact on water quality, the treatment of municipal sewage effluent with microbes or activating the microbes already in the pond can mitigate their environmental effect.

The Government has taken a number of steps, the most recent have been the National Policy Statement and putting in place  a framework to measure the quality of our water and the progress that is being made. According to the Prime Minister, however, the National Policy Statement has nothing new in it, which raises the question as to whether we are actually making progress or are we going to continue to do the "same old same old", generating the same old outcomes.

Ravensdown to its credit has recently acknowledged the deleterious effect of applying excessive amounts of fertiliser in the environment and are "up for smarter farming".

If water quality is indeed the litmus test as to whether we are applying too much fertiliser as Ravensdown has acknowledged, its assertion that it is prepared to sell less fertiliser is welcomed. We needed however to have received good leadership from Ravensdown and other companies on this issue much earlier.

The key we need to address is not only the amount but the form in which the fertiliser is applied.

Our farmers cannot be expected to have a good understanding of the nutrient requirements of their farm but they, too, of course, want to be able to farm in a more environmentally friendly way.

To this end we need to deal with the very real problem of giving farmers conflicting advice and mixed messages.

Scientists who have worked with me on sabbaticals have all expressed surprise and concern as to the state of our environment and the state of many of our dairy farms.

About half of New Zealand's greenhouse gas emissions are  from agriculture. According to Dr Jan Wright, the Parliamentary Commissioner for the Environment, there is "no direct link between New Zealand climate policy and reaching the Paris COP21 target".

The bottom line is, we need to protect our clean green brand. The brand is a major asset to us and we cannot continue to live off our reputation that we are clean and green. The future commercial success of our farming enterprise is dependent on it.

One of the ways to do this is to protect our rivers, lakes and atmosphere. If we don't do this, we could lose our valuable clean green market brand, have non-tarrif trade barriers imposed on us and face the possibility of our naturally produced farm products being replaced with equivalent cellular tissue synthetics.

We don't have to compromise economic growth for a healthy environment. We just simply need to get real, bite the bullet and accept what is causing the high environmental footprint of our farms.

To this end, an effective road map for the future is given in the seven bullet points provided above. The smart option would be to simply apply products that do not require a mitigating action in the first place.

In addition, farmers can also create their own riparian plan by going to the DairyNZ Riparian Planner (

The bottom line is we need to protect our environment and clean green image, our tourism and recreational industry, and ensure our farmers are profitable with secure markets producing quality food products.

We already have the technology to do this but one wonders if we are simply treading water in not addressing the real issues. Regrettably there are many who think there is nothing much that we can do; that farming and a high environmental footprint go hand-in-hand. They are quite wrong.

Graham Shepherd is a soil scientist and farm advisor, Managing Director of BioAgriNomics and author of the widely commended Visual Soil Assessment (VSA) method (