Otago Daily Times Comment "Over the Fence" · Tax Breaks do not Address Root Causes of Environmental Problems July 22 2013

04/09/2013 at 22:17 in Otago Daily Times

While riparian plantings look pretty from roadsides they fail to address the root cause of many environmental problems facing rural communities.

Farmers are now able to claim planting of riparian areas as operating expenses.  I applaud this development but wish it included ongoing maintenance costs as well.  While politicians and environmentalists congratulate themselves on this policy change is it really going to make a difference?  Both Environment Southland and Waikato have commented that despite having over 95% of waterways fenced off, water quality has not improved.  How can that be?

Riparian planting helps reduce movement of soil across surface of stream and river banks.  This reduces movement of phosphorous in particular.  However, if farmers lifted their post grazing residuals in paddocks this would achieve the same thing without needing to fence off riparian strips; a classic example of policy focusing on the wrong side of the fence.

The major polluter of waterways is nitrogen which leaches through soil rather than binding to it like phosphorous.  This is why despite all riparian plantings in Southland and Waikato, water quality fails to significantly improve.  This pollutant does not travelling overland but leaches through field tiles and drains into waterways.  Riparian planting doesn’t address that.

The influence of nitrogen on anything but pasture production is ignored by agricultural scientists.  At a recent SIDDC field day I attended dairy farmers challenged scientists they were measuring everything environmental except milk urea.  Milk and blood urea tests record nitrogen levels in livestock and are considered unimportant by industry professionals to detriment of farmers and wider community alike.  Maybe this is what regulators should be looking at?

Blood nitrogen attaches itself to haemoglobin, the body’s oxygen carrier.  In livestock this reduces gas exchange in the lungs, very similar to what is known as blue baby syndrome in humans.  Not only does haemoglobin carry oxygen but many other elements essential for metabolism.  When clogged with nitrogen livestock performance declines.

Secondly it raises pH of body fluids.  Blood pH is about 7 and is quickly buffered by liver function but with excess nitrogen milk and urine pH can climb over 8.  When body fluids get this high it can result in metabolic diseases like ketosis and alkalosis which can kill livestock.  High milk pH results in ideal conditions for mastitis.  As incidences of mastitis increases milk has more pus resulting in more processing to remove pathogens and more treatments to replace nutrients which are lost as part of the process. 

Not only does high pH increase mastitis but all bugs consumers worry about; streps, ecoli, and coliforms.  The incidence of these organisms in dung also increases because when pH of blood increases due to high nitrogen, so does the pH of dung and urine.  These are the same life forms communities complain about in their waterways.  Riparian planting doesn’t address that.  These organisms also pollute pastures livestock are currently grazing meaning they ingest these microbes and repopulate rumen communities repeating the cycle.

High blood pH means livestock put more energy into addressing illnesses than productivity reducing their efficiencies.  It lowers conception rates which is why livestock health bills and herd turnover often increase with higher chemical fertiliser applications.   

Industry promotes high nitrogen use because farmers are rewarded for protein as if protein is the only nutrient of healthy milk.  Industry is not concerned with nutritional quality of milk, only its safety for consumption as evidenced by recent DCD warnings.  High nitrogen also encourages formation of scatoles in milk, aromatic compounds which gives dung its characteristic smell.  This is another reason why milk is screened and processed which raises costs for consumers.

Not only does offering tax breaks on riparian planting not address root causes of environmental pollution from excess fertiliser; it also imposes additional costs for farmers.

It is well known in rural circles that mature riparian vegetation creates higher debris flows from eroding stream banks.  During times of flooding, swirling water pulls established vegetation into waterways. 

Who bears the cost of maintaining and cleaning up waterways after significant events?  Not policy makers whose brilliance a generation earlier looking for votes imposed this cost on farmers.  Failure to understand basic long term ecological relationships stifles innovation and creativity by regulators.

In North America for example, grazing goats are used to control riparian areas.  They are less invasive and graze further into waterways than cattle removing vegetation to increase area available for waterfowl to land and reduce erosion.  What is interesting is farmers are contracted and paid by local councils to provide this service for the common good of the community.  In such communities farmers and their livestock are respected for benefits they bring to environmental management.

John King is a Christchurch based agribusiness tutor, facilitator, speaker, and grazing advocate.

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