Concrete Vineyard Posts
IN the viticulture industry, good ideas, like their fine wines, take time to mature. Concrete vineyard posts provide an excellent case study of the resistance within a traditional industry, to promising new technology.
In my younger days, I was working in the concrete industry in Blenheim, during the beginnings of the large-scale plantings by Montana Wines. My employer, R.T. Scott Ltd, manufactured an extensive range of prestressed concrete fence posts at that time. These were popular with the local farmers because they were easy to drive into the dry, stony Marlborough soil; and they survived the regular burn-offs that were a feature of hill country farming in those days. This was back in the mid 1970’s: there was no Resource Management Act, and farmers ran the country.
My colleagues and I thought that it would be a simple matter to convince the grape growers, that concrete posts would provide a very economical, long-life, answer to their needs. On the scale that their projected plantings required, we were looking forward to millions of posts. Unfortunately, it was not to be: the vineyard experts found a tropical paradise that was clear-felling its rain forests and opted for the “more natural” look of sawn hardwood posts. These weathered to a pleasing “concrete grey” colour, after a few weeks in the Marlborough sun. We were disappointed, but consoled ourselves that we would get another chance, when the hardwood posts rotted in a few years time.
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That next opportunity came sooner than we all expected, but the second time around it was a chance to try another “natural” product; H-4 treated, softwood posts. Pressure treated with copper, chrome and arsenic, these round posts from plantation thinning operations were not as offensive to the environmentalists as the tropical hardwood posts had been. The Rio Earth Summit made it difficult for countries to buy products from regions that were not doing justice to our planet. Tropical rain forests had some protection at last and plantation timber was an acceptable alternative, even if it had to be soaked in highly toxic chemicals. Concrete posts, although they were becoming popular in Europe, were still considered “unnatural” by our wine industry.
Attitudes began to change towards the end of the twentieth century. Scientists began to detect increasing traces of timber treatment chemicals in the environment, in vineyard soil, and even in the finished wine. The wine industry argued that the amounts of arsenic were minute, but in export markets, why would you accept any poison with your wine? Remember the fuss about toxic timber in school playgrounds? It was time for concrete to make another assault on the New Zealand viticulture industry.
This time we were much better prepared: machines for manufacturing slender prestressed posts were technologically advanced and there was a range of purpose-built machines designed to drive them into the ground. In addition to the absence of toxic leachate, concrete posts drove easily into stony soil; with simple wire clips, they could be installed in stages - as the grapevine load increased; they had a design life well in excess of any treated timber post; and they had the ability to bounce back if they were hit by harvesting or mowing machines.
A few disgruntled viticulturalists were also seeking alliances with precast concrete manufacturers, to service a market that appeared to be ready at last. Treated timber posts became brittle with age and replacing broken wooden posts was a frustrating exercise. In this changed environment, Pali Posts Ltd was born - a marriage of Stresscrete and Peter Iremonger. Stresscrete ordered a postcasting machine from Europe and set up long-line casting beds, while Pali Posts set up the sales and installation network, and developed the wire fastening clips and ancillary hardware that supports the system.
After 30 years of gestation, the mass-produced New Zealand concrete vineyard post is at last a reality. Now, with production commencing for this season’s grape planting, growers of other horticultural crops, who are aiming their produce at the “Certified Organic” end of the market, are also placing orders for Pali Posts. Why poison your soil when there is more acceptable alternative?