0800 843 809 info@esi.org.nz

P.W. Burton

 

The assertion by some farmers that a loss of short term income justifies continued land and water degradation, is wrong on two counts.

The increase in nitrates and phosphorus in our groundwater is a result of the over application of bag N, partly compounded by the resultant loss of soil carbon.

The loss of soil carbon means less filtering ability and nutrient storage capacity, and for water in drier times to be rapidly flushed through the topsoil, rather than being held for use by plants.

This means a steady reduction in annual pasture production and, although bag N is an effective development tool, the current reliance on it for the maintenance of permanent grazed pastures (the backbone of our farming systems), means a continued on-going reduction in low-cost production.

This results in less income or higher costs for land owners, reducing the amount of genuine cash surplus at the end of the season.  It’s only a matter of time, possibly within the next five years, before some currently well regarded intensive farming enterprises become uneconomic.

It’s also wrong because continuing to apply an average of 160kgN/ha to our best land isn’t necessary.  There is available technology to replace it, which recent testing indicates a steady building of soil carbon, reducing nutrient lost to groundwater, and increasing pasture and total farm production.

The replacement is simple stuff which has been developed in this country using knowledge gained from work by DSIR, MAF, and Landcare Research, from as far back as the 1940’s when the physical soil structures, nutrient content and living organisms were examined and recorded in detail.

Farming systems, using clovers to fix the required nitrogen, for the sustainable production of over 18,000kgDM/ha have been in place for much longer than systems based on fertiliser N.

There are a number of other well-documented production benefits to a system founded on legume production, but ignored and largely forgotten in the stocking-rate-first driven systems of the last 25 years.

Under astute management carbon can be rapidly sequestered. In fact, potentially, intensive pastoral farming is the quickest and most efficient way to remove carbon dioxide from the atmosphere, allowing oxygen to be released while the carbon is stored, and ground water purified.

The importance of this process is reinforced by the statement made by Dr Graham Sparling in the 2004 Norman Taylor Lecture, “The soil biological process is the only process whereby we can get reactive nitrogen from the soil and water back into benign nitrogen gas.  But at present we seem to be headed in the opposite direction, adding ever more nitrogen and phosphorus to our soils.”

As Philippa Stevenson wrote at the time, “Only 0.1 per cent of 5 million researchers worldwide make the scientific community’s international highly cited list.  Dr Sparling is one.”

The initial change required, for New Zealand’s pastoral farming to again be regarded internationally as “the best in the business”, is primarily one of focus.  The way forward is to put soil fertility systems in place that genuinely build top soil, and then stock and manage appropriately.

There are a selection of properties nationwide that can be used as examples, which scientists, researchers and farmers can gain information from, once the determination to make the necessary fundamental change ‘kicks in’.

Shifting to a genuinely sustainable system can be seamless, with an increase in pasture production available in the first twelve months.  It does involve taking on board some new information and adjusting a few management practices.  However, those that have already made the switch find the new processes surprisingly simple and intuitive, with the results both satisfying and rewarding.

For more information contact Peter on 0800 843 809.