Warmer, drier and more floods

02-08-2010 | Annette Scott

As this century progresses New Zealand agriculture can expect to be plagued with more warm years, more droughts and greater risk of floods.

Year to year variations in temperature, rain and drought caused by natural features will be reasons for concern, NIWA chief climate scientist Dr David Wratt told farmers at the Foundation for Arable Research (FAR) conference in Ashburton last week.

NZ had since 1995 experienced 13 of its warmest years ever recorded.

The sea level continued to rise and recent observations reinforced concern of climate change, Wratt said.

But overall NZ Agriculture was "pretty resilient" to climate change and not as vulnerable as other countries.

Building resilience in conjunction with adaptive management to current climate extremes would be a sensible start as the century progressed and further change was experienced, Wratt said.

Long term planning of the country's water resource taking in water storage and changing land use had to be part of the resilience building.

It was not a cause for immediate panic but an eye had to be kept on where things were going and management adaption structured accordingly, Wratt warned.

Knowing the greenhouse gas emissions of a product might not be of interest to everyone but benchmarking, tracking and optimising an operation's resource use inputs would interest most business managers because that directly affected the bottom line, AgriLINK NZ's Andrew Barber told the conference.

"If you are not motivated by the climate change your customer probably is so you need to be.

"Consequently if calculating your carbon footprint doesn't motivate you then think of it as better understanding and optimising your operation's resource use profile."

Barber talked about a joint-funded FAR and MAF arable carbon footprinting project that began this year to carbon footprint wheat, maize grain, maize silage and ryegrass seed production to the farmgate.

As the arable industry was often an ingredient supplier to a further processed product such as wheat to bread and maize silage in dairy production it was anticipated that in the future growers would be asked to supply the GHG footprint of their products as part of their customers' GHG footprinting requirements.

Barber reminded farmers that the customer was king.

"If he believes in climate change then you have too.

"If we don't get better then our competition will and we will get overtaken."

Barber said it was not about where farmers started nor how they compared to the guy next door - but how they changed.

He acknowledged that arable was the most complicated sector of the agriculture industry because of its additional interaction with livestock.

Dr Hamish Brown of Plant and Food Research looked at adapting to a drier climate through better irrigation scheduling as physical climate change reduced rainfall and increased evapotranspiration and social climate change increased competition for fresh water resources resulting in reduced irrigation allocations.

Both meant arable farmers had to improve irrigation efficiency to ensure maximum profit could be delivered from each millimetre of irrigation applied.

To help growers with irrigation scheduling FAR has recently commissioned the Arable Whole Farm Irrigation Calculator (WFIC).

It is a computer based tool that simplifies the process of water scheduling as users input basic information about the crop type, sowing date, soil data and update weather and irrigation information throughout the season.

The WFIC has been tested on a number of arable farms over the past two seasons with training sessions scheduled for the end of August.

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