Farm Ireland

Wednesday 25 April 2018

New Kiwi 'super grass' will slash emissions

Ryegrass has too high a protein for cows to utilise
Ryegrass has too high a protein for cows to utilise

Darragh MCCullough

A new grass with the potential to slash greenhouse gas emissions and increase production is being rolled out by New Zealand researchers.

The product of close to €15m and 15 years of research, the state-owned AgResearch has engineered a grass plant that has almost triple the amount of lipids (fats) compared to standard ryegrasses and mimics the more efficient C4-type photosynthesis that characterises fast-growing plants such as maize.

"Indoor trials have shown us that this grass has a 25pc higher growth rate, which translates into a 12pc increase in milk solid production," said Prof Gregory Bryan who lead the research.

However, it is the ability of the new grass to reduce greenhouse gas emissions that may be the biggest benefit for an Irish agriculture coming under increasing pressure to address it's rising impact on climate change.

"We estimate that the grass results in a 30pc decrease in methane emissions and a 20pc decrease in nitrous oxide.

"One of the problems with typical perennial ryegrasses is that they have too high a protein content for the cow to utilise fully.

"Lipids are like little oil bodies in the leaves, which have twice the amount of energy as carbohydrates. So by increasing the lipid content from 3pc to 8pc we are able to increase the amount of energy available in the gut by 10pc," he said.

The plant is able to grow faster by adopting the charateristics of photosynthesis in a maize plant, which is more elaborate than the C3 carbon fixation more commonly found in grass plants.

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"We don't know yet how well the plant will perform outdoors, but even if it gives half of what it achieved indoors, it would be a massive productivity boost for farmers," said Prof Bryan, who was speaking at a grass research seminar in UCC.


Until breeders manage to introduce the traits by traditional breeding methods, researchers are faced with using genetically modified (GM) versions of the plant.

"There is no ban on GM crops in New Zealand, but they are not common and so industry is nervous about how it might impact on consumers' perceptions.

"It's more likely that we'll roll out trials in the US first, and with the 20 million acre alfalfa crop so important there we will probably try it in that crop first.

"At least that would be a way to get the technology out there into the market," said the researcher.

It is likely to be 2021 before any variety will be commercially available to farmers.

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