Forage Science

Key step forward for game-changing grass

Key step forward for game-changing grass

An important milestone has been reached in AgResearch’s development of a new generation grass that could prove a game-changer for agriculture.

With funding from the Government and industry partners, including DairyNZ, the genetically modified High Metabolisable Energy (HME) ryegrass has been shown in AgResearch’s laboratories to grow up to 50 per cent faster than conventional ryegrass, to be able to store more energy for better animal growth, to be more resistant to drought, and to produce up to 23 per cent less methane (the largest single contributor to New Zealand’s greenhouse gas emissions) from livestock.

Modelling also predicts less nitrogen excreted into the environment by animals feeding on the ryegrass, and consequently less nitrate leaching and lower emissions of another greenhouse gas, nitrous oxide.

Development of the HME ryegrass is now progressing in the mid-west of the United States, where genetically modified organisms can be field tested outside the lab.

After a successful preliminary growing trial last year confirmed the conditions were suitable, AgResearch principal scientist Dr Greg Bryan says the full growing trial began in the United States last month and will continue for five months.

“The preliminary trial was only two months, so it’s not over a timeframe that has any statistical merit, however we did see the increased photosynthesis that we saw with the plants in the greenhouses in New Zealand,” Dr Bryan says.

“In this full trial now underway, we will be measuring the photosynthesis, plant growth and the markers that lead to increased growth rates. While the growth has previously been studied in glasshouses in pots and as plants spaced out in the field, this will be the first opportunity to assess the growth in a pasture-like situation where plants compete with each other.”

“The five-month timeframe will allow us to determine if increased growth is consistent across the summer and autumn, and we will simulate grazing by cutting plants back every 3-4 weeks.”

“Animal feeding trials are planned to take place in two years, which we will need regulatory approvals for, and the information we get over the next two years will help us with our application for those feeding trials.”

DairyNZ strategy and investment leader for new systems and competitiveness, Dr Bruce Thorrold, says the HME ryegrass is a science breakthrough and holds great potential for New Zealand farmers.

“HME ryegrass could help us achieve less nitrogen leaching and reduce greenhouse gas emissions, as well as improving pasture quality and productivity,” says Dr Thorrold. “This research could be transformational in future and so it is important we explore all promising avenues which could help dairy farmers respond to the challenges we face.”

While New Zealand has not yet approved the release of genetically modified crops, Dr Bryan says it is important that the science keeps our options open, and there is strong scientific evidence on any benefits or risks that policy makers can draw on.

“As the Royal Commission on Genetic Modification found, `it would be unwise to turn our backs on the potential advantages on offer’. We think the advantages here could be very significant – with modelling to date showing the HME ryegrass could boost farm revenues by as much as $900 per hectare, while providing a tool for farmers to manage nitrogen run-off and greenhouse gas emissions.”

“The Royal Commission also talked about the need to proceed with caution, minimising and managing risks – which is how we are approaching this work with the ryegrass.”

PROVEN RESULTS
START WORKING WITH US