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20/05/24

Monitoring grazed pasture quality from space

Image of New Zealand from space with the sun in the northeastLincoln Agritech is one of 12 New Zealand research organisations taking a bold leap into space, in a new work programme funded by the New Zealand’s Space Agency and working with NASA.

Called Catalyst: Strategic – New Zealand – NASA Research Partnerships, the programme provides up to $75,000 for six-month feasibility studies unlocking information about the environment, Earth systems and climate through observation from space.

NASA’s contribution is in kind, making its experts available for consultation and advice. Research began in April. The New Zealand Space Agency is part of the Ministry of Business, Innovation & Employment (MBIE).

Lincoln Agritech is working with partner AgResearch to investigate monitoring pasture quality through satellite imagery.

“It’s already possible to assess the amount of feed available for livestock through satellite imagery, but we don’t know the quality of that feed,” says Lincoln Agritech’s Group Manager, Precision Agriculture Armin Werner.

“Just because it’s greener doesn’t mean it’s more nutritious or more easily digestible for the livestock – it just means it has more nitrogen,” he says. “The quality of the feed – what proportion can the animal use, how digestible it is, or how much energy can the animal access from the pasture – can vary even within the same paddock.

“Currently the only way to test the nutritional value is by getting it analysed in a laboratory, and not many farmers do that.”

How nutritional the pasture is depends on the biochemical composition within the plant, which is not externally visible, so this feasibility study will investigate whether satellite imagery can identify signals of the underlying processes.

“Any satellite sensing must be capable of being scaled up – it must work across not just an individual paddock, but several paddocks or several farms, without the need for individual calibration,” Armin says.

The project will focus on methods that model the physical and biological processes when measuring canopy reflectance with currently available satellite sensors.

Stage one involves assessing what is currently known, through a literature review. The next stage will be to prepare a hypothetical sensing method using satellite-based data, and the final stage will be to use data collected from AgResearch’s fields to see how far current methods and technology can go.

“By the end of this feasibility study we hope to have shown a way forward to develop satellite sensing tools that give livestock farmers reliable information on the quality of the food available to their stock,” says Armin.