Satellites could be a new weapon to help New Zealand farmers to see how much grass is on their farms, and even predict how fast it will grow.
Many important farm decisions depend on how much grass farmers have or can expect to grow in the near term. But despite the amount of grass being such vital information, it is not easy to estimate grass stocks on farms accurately.
In Australia, for the past few years, farmers have been using satellite technology to understand just what is going on with their pastures.
The ‘Pastures from Space’programme, led by the public research institute, Commonwealth Scientific andIndustrial Research Organization (CSIRO), uses satellites orbiting 700 kilometers above Earth to estimate the amount of feed available in pastures. The technology can provide Australian farmers data on pasture cover at the paddock level for any area over six hectares and has proved almost as accurate measurements made on the ground.
Having more precise estimations of feed enables Australian farmers to manage better activities like fertilizer application, grazing rotations, and feed budgeting says CSIRO Livestock Industries’, Dr. Rob Kelly.
Now Fonterra and scientists at Dexcel and AgResearch want to see exactly how well the technology performs in New Zealand. In June, the New Zealand group hopes to start a year-long trial with Waikato farmers.
The satellites would measure the electromagnetic energy reflected from the farms below — the process is the same for the human eye — and these sensors detect varying proportions of reflected, transmitted, or absorbed energy to identify oil and different types of vegetation and their mass.
The satellite data are then combined with weather forecasts to give farmers a prediction of how their pastures will grow. At present, the satellite information would be valid for one week, but the New Zealand team hopes that this can be extended to be able to give a six-week forecast.
“While we might lose a little bit of accuracy by doing it from the satellite, on measuring a specific area — although that’s even clear as the accuracy seems to be quite good — you’re compensating by sampling every area of the farm which you just physically can’t do on the ground,” says AgResearch scientist Annette Litherland.
At present, only a small proportion of New Zealand farmers find the time to measure their pastures regularly and use the information to prepare a formal feed budget.
“It’s really hard work for the farmers to go out there and try and get some sort of assessment of how much grass they have on their farm,” Litherland says.
If the project is successful, the scientists envisage New Zealand dairy, cattle, and sheep farmers either dialing into the world wide web to collect information about their farm or receiving it via email at regular intervals.
Eventually, they may also be able to compare their pasture growth and the way it is being used, against other farms and previous years, to help them improve their performance.
“The ultimate use is that a farmer will have a standardized measure of his pastures and long term, we will hope to bring in quality…so he will be able to work out exactly how his farm’s doing relative to a high-performing farm,” says Litherland.
how do you measure grass?
The first method is to cut a section of your lawn and use a yardstick to determine the height of your grass. This is usually how people calculate their mowing height, but it is not always accurate. If you have a tape measure, then you can use this to get a more accurate measurement. You need to find a good measuring tape that measures in centimeters.