Ravensdown and Massey are also completing a further project to ensure the technology in a topdressing aeroplane is capable of applying fertiliser with sufficient accuracy to allow these better decisions to be delivered on the ground.
How the sensor works is difficult to describe in layman's terms, but if we think about our own vision for a moment, we see in the visible range of the electromagnetic spectrum and we can basically see red, green and blue.
Many animals have a more limited range of vision so, for example, when we go hunting we can use orange blaze because the colour is outside a deer's (or herbivore's) visual range. In the same way this sensor has a much wider range than humans, about 10 times wider, and can see in the visible (VIS), the Near Infrared (NIR) and the short wave infrared, (SWIR), parts of the electromagnetic spectrum.
Using this greatly extended range, it can evaluate the bio-chemical content of any vegetation it sees. One thing humans can see, because it happens in the visual range, is change in nitrogen content, higher levels produce darker green grass because higher N allows the plant to absorb more light in that part of the visual spectrum that we can see.
Every living thing has a spectral signature and it is through understanding these spectral signatures that the team can work out the concentration of nutrient in pasture, crop, forestry or any other vegetation.
As well as identifying nutrient levels in vegetation it is capable of identifying changes in vegetation brought about by disease or nutrient deficiency, it can detect individual species of tree or plant in a bush or forest canopy and so could provide a cost-effective way to survey changes over time. The sensor can also identify different cultivars of the same species -- it is an extremely versatile technology.
In addition to information about better fertiliser application, the instrument can also give information about the amount of biomass, metabolisable energy (ME), protein, dry matter and other important nutritional quality parameters of pasture to farmers. The information could be used to create a better understanding of how pasture quality changes throughout the year and how farmers could better match pasture quality to livestock needs for optimised returns. All too often pasture quality diminishes quickly through the season, leaving stock stranded on poor-quality pasture.
The sensor is used from an aircraft, it can cover about 1000 ha per hour, flying back and at forth at 2000ft. The sensor is built by the Finnish company Specim, a specialist in the field, and the sensor is called FENIX, each pixel in an image has 450 layers of data that can be used to produce useful information for farmers, which can then be mapped for easier interpretation.
The sensor can also be used to complete basic resource inventory tasks, such as working out area of pasture, area of bush, weed, thistle etc. It will allow farmers to make better decisions based on real information and target their response for greatest return.
Massey University has built the capability to process the data and although the project is still in the research phase initial progress has been very good and the potential seems almost limitless.
Details of the PGP project are available on: www.ravensdown.co.nz/nz/Documents/pgp-brochure.pdf
