Onleys are excited to announce that we can now provide atmospheric corrected, in-season NDVI imagery for the entire 2015 winter cropping season, with a new image potentially available every 16 days from May to November.

Satellite imagery is a valuable tool to assist you and your agronomist to spot issues within a crop, often before your eyes can pick them up. Imagery can be used to determine management zones within a crop allowing for variable rate fertiliser application potentially saving dollars on inputs and leading to more uniform yield or quality.
The most useful and common in-season imagery available for farmers is NDVI or Normalised Difference Vegetation Index. Without getting too technical, healthy green plants are very good at absorbing most of the light energy in the visible wavelengths, while dead or unhealthy plants absorb less light in the visible spectrum and more light in the near infrared. NDVI imagery is really a scale of greenness.

By mapping greenness across the paddock and ground truthing the different regions, the potential is there to treat the paddock on a square meter basis, rather than a one size fits all approach as is commonly the case. This can lead to huge savings in expensive fertilisers and chemicals or a lift in production, depending on what you and your agronomist decide is the best course of action. A 2007 report by CSIRO and GRDC looking at precision agriculture use on 6 Australian farms estimated that the benefits of using precision

fertiliser application both at sowing and throughout the season averaged in excess of $12/ha.

Imagery products are generally measured by the size of each pixel, so a 30m NDVI image means that each pixel represents a 30m x 30m area. At this sort of scale, it isn’t that useful for in-paddock work, unless the paddock is very large. With some sophisticated GIS techniques, the NDVI imagery that Onleys are able to supply is resampled down to 5m.

NDVI imagery is often only useful for comparing trends over time as the real NDVI value associated with each pixel is distorted by atmospheric changes from one pass to the next. The imagery that we have available has been corrected for atmospheric differences so that the NDVI number, or colour within the image can be compared throughout the growing season. This is a huge breakthrough for imagery in this sort of price range.

Farmers and agronomists can gain access to the imagery by enrolling their paddocks in Onleys Precision Ag services for the 2015 season. Prices start from about $5/ha depending on the number of paddocks and size of the area enrolled. To find out more about what these packages include or to find out more about getting access to NDVI imagery, contact Eric at Onleys on (03) 5821 7171 or eric@onleys.com.au.