1 August 2019
FARM ADVISORY
Know what’s under the surface with Precision Nutrient Management
By Dan Copland, Ravensdown Senior Agri Manager
When it comes to managing fertiliser application, it makes sense to apply the right amount of nutrient to the right
place at the right time. Ravensdown’s Precision Nutrient Management process helps give farmers an agronomic and economic
advantage.
Working to reduce variability within soils at a paddock level can not only improve yield, it’s also a more
environmentally sustainable and cost-effective approach to managing soil fertility.
Precision Nutrient Management (PNM) is a nutrient input approach developed by Ravensdown and Methven-based precision
agriculture specialists Agri Optics to help farmers achieve these objectives.
“Understanding soil properties and fertility is an important part of profitable and environmentally conscious crop
production,” says Dan Copland.
“It’s important to get the fundamentals right, such as the pH and Olsen P, as these can take the longest time to change
if they are not optimal.”
Elements such as potassium and magnesium can be more easily managed depending on the crop being grown.
“There are a couple of ways of doing it,” Dan says. “You can work out what your optimum Olsen P needs to be at the end
of the crop and then work out what the requirement for that crop is.
“Once the Olsen P and pH levels have hit the predetermined targets, we use modelling created from yield data to make
sure the levels are maintained. This modelling is generally used for two to three years before the paddocks are tested
again.”
The next step is the variable-rate spreading technology that avoids areas above target levels, making it a
cost-effective way to apply nutrients and even out variability.
Once the spreading is complete, a proof of placement map can be generated and uploaded into Ravensdown’s decision
support tool, Hawkeye®.
“The ultimate goal is squeeze out the variability in results,” says Dan.
Typical areas where variability is most often seen include old fence lines where paddocks have been merged, treelines,
stock camps and where soil types change. Variability is also seen where there has historically been border dyke
irrigation.
Key benefits of Precision Nutrient Management:
• Nutrients and soil conditioners are only applied where they are required
• An environmentally sustainable and responsible way to apply fertiliser
• Regular soil testing and associated data collection over a period gives a far more accurate assessment of in-paddock
nutrient status
• Gives an understanding of individual crop and pasture demands, achieving higher yield potential
• It ties in with other precision ag and digital tools such as yield monitors on harvesters
• It leads to potential cost savings – fertiliser is a big expense, so it makes economic sense to use it as efficiently
as possible.
ENDS