In the previous blog about the EM surveying service provided
by Agri Optics I touched on an aspect of our software platform which helps you
evaluate the variability in monetary terms. In this post I will go into it in more
detail and explain how it can help you evaluate the likely financial benefits
from the installation of VRI. This is another service that is unique to Agri
Optics in New Zealand.
The VRI Design Evaluator allows you to enter the cost of
your VRI system, (for example a standard
budgetary figure of $100/metre of pivot) then put your expected yield and value
of crop – for example wheat yielding 12
t/h at $400/t or grass at 25c per kgDM and 12,500kgDM/ha per year.
The software works on the theory that by not over watering
the high EM areas or under watering the lighter low EM areas you are not inhibiting
yield from water stress and therefore getting a yield penalty. These areas will then yield more like the average
EM area i.e. 12t/ha. By altering the water application to match the soil’s
requirements you are reducing the effect of soil variability therefore gaining
a greater yield, as there are no water based yield penalties.
This is a very useful tool for showing the amount of yield
benefit that can be made by applying VRI to your lateral or pivot. However it
doesn’t take into account the added benefits of savings in water, power, a
quicker return time and in a dairy scenario reduced track maintenance, reduced
lameness and the milk penalties tied to that. Nor does it take into account
environmental benefits from reduced nutrient leaching or soil erosion.
In the screenshot above, using a yield of 12t/ha for wheat
at a value of $400/t, a cost of VRI at $100/m (figures underlined in green) on
a 476m pivot at a total cost of $47,696 (underlined in blue) there is an annual
benefit in the region of $43,302 (underlined in red), so in this scenario the
VRI system would pay for itself by the second year.
This can be very useful information for anyone who is trying
to decide if VRI would work for them and is one of the options we can provide
when conducting an EM survey.
Chris Smith - Agri Optics NZ Ltd.
