An independent panel of experts set up to review the nutrient management planning tool OVERSEER® made wide ranging recommendations for improvements to the way it deals with arable crops. The panel found that OVERSEER® is currently the best tool available for estimating long term, average nitrate leaching losses from the root zone across the diversity and complexity of farming systems in New Zealand, but that further work (was needed) on the cropping model is needed to enhance confidence in OVERSEER® estimates of nitrate leaching from arable farms.
OVERSEER® already has an established role in guiding nutrient management in pastoral farming.
This is due in part to its ability to capture the complexities of whole farm systems. This functionality
has been optimised for pastoral production over many years of development and user testing. A
relatively recent enhancement is the capability to model nutrient flows in arable crops.
This new capability has been developed using a number of simplifications. These are consistent
with the approach taken in modelling pastoral systems within OVERSEER® but contrast with
approaches taken in other crop-soil interaction models.
In conclusion, OVERSEER® is the best tool currently available for estimating N leaching losses
from the root zone across the diversity and complexity of farming systems in New Zealand.
https://www.far.org.nz/resources/far-releases-findings-on-overseer