This independent analysis of 1,269 farm records in OverseerFM from dairy farms in Canterbury shows a 27.5 per cent decrease in mean nitrogen loss per hectare over five years to 2021-22.
The analysis finds that across about 302,000 hectares of dairy production land, the mean nitrogen loss per hectare in 2016-17 was 63.8 kg per hectare. This had reduced to 46.2 kg per hectare in 2021-22.
The assessment provided estimates of trends in nitrogen loss after considering the size of dairy farms in terms of herd size and productive area. The analysis assesses within-year variability in nitrogen loss across farms and sub-regions and concludes that despite this variability, there is a statistically significant downward trend year-over-year.
The assessment was commissioned by Overseer Limited, but produced by Dragonfly Data Science.
To be cited as:
Thompson, F.N. and A’mar, T. and Berkenbusch, K. and Selvaraj, S. (2023).
Trends in nitrogen loss from Canterbury dairy farms. Report prepared by Dragonfly Data Science
for Overseer Limited. 32 p