The Department of Agriculture will not be updating 2024 organic nitrogen (N) and phosphorus (P) statements, despite previously pledging to back-date changes based on the new excretion rates.

A spokesperson for the Department has instead suggested that any farmer who is in breach of the 2024 nitrogen rules will be automatically subject to an internal review to determine their compliance under the new set of excretion rates, which entered into law this February.

There are three main changes to the nitrogen excretion rates. The first is for young calves less than 90 days of age.

Previously, all calves were assigned 2kg of N per month, but now the rate is set at 1kg for the first 90 days and 20kg when they are aged between 91 days and 12 months.

Animals in their second year of life have a different nitrogen excretion rate depending on their gender, with males moving up from 57kg to 61kg and females moving down from 57kg to 55kg annually.

Other key changes are for dairy animals fed low crude protein concentrate. The excretion rates for dairy cows of 80kg, 92kg and 106kg for cows in band one, two and three respectively are based on feeding 16% crude protein concentrate on average across the year.

Farmers who opt to feed lower crude protein concentrate on average across the year will now have a lower nitrogen excretion rate.

For example, herds in the middle band that feed a 14% crude protein concentrate will see their nitrogen excretion rate fall from 92kg to 89kg per cow per year.