Emissions fall as stock reduced
New Zealand’s largest high country station has cut its greenhouse gas emissions by
40 per cent in the past two decades, a new report shows.
Over that time, the
180,000-hectare Molesworth Station has reduced its stocking rate by 40 per cent, halved phosphorus applications, and reduced total nitrogen loss by
9 per cent.
An integrated land use and farm management plan, released in April, said it was unique as a commercial farm operating in a recreational reserve.
‘‘As such, there is a need to meet environmental, economic and recreational goals, which can often conflict,’’ the report said.
The station is leased and farmed by state-owned enterprise Pa¯mu NZ, formerly Landcorp, and managed by the Department of
Conservation on behalf of the Crown. Sitting beneath the highest peak in the Kaiko¯ura Ranges, Molesworth is known for its volatile climate with hot and generally dry summers followed by harsh winters.
Jim Ward, who has been farming the station for about 20 years, said climate resilience was the key driver for reducing the stocking rate. The goal was to ‘‘drought proof’’ Molesworth, which meant having a number of stock that could be sustained even in the toughest year. This season, there were 5300 head of cattle.
According to the farm management plan prepared by Erica van Reenen, emissions from Molesworth included carbon dioxide, methane and nitrous oxide. Carbon dioxide emissions were generated from fuel and electricity use. Although there were limited options to reduce these, solar power might provide an option. Agricultural gases of methane and nitrous oxide were also ‘‘challenging’’ to manage, the report said. Since 1990, total agricultural emissions from Molesworth had reduced by about
30 per cent from the equivalent of
153 kilograms of carbon dioxide each hectare every year, to 106kg.
Methane made up 65 per cent of the emissions, with 31 per cent coming from nitrous oxide.
Carbon dioxide emissions were
4 per cent of the total and estimated at 4kg of carbon dioxide per hectare every year.
The farm management plan is separate to the Molesworth Management Plan which is under review by Te Ru¯nanga o Kaiko¯ura and the Department of Conversation.
Pa¯mu’s grazing lease was due to expire at the end of June but has been extended until June
2023 to allow time for the review to be completed.