Environmental gains can be made on a farm while its production improves, scientists say.
Central South Island Beef and Lamb New Zealand director Bill Wright and his wife, Shirley, have been farming a sheep and cattle property near Cave since 1991. Scientists used their records to study the profile of greenhouse gases while the farm evolved.
The last two years’ data also gave insights into nitrogen leaching.
“Farmers are conscious of their collective responsibilities to restore water quality and minimise their environmental footprint,” Mr Wright said.
“But this is material we are now only learning how to manage in a way that not only protects the environment but provides opportunities to be more productive with less impact.”
The Wrights’ records showed their farming system improved in efficiency and reduced its greenhouse gas emissions per kilogram of meat or wool by 18% between 1991 and 2014, then by another 17% by 2015.
The 1991 emissions were 16.9kg of carbon dioxide equivalent gas per kilogram of product. In 2014 they had dropped to 13.8kg, and in 2015 to 11.4kg.
The farm changed from mainly lamb and wool in 1991 to a greater proportion of beef and, in recent years, dairy support. The quantity of goods it produces has risen dramatically through greater forage growth and use, plus new technologies.
The dramatic drop in gas emission from 2014 to 2015 was largely due to lower livestock numbers because of dry spring conditions in both years.
“What these numbers show is that with the right choices, the emissions intensity can be effectively reduced while also developing a farm that is more resilient, more financially viable and still producing quality products,” AgResearch farm systems team leader Robyn Dynes said.
“For the Wrights, as for many sheep and beef farmers, increasing the efficiency and resilience of their farming business had huge spin-off benefits for the intensity of greenhouse gas emissions.
“New Zealand farmers are playing a big part in lowering the emissions intensity of New Zealand’s agricultural production.
“Without efficiency gains, New Zealand’s agricultural emissions would now be more than 30% higher than in 1990 due to increased production,” Dr Dynes said.
The nitrate research showed 18kg per hectare was leached in 2014, and only 13kg in 2015.
Forages for Reduced Nitrate Leaching (FRNL) programme leader Ina Pinxterhuis, a DairyNZ senior scientist, appreciated having a network of monitored farms.
“The farmers keep the researchers focused on delivering practical solutions that maintain the viability of the business. They also test the FRNL options on their farms, which is highly valuable for demonstration to other farmers and for determining what information is required for decision-making and management support.”
Working together on nitrate leaching and greenhouse gas emissions was important in discovering mutually beneficial solutions, Dr Pinxterhuis said.
Mr Wright said he and his wife could make choices backed by good facts.
“Farmers are the first to want to protect the land, water and air, but now we are developing some useful tools that will enable us to do this while protecting our incomes, communities and the opportunities for future generations to farm the land.
“I think that although we do face a new era in the environmental awareness, farmers and our families will with new knowledge – through research, science and technology – have a sustainable future.”
AgResearch scientists, funded by the New Zealand Agricultural Greenhouse Gas Research Centre and Ministry for Primary Industries, studied the gas emissions.
The nitrate work, part of the FRNL programme, was paid for by DairyNZ, the Foundation for Arable Research, AgResearch, Plant and Food Research, Landcare Research and the Government.