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Putting a farm on paper

AgResearch scientist Ronaldo Vibart is part of the organisation’s ‘Land and Environment’ group and works in a team called ‘Sustainable land use and global change.’

The scientists in his group work across a number of disciplines including soil and land use, nutrient management, water quality, greenhouse gas emissions and mitigation, climate changes and adaptation, and environmental foot printing.

“We analyse pastoral land use and land management in relation to environmental impacts and climate change,” says Ronaldo, who describes himself as a farm systems analyst.

“We aim to improve dairy, beef, sheep and deer production systems by carrying out innovative research on soil and water management, pasture fertilisation and farm nutrient management. Our team is working on solutions to reduce negative impacts on the quality of soil, water, atmosphere and ecosystems. My role is to interpret these production systems, as best as possible, using models that simulate farm-scale operations throughout New Zealand.”

Ronaldo uses two farm-scale simulation models to carry out this work – FARMAX and Overseer. Both software systems are the original brainchild of AgResearch scientists and now widely used by farmers and rural consultants across the country.

“We need to be able to decipher what’s happening and run a few scenarios to look at production and environmental outcomes. FARMAX provides the farm setting – the financial and biophysical parameters – and I then feed that into Overseer, which gives me the environmental outcomes.”

"One of the most useful features of the FARMAX system in the environmental science field is its ability to capture a farm setting and ‘put it on paper’."

- Ronaldo Vibart, AgResearch

He describes FARMAX as a “natural and instinctive tool” to use if you’re trying to capture some of the dynamics of farming and says he uses the system in three different ways.


Ronaldo and the team recently carried out a climate change project, looking at Southland, Hawke’s Bay and Waikato sheep and beef farms, specifically.

“By coupling the information NIWA provided us with forecasted weather trends, we were able to develop pasture growth curves for individual years between 1980-1999 and 2030-2049, based on rainfall, radiation and other factors,” tells Ronaldo.

“By having weighted average growth rates, we were able to see what the past pasture curve looked like for particular regions, and what the future pasture growth rate might look like with environmental factors included, such as an atmosphere high in CO2 - and then compare the two.

“I then used FARMAX to adapt a farm system hypothetically with the pasture growth curves in mind, so we were able to make a number of adjustments to adapt our farm to future growth rates and analyse the resulting financial impacts.”


Ronaldo says one of the most useful features of the FARMAX system in the environmental science field is its ability to capture a farm setting and “put it on paper.”

“We were asked to develop farms that were highly profitable but low greenhouse gas emitters. Once we identified these farms, we interviewed the farmers, toured the farms and used FARMAX to capture their land resources, livestock and management policies.

“We then put that information into Overseer to see whether the farms were producing emissions as we thought they were, or not. It was a fascinating process; we ended up choosing four dairy and four sheep and beef farms from throughout the country as case studies.”


“What I’m after with FARMAX is gauging whether farms are biologically feasible – the feasibility comes from matching what is demanded by livestock and what are we supplying in terms of feed energy,” says Ronaldo.

He tells of another study that tried to determine what the average farm looked like for particular regions.

“We integrated FARMAX information with geo-spatial information where we were able to take the actual farm and put it into a grid of farms for the region and then apply some of the social interactions of these farmers.

“By doing that, we had a mass model which came in very handy to assess some of the regional nutrient losses and potential policies that could be applied to slow them down.

“FARMAX is an important tool for us here at AgResearch, especially because we deal a lot with hypothetical and ‘what if’ situations, so it’s a great fit for our work.”