Enviroschools facilitator Jennie Upton said Enviroschools worked with Otago South River Care to take more than 40 pupils from Taieri College and Kaikorai Valley College to two farms to showcase regenerative agriculture techniques.
Ms Upton said the aim of the field trip was for the pupils to think about how food production on farms could continue without damaging the environment.
"That’s why we are here today," Ms Upton told the years 9 and 10 pupils after arriving at the first stop, the 300ha sheep and beef farm Rehoboth Farm in Ashley Downs, where the Pomahaka and the Clutha Rivers meet.
Rehoboth Farm co-owner Hamish Bielski told the pupils he was aiming to create a sustainable farming system able to operate for more than 1000 years.
"Livestock farming is absolutely sustainable."
He believed more livestock was needed in New Zealand but at a lower stocking rate per hectare.
More animals were needed because if there were fewer animals recycling nutrients then more synthetic fertiliser would be used, he said.
When he started at Rehoboth, about 30% of the farm was "turned over by the plough" to grow barley, wheat and oats.
He attended a presentation by Australian ecologist Christine Jones in 2016, which "opened my eyes" to the impact of some of his farming techniques on soil, water, air, energy and resources, he said.
"It was quite uncomfortable for me at the time. I was quite antagonistic towards her at that meeting and asked her a whole lot of curly questions from the paradigm of what I was used to, which was putting on lots of fertiliser and lots of crops."
"I realised how much chemical we were using to grow arable crops and how much nitrogen fertiliser we were using so we reverted back to all sheep and beef."
The soil in the paddocks once used to grow crops were "compacted and lacking life" and the damage caused was one of his biggest regrets during his tenure on the farm.
He did not want to grow any crops but after three years of drought he grew a mostly kale crop so his sheep had something to eat when the dry conditions start to bite.
To establish the crop, he used glyphosate, which caused "a bit of a dilemma" for any farmer wanting to embrace regenerative agriculture.
"We don’t want to use glyphosate. We know it’s no good but when you have high debt and you need to make money, you need to compromise on some of the activities you do — remember, nothing in this world is perfect," he told the pupils.
A goal for the farm was to be able to run a system which did not require any chemical inputs, relying only on livestock to spread nutrients.
"That’s why we came back to sheep and beef because they are turning this sunshine into superfood."
The pupils also visited Mark Anderson’s dairy farm in Waiwera South to learn how he was using regenerative agriculture techniques including composting.
Enviroschools is an environmental action-based programme aiming to empower young people to design and lead sustainability projects.
