"You can't get much better than that," he said.
That worked both ways, as the couple's daughter Kylie Stenton and son-in-law James were now a big part of the business, which also included a farming operation.
Both generations were recognised at the recent New Zealand Groundspread Fertilisers' Association awards; Stenton, who is also a volunteer firefighter, won the health and safety award while her father was runner-up in the President's Award for contribution to the industry.
It was appropriate recognition for a family that has been heavily immersed in the industry, operating a business with a simple philosophy based around service.
Ask Schultz what the secret to running a successful business is and he shrugs, saying there is no secret.
"Just show people the respect you want to be shown."
The Schultz family moved south from Mt Maunganui in 1992; it was either going to be Saudi Arabia or Oamaru, and North Otago won out due to the Gulf War conflict.
They were dairy farmers who were attracted by the herd sizes in the area. When they later sold their cows, they decided they liked the area and would stay.
The groundspread business started with two trucks and there are now nine trucks based in North Otago and another three at their Milton base.
Schultz, who has always had a passion for trucks, said they always had a clear vision of the service they wanted to provide, but he never imagined what the future of the business would look like.
"Just rock on out there and give it a crack Nigel," he said.
They covered an area from Rangitata to Omarama and south to Balclutha "with a few gaps in between" and had about 15 or 16 staff.
Staffing was something they had always worked on; like many other industries, there were difficulties with recruiting, and that was not just since Covid-19 had hit.
They had always been invested in bringing new people into the industry, whether they were young or coming from another industry, Stenton said.
A joint venture occurred with Ravensdown in 2015 but it was still run as a family business, which extended to their staff, Schultz said.
Stenton said growth had been organic over the years, and they had never set out to take over the area.
In some cases, people they had done work for had moved out of the area and asked them to continue doing their spreading and those relationships had continued, her father added.
During the pandemic, it was business as normal operationally, which posed its own difficulties as a lot of industries had not worked through lockdowns.
But being able to see clients from afar was important - "having boots on the ground, especially in the rural sector" - and in some cases, it had strengthened relationships, Stenton said.
She has been involved in the family business for about 15 years; when she started, her parents were still operating from a room in their house and it "got a bit crowded". So they later developed an office on the outskirts of Weston, near both the yard and their homes.
Stenton had done her OE, worked in kitchens and been dairy farming. It was at the stage where her father was trying to drive full-time and also handle office work, so she stepped into the office.
There were no job titles in the business and staff did not work for them, they worked with the family, Schultz said.
Family was also vitally important for Stenton and she believed North Otago was a "pretty awesome" place to bring up daughters Ayda (9) and Reed (7). Her husband James had been in the business for about five years.
Asked whether having so many family members involved in the business was difficult, Stenton said they had always been around each other, so they were used to it, and that was just the same when her brother Cameron was involved.
Cameron, a talented and popular rugby player and father-of-two, who worked for Mainland Spreading, died in a workplace accident on a rural North Otago property in December 2019, aged 34.
His presence was still very much felt at the business of which he had been such a "huge part", Stenton said.
"It felt like he's here and it's been easy for me to come here and feel him ... he's very much still integrated into everything that we do, life and business and otherwise," she said.
Cameron and his wife Rihi's two children, Taurima (10) and Reihana (8), who now lived in Auckland with their mother, enjoyed holidays back in North Otago and catching up with their cousins.
It was a difficult time in the aftermath of his death but the team they had around them, and the wider community, had been "amazing" with their support, Stenton said.
At that stage, they had a branch in Winton, in Southland, but that was sold to consolidate closer to home, as Cameron was travelling two or three days a week and it was too much.
Middle sibling Matt Schultz lives in Melbourne and works in the renewable energy sector.
John Schultz said his daughter's acknowledgement in the health and safety arena at the national awards was "well deserved", while Stenton said the announcement came as a "bit of a shock" but she felt very honoured.
Mainland Spreading had implemented safety technology into its trucks using Safetrax, a GPS roll-over and critical alerting system developed by Christchurch-based company Fleetpin.
There was an SOS button that could be activated and a roll-over alert system that was automatically applied by the vehicle when it reached a certain pitch, and it also had warning levels.
Stenton said the team had been talking about the issue for the past eight or nine years, in terms of having some sort of technology in the trucks or on the driver.
It was decided they needed something that was set off by the truck, rather than by person, and it needed to be satellite-based, rather than cellular given the remote areas they were often working in.
They heard about Fleetpin at a field days event in Canterbury; at that stage, the technology was being used for farm ATVs, and it was adapted for groundspreading
Stenton said the company had been "fantastic" to deal with and very proactive working with their business.
She took the initiative to the Canterbury branch of the groundspreading association and those attending the meeting were very impressed with it.
Technology had changed the landscape in the industry, as had communications. With that, expectations had also changed, Stenton said.
"It's getting to the point now we've got so much technology, you really have to make sure all of it is absolutely necessary or useful," she said.
Asked whether there were many women involved in the industry, Schultz said it was a little like farming - there had always been women actively involved in the industry but, for whatever reason, they tended to "take a back seat" when it came to industry matters.
When Nivonne Schultz went to her first conference in 1999, she was the only woman who attended the business sessions. Now, there were "far more" women involved.
Stenton served as Canterbury branch secretary for the past three seasons, before stepping down, taking the role over from her mother.
"She's been a fantastic trailblazer in the industry, she goes to all the meetings and has really pertinent questions. She made it easier for a lot of us after to feel like we can," she said.
Schultz was president of the national association until last year and he was full of praise for this year's President's Award winner, Tina Powell, of Southland, saying she was a "remarkable lady".
Judges commented she had brought a great deal of collaboration, enthusiasm and energy to the Otago-Southland branches, the national association and the direct partners she worked with out of The Key consignment store in Te Anau.
She was also passionate about championing the growth and improved engagement of women in the fertiliser industry and the Ground Spreaders Association.
North Otago punched above its weight when it came to industry involvement; Oamaru woman Rose Hyslop is the executive officer of the New Zealand Groundspread Fertilisers' Association and her husband Nick is vice-president.
Schultz said there had never been expectations for his children to join the family business, but the opportunity had always been available.
He acknowledged there were higher expectations of family members - "and they've always delivered".
At the moment, he was mostly in the truck - as there was a gap with hill drivers - and he was not in the office much.
"As soon as his coffee fix for the day is up, he's out," Stenton said.
