Mr Morrison was rounding up hoggets for shearing while driving a quadbike in Waikaka Valley about three weeks ago.
He was towing a trailer carrying dogs and braked the bike as he was travelling down a hill.
The ground was hard and the long grass was greasy from rain, he said.
"The bike slipped into a strainer post and I broke my leg."
His leg was in a cast and he would be unable to put weight on it for six weeks.
"When you’re on crutches around a farm, you’re not a lot of use to anyone."
Luckily, his wife was highly capable, he said.
"It puts pressure on those other people in your business because, if you’re out, somebody’s got to cover for you."
People would be needed to help at weaning, he said.
Usually he would be spraying crops, but a contractor was now needed to do the work.
"You’re vulnerable. You need people to come and help you or cover for you."
Accidents could happen on the most benign days, he said.
His quadbike was fit-for-purpose and had rollover protection, good tyres and was regularly serviced.
The accident happened because he did not factor in the greasy ground conditions and should have been driving the bike more slowly.
"The ground conditions had changed from a wet winter, where your tyres are digging in the ground, to a hard top on your surface, where your grass is growing like stink and it’s like driving on an ice-skating rink."
Safer Farms chairwoman and farmer Lindy Nelson urged farmers to "take a moment" as the sector headed into the traditional peak period for injuries and fatalities.
The industry-led organisation dedicated to fostering a safer farming culture across New Zealand was encouraging farmers to pause, think through a plan, share it with others and set the job up right before getting under way.
"Summer’s always busy, and this year is no different."
For the first time in several years, many farmers were generating profit as red meat and dairy prices were stronger.
"Now is the time to invest in the things that keep us safe, strong and resilient, whether that’s crush protection devices, improved systems or simply better planning."
Accident Compensation Corporation data showed the average time away from work following a serious vehicle-related farm injury was 82 days, which put pressure on families, finances and the wider farm operation.
Many farming businesses had invested in new technology and crush protection devices and strengthened visitor and induction processes to ensure people could get where they need to go safely.
"We all want to be celebrating Christmas together, so now’s the time to think about what we can put in place to make this year different."
