Mr Lamb (61) has spent four years in the role. During that time there had been operational or practical reasons for the school to require high safety standards for its students when they entered agriculture.
He said the focus of farm safety needed to extend beyond day to day safety practices and encompass mental health.
''It's a huge issue in the rural community; it's absolutely enormous. It's the biggest challenge the rural community has got,'' he said.
''You tend to look at rural people and think they're stoic and hard and independent, but quite often those environments they are working in can be incredibly challenging for people's mental states.''
Mr Lamb ends his more than 30 year career with Lincoln University on Thursday. He was offered a move back to Christchurch after a review and restructuring programme, but opted for redundancy instead.
In its 50th year, Telford still had a strong vocational focus, he said, and farm safety was integral to that continuing. The school's 920ha farm for 100 students was not nearly large enough by other schools' measures.
Between 8000ha to 10,000ha for 20 students, or 15,000 stock units per 10 students, would be required by other leading agriculture schools around the country, he said.
Preserving opportunities for work experience for students at the school became a necessity, he said.
''We've got lots of students and not enough farm, so that requires us to put students on farms throughout Southland and Otago.''
The school has relationships with more than 80 farms in the area, which host students on up to two week work experience programmes. Placing students on farms had been seen as a ''huge risk'' in terms of liability for farmers.
In his first year, in 2011, the school facilitated 1070 student weeks on farms.
''What I saw ... was to turn that on its head and say, `Don't look at that as a risk','' he said.
By making health and safety a focus at the school, he said, farmers no longer saw students as potential risks during their field experience, he said.
''If they [Otago and Southland farmers] can't take the kids, this place shuts down, because there's no work experience.''
But all too often, he said, a crucial element of health and wellbeing was overlooked in traditional thinking on farm safety.
Quad bikes with rollover protection are the norm and helmets are required for Telford students, he said. There was now a nurse on campus for the first time. Random drug and alcohol testing had become the norm.
''There has been a whole change in philosophy over the past four years to normalise safe practice on farms,'' Mr Lamb said.
He said of the 379 deaths in agriculture between 2007 and 2013, ''123 of those were suicides; 28 of them were quads''.
''We talk about quads and we talk about chainsaws but the unspoken thing is the suicide rate.''
The importance of health and wellness, particularly mental health, had gone unrecognised for too long in New Zealand's agriculture sector.
Mr Lamb said traditionally New Zealand's fear of ''copycat activity'' had prevented a public conversation about suicide. Attitudes must change, he said.
He said there needed to be better training for students starting farming, so they understood the environment they were entering.
''Our rural community is one of the least protected. There's no social net that they can just rock down and get help at,'' Mr Lamb said.
Since the former air force pilot and lecturer at Lincoln became director at Telford, sub degree agricultural training funding had been cut by 20%.
It had been reduced through the Telford division from 1000 full time equivalent students to 800 full time equivalent students during his four years. It had been halved since 2006.
Putting funding back into the system would allow students to leave school better prepared for a career that can take a toll on mental health.
''The one thing we've battled here since I've been here is funding issues, issues around government funding: that's been our biggest challenge.
''The question I have around that, around educational training and health and welfare, is that sector pays a hell of a lot of tax. And it doesn't seem to get a lot invested back in those critical areas of training and education and health and welfare.''
Telford offers level 2 to 5 training in agriculture.
The school's Balclutha campus represents 10% of its work nationally. It serves between 4000 and 6000 students across the country and includes beekeeping courses at Kaitaia in the Far North.
While there were only 120 students on the Balclutha campus at one time, teachers work with 163 high schools through broadcast studios on site that allow video conferencing into remote school rooms.
Later this month Mr Lamb said he would fly to Australia where he would spend a gap year, before his planned retirement to Central Otago.
