A safety device for travelling irrigation systems has won the supreme innovation award at this year's National Agricultural Fieldays.
The Irrisafe technology has been developed by Technipharm in response to concerns about effluent and nutrient management on dairy farms.
The technology is towed behind an irrigation system and shuts it off if it stops working properly.
Designer Kevin Smith says he will develop it further so it can be marketed.
Other inventions on show include electric fence shifters, women's overalls, animal handling systems.
And inventor Bertie Strickland, from Massey University, who produced a thistle spade, says he designed it because he got sick of the tiresome work of grubbing thistles on his parents' farm.
A robotic milking shed is also among the innovations unveiled. The technology was made by the global dairy supply company De Laval.
The company's solution manager of herd management, Ron Mulder, says it's a 24-point rotary unit that has two robotic arms and can milk between 300 and 800 cows.
Mr Mulder says the unit has been installed on a Waikato farm this season, with interest from other farms.
A lawn or seed mat that combines sheep wool dags and jute fibre, called Woolgro, has been designed to hold seed within its layers so they cannot get scoured out by rainfall or picked away by birds.
One of its designers, Geoff Luke, says dag wool has been used by organic gardeners for generations and is 100% biodegradable.
The young inventor of the year award went to Lincoln University farm manager student, Ben Shannon, for a stock crate designed for the back of a ute.
On Wednesday, almost 26,500 visitors attended opening day - 1% more people than at last year's opening day.
