The judging process is conducted in a relaxed manner, and judges always take climatic factors into account.
Mrs Hanna said the competition offered an educational opportunity for any farmer wanting to learn more about how to improve business profitability and environmental management. Past-entrants had described their participation as a worthwhile experience.
The awards cover a wide range of categories, so farmers who are performing well in one specific area have a chance of picking up a category award.
Supreme winners from each region are honoured at the trust's annual Sustainability Showcase, where the Gordon Stephenson Trophy is presented to a national winner.
This year, the trophy and national winner title went to Bay of Plenty's John and Catherine Ford, who urge all farmers to enter the 2016 competition.
"We need to promote our industry by providing examples of the things farmers are doing to care for the environment," Mr Ford said.
The Fords said the judging process was educational and inspirational.