The Central Districts field days begins on Thursday at Manfield Park near Feilding.
More than 500 agricultural exhibitors from New Zealand and Australia are taking part.
Marketing manager Cheryl Riddell says the recession appears to have had little impact on demand for sites.
Last year's event drew a record attendance of 40,000 over the three days.
Feature events include the national excavator competition, the only three day wood chopping event in New Zealand and a lumberjack show.