An exhaust conditioning system for use with a tractor towing an air seeding implement comprises an exhaust duct arranged to communicate exhaust emissions from the engine of the tractor to the seed fan of the air seeding implement. A condenser receives the exhaust emissions of the exhaust duct therethrough between the engine and the seed fan. A condenser fan cools a surface of the condenser. A computer controller controllably varies a rate of at least one of the condenser fan, the seed fan or revolutions per minute of the engine responsive to a sensed temperature of the exhaust emissions to maintain the temperature of the exhaust emissions within a selected temperature range and such that the exhaust emissions are arranged to influence germination of the seeds either by humidity, oxidised organic matter or bio-char.