A tyre inflation system for an agricultural seeding machine is disclosed Theagriculturalmachine includes a jump arm supporting at least one press wheel The tyreinflationsystem comprises an air delivery path arranged to be in air flow communicationwith acavity of a tyre of a press wheel, and an air flow controller operable tocause a delivery ofair through the air delivery path to adjust an inflation pressure of the tyrein situ during useof the agricultural machine A planter assembly including a tyre inflationsystem and atyre for use with the tyre inflation system are also disclosed
