It is a time of fasting and prayer and, as the collect for the Rogation Days masses puts it, we pray that God would "pour forth" His blessing not only on the upcoming harvest, but also "upon this land" as a whole.
The lesson from Ezekiel speaks of the fruitfulness of the land being given by God, and in the gospel reading Jesus speaks of providing one's neighbour with food when asked, and puts it into the universal Truth of God's relationship with man by saying "Ask, and it shall be given you; seek, and ye shall find; know and it shall be opened unto you."