Until the middle of this century farmers had been benefiting from New Zealand's 31 million acres of pastureland without applying any fertiliser to the soil.

During 1948-49 the Government realised the urgent requirement for aerial fertilising to restore this soil to its correct chemical balance and the Royal New Zealand Air Force was made responsible for research, and extensive fertilising was undertaken with large aircraft, such as the DC-3. The work was charged for on a “county” basis and thus the cost was eased by the local rates.