There has certainly been enough fertiliser...of course you also need seeds or small plants, plus a suitably supportive environment to cultivate them and effective weed control. That usually costs money, unless you're hoping that the seeds/plants will fall from the sky into your fertiliser filled paddock and the weeds decide to go somewhere else. Strangely enough, that doesn't usually happen.
"Weeds that are declared noxious are those weeds that have potential to cause harm to the community and individuals, can be controlled by reasonable means and most importantly, have the potential to spread within an area and to other areas. A weed is declared noxious because its control will provide a benefit to the community over and above the cost of implementing control programs."
Weed definitions & FAQs | NSW Department of Primary Industries
Doesn't sound like any company board I know of...
No doubt Qantas hope that Pilatus Desperadum and LAME Aspirare seeds keep magically falling from the skies...even if there are no suitable soils for them to fall on, and a serious lack of irrigation and weed control.
Don't worry, we'll just import them, if we spray them with enough urea, they'll grow...