"The earth" simply can refer to the land, the ground, the yard etc. The heavens" refers to the sky or all that can be seen above. There is not enough to point out it is specifically talking about the entire planet. I move all of the plants of the earth too when I pull weeds in my front yard, but I don't kill every plant on the planet when that happens. It's simply referring to farm animals and enough of them for him to restart his trade in order to survive after and during the flood. Also taking every kind of food that is to be eaten would mean every thing that a human could eat possible on the planet and that for all the animals on the planet to eat stored on the boat with them. If there already millions of animals aboard, imagine all of that different food too. Nothing could fit. That's what happens when it is taken in that context of a global wide flood. It would already be hard enough for only about eight people to take care of that load already, especially during the Bronze Age. It's really saying that Noah should bring enough animals to survive on the land with after the flood and enough food for his family, himself and the animals as the event came.