Hi Gwen,
Thanks for your comment.
You are right. Some plant products are currently grown with animal manures (but most grains are not). When animals are removed from the agricultural industry, we will use green manures and other methods. These farming techniques are called veganics or stockfree farming. See http://youtube.com/watch?v=X_eq0V5PBcA
At the moment we don’t know of any business in Australia advertising veganically farmed vegetables. Until we have a true vegan agricultural system, we will have to do our best with what is available.

I don’t know how to find vegetables that have not been fertilised with animal by-products. It seems most organic vegetables are fertilised with fish or animal blood and bone mixtures. I know it sounds strange, but how do I find vegan vegetables?