One of the elective classes here at school is agriculture. The ground here is increadibly hard! There is alot of clay and not much top soil at all. I always thought that the tropics had wonderful rich soil but that is not always true. They use alot of fertalizer down here also.
It was all these guys could do to make a dent in this ground. Good thing the school has a rototiller. You really have to have someone come with a tractor and work it up for you in order to be able to do a good job growing anything.
one thing that is neat though is that you can transplant pretty much anything and because of the rain and heat it'll do well if you've got a decent place to put it.