Small note, when you place the fertility boost, you'll notice that there will be little up arrow graphics kinda glowing on that square. Sometimes that fertility bonus is already on other squares! I don't know the mechanics behind it, but I think fertility bonuses will just kinda pop up here and there. It's not something you should really focus on, but it's a nice bonus when it happens.Yep, and if you select a patch with the arrow it says something like "90 seconds left" so these are indeed temporary. Ok, it's more or less clear now. I'm one development away from the first unlock. At this stage I'm still not sure if I like the game, I have a lingering suspicion that it maybe a spreadsheet, just very masterfully disguised =) I need to experience more content to be sure, and that's exactly what I'm going to do.
As a side note I found this tips & hints thread quite informational (i.e. non-trivial) http://forums.abbeygames.com/viewtopic.php?f=12&t=611