Mmm, I agree that having a proper techtree as part of the UI is a necessity. I don't think it's remotely true that there's "too much research", however. I also think that the call for "better, intuitive research" is a little puzzling, given that the proposed solution of just having a single food production research fulfils neither of those criteria.
I do agree that in certain specific cases, there are some techs that could be consolidated. For instance, in the OP's example, if bees and fruits and wheat were rarer than fertile land, then I could see the three of them being condensed into a single research. However, fertile land would not be condensed in. That way, the basic farming tech is the one that everyone will most likely eventually research, even if they're playing with a heavily warfare-oriented research strategy in mind. Whereas the advanced farming tech would have enough stuff in it to make it worth its high cost, since it isn't exactly early in the tech tree, when you factor in that you pretty much have to branch out into other civilisation techs before going that far.
Of course, the other alternative is to do as Civ4 does, and have all the food resources each with their own tech at roughly equal point in the tech tree. However, this is less well suited to Elemental, since the exponential tech costs makes a broad techtree significantly less feasible.
I have to say, I have yet to run into any issues with the exponential costs. But thinking about it now, would I prefer to have fixed costs? I think that might just be the case. Having fixed costs allows you to go back and cover the long-obsolete techs that you miss by specialising, with only a minor detour to your current tech progress. Which is exactly as it should be, since these are long-obsolete techs, after all, and you've already suffered the drawback of not having those techs when they were actually useful. Whereas reaching parity in this neglected branch of the techtree would require a substantial diversion of time, but could still be an interesting strategic choice.
Compare that to the current system, where generalising in the civilisation tree makes it less worthwhile to get orchards. Or beelining for beekeeping leaves you pretty well screwed when it comes to resource production, and iron production, and consequently troop training, as well as housing, and prestige, and... You get the picture. And sure, you could argue that that's supposed to happen. But really, what's supposed to happen is that you get something useful from having specialised to that degree, not end up just having more of what you started with.
Actually, I think this is possibly leading me to conclude that it's too early to make too many sweeping statements about the techtree, given that three of the trees aren't even in yet.
(Oh hey, I didn't mean to write an entire essay )