Hmm,
I comoletely agree that university, or any form of higher education is great, especially if you are very keen on the subject, and not just going to start a career... (makes lectures and coursework actually 'enjoyable; which was my case).
However, given the cost of a degree these days, even with your own accomodation, it is very expensive indeed. And with a subject like electronics, the internet provides far more resources than a university ever could...apart from perhaps being able to ask professionals face-to-face about things. I'm not saying self-teaching is better, but, you already have certain technical problems that you wish to solve, and thats is, IMHO, one of the best ways to learn. Start with an idea, something that needs to be built to perform a certain task, then research on methods...then research on specifics, then experiment
It must be noted that, perhaps this was purely the course I took (Electronic Engineering BEng) but it was VERY software heavy. A majority of the students were very apt at high level programming, C, C++, VB etc.. but could not solder, nor recognise basic passive copmonents...let alone design any form of circuit. This was even the case in the final year. it seems, because of the way industry is going, it is quicker and cheaper for companies to rely more and more on computer designs, or embedded cofigurable 'modules' to perform tasks. These require only basic code to do almost anything, qithout requiring any form of hardware knowledge whatsoever.
Home learning, IS hap-hazard. No real structure, and with so many different websites explaining idea's/methods/theories in different ways (some even getting it awfully wrong) its a minefield.
Perhaps this may not be an option depending on where you live, but, is there some form of short college course you can do before hand? These lower courses, altohugh not at all degree level, are far more practical, cheaper, and will cover the basics of 'electronics' rather than VHDL, Verilog, C++ and all other forms of language. Its gerat knowing how to program FPGA's to form a fast 32-bit DSP from scratch...but for the sorts of circuits you are likely to need for your farm, its over kill.
Just my two cents. Not trying to put you off, but I was somewhat disappointed with my university course. Since I chose it purely out of interest (and now I work as a surveyer...nothing to do with it at all).
Blueteeth
Edit:
Ooooh you're from Devon! lovely place
I'm sure college courses would be a great start...plus, if for some reason you don't wish to work on the farm anymore, they are more helpful in getting jobs in the industry trhan degree's. Since...jobs that ask for a degree, almsot always ask for 'plus 4 years experience' - which you can't get without a job, or a college course