Why would a relatively sane farmer of 25+ yrs. go to organic?

This story is going to take more than one session but I think it's the best place to start for my first blog attempt.  I remember always being attracted to a more natural way of farming but never once considered trying straight up organic methods because  I didn't believe they would be sustainable for the soil or my family.
As I continued to farm using more fertilizer, I noticed my chemical usage started becoming more a significant line item in my budget, but because my yields were increasing and we were making  a profit, I didn't mind spending a little more.  Where once we were able to cultivate the weeds out of our potatoes sufficiently for the vines to keep the weeds down, now nothing short of herbicide could do the job.  Yields continued to increase but expenses also continued to rise.
  Just as the weed pressures increased, tuber diseases became more of a problem.  Sometimes there would be small spots in the storage pile that would rot, other times the whole pile would start going bad.  Add to this the huge fluctuation in potato prices due to over production, and subtly my expenses were reducing my margins. Unlike my starting out years of making slow but steady progress, I now found myself making a huge step forward one year and then three or four years of breaking even or losing and usually losing big one of those years.
I found myself in a catch-22.  I needed to cut expenses, but the increased disease pressures required more fungicides and herbicides.  Costs for new machinery, electricity (we rely totally on pumped water through center pivots), seed, labor, as well as chemicals all were increasing.  As much as the term "sustainability" is over-used, I must say my situation certainly appeared to be just that, unsustainable.  I found myself in a similar position as a gambling addict waiting for the next big crop year with high prices.
In 1998 I went to day-long workshop on the soil food web put on by Elaine Ingham and  sponsored by our Coop.  The information I learned that day started to changed my way of thinking about soil and farming drastically and I was very determined (my wife would say indeed obsessed) with learning more about what the organic approach was all about.  In part II I will  go into some of changes in my thinking and approaches to how I farm.