So far I tried and continue trying

Lambert
The location is 58:28 latitude in northern Europe. Climate about 2 weeks behind Toronto, Ontario; Buffalo NY.
In late August 2012 I seeded winter rye to an old abandoned field of freshly mowed grass. By early October the rye was about 16 inches tall over the native grass. There was lot of snow in winter and in spring there was no trace of the rye.
In spring I seeded the Fukuoka way a mixture of about 20 "heritage" vegetables and white glover into the same plot and some to an area of lawn near some 15-year old oak-trees. I went away for about 2 months, came back to find ... nothing except the old mixed grass and some white glover.
I know how to keep a conventional vegetable garden. My grandfather was a farmer and in childhood I spent summers on his farm curious what was going on. I just wanted to try to make it the Fukuoka way. It just did not work out.
This time I missed the fall seeding, but want to start again in spring 2014.
Can anybody write me what I did wrong sand what should I watch when I seed in spring?

Seems to me your climate freezes hard enough to have killed off the rye. You might need to try planting it in the early spring. Are other people growing it over winter nearby, in tilled fields? Fukuoka's methods were developed for a particular climate. It will take many years of research and trial to extend these methods into other areas. Most classical permaculture seeks to rely on perennials at least, and tree crops in climates that will support them, as the foundation of subsistence. It also acknowledges that you may need to jumpstart your system by means of a one-time initial disturbance event to knock back existing vegetation and replace it with a new, productive, and hopefully self-regenerating managed ecosystem..... A "sheet mulch" is the traditional permaculture method to do this on a small scale. On a larger scale, rotations with animals, earthworks followed by plantings, and even various kinds of tillage, may all be appropriate when done sparingly and with utmost care as to the dangers of erosion, etc.