This isn't exactly permaculture, but if you have a good stand of Caragana and can find a wood chipper somewhere, it makes the best garden mulch in the world. Earthworms love it and it rots fast and contains its own nitrogen. I use wood chips between my raised beds and then incorporate them into the soil the next year in the fall. I never have to use other fertilizer (though I often use compost tea to water). Best gardens I've ever had since I started doing this.