Pedal powered seeder... http://www.rngr.net/publications/tpn/42-3/42_3_9_12.pdf - see the pdf document download
Pedal powered grass cutters... http://www.treehugger.com/bikes/the-cutting-edge-bicycle-lawnmowing.html they're more for cutting lawns but maybe there's potential for making a brush cutter or sickle scythe mower by crossing it with this... http://www.yardsickle.com/
Pedal powered harvesting and general utility machine... http://picasaweb.google.com/lh/photo/1IvQ7Ch71vVG3ZRTlzC5OA.
This is a great book on pedal power in work, leisure and transport, now out of print but downloadable for free... http://www.letsremake.info/library_2.html#peda
Pedal powered seeder... http://www.rngr.net/publications/tpn/42-3/42_3_9_12.pdf - see the pdf document download
Pedal powered grass cutters... http://www.treehugger.com/bikes/the-cutting-edge-bicycle-lawnmowing.html they're more for cutting lawns but maybe there's potential for making a brush cutter or sickle scythe mower by crossing it with this... http://www.yardsickle.com/
Pedal powered harvesting and general utility machine... http://picasaweb.google.com/lh/photo/1IvQ7Ch71vVG3ZRTlzC5OA.
This is a great book on pedal power in work, leisure and transport, now out of print but downloadable for free... http://www.letsremake.info/library_2.html#peda