Porsche's interest in the manufacture of tractors began in 1934 and continued until the early sixties. PorscheTractors (a member of the PurelyPorsche family of web sites) provides details and photographs of the tractors of this era.
You can discover the specification, details, driving impressions and more for every road-going Porsche car at PorscheArchive.
A fully researched directory of Porsche Suppliers and Resources is available at PorscheFile (one each for UK, US, Australia and Germany).
Generic information on diesel tractors can be found here and information on farming equipment here.
Allgaier R22
This is a true Allgaeir tractor, having been built before the relationship with Porsche. The AP16 develops 22 BHP at 1500 RPM from its single-cylinder diesel engine.

Capacity: 1840cc
Maximum Power: 22bhp
Length: 2600mm
Width: 1520mm
Height 1570mm
Wheelbase 1500mm
Weight: 1700kg