2026-06-28http://hdl.handle.net/123456789/315632The purpose of this bulletin is to serve as a guide for the specialists in the laboratories in developing countries. It is the first attempt to compile and develop from the experience and information of various successful soil testing laboratories a suitable methodology for each step of the soil test calibration into a calibration system which can be applied under most varied soil and climatic conditions.76application/pdfFAOBook (stand-alone)