This review covers the literature reported from January 1, 1977, to December 31, 1978, and includes procedures recorded in readily available journals, in Chemical Abstracts, and in Fertilizer Abstracts (62). Some selectivity has been exercised to include only those procedures especially pertinent for direct application to fertilizers, easily adapted to fertilizers, or containing information related to research in fertilizer methodology. In the Literature Cited section of this review, Fertilizer Abstracts (62) are abbreviated as Fert. A.