Soybean (Glycine max(L.) Merril) production within Brazil is a major source of oil and meal exports for world markets. Vast underutilized areas within Brazil have favorable climates with potential for increased production. However, nonfavorable soil fertility factors and erosion losses are restraints for high yield soybean cropping within most neotropical regions. The objective of these studies was to determine influence of basic soil cations Ca, Mg and K with P amendment governing growth, nodulation, nitrogenase activity C2H2red.), ureide and associated nodule components of Forrest cultivar soybeans grown on a Typic Eutrustox (dark red latosol) of Jaiba, Minas Gerais, Brazil.