An investigation was carried out to evaluate soybean germplasm response to (1) manganese deficiency and toxicity, (2) various rates of manganese application, and (3) to different soil pH levels on manganese accumulation by the germplasm lines and their yield. Manganese rates were 0, 10, and 20 kg/ha. The pH levels were 5.3, 6.3, and 7.0. The germplasm lines tested were PI 159319, PI 324924, PI 960895 and L-76-0132.