Abstract Cotton tree is often called silk cotton tree containing non edible oil in its seeds and grows widely in hilly areas in Bangladesh. Oil extracted from the seeds of this plant is used as energy source as well as in tanneries while the cake (a byproduct after extracting oil) was found to be rich in all plant nutrients. In order to reduce the production cost by minimizing or utterly eliminating the use of chemical fertilizers, decreasing environmental hazards, improve soil structure, promote leveraging agriculture and obtain high quality crops, cotton seed oil cake getting importance due its rich mineral contents. Cotton seed oil cake was assessed and it was found to be a potential source of bio-fertilizer due to richness of minerals in the form of plant nutrients. The analysis of valuable elements present in this oil cake was done by Atomic absorption spectrophotometer.
Keywords Cotton seed oil cake, Bio-fertilizer, Atomic Absorption Spectrophotometer, elemental compositions.