Abstract: This study reports on the evaluation of four organic materials as key ecosystem resources for maize intensification in the Nigerian savanna. Two aspects are examined, first the qualitative value of the organic materials as sources of nutrients and secondly the quantitative significance of the organic materials within the context of the Nigerian savanna. The results showed that cow dung, M. pruriens vines and L. leucocephala pruning contained sufficient nutrients to meet the N and K requirements of a maize crop at an application rate of 5 t ha-1. Phosphorus contents of maize stover and L. leucocephala pruning were not in sufficient quantities to meet crop demand. The calcium and magnesium requirements can be adequately met by this rate for all the organic amendments used. When the organic materials were evaluated based on the contents of nutrients and deduced ratios, cow dung, M. pruriens vines and L. leucocephala pruning were characterized as high quality materials, while maize stover was considered to be a low quality material. Based on their nutrient concentrations and deduced ratios, cow dung, M pruriens vines and L. leucocephala pruning were characterized as high quality materials. Maize stover may be considered as a low quality material. This grouping of the organic materials was confirmed using principal component and correlation analysis. The study also indicated that there are insufficient amounts of organic materials available to support crop production at a scale wider than small on-farm levels.