Organic materials are an important source of nutrients for many smallholder farmers. The use of composted organic amendments is constrained by their variability and maturity. The aim of this study was to evaluate the potential of aerobically composted chicken blood and maize stover mixtures on maize N uptake and to determine the effect on seed emergence in a greenhouse pot experiment. Four composts with proportions of 10%, 30%, 70% and 100% maize stover were used as soil amendments and compared against an unamended soil (control). The greenhouse pot experiment involved planting 10 maize seeds in each pot. Seed emergence percent was determined a week after sowing to ascertain whether the composts had phytotoxic effects. Percent emergence did not differ significantly among treatments (p =0.26). Two plants were allowed to grow in the pots for five weeks after which maize dry matter yield and foliar analysis followed.