Two field experiments were conducted to examine the agronomic value of poultry manure composted in the presence of both phosphate rock (PR) and elemental sulphur (S°) (sulphocompost) and PR alone (phosphocompost). Winter cabbage and summer maize were used as test crops. For the first season's winter cabbage, the phosphocompost and sulphocompost were approximately 12% and 60% as effective as urea and both composts were equally effective as urea for the second season's maize crop. The greater agronomic effectiveness of sulpho-compost could be attributed to the improved nitrogen (N)-use efficiency increased PR dissolution and improved S nutrition. Distribution of nitrate-nitrogen (N03-N) in the soil profile of field plots indicated greater potential for winter leaching of N from urea than poultry manure which could be the reason for the improved residual value of the manure reflected in summer maize yields. The results from the field experiments indicated that composting poultry manure with S° and PR not only reduces environmental pollution associated with manure application, but also increases the agronomic effectiveness of manure.