Effect of sewage sludge on nitrogen availability in peat

Summary We studied the effect of incubating peat with lime and sewage sludge in small proportions on biological activity and N mineralization. The peat response was dependent on pH and, in acid peats, on mineralization capacity. In acid peats, the addition of sewage sludge inhibited biological activity. Only the most eutrophic peats (Herbosa) responded with accelerated mineralization. The addition of lime to acid peats favoured organic matter mineralization, shown by a greater CO₂ release. The best results were obtained by adding lime and sewage sludge together. In saline peats, the best N levels were obtained without incubation.