3.2. Soil characteristics
The field trial was established in an area with low spatial variability in soil texture and mineralogy. As expected, there was no treatment effect on soil texture even after 6 years of amendment (Table 3). After 4 years the SOM C content was strongly correlated with the treatments (R2 ¼ 0.84, p < 0.0001). The accelerated compost treated soil had the highest content of organic carbon and the unfertilized soil had the lowest content (Fig. 1). The C/N ratio was between 9.3 and 9.9 for all soils (data not shown). The pH of the soils (Table 3) varied between 7.16 and 7.84, and was significantly affected by treatments (R 2 ¼ 0.58, p < 0.01). Similarly SMB C (Fig. 2A) was significantly affected by treatments (R2 ¼ 0.62 , p < 0.01), but only sludge and accelerated compost treatments had significantly higher SMB C than unfertilized soil. CO 2 respiration was similarly affected by treatment (R 2 ¼ 0.65, p < 0.005). The treatment effect on qCO 2 was not significant, but the unfertilized treatments showed the highest values. Heterotrophic bacteria that were able to form colonies on solid media were enumerated on R2A plates (Fig. 3). The treatments with accelerated levels of composted household waste and sewage sludge had the highest number of CFU, and were significantly higher than the human urine treatment which had the lowest number. The growth pattern, as indicated by how fast the colonies appeared on the plates, did not differ between treatments (data not shown).