N-Viro Soil (NVS) is an alkaline-stabilised biosolid that has been shown to suppress Meloidogyne incognita. In separate microplot studies, NVS was applied either alone at different rates (0, 25, 50, 75, 100 dry t ha−1), or in combination with M. incognita-resistant and M. incognita-susceptible cultivars, to different M. incognita initial densities (0, 37 500, 75 000 eggs/microplot). NVS suppressed M. incognita. During year 1, increasing rates of NVS resulted in higher soil solution pH and greater M. incognita J2 and egg suppression. Soil solution pH remained higher in NVS-amended plots compared to the unamended control in years 2 and 3. NVS was more effective in reducing moderate than in reducing high initial nematode populations, with 94-100% reduction in egg and juvenile populations compared to 75-79%, respectively. In all experiments, a reduction in nematode populations by NVS, alone or in combination with a resistant cultivar, did not occur consistently in years 2 or 3. Unfortunately, the application rate of NVS required to achieve this reduction in nematode populations is probably not agronomically realistic. Additional research may allow the rate of NVS required to suppress plant-parasitic nematodes to be reduced.