Submitted to: Nematology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/30/2006
Publication Date: 2/1/2007
Citation: Zasada, I.A., Rogers, S.T., Sardanelli, S. 2007. Application of Alkaline-stabilized Biosolids for MeloidogyneIIncognita Suppression in Microplots. Nematology. 9:123-129. Interpretive Summary: Plant-parasitic nematodes are microscopic worms that attack plants and cause ten billion dollars in crop losses annually in the United States. Farmers face an enormous problem because they lack safe and effective ways of reducing the numbers of nematodes in soils. Previous USDA research has shown that two species of nematodes can be killed upon exposure to N-Viro Soil, a product that is formed from municipal sewage treatment wastes that have been freed of human disease organisms through a sanitization and stabilization process. In this study, ARS and University of Maryland researchers evaluated N-Viro Soil for its ability to control nematode populations on three different soybean varieties in small field plots. The results indicated that higher rates of N-Viro Soil resulted in lower nematode populations, and that a combined treatment of N-Viro Soil with a nematode-resistant soybean variety suppressed populations greater than either practice alone. These results are significant because they indicate that N-Viro Soil can be combined with another management strategy to increase nematode suppression. This research will be used by scientists developing safe and effective ways of controlling the diseases caused by plant-parasitic nematodes.
Technical Abstract: N-Viro Soil (NVS) is an alkaline-stabilized biosolid that has been shown to suppress Meloidogyne incognita. In separate studies NVS was applied in microplots either at different rates (0, 25, 50, 75 and 100 dry t/ha), or applied in combination with M. incognita resistant and susceptible varieties and to different M. incognita initial densities (low, medium and high). N-Viro Soil did suppress M. incognita in a field setting. During year 1, increasing rates of NVS resulted in greater soil solution pHs and M. incognita J2 and egg suppression. Soil solution pH remained higher in NVS-amended plots compared to the unamended control in year 2. N-Viro Soil was more effective in reducing moderate initial nematode populations rather than high, with 94-100% reduction in eggs 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 variety, did not consistently suppress M. incognita in year 2 or 3. Unfortunately, the rate required to elicit this reduction in nematode populations is probably not agronomically realistic. Additional research needs to concentrate on reducing the rate of NVS necessary to suppress plant-parasitic nematodes.