title: Effects of natural products on soil organisms and plant health enhancement.
abstract: TerraPy, Magic Wet and Chitosan are soil and plant revitalizers based on natural renewable raw materials. These products stimulate microbial activity in the soil and promote plant growth. Their importance to practical agriculture can be seen in their ability to improve soil health, especially where intensive cultivation has shifted the biological balance in the soil ecosystem to high numbers of plant pathogens. The objective of this study was to investigate the plant beneficial capacities of TerraPy, Magic Wet and Chitosan and to evaluate their effect on bacterial and nematode communities in soils. Tomato seedlings (Lycopersicum esculentum cv. Hellfrucht Frühstamm) were planted into pots containing a sand/soil mixture (1:1, v/v) and were treated with TerraPy, Magic Wet and Chitosan at 200 kg/ha. At 0, 1, 3, 7 and 14 days after inoculation the following soil parameters were evaluated: soil pH, bacterial and fungal population density (cfu/g soil), total number of saprophytic and plant-parasitic nematodes. At the final sampling date tomato shoot and root fresh weight as well as Meloidogyne infestation was recorded. Plant growth was lowest and nematode infestation was highest in the control. Soil bacterial population densities increased within 24 hours after treatment between 4-fold (Magic Wet) and 19-fold (Chitosan). Bacterial richness and diversity were not significantly altered. Dominant bacterial genera were Acinetobacter (41%) and Pseudomonas (22%) for TerraPy, Pseudomonas (30%) and Acinetobacter (13%) for Magic Wet, Acinetobacter (8.9%) and Pseuodomonas (81%) for Chitosan and Bacillus (42%) and Pseudomonas (32%) for the control. Increased microbial activity also was associated with higher numbers of saprophytic nematodes. The results demonstrated the positive effects of natural products in stimulating soil microbial activity and thereby the antagonistic potential in soils leading to a reduction in nematode infestation and improved plant growth.
authors.affiliation: Soil-Ecosystem Phytopathology and Nematology, Institut für Pflanzenkrankheiten, Universität Bonn, Nussallee 9, 53115 Bonn, Germany.
authors.lastname: Mulawarman
authors.forename: J
authors.initials: J
authors.lastname: Hallmann
authors.forename: D
authors.initials: D
authors.lastname: Bell
authors.forename: B
authors.initials: B
authors.lastname: Kopp-Holtwiesche
authors.forename: R A
authors.initials: RA
authors.lastname: Sikora
mesh_terms: D000383:Agriculture / Q000379:methods; D000818:Animals; D001419:Bacteria / Q000187:drug effects / Q000254:growth & development / Q000472:pathogenicity*; D002686:Chitin / Q000031:analogs & derivatives* / Q000494:pharmacology; D048271:Chitosan; D017753:Ecosystem; D005308:Fertilizers; D018551:Solanum lycopersicum / Q000254:growth & development* / Q000469:parasitology; D010572:Pest Control, Biological; D010935:Plant Diseases / Q000382:microbiology / Q000469:parasitology; D012987:Soil / Q000032:analysis / Q000469:parasitology*; D012988:Soil Microbiology; D014431:Tylenchoidea / Q000187:drug effects / Q000254:growth & development / Q000472:pathogenicity*
chemical_list: D005308:Fertilizers; D012987:Soil; D002686:Chitin; D048271:Chitosan