Pelletized cyanobacterial soil amendments: Laboratory testing for survival, escapability, and nitrogen fixation

The escape and growth of Microcoleus vaginatus from alginate pellets onto soil crusts under controlled laboratory conditions were examined. Soil crust samples were collected and placed in petri dishes. Selected samples were sterilized, and three treatments were established: 75 g m(-2) Microcoleus pellets added to sterilized soil, 75 g m(-2) blank pellets added to sterilized soil, and unsterilized soil with no additions. Chlorophyll a readings were significantly higher in unsterilized soils. Microcoleus biovolumes were highest in sterilized inoculated soils and significantly higher than sterilized untreated soils. Microcoleus filament density was significantly higher in Microcoleus-inoculated soils than in the other two treatments. Nitrogen fixation activity was recorded in unsterilized soils after only I month, and rates increased as the experiment progressed. Microcoleus-inoculated soils had significant nitrogen-fixing activity during the last sampling period.