PELLETIZED CYANOBACTERIAL SOIL AMENDMENTS - LABORATORY TESTING FOR SURVIVAL, ESCAPABILITY, AND NITROGEN-FIXATION

The escape and growth of Microcoleus vaginatus from alginate pellets o nto 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 p ellets added to sterilized soil, and unsterilized soil with no additio ns. Chlorophyll a readings were significantly higher in unsterilized s oils. Microcoleus biovolumes were highest in sterilized inoculated soi ls and significantly higher than sterilized untreated soils. Microcole us filament density was significantly higher in Microcoleus-inoculated soils than in the other two treatments. Nitrogen fixation activity wa s recorded in unsterilized soils after only I month, and rates increas ed as the experiment progressed. Microcoleus-inoculated soils had sign ificant nitrogen-fixing activity during the last sampling period.