Characterization of Eight Soil Types Using the Selenastrum Capricornutum Bioassay

A recently developed bioassay protocol was used to characterize seven different soil types and Promix BX. The green alga Selenastrum capricornutum was used as the test organism. A ruggedness test which altered seven variables was conducted to identify procedural stipulations that should be carefully controlled in the Selenastrum capricornutum bioassay. Stimulatory or inhibitory effects as measured by population growth were compared to a control using two different nutritional methods termed proportional amendment (PA) and complete amendment (CA). Population growth, calculated effect (CE) values, and EC50 values are given for each soil. A wide range of effects were documented indicating a substantial difference among soils with respect to their ability to stimulate or inhibit algal population growth.