| Soil health changes under commercial organic potato production were evaluated using a minimum data set of chemical, physical and biological indicators throughout 5-year potato/grain/forage rotations in 2006 and 2007. Long-term pastures were included as reference fields. Biological indicators (microbial biomass C, microbial quotient, earthworm abundance and biomass) were more sensitive to rotation phase affects than light fraction, bulk density, pH, and total organic carbon and nitrogen. Soil health was affected during the potato phase, generally requiring four years in the rotation to return to reference field levels. The Collembola, Folsomia candida, was assessed as a potential bioindicator of soil health by examining its development on diverse treatment substrates. Growth of Folsomia candida was more sensitive to the different substrates followed by reproduction. One-day old Folsomia candida was more responsive than ten-day olds as they are more metabolically active and should be used in the development of future soil health tests. |
