2006 Annual Report 4d.Progress report. This report serves to document research under Assistance Type Cooperative Agreement 59-1935-3-324 with The Rodale Institute. This agreement also services the SARE grant detailed above (1935-12000-010-01R). Additional details of this research can be found in the report for the parent CRIS 1935-12000-010-00D Development of efficient and practical methods for producing arbuscular mycorrhizal fungi. Modifications to the on-farm system of arbuscular mycorrhizal fungus inoculum production were studied. Normally, bahiagrass seedlings colonized by mycorrhizal fungi are transplanted into the compost+vermiculite mixture. We tried a new procedure in which field soil was mixed into the compost and vermiculite and uncolonized seedlings were transplanted. This method is a potential improvement because it allows propagation of mycorrhizal fungi indigenous to the site. These indigenous fungi were produced, but at lower levels than via the routine system. In addition, we tested light expanded clay aggregates as a replacement for the vermiculite in the growing medium. The idea here was to see if the mycorrhizal fungi would grow into the aggregate. If this happened, the aggregate then would become a unit of inoculum more readily applied to the field via farm machinery. This work was unsuccessful. NP 202 Action Plan component V Productive and Sustainable Soil Management Systems, Performance Measures in the ARS Strategic Plan, 5.2.2 and 5.4.2).