Comparison of microbially enhanced compost extracts produced from composted cattle rumen content material and from commercially available inocula

A comparative study was performed on compost extracts prepared from cattle rumen content composted for three and nine months, nine month old compost inoculated with a Nutri-Life 4/20® inoculum, and two commercial preparations (LivingSoil® and Nutri-Life 4/20®), all incubated for 48h. Nutri-Life 4/20® had the highest concentrations of NO3--N and K +-K, while rumen compost extract had higher humic and fulvic acids concentration. The bacterial and fungal community level functional diversity of three month old compost extract and of LivingSoil®, assessed with Biolog®, were higher than that of nine month old rumen compost extract, with or without Nutri-Life 4/20® inoculum, or Nutri-Life 4/20®. No difference in fungal diversity was observed between treatments, as indicated by Denaturing Gradient Gel Electrophoresis (DGGE) analysis, however, bacterial diversity was higher in all compost extracts and LivingSoil® compared to the Nutri-Life 4/20®. Criteria for judging the quality of a microbially enhanced extract are discusse