Students from Vanderbilt University School of Engineering conducted a project at Caney Fork Farms to explore compost extract application through irrigation drip tape. Their objectives were to develop a pilot irrigation setup capable of delivering living microbiology to plants in a greenhouse setting and to address the problems of biofilm and sediment accumulation in the drip lines.

Krisi Olivero of Alter Eco Farms performed microscopy analysis to assess the impact of different delivery systems on the microbial population in the extract.

Introducing extract with a fertilizer injection pump killed most of the microbes and diluted the extract excessively, resulting in microbial numbers so low they could not be reliably measured. Running pure compost extract into the tape with a diaphragm pump was more successful, delivering all key microbial groups in the recommended numbers for annual vegetable crops through both 80 mesh and 120 mesh drip tape.

Flushing the lines with water after the extract application successfully removed all significant sediment from the drip lines.

Microscopy analysis results:

• Grozome Compost
• Compost Extract
• Extract from 80 Mesh Emitter
• Extract from 120 Mesh Emitter