A Report from the Compost Tea and Air Spading Workshop on August 9, 2012

Compost Tea and Air Spading Advanced Workshop

Review by Jenna Messier

On August 9, 2012, the NOFA Organic Land Care Program held its second Advanced Workshop, “Compost Tea and Air Spading” at Rye Country Day School in Rye, New York.  The workshop was a huge success, with over 50 attendees from 5 states, informative presentations, and two outdoor demonstrations.

Michael Almstead, Vice-President of Almstead Tree and Shrub Company, developed the workshop and taught sessions:  Setting up the Business, Soil Food Web Tests, Estimating the Hidden Costs, and Intro to Brewing.  Dan Dalton, ISA Master Arborist, taught the Soils and Air Spading Protocol sections.  The full presentation may be seen at:  www.almstead.com/presentations/8-9-12.pdf.

Michael made some excellent recommendations regarding compost tea.  Before brewing your tea, assess the quality of your compost source by requiring the supplier to provide you with Soil Food Web test results.  Secondly, Michael suggested using annual Soil Food Web test results to measure the effectiveness of your compost tea program over time on an individual property, and to determine future applications. Thirdly, Compost tea is a knowledge-based practice, and anyone who brews tea must be trained to use the microscope and to identify beneficial or harmful microorganisms – or you may just be spraying “dirty water.”

Dan Dalton presented a soil review and then described the different forms of Air Spading such as radial trenching, root collar excavation, vertical mulching, and sheet excavation which are different patterns of excavating the tree roots by blowing pressurized air into the soil surrounding roots.  The exposed roots’ health is then evaluated and the area backfilled with compost and amendments, such as zeolite to reduce compaction and rhizoscience containing humates and kelp.

Russell Wagner of Almstead Tree and Shrub Company led the on-site Air Spading demonstration of an old Cut-Leaf European Beech tree which was suffering under compacted soil.  He shared best practices with the group, such as inspecting your equipment before use and always using ear protection.  AOLCP Eileen Fisher volunteered to try out the air spade and extended a radial trench.  The group was able to inspect the roots of the tree for damage, noting the lack of root hairs, before back filling the area.

The day finished with a compost tea application on turf, performed by Marc San Phillipo  The tea which had been brewed that morning was poured into the tank of a large spray truck.  Two employees reeled in the hoses while Mark walked across the lawn lengthwise while spraying 10 foot sections.  He also used a root feeder attached to the compost tea tank and applied tea directly to the root zone of an elm tree.

NOFA Organic Land Care Program extends many thanks to Almstead Tree and Shrub Company for donating their time, equipment and expertise in order to create and run this informative program.  Thanks go out to Rye Country Day School for hosting the event as part of their commitment to environmental sustainability.  Thanks to Peter Schmidt from Compostwerks who sponsored breakfast and brought his truck and equipment for attendees to view.