John Biernbaum

John Biernbaum

John Biernbaum

Speaker | Department of Horticulture, Michigan State University

East Lansing, MI | 517-282-8752 | biernbau@msu.edu

John Biernbaum is Professor of Horticulture at Michigan State University, where he teaches courses in organic farming principles and practices, organic transplant production, compost production and use, and protected cultivation in passive solar greenhouses. He does research and farmer/community outreach on organic soil and fertility management, use of high tunnels and vermicomposting of food scraps for year-round diversified organic farming and urban agriculture. He currently serves on the Michigan Organic Food and Farm Alliance (MOFFA) Board of Directors and education committee.

Presentation Title: Compostponics-Manufacturing Growing Media while Composting

Session: Compost Uses and Markets: Expanding Opportunities

Time: Wednesday, January 30, 11:00 AM – 12:30 PM

Presentation Summary: Compostponics is making physically stable, biologically active and mineral balanced compost from local feedstock materials for the purpose of growing plants in raised beds and containers using 100% compost.We can observe weeds or pumpkin vines or tomato plants grow in a compost pile. Compost has been used as a growing media for urban agriculture for decades. Compost suitable for container plant production can be marketed direct to the end user or growing media producers.

Compostponics is based in part on the assumption that increasing the quality, value and price of compost will increase organics recycling and the economic viability of commercial composting.Commercial composting is more challenging in the Midwest US due to low landfill tipping fees compared to coastal US regions. Compostponics is based on10 years of prior research of peat-based container media for greenhouse production and the following 20-years of research and experience working with organic farmers and gardeners to increase the use of compost as a soil amendment for healthy soil, a component of greenhouse container plant growing media for seedling transplants,and as a medium for container-grown plant sand urban agriculture.

Research testing of compost for container growing media over the last 40 years has typically been based on asking whether a particular compost will work as a component of growing media and at what rate of addition. The research needed instead is development of a protocol for how to produce compost suitable for use as a container growing media by either blending multiple types of compostor the addition of fertility amendments prior to composting.Desired physical (air and water holding), chemical (pH, soluble salts, mineral balance) and biological (minimal plant disease, mineralizing and nitrifying bacteria) characteristics have been well defined for peat and bark based container growing media. Based on our research,the addition of calcium to balance cation minerals and sulfur to lower pH are beneficial. The protocol likely will include the blending of different types of composts (municipal, manure, food scrap, etc) varying in maturity, particle size and nutrient levels. Ramial wood chips or charcoal added at the start of composting can provide necessary stable particles for aeration. A very mature compost may have excess soluble minerals and low available carbon to maintain biological activity while an immature compost may have excess biological activity and low available nutrients; but a blend may provide the desired characteristics. We have also developed low cost methods for larger scale production of vermicompost to be blended into the growing media. Vermicompost can also be used as a nutrient addition during container plant production.

The topics covered in this presentation will include an introduction to:possible feedstocks, recipes, production methods including vermicomposting, maturity considerations,the importance of multiple types of organic matter for healthy soil, ideas related to blending composts,the impact of particle size and container height on aeration,current research on fertility additions and methods of compost analysis.