Aerated Compost Tea- Field Guide

Project Overview

Project Type: Farmer/Rancher
Funds awarded in 2015: $14,560.00
Projected End Date: 12/31/2017
Region: Western
State: New Mexico
Principal Investigator:
Minor Morgan
North Valley Organics

Annual Reports

Information Products


  • Additional Plants: herbs


  • Soil Management: composting


    This project began in 2015 after a review of literature revealed that little information was available about how the Food Safety Modernization Act (FSMA) would affect the on-farm production of compost tea by farmers. While there is a wide range of literature regarding the uses for compost tea and some literature about the effectiveness of compost tea, there is little concrete information on the specific steps required to make a high quality compost tea. In addition, we could find no literature that specifically addresses FSMA and the production of compost tea. FSMA itself discusses "agricultural products of animal origin" which can include compost and compost tea and discusses 2 methods of making compost that are acceptable under FSMA. However the regulations do not list a specifically approved process for making compost tea.


    Over a 2 year period we developed a process for making compost tea that, we believe, meets FSMA Standards. An important outcome of this research was the development of 3 specific assessments that farmers can complete to help them understand all the issues relevant to making a safe compost tea.


    We also trialed several sources of compost and several variations of making compost tea and listed the results of these trials. The main 2 products resulting from this work are an 85 page Monograph "field Guide" and a set of PowerPoint slides. Both of these are available as a pdf document.


    We believe that this information will be useful to farmers not only to help them become compliant under FSMA, but also as an important component of an overall food safety plan for the farm.


    In January, 2011 the Food Safety and Modernization Act (FSMA) was signed into law, with a 5 year review period for receiving feedback and modifying the regulations. FSMA covers a wide range of issues regarding food safety and agricultural production and consists of thousands of pages of regulations, rulemaking, etc. FSMA was promulgated by the Food and Drug Administration (FDA) and grants broad authority to the FDA to regulate its Standards, including regulating on-farm production activities.


    One part of FSMA- The Final Rule for Produce Safety- was the focus of this research. The Final Rule was published in November, 2015 and went into effect in February, 2016. There is a timeline for beginning of enforcement activities that ranges from 2016-2020. The Produce Safety rule establishes: "Standards for the Growing, Harvesting, Packing, and Holding of Produce for Human Consumption". In subpart F of this rule, compost and compost tea is addressed.


    In the last few years there has been a resurgence in interest in biological farming- maximizing the natural biologically based processes that occur on a farm, to the benefit of the farmer and the farm ecosystem. Elaine Ingham, the Rodale Institute, Cornell University College of Agriculture and the Sustainable Agriculture Research and Education program (SARE), to name a few, have long championed the critical role microbes play in soil health and improving the farm eco-system.


    New research is emerging about how these microbes are present at every level of plant production and play a critical role in plant growth, carbon cycling, pathogen suppression and a healthy environment. The specific focus of this research was on developing an on-farm process for making aerated compost tea that meets the newly promulgated Standards for "biological soil amendment of animal origin" under the Food Safety and Modernization Act (FSMA). We outline what a farmer must do on his own farm to meet FSMA standards for compost tea safety.

    Project objectives:

    The following have been identified as objectives for this grant. All have been met:


    1. Identify by name and source all components used in compost tea production.


    1. Identify quantities, how quantity measured (weight, volume, etc), storage requirements and other parameters for all materials used in compost tea production.


    1. Identify by description all equipment and implements used in compost tea production.


    1. Identify each step in the process of brewing compost tea and describe in detail all parameters involved.


    1. Create a pictorial and/or video documentation of all procedures and materials used.


    1. Identify laboratory facilities available for testing including testing of dry compost, water source and finished compost tea.


    1. Identify key assays to be used in laboratory testing for each material (compost, water and compost tea) and include copies of reports from each lab.


    1. Identify and describe an "on-farm" simple process to use in identifying major components (microbes) of a finished compost tea using visual identification under a microscope.


    1. Identify how timing and temperature affect the production and application of compost tea.


    1. Identify how various methods of application (i.e. spray, side dressing, injection in drip tape) influence the effectiveness of compost teas on vegetable crops.


    1. Particularly for spray application, determine if and how spray orifice size, orifice pattern and output pressure affect effectiveness of compost tea.
    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.