Aerated Compost Tea- Field Guide

2016 Annual Report for FW15-037

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

Aerated Compost Tea- Field Guide


We have made good progress in meeting all our goals. We have moved from the planning/organizing stage into the implementation stage with field work testing the various components of our research. In 2015 we organized the “Brain Trust” of advisors and this group met throughout 2016 as well. the “Brain Trust” is composed of:

– Minor Morgan, Lead Investigator and organic farmer
– John Garlisch, Bernalillo County Extension Agent and Food Safety expert. Also a farmer
– Dr. Fred Koster, retired physician, microbiologist and organic farmer
– Walter Dodd, manager of Soilutions in Albuquerque, a commercial compost production
facility certified for use on organic farms.
– Matthew Draper, farmer and educator

In 2016 we have finalized our field process for brewing tea, systematized the testing process and outlined the critical parameters to assure safety for compost tea. We have built a network of laboratories, suppliers and vendors that can be shared with other farmers.

Objectives/Performance Targets

When we began this project, we assumed it would be straightforward and relatively simple to locate a laboratory capable of testing compost and compost tea with the Standards required under FSMA. This has turned out to be quite challenging. It turns out that many laboratories test for E Coli, but very few have the capability to test for all 4 pathogens listed in FSMA. We have reviewed and worked with 17 different laboratories to identify who can test for all 4 pathogens, in both liquid and solid form, with reporting and testing methods approved under FSMA. We have made a national search and have identified 2 laboratories- both in California- with full capabilities. Primus Labs is a specialist in food safety testing and is excited to be working with us on clarifying and complying with the exact Standards specified under FSMA. For Primus, this work is an extension of their testing, auditing and quality control work around food safety. They are not a specialist in compost testing, but have the full laboratory capabilities to test compost and compost tea. Control Laboratories in Watsonville, California, is a specialist in compost and are members of the US Composting Council. While food safety is not their specialty, pathogen testing for compost and compost tea is, and they also are excited to work with us.

We spent a considerable amount of time working with our local and regional laboratories here in New Mexico and Arizona, in an effort to identify a lab closer in proximity. With any microbial testing, time from sample draw to sample test is critical and we had hoped to identify a laboratory within 4 hours of our location. There are none.

We have also identified a laboratory for testing water quality: Hall Environmental Laboratory in Albuquerque, New Mexico is a full service lab that tests for all necessary parameters to assure that water complies with Bernalillo County drinking water safety standards.

Throughout 2016 we have used all three laboratories for testing compost, compost tea and our water source. Systematizing the testing, shipping and reporting process has been a major achievement in 2016.


Our major accomplishment in 2016 was to operationalize the research and evaluation parameters we have spent the last 2 years developing. We have developed the following instruments that are useful to farmers in complying with the FSMA standards for compost tea safety:

A. “Farmer Self Assessment regarding use of compost and compost tea on the farm”

One of our major findings this year is that developing an on-farm replicable process for producing compost tea that is consistent and routinely follows the same steps every time- this is much more involved than just randomly brewing tea. Issues of storage, testing, water quality, compost source, brewing process, record keeping- and many more parameters- require a high degree of commitment and forethought on the part of the farmer. The core principle of assuring tea safety is the replicability and consistency of the brewing process.

The “Self Assessment” inventory requires the farmer to think through the many issues he will face when developing a consistent brewing process.

B. Step-by-Step compost Tea: Preparation”

This document outlines the routine processes that need to be established on a farm to properly make tea. This is a follow-up to the “Farmer Self Assessment” and outlines all that a farmer needs to do to be prepared to regularly brew compost tea.

C. Step-by-step: Field Production of compost tea”.

This is a detailed document outlining each step to brew compost tea. For our final publication this document will contain detailed photographs illustrating each step, along with a listing of the critical issues that affect each step.

D. “Step-by-Step: Testing and Shipping Protocol”

We have outlined how to properly gather and mail in the compost and compost tea for laboratory analysis. Since we have only found 2 laboratories- both in California- that test for all pathogens listed under FSMA, we expect this information to be valuable.

E. “Process specifications”

This document lists for our particular operation all the details and critical measurements and provides a template for other farmers.

F. “Compost Tea brewing log”

This document is a sample log for tracking each incident of brewing compost tea.

Impacts and Contributions/Outcomes

We have done an extensive literature review of the research and information available regarding compost tea. We are preparing a major presentation which will occur at the 2017 New Mexico Organic Farming conference on February 18, 2017.

We also presented preliminary information at a USDA sponsored workshop that occurred in Lordsburg, New Mexico on November 1, 2016.

We have shared information on compost tea use with Navajo Nation small scale farmers through the “Earth Mother Agriculture Initiative”. We presented at an all-day workshop on sustainable farming, including compost tea use, at the “Nenahnezad Harvest Festival” which occurred on September 23, 2016, in Shiprock, New Mexico.


John Garlisch

[email protected]
extension agent
Bernalillo County Extension
1510 Menaul Blvd, NW
Albuquerque, NM 87107
Office Phone: 5052431386