Partners in Sustainability™

Organic Transitions
Willamette Organics Quarterly Newsletter
Volume 4, Issue 3 Summer 2009

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Don’t Kill the Messenger

An article by Paul Sachs


Paul Sachs is the founder of North Country Organics and Ecological Turf Consultants. He has authored a number of books on sustainable turf care and sport field management. The following article by Paul was recently published in a number of professional periodicals. It is reprinted here with Paul’s permission.


Killing the Messenger

When an eclectic group of ailments finally send you to the doctor’s office and, after a barrage of tests, the physician tells you to decrease your current level of stress, do you then spray him with homicide? No! When the severity of heat, drought, cutting height, and traffic all increase to a critical point and your turf finally succumbs to disease, do you spray it with fungicides? Yes! This analogy may not be bulletproof but here’s the point: killing the messenger rarely corrects the problem. In fact, it often makes the problem worse.

Evidence is mounting that pesticides and soluble fertilizers dramatically alter the biological balance in soil. It is also becoming clear that the suppression of specific groups of soil organisms—especially beneficial fungi—affects the stress tolerance and overall health of turf plants.

If we take a superficial look at how soil life evolved, a relationship is evident between the soil’s biological balance and the type of plants that naturally proliferate. During the beginning stages of soil development, only photosynthesizing (autotrophic) microorganisms could exist. At this point the soil was completely dominated by bacteria. These microscopic plants eventually produced enough organic energy to support various groups of decay organisms (saprophytes) that consumed the residues of the autotrophs. As these saprophytes began to proliferate, more biotic diversity accumulated and fungi began to appear on the scene. In the early stages of fungal development bacteria still outnumbered fungi by a wide margin but slowly, the ratio between fungi and bacteria began to narrow. At the stage where visible plants had enough resources to grow, the ratio of fungi to bacteria was probably about 0.1:1 (i.e., 1 fungus to 10 bacteria). The only plants that could grow in this austere environment were wildflowers and weeds but these plants contributed resources to advance soil evolution. Eventually, the ratio of fungi to bacteria (F:B) narrowed to about 0.3:1 and early species of grasses began to appear. These grasses produced more resources for fungal communities and as the F:B ratio narrowed more, later species of grasses were able to proliferate. At this point the F:B ratio was probably between 0.75:1 and 1:1. As soil fungi began to outnumber bacteria ( 2:1), more woody plants, such as shrubs and vines began to appear. These plants were eventually succeeded by trees and as old growth forests evolved the F:B ratio in the soil grew to between 100:1 and 1000:1.

Turf naturally grows best in soil where the F:B ratio is somewhere around 1:1. As the ratio drops, grasses naturally thin and weeds and wildflowers usually begin to appear. There is evidence that applications of pesticides (especially fungicides) and soluble nitrate or ammonium fertilizers can suppress fungal growth and inadvertently favor a more bacteria dominated soil. This biological condition does not naturally support a strong community of turf plants. In response to the waning vitality of our turf, we typically apply more soluble fertilizers to push growth and pesticides designed to either suppress the plant’s competition (weeds) or pests (attracted to stressed plants). Unfortunately, it is likely that we are further inhibiting fungi’s ability to recolonize in the soil.

The weeds, wildflowers, and pests are messengers. They are trying to tell us that something is wrong and that our turf plants are stressed. The problem may not be immediately evident but the messengers make it clear that a problem does exist. If the soil is fertile and not compacted, we may want to explore the possibility of a biological imbalance.



Organic Land Care Qualified Compost
for
Professional Partners in Sustainability


This article is one relating to the Oregon Tilth Organic Land Care program that is scheduled to be introduced next winter with a multi-day training program and qualifying test. I will keep our Professional Partners in Sustainability informed about the program as we go through this year. I have been involved with the development of this program for the last few years.

Certified organic farmers are restricted in the use of compost on their crops because some compost may contain pathogenic organisms that can contaminate crops. All compost that does not meet the requirements of CFR 205.203 must not be applied to crops within 90 or 120 days of harvest, depending on the crop. CFR 205.203 requires compost used within the “pre-harvest” interval to have a prescribed carbon to nitrogen ratio and to have been held at a specific temperature for a period long enough to kill any possible pathogens. (It also kills weed seeds).

The Oregon Tilth Accredited Organic Land Care program will require a minimum standard of compost quality as well. Most major composting facilities subscribe to a program of quality control, such as the US Composting Council’s (USCC) – Standards of Testing Assurance (STA) program. USCC does a comprehensive lab analysis on the compost samples submitted and issues a report to the supplier. The lab reports contain information on nutrient content, organic matter levels, heavy metal contamination, stability, pathogen levels and germination rates. Compost producers who participate in the STA program are required to make a copy of the report available to their customers upon request. USCC members who follow the sampling protocols of the STA program are said to have “Certified Compost”. The STA program is a tool for the compost industry to monitor and improve the quality of their product but there are no minimum levels of quality for the compost tested. It is possible then that “USCC Certified Compost” could contain elements or organisms that are harmful to people, soil quality and the environment as a whole.

For this reason, the Tilth program has been working with composting facilities and a USCC authorized consultant to develop a minimum standard of quality for compost used in their Accredited Organic Land Care program. Organic Land Care Practitioners will be required to specify this “Qualified Compost” when it is used for soil incorporation or lawn top dressing, where it’s available, on all sites managed under the Tilth program.

Major composting facilities will be made aware of the Organic Land Care Qualified Compost standards and encouraged to participate with Tilth Accredited Practitioners in raising the bar on compost quality by carefully monitoring the composting process to produce a high quality product that meets the Qualified Compost standard.



Coming Next Edition!

Willamette University brings their whole campus under Organic Land Care protocols.



More about Humic Substances



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