What is Compost Tea anyway?

I get asked this question a lot. So much in fact, that I hesitate to even use the term 'compost tea' because everyone's understanding of what this is seems to be different. Often times nowadays I'll talk about 'compost extract' of 'actively aerated compost extract,' just to avoid the confusion that comes whenever I say 'compost tea.' In my experience, people have told me that compost tea is anything from a burlap sack filled with horse-poo steeped in water for three days in a closed container, to the smelly liquid that seeps out the bottom of your compost or worm bins. These definitions make me cringe. It feels to me like someone saying that making bread is no more than some flour and water. Similarly, the reductionist understanding of compost tea often leads people who might be expecting a 'loaf of bread' to be disappointed by the tasteless lump of dough they pulled out of the oven.

A slight dated photo of me next to my compost tea brewer

In my search for how to amend this, I went to the source (or at least the most popular source of relevant information in today's modern age), Wikipedia. According to the general masses:


"Compost tea is a liquid solution or suspension made by steeping compost in water. It is used as both a fertilizer and in attempts to prevent plant diseases.^[15] The liquid is applied as a spray to non-edible plant parts, or as a soil-drench (root dip), such as seedlings, or as a surface spray to reduce incidence of harmful phytopathogenic fungi in the phyllosphere.^{[16] "}


While this definition certainly seems to reflect the general attitude, it is a big source of frustration for me. The very most basic premise is spot-on. Compost tea is a combination of compost and water, and yet it is really so much more.

Compost Tea Equipment from my company BioLogic Systems

What irks me about this definition is the lack of recognition that compost is much more than a fertilizer. In so many ways, we are still approaching farming and gardening from a very conventional NPK perspective. I will often see compost branded as a fertilizer, and while it is true that compost does have a nutritive chemical component, that chemistry is all a result of, and dependent on, the microbiology that really makes compost what it is.

My own definition of compost is: "Organic matter, and the microorganisms that eat it." I find this to be a simple and accurate description of what compost really is, and why it is so important. As an example, one teaspoon of healthy compost will contain around 33,000 different species of bacteria and fungi. That isn't even counting how many of each species there are... Without the microbes, nothing would compost. The process of composting is almost entirely a biological process, not a chemical one, and though there are certainly chemical reactions happening within a compost pile, most of those take place in the guts of microorganisms.

Therefore, compost tea is much less a fertilizer, and much more a biological inoculant. I recently spoke with a agricultural extension agent who told me that the farmers using biological inoculants are a fringe group within organic farmers. I asked him how many farmers use compost, to which he replied that most, if not all of them do. I didn't dare correct him in the moment, but in my mind I was shouting "That means everyone uses bio-inoculants!"

A photo (through a microscope) of my own Compost Tea

So, in my efforts to dispel the myth that compost is an inert fertilizer, similar in some way to the synthetically produced fertilizers we all know and love, here is my definition of compost tea:

"Compost tea is a liquid suspension of compost-dwelling microorganisms, the organic matter on which they feed, sometimes with the addition of specific ingredients to further feed those microorganisms. The liquid is actively aerated (brewed) until the organisms have reached a peak in their population levels at which time the liquid is applied foliarly and as a root drench for plants."

While it may be true that my definition is not necessarily better than wikipedia's, it feels to me to be more accurate. It is one of my deeply held beliefs that if we can start to recognize the living nature of our compost, compost teas, and soils, we would change the way we manage land, grow food, and treat our soil.

More information on this topic in a recent post of mine about resources!

A Healthy GMO Debate

photo courtesy of Economist.com

This week, Economist.com is hosting a debate around GMO plants. The debate is around the statement that

"This house believes that biotechnology and sustainable agriculture are complementary, not contradictory." 

 The invitation is to either agree or disagree with this statement. The opposing sides are being led by Pamela Ronald, Plant Pathology prof at UC Davis (representing the 'defending the statement' side) and Charles Benbrook, chief scientist for the Organic Center (representing the 'against the motion' side).

The debate is open all the way till friday, and there is space for anyone to participate. This is a hot topic these days, considerably more so in light of the recent ordeal with 'roundup ready' sugar beets. Interestingly, the majority opinion has been moving back and forth a bit, starting out with almost 80% of people agreeing with the motion that biotech and sustainable agriculture are complimentary. Soon after, the opinion swayed and 60% of participants disagreed. Today it seems to be balancing out a little more.

I thought I might take the opportunity to add my 2 cents.

Recognizing that we, as a species, have been modifying the genetics of plants for thousands of years to our benefit, it seems like this next step may be just that, another step in the evolution of our relationship with plants. We have long selected the seeds from our crops that bear the healthiest, biggest products, and replanted them. This has long been the way for us to manipulate the plants we grow to better serve us as people.

Here is where I get to my stance on the issue. This is also where I see a crucial distinction in the debate. Biotechnology has for a long time served us. Currently, the way we use biotech has made me question who the manipulation really serves.

Possibly our most famous BioTech company is Monsanto, who has given us such wonder-substances as DDT (see Silent Spring), rGBH, terminator seeds, 'RoundUp' (and the gmo plants to withstand the toxic effects of it), and more.

My question, or rather my contention here is about what biotech has become for agriculture. It seems to me that instead of engineering plants that are higher yielding, healthier, and support the farmers, they are creating ways to contribute to Monsanto's net income.

Terminator seeds, while protecting against the risk of the modified genes from spreading (which clearly hasn't worked all that well considering the amount of farmers being sued for having their crops pollinated by GMO plants), also creates a dependence on a single source for farmer's seeds. They've taken away the ability for farmers to inexpensively produce their own genetic stock for the following year.

The recent fiasco around sugar beets was specific to the Monsanto brand of 'roundup ready' seeds. These plants have been engineered to be able to withstand fatal levels of the herbicides glyphosate (aka RoundUp). What strikes me here is that farmers a) have to buy the seeds from the company, b) then have to buy the herbicide from the company as well, and c) since weeds are evolving resistances to this poison, farmers have to be continually applying more and more of this chemical to their lands. This seems suspiciously to me like a way to create a dependence on a company... especially considering the amount of farmers who are in debt to Monsanto, and who likely won't be able to pay off that debt in their lifetimes.

My basic point here is that biotech has been around for a long time. It is a TOOL we have used as a species to support our continued subsistence on this earth. Just like any tool, biotech can be used in ways that benefit the most people, or in ways that are destructive to some and highly beneficial to a choice few. The way we are using biotech today is in support of a petroleum-dependent form of agriculture which is not only unsustainable, but is already (after about 50 years) showing diminishing returns. Pests and weeds are developing resistances to the chemicals, yields aren't what they used to be, costs of chemicals are generally rising, and the food produced is shown to be inferior in taste and nutrition.

Biotech today is contradictory to sustainable agriculture. As long as the focus of biotech is on supporting the current chemical-based land management paradigm, it will continue to contradict a model of agriculture that would genuinely sustain us for generations to come.

A little political... WA Chooses Soda over Health and Education

A highlight this year for me was the implementation of a tax here in Washington State on soda and candy. As far as unhealthy items of consumption go, soda and candy are major contributors to obesity, diabetes, heart disease, and other major (and costly) concerns for which we taxpayers often foot the bill. The proposal to tax those items (by roughly $.02 per can of soda) would have generated an estimated $107 million in the first year to go to health and education programs (or at least to prevent budget cuts in health and education).

[Creative Commons photo by Kevin Wong]

Today I've been reminded of the massive power that 'Big Food' wields. The American Beverage Association (which represents the Soda industry) spent $17 million dollars to squelch this tax. They paid for the signatures to be collected to get the measure on the ballot, they spent millions of dollars in advertisements making it seem like this tax would put people out of jobs, threaten our farmers (what? and just how many sodas use any fruit?), and be unfair to tax this food and not others. Hold on, did they say food? Really? So to be clear, a bottle containing water, corn syrup, and flavorings qualifies as food? Now I know my perception on food might be a little swayed thanks to Michael Pollan, but really? Soda and candy are food? A substance that 7 PhDs and MDs recently stated in the New England Journal of Medicine is significantly contributing to obesity, diabetes, and heart disease (download the full pdf here) is a FOOD!? I'm not even sure if I should be writing about this topic, since in my estimation, these substances fall more under the 'drugs and other intoxicating substances that somehow in a very abstract way resemble food' category.

So, based on millions of dollars in corporate spending, Washington state's voters have decided to repeal this tax. The fat cats of big soda and big candy are patting themselves on the back, congratulating themselves not only for defeating a meager tax which would have done way more good than ill, but for something else as well. Following the footsteps of the other mega-players in the food industry, Big Soda has now also established that they are willing to spend whatever it takes to keep their profit margins the highest, even if it means contributing to a national health epidemic. Once again has the monetary influence of large corporations proving that they actually wield the power in our country. Even on a measure that would give opportunities to our children and our sick, they have the ability to convince the masses into seeing things their way, even if it is through manipulative half-truths or outright 'pants-on-fire' false statements.

Blech. This post leaves a bad, sugary, HFCS taste in my mouth, but then again, so do many of the results of yesterday's voting.

I hope that this can become a cause for people to rally around, to recognize what corporations are doing to manipulate our perspectives and beliefs in order to advance their own quarterly profits. THEY DON'T CARE ABOUT US! So lets stop caring about them and their propaganda. Lets start listening to our doctors and scientists, and stop listening to the multi-billion dollar industry spokespeople. Please?