microbes in the community

"summer's here and the time is right, for..." ...dancing in the streets 

attending garden parties and hearing all about microbes?

Ok, so that may never take off as a remake of the famous Motown hit, but nonetheless, this weekend saw a raft of garden parties, fêtes, school fayres and the like, full of festive folks enjoying the wonderful English summer, whilst supporting local good causes.

On Saturday and Sunday, the sun was shining brightly, the summer breeze was wafting gently and the stall at our local Old Town Festival event was well attended, with visitors eager to see what BUGS was all about, smell the difference between the untreated bran and the microbe-rich BUGS bran (which most people agreed smells like really strong salt and vinegar crisps, crossed with wheatabix!). The pictures of worm nests drew particular interest, yet although most people claimed to be squeamish, not one turned the page to avoid the close-up pictures but instead bent forward, looked more closely and asked all sorts of intelligent and interesting questions about what it was they were looking at. (more to follow on that subject, over the next few blog posts, given it proved so popular)

We gave away samples of microbe brews, for those interested to try for themselves, we spoke about peak oil and what this would mean for food growing in the future (if we can't afford the rising cost of synthetic Nitrogen, how exactly are we going to feed ourselves?) as well as the even more troubling concept of peak phosphor, given that whilst Nitrogen at least can be synthesized, phosphor can't be.

All in all, visitors to the stall were interested, engaged and wanted to know more, even though not all those attending grew organically. Hopefully we gave those we saw something new to think about and encouraged some to think about what they might do to start growing food for themselves, organically (and with the help of beneficial microbes).

At various points during the afternoon, those attending the garden fête gathered around to hear a variety of speakers give presentations, which the organisers had arranged. Nobody had expected a talk all about "the fascinating world of micro-organisms" but there it was - like a living example of the nerd in the yakult advert (you know the one - that poor nerdy chap who talks endlessly about bacteria and who pretty girls avoid at all the hippest parties) waxing lyrical about the role of beneficial microbes and what they can do for plant and human well-being.

Contrary to expectations, the talk went down rather well (who'd have thunk!) with many listeners making a bee-line for the stall to learn more and see what it was all about in greater detail.  One illustrative graphic was employed, showing the scale of the microbial world under discussion.  In fact, the graphic (see below) set the scene in describing the otherwise hidden world, bringing it to the light of day and into the focus of attention.

So when otherwise trivial facts emerged from the talk, such as the fact that, in a typical teaspoon of garden soil, there are approximately 5,000,000 bacteria - it became a figure not entirely meaningless, but an illustration of just how diverse and biologically active this hidden world beneath our feet really is.

Other fascinating facts, such as the mind-boggling statement that over 90% of the cells in our bodies are actually bacteria, carried real weight. Here in this blog (and in the "about this blog" page), we've referred to the fact that as a society we've been conditioned to think of bacteria as products purely of disease, of illness and of harm.  Now, taking the above graphic into consideration and coupled with that 90% bacteria by volume factoid, do you still think it's all about disease?  Hopefully not... and hopefully the door is opening on seeing bacteria as a natural part of who we are and what we are, as creatures who are partners to an invisible army of allies.

The soil food web is a subject we've yet to cover in depth in this blog, but as is the case with the above 90% of our bodily system factoid, so is the case within the soil - bacteria (and other microbes) form the foundation for an entire mini-ecosystem of partnership, of beneficial biological action that unbeknown to us humans at our scale, nevertheless benefits us in ways we simply can't perceive - or at least not without the help of tools such as powerful microscopes.

So, in summary, the sun shone, the breeze wafted gently and in one small corner of traditional English culture, science, tea and home-made cakes mixed to create an eclectic diversion for those in attendance.

capturing carbon in the soil - chelation in action?

Discover Magazine ran an interesting article the other day, following studies at Ohio State University to look at how much Carbon Dioxide soil might soak up.  Claims that the agricultural soils of the world have the potential to soak up 13 percent of the carbon dioxide in the atmosphere today—the equivalent of scrubbing every ounce of CO2 released into the atmosphere since 1980- may be bold, but research suggests that biologically rich and diverse soil may be able to help current concerns.

Rattan Lal first came to the idea of soil as a powerful carbon sink (pdf) not through an interest in climate change, but rather out of concern for the land itself and the people who depend on its productivity. While carbon-depleted soils tend to be dry and prone to erosion, carbon-rich soil is dark, crumbly, fertile, and moist. In the 1970s and 1980s, Lal was studying soils in Africa so devoid of organic matter that the ground had become like hardened cement. There he met Roger Ravelle, a pioneer in the study of global warming. When Lal made a despairing remark about the impoverished soil, Ravelle suggested that the carbon had moved into the atmosphere. “I told Roger I didn’t know where it had gone; I just wanted to put it back,” Lal recalls.

Ravelle was right. For millions of years, a natural partnership between plants and soil microbes has helped regulate carbon dioxide levels in the atmosphere. During photosynthesis, plants absorb carbon dioxide from the air and transform it into sugars and other carbon-based molecules. Some of those carbon products transfer from the roots to symbiotic fungi and soil microbes, which store the carbon in the soil as humus.

The invention of agriculture some 10,000 years ago disrupted these ancient soil-building processes. When humans started draining and plowing up the natural topsoil for planting, they exposed the buried carbon to oxygen, creating carbon dioxide and releasing it into the air. Animal husbandry made things worse, as domesticated animals began grazing grasslands down to the earth. In places where the ground is bare—from overgrazing or from the common practice of leaving fields unplanted for part of the year—photosynthesis stops, and so does the storage of carbon in the soil. Lal calculates that land-use changes such as these have stripped 70 billion to 100 billion tons of carbon from the world’s soils and pumped it into the earth’s atmosphere, oceans, and lakes since the dawn of agriculture. Today agriculture and other land-use changes account for about a third of global greenhouse gas emissions.

To quantify soil’s carbon sequestration potential on agricultural lands, soil scientist Whendee Silver of the University of California, Berkeley, is conducting a first-of-its-kind study on a 539-acre cattle ranch near Nicasio, California. In a collaboration with ranchers and local and state land management organizations called the Marin Carbon Project, she and her students are testing the effects of compost created from city yard waste (such as leaves, branches, and lawn trimmings) and agricultural waste (including manure and cornstalks) on carbon storage.

Although previous experiments have shown that compost increases soil carbon, Silver is among the first to examine whether real-world ranchers can use it effectively to enrich the soil on their rangeland. She has already found a large increase in soil carbon two years after a single application of compost, probably due to enhanced vegetation growth. On the basis of her results, Silver projects that 28 million acres of grazing land in California could absorb 42 million tons of carbon dioxide—nearly 40 percent of what the state’s electrical power plants produce in a year. To accomplish that, each acre of land must absorb just 1.5 additional tons of carbon dioxide. “Given what we’ve seen in our experiments,” Silver says, “one and a half tons is doable.”

In Australia, Christine Jones, soil ecologist emerita of the New South Wales Department of Land and Water Conservation, is testing another promising soil-
enrichment strategy, one that relies on perennial grasses. Since carbon sequestration stops in the absence of living plants, Jones and 12 ranchers in Western Australia are working to build up soil carbon by cultivating grasses that stay green year-round. 

Like composting, the approach has already been proved experimentally; Jones now hopes to show that it can be applied on working ranches and that the resulting carbon capture can be accurately measured. Over the course of four years, she has charted the carbon content of the grasslands, and when the first phase of the project concludes this August, philanthropist Rhonda 
Willson will pay the ranchers for every additional ton of carbon tucked away in their soils. 
“The changes we’ve registered over the past few years will surprise the world,” Jones says.

Silver and Jones hope that projects such as theirs will demonstrate the role that farmers, 
ranchers, and other land managers can play in mitigating the effects of heat-trapping greenhouse gases. Lal says that the greatest opportunities lie in the world’s most depleted and eroded soils, in sub-Saharan Africa, south and central Asia, and Central America. Success there will rely on providing farmers the tools and knowledge to improve their land, as well as financial compensation for their carbon enrichment of the soil.

The same is true in wealthier societies like the United States, where most farming operations chase productivity through large applications of fertilizer. Changing long-standing habits will require a system that rewards land 
managers not just for the corn or beef they produce, but also for the carbon they can build into their property. “Farmers should get compensated for protecting the ecosystem,” Lal says. “This is something worth paying for.”

Regenerative 
 Agriculture 
 An approach that aims to protect natural resources such as soil through techniques including crop diversity and rotation.

Carbon Sink 
A reservoir that can hold carbon and prevent it from escaping into the atmosphere. Proper management could turn agricultural soils into a powerful sink.

Marin Carbon Project A joint effort by scientists and ranchers in California to study rangeland’s potential to soak up carbon.


Compost 
Fertilizer made of decaying organic matter. By boosting plant growth, compost helps to increase soil carbon storage.

Perennial Grass 
 According to an ongoing study in Australia, planting ranch lands with grasses that remain alive year-round also increases the amount of carbon trapped in the land.

the fascinating world of bacteria

here's Bonnie Bassler's take on the subject of bacteria:

in the last post, we saw how to make a compost tea (the 24 hour recipe) which is essentially a way of moving bacteria and other microbes from the contents of the compost pile into a liquid that can be applied to our precious plants.

but is that the only method of improving the bacterial content of our soils?  compost teas is but one route to take, as caretaker of the organic realm:

Compost Teas vs. Compost Extracts

First, it may be helpful to share some common terminology and practices associated with compost teas. How do compost teas differ from compost extracts or compost leachates?

Compost Leachate

Compost windrow leachate—the dark-colored solution that leaches out of the bottom of the compost pile—most likely will be rich in soluble nutrients; but, in the early stage of composting it may also contain pathogens. It would be viewed as a pollution source if allowed to run off-site. Compost leachate needs further bioremediation and is not suitable or recommended as a foliar spray.

Compost Extract

Compost watery extract—made from compost suspended in a barrel of water for 7 to 14 days, usually soaking in a burlap sack—a centuries-old technique. The primary benefit of the extract will be a supply of soluble nutrients, which can be used as a liquid fertilizer.

Compost Tea

Compost tea, in modern terminology, is a compost extract brewed with a microbial food source—molasses, kelp, rock dust, humic-fulvic acids. The compost-tea brewing technique, an aerobic process, extracts and grows populations of beneficial microorganisms.

Summary

Compost teas are distinguished from compost extracts both in method of production and in the way they are used. Teas are actively brewed with microbial food and catalyst sources added to the solution, and a sump pump bubbles and aerates the solution, supplying plenty of much-needed oxygen. The aim of the brewing process is to extract beneficial microbes from the compost itself, followed by growing these populations of microbes during the 24- to 36-hour brew period. The compost provides the source of microbes, and the microbial food and catalyst amendments promote the growth and multiplication of microbes in the tea. Some examples of microbial food sources: molasses, kelp powder, and fish powder. Some examples of microbial catalysts: humic acid, yucca extract, and rock dust.

Liquid Organic Extracts vs. Compost Teas

Building on the concept of compost teas as a liquid organic extract, what are some other common organic extracts used as a liquid drench or foliar spray?

Manure Tea

Manure-based extracts—a soluble nutrient source made from raw animal manure soaked in water. For all practical purposes, manure tea is prepared in the same way as the compost extracts described in the preceding section. The manure is placed in a burlap sack and suspended in a barrel of water for 7 to 14 days. The primary benefit of the tea will be a supply of soluble nutrients, which can be used as a liquid fertilizer.

Herbal Tea

Plant-based extracts—stinging nettle, horse tail, comfrey, clover. A common method is to stuff a barrel about three-quarters full of fresh green plant material, then top off the barrel with tepid water. The tea is allowed to ferment at ambient temperatures for 3 to 10 days. The finished product is strained, then diluted in portions of 1:10 or 1:5 and used as a foliar spray or soil drench. Herbal teas provide a supply of soluble nutrients as well as bioactive plant compounds.

Liquid Manures

Mixtures of plant and animal byproducts steeped as an extract—stinging nettle, comfrey, seaweed, fish wastes, fish meal. Liquid manures are a blend of marine products (local fish wastes, seaweed extract, kelp meal) and locally harvested herbs, soaked and fermented at ambient temperatures for 3 to 10 days. Liquid manures are prepared similarly to herbal tea—the material is fully immersed in the barrel during the fermenting period, then strained and diluted and used as a foliar spray or soil drench. Liquid manures supply soluble nutrients and bioactive compounds.

Summary

Compost teas and herbal teas are tools that can be made on the farm to enhance crop fertility and to inoculate the phyllosphere and rhizosphere with soluble nutrients, beneficial microbes, and the beneficial metabolites of microbes.

Caution

Wheareas raw animal manures are used as a compost windrow feedstock, the composting process—thermophyllic heating to 135-160° F for 10-15 days—assures pathogen reduction. The raw organic matter initially present in the compost windrow undergoes a complete transformation, with humus as an end product. Any pathogens associated with raw manures will be gone. So caution is extended: Manure teas are NOT the same thing as compost teas or compost extracts. Because of concerns over new pathogenic strains of E. coli, the author advises growers to reconsider manure teas and/or to work with a microbial lab to ensure a safe, worthwhile product.

references above are available from NCAT - National Centre Appropriate Technology

compost tea - the 24hr recipe

there's been a rare old hoo-har about compost tea, here in the uk, since Gardener's World broadcast their April 1st look at the RHS's experiments with this organic method of keeping our plants tip top and healthy.

Of course, the recent e-coli outbreak in mainland Europe shocked many folks into thinking about what goes on to our commercially grow veggies - whether manure-based feeds were robust enough to prevent the transmission of pathogens, or whether they were in part to blame for such a devastating pathogenic outbreak.

The issue of creating safe organic feeds is therefore a crucial one - the oldest form of compost tea comes from the Victorian country garden.

Simply put: a collection of dried "cow-pats" would be placed in a burlap sack, weighted down and placed into a water butt to steep for a few days, before the liquor would be watered into the veggies and flowers for the full fertilizer effect.

It worked well in that time, of course, as they had precious few petrochemicals which might upset the delicate food-chain in the soil food web ( fascinating subject we'll cover in more detail in later blog posts) and no long-lasting man-made compounds which might survive the journey through a cow's intestine and go on to mutate crops, as we had a few years ago with herbicides.

So, what with the concern over e-coli, pathogens from manure, i was reading through a couple of homesteading blogs and came across this recipe from the small measures blog.  It's a guest post by Indio of saving the big money blog in the states and gives a 24 hour recipe for compost tea:

I started out with a control group of plants that didn’t get the compost tea as a point of comparison. Eventually, I took pity on this group and one by one they got hooked on the delicious beverage. There is only one remaining anemic plant from my group of test plants.

This is my first year using compost tea and I quickly became a convert. It’s not a difficult process so I usually have a 5 gallon bucket of tea percolating daily. I alternate between my two vegetable beds and every other day they get a drink when it isn’t raining. With the recent ecoli outbreak in Europe, compost tea is one of the safest ways to add nutrients to soil instead of using animal manure. Rather than worrying about whether or not the manure has aged enough to be safe on root crops, or if it will splash on fruiting crops I’ve found that compost tea is a way to take the worry out of soil enhancement and organic nutritional supplements.

At its most basic, compost tea is made by soaking the compost in non-chlorinated water for twenty four hours to encourage the growth of bacteria, fungi, protozoa and beneficial microbes that will feed the plant either through the leaves or the root system. The tea can be either sprayed on the plants as a foliar spray or used to water the plants. If you soak the compost longer than 24 hours, you risk the microbes dying before they get to the plant so it’s important to use it as soon as it is ready.

The Four Step Process

1. Fill a large bucket with water (water temperature doesn’t matter). If you don’t have well water, then let the water sit for 24 hours prior to adding the compost to let the chlorine evaporate out of the treated water. Depending upon the size of your garden you may want to use something larger than a five gallon bucket, which is what I use for my two modest veg beds.

2. To encourage the microbe development, I add two tbsps of tea catalyst to the water and stir to dissolve it. This is not a mandatory step, but it does accelerate the development of the microbes.

3. An air pump, the kind that is typically used in an aquarium, with two air stones attached to the end of the pump tubing, are used to circulate the bucket water. The air stones are placed on the bottom of the bucket. The whole set up must be located near an electrical outlet because the pump will need to be higher than the bucket so that water doesn’t get sucked back into the pump and break it. The pump speeds up the process by circulating the water and organisms.

4. To make the tea, I use either worm castings or arctic humus. I usually run out of humus quickly, but worm castings I can dig out of the vermicompost bin in my basement. If you don’t have a worm bin, check with your local garden shop for bags of worm castings. Next put the compost in a mesh bag and hang that over the edges of the bucket. Stirring the compost every now and then helps distribute the organisms, rather than letting them get stuck in the compost.

In 24 hours, you can pour the tea into a watering can or use it as a foliar spray. Your plants will show their appreciation by being bountiful.

Now i'm not exactly sure what the tea catalyst might be, but i suspect it may be a commercially available additive from the varying compost tea suppliers in the States.

As we'll find out through the pages of this blog, there are a myriad of ways in which to make compost teas, wines, microbe brews and so on - with varying effects claimed and shown.  The main point that people are finding out, however, is that we don't need chemical or synthetic feeds to care for our plants - in fact these synthetic feeds may have done more harm than good since their introduction (in terms of damaging soil structure and allowing pathogenic species to flourish).

BUGS are part of the coming new understanding about how we can feed ourselves whilst taking care of nature, but remember -
the revolution will not be pasteurized*

* see the about this blog page for more