Source: Geoff Wilson, Aquaponics Journal #39- Greenhouse Aquaponics Proves Superior to Inorganic Hydroponics

On April 1^st I’m giving a presentation at the Progressive Gardening Trade Association annual conference titled “Secrets to Selling Aquaponics”.  The audience will be primarily owners and managers of hydroponic stores.

When I started thinking about the notion of “selling” aquaponics, the first thoughts in my business school-trained brain were about target markets.  How is the typical buyer of aquaponics different than the typical market for these hydroponic businesses?

That thought, however, was immediately crowded out by a second, more basic thought.  In order to sell aquaponics to a hydroponics customer, you really need to understand how aquaponics differs from hydroponics … which leads me to the point of this article.  How does aquaponics differ from hydroponics?  Let me count the ways…

1. Startup speed – This is perhaps the biggest downside to aquaponics from a hydroponics perspective.  In hydroponics you just add commercially formulated nutrients to your nutrient reservoir and you are off to the races.  With aquaponics it takes about a month to start your system by developing a colony of nitrifying bacteria through a process called “cycling”.  The ammonia from the fish waste will not be converted into the nitrates that the plants are seeking until this process is complete.
2. Relationship with bacteria – Hydroponic systems tend to be fairly sterile.  I’ve visited hydroponic growing facilities where I had to wear coveralls and a hairnet to enter.  Not so with aquaponics.  Bacteria are revered by aquaponic gardeners because, as described above, they are the engine that drives our systems.
3. Flood and Drain cycle – Hydroponic growers using flood and drain techniques generally only fertigate their plants once every four to six hours.  Academic studies and vast, collective experience have shown that this optimizes the water and fertilizer the plants need.  When you move to an aquaponics system, however, the ideal schedule changes to flooding for 15 minutes every 45 minutes.  The reason is that the grow bed now has taken on the additional role of being the filter for the fish waste.   If you only ran the fish water through the filter every four to six hours, fish waste would build to dangerous levels.
4. Grow bed depth – Hydroponic growers tend to use standard 6” deep flood tables and put pots or cubes with plants in them in the flood trays.  Again, because an aquaponics grow bed is serving a dual role of both home for the plants and bio-filter for the fish waste, both need to be considered and optimized.  Most media based aquaponic gardeners use 12” deep grow beds filled with an inert media. Over the years, side by side trials have shown that this depth of grow bed develops the kind of robust bacteria colony needed to not only filter the liquid waste, but also to provide an excellent home for composting red worms and the heterotrophic bacteria needed to break down the solid waste from the fish.
5. Nutrients ( supplementation) – Hydroponic gardeners live and die by their nutrients, and the supplements to those nutrients.  Not so with aquaponic gardeners.  The goal of an aquaponic garden is to achieve a state of balance within it’s eco-system.  Everything that goes into the system must work towards this end goal, and not harm any other element of the system.  Anything added to the system to boost plant growth could, and probably will, harm the fish and possibly the bacteria colony and the compost worms.  There are a few exceptions to this, including the use of liquid seaweed, small amounts of chelated iron, and a few minerals to adjust pH. But beyond those, aquaponic gardeners will think long and hard before adding anything to their systems except of course, fish feed.
6. Nutrients (dumping) – Hydroponic nutrients must be dumped and replaced on a regular basis to address nutrient imbalances that arise over time.  This concept mystifies an aquaponic gardener.  We only top up the fish tank with water and never dump and replace it unless there is a severe, unexpected problem.  “Why on earth would you get rid of all that beautiful fish waste?”, the aquaponic gardener would query.  The notion of nutrient imbalance is as foreign to an aquaponic gardener as it is to an organic soil gardener.  Just as with healthy soil, a healthy aquaponics system just keeps getting better and better the longer it operates.
7. Plant disease – When I oversaw the plant grow lab at AeroGrow, we were constantly worried about disease.  We sterilized anything that ever came into contact with the plants, their roots or the nutrient solution.  The disease we feared the most was a fungus called pythium, or “root rot”, which is widely considered the scourge of hydroponics.  Fortunately, pythium is almost non-existent in aquaponics.  Researchers in Australia are currently studying why this is so, but my money is on all the bacteria and other living organisms in an aquaponics system.  Logically they would help boost immunity; just as bacteria helps boost our own body’s immunity.  Hydroponics is more of a “boy in the bubble” by comparison.  In addition, the very high oxygen levels in an aquaponics system and the activity of the composting worms to clean up dead plant matter probably both help mitigate disease outbreaks.
8. Temperature – An important part of an effective program to prevent pythium outbreaks in hydroponics is to make sure that the nutrient solution doesn’t get above 70°F.  Warm water is a perfect breeding ground for fungus, so keeping the water temperature below optimal breeding conditions for pythium makes sense.  In aquaponics, however, the primary drivers of temperature are the requirements of the fish.  The most widely used fish in North American aquaponics, after goldfish, are tilapia, and tilapia does best in water that is between 82° and 86°.  The bacterium that drives the system is also happiest in that temperature range.  Fortunately, because pythium is so rare in aquaponics this isn’t an issue. The plants don’t seem to mind either, as a 2005 report by Dr. Nick Savidov at the Crop Diversification Center in Alberta, Canada showed, aquaponics is every bit as effective at growing plants as hydroponics.
9. pH – Optimal pH in a hydroponics system is 5.5 to 6.0.  In aquaponics, pH is another factor that is compromised between the plants, fish and bacteria.  Optimal pH is 6.8 – 7.0, which is again more closely related to what an organic soil gardener would target.
10. EC – Along with pH and water temperature, EC is the other measure that is closely tracked in hydroponics.  EC, or Electrical Conductivity, is a measurement of the salts in the nutrient reservoir, which tells the hydroponic gardener how concentrated the nutrient solution is.  This works because hydroponic nutrients are generally delivered in mineral salt form.  Aquaponic plants, on the other hand, are fed by the organic waste from the fish, which has very little salts.  EC is therefore not a useful measurement for the concentration of nutrients in an aquaponics system.  Aquaponics requires confidence in Mother Nature, rather than a managed system requiring intense control.  Once a system has been constructed using a set of generally accepted “Rules of Thumb” and has been fully cycled (ammonia and nitrite levels have dropped to zero), the only measures an aquaponic gardener monitors are temperature, pH, and nitrates.  If nitrates are low (close to zero), more fish should be added to the system.  If nitrates are high (above 50) more grow beds and/or plants should be added.  It’s as simple as that.
11. Insect control– You’ve probably guessed by now that because aquaponics is an organic system that uses fish, special care needs to be taken with regard to insect control.  Even commonly used organic sprays such as insecticidal soap or neem oil could be harmful if over-sprayed into the fish tank.  On the plus side, however, you can engage your fish in your insect control efforts.  If I have an insect problem on a small plant, such as young peppers or salad greens, I’ll remove them from the grow bed and let them soak in the fish tank for up to an hour.  The bugs eventually loosen their grip on the plant and become fish food.  And if you are lucky, the fish may even accelerate the process by nibbling the bugs directly off your plants.  I also know of people who have even hung Bug Zappers over their fish tank as an additional form of feed for their fish.
12. Eco-system!! – Hydroponics is a system for growing plants under highly optimized conditions. Aquaponics creates a complete eco-system in which various living creatures all interact to create a symbiotic whole.  We use worms, liquid seaweed and beneficial insects as “team members” , each with jobs to perform rather than trying to isolate the plants and nutrients into single, definable, segregated components.  Aquaponics is, above all else, an ecosystem where plants, fish, bacteria, and worms all live together in a beautifully balanced symbiotic relationship.

Words: Sylvia Bernstein, www.theaquaponicsource.com

How do you measure the price of oil?

Many of us here in Internet land have developed an entirely different perspective regarding Middle Eastern events.  It is an understanding not aired by BBC or CNN.  Here are a few pieces to the larger puzzle.

Start by Google searching for John Perkins interview titled “Confessions of an Economic Hit-man”
http://www.brasschecktv.com/page/1036.html
or here:  http://naturalnews.tv/v.asp?v=83B1AF93091799E7CEB88C5C459A530B

Here is an interview with an American muslim minister, who basically says the same thing as former economic hit-man John Perkins has described.  Egypt’s dictator, Mubarak, was already sold out to British/American corporate interests (buying off the next leader won’t be too difficult in their eyes)…..so the West stayed out of the revolution to some degree.  On the other hand, in order to overtake Libyan resources, the corporate Western leaders had to paint Gadhaffi as an enemy of the state, instigate a revolution,  and then justify bringing in the military/airforce.
The interview is titled: Farrakhan warns Obama
http://www.rumormillnews.com/cgi-bin/forum.cgi?read=199710

Chossudovsky on Battle For Libyan Oil:  He says basically the same thing as John Perkins and Farrakhan:
http://www.youtube.com/watch?v=fjMDO9qWeTw&feature=relmfu

Under Gadhaffi a 25 billion dollar man-made river system has been completed.  This is a prize that the British/American/European oligarchy would also love to control.
http://twelfthbough.blogspot.com/2011/03/virtually-unknown-in-west-libyas-water.html

Or here is a present day look at US Middle Eastern foreign policy…through the eyes of Noam Chomsky:
http://www.youtube.com/watch?v=vTGf4X_Qjew&feature=related

As far as Egypt goes, covert control of the Egyptian government and the strategic Suez Canal…despite the appearance of a successful ousting of President Mubarak… will continue by “corporate” British/American/Israeli influence. The common people, both Egyptian Christian and Egyptian Muslim, are beginning to understand that a counter revolution is being instigated by Government Intelligence operations to foment strife and thus justify a military intervention (in other words to quell dissent once and for all).
http://www.wsws.org/articles/2011/mar2011/egyp-m14.shtml

Regarding Libya, this is a completely different revolution which has been fomented by corporate interests to take back control of the Libyan nationalized oil fields. It may look like a drive for democracy and freedom, but how can we call Gadhaffi a terrible leader when he overthrew a corrupt monarchy, modernized the country, won the highest HD (Human Development Index) in Africa, and applied a direct democracy system of government?”  And let’s not forget Gadhaffi reinvested oil profits into the completion of the 25 billion dollar Libyan, man-made river system….thus bringing  farming and agriculture to a level never seen before.
http://www.informationclearinghouse.info/article27727.htm

This was reported leading up to British/American bombing of Libya:
“What we can confirm, is that the entire Libyan rebel movement has been backed by the US and UK for nearly 3o years. We can confirm that the initial calls for a Libyan “Day of Rage” came not from the streets of Benghazi, but from the London based National Conference for Libyan Opposition (NCLO). We can confirm that NCLO leader Ibrahim Sahad was literally sitting in front of the White House giving an interview to the Western media in the opening stages of the Libyan unrest, parroting verbatim the West’s desire to militarily intervene with a no-fly zone.”
http://www.activistpost.com/2011/03/libya-another-war-another-pack-of-lies.html

Here is an article which gives some of the history of the drive by Western corporatists to overtake and privatize Libyan oil fields in the past….and how Gadhaffi took back control and nationalized those oil fields.
http://www.globalresearch.can/index.php?context=va&aid=23414

This was posted three weeks before British/American bombing of Libya started up.
US military advisers were seen in Cyrenaica, Libya weeks prior to the US air strikes:
http://www.debka.com/article/20708/
“What is brewing in Libya is not a “protest” or “demonstration” that has spread across the country, but an attempt to overthrow the government, militarily. We hear already about “rebel soldiers” and see images of men shaking their powerful guns, waving flags from the pre-Gadhaffi period, which appear out of nowhere, en masse. The question is who is behind this force and what is its aim? This question is not being addressed in any way in our media and by our political representatives, and any real information and analysis has been replaced by sentimentalizing about “people power.”

“We are facing soon another illegal war, an invasion to dismantle yet another country in “western” i.e. ”Corporate” interests. Libya is the target nation this time, and already has “military advisers” from U.S., Britain and France, and perhaps also from Israel, on its soil. Although
genuine internal opposition to the regime exists, the Libyan “protesters” we see supported by a Western media frenzy are by and large a military force, now being trained and equipped by foreign powers who are intent on getting hold of Libyan oil to have it “privatized, i.e. to become foreign owned instead as it was nationalized by Gadhaffi 40 years ago. The eastern part of Libya is where the oil fields by and large are.”

I would ask the reader:  “Does instigating war and proceeding to pillage, plunder, and overtake the resources of weaker foreign nations sound like ‘establishing democracy and freedom’ to you?”

Or, are these oil-bearing nations that are purported to be ‘enemies of the state’, in actuality, nothing more than  prizes to be won by the corporate oligarchy who pull the strings of government in the Western world today?

Author: Bill Woollam

Article source: http://www.blissful-wisdom.com/the-battle-for-libyan-oil-fields.html

Wake up North America! Demand proper labeling for your food!

Westwood, CA  – A growing number of consumer activists are staging demonstrations all over the US, with the largest so far at the White House on March 26, 2011.

They demand labeling of genetically modified foods and they’re urging activists around the country to “Rally for the Right to Know” locally. The idea has spread like wildfire with other grassroots rallies already being planned in Colorado, Wisconsin, Indiana, Tennessee, Florida and Oregon to coincide with the rally in Washington DC.

Their demands are simple:

1.We have the right to know and want genetically modified foods labeled.

2.We want factory farmed animal and genetically modified animal products labeled.

3.We want independent, transparent, long-term studies done on the safety of GMOs for animals, plants  and humans.

4.We want the organic industry protected from cross-contamination and law suits to organic farmers.

The FDA currently considers GM foods “substantially equivalent” and therefore doesn’t require labeling.

There is a growing body of evidence that shows:

•        Health risks and environmental dangers,

•        Corporate control of world food and seed supplies,

•        Monopolization through patents,

•        Government lobbying and corporate interest over human interest in all levels of government.

Monsanto owns 90% of all GM seeds and is the leader in GM patents.

Rally Organizer, Trish Wright “We will not stop in our efforts to accomplish our goals. If the FDA won’t tell people, we will. Our freedom of choice is being violated by the FDA not requiring these products to be labeled.”

To date, the majority of commodity crops are genetically engineered. (Soy, corn, canola, cotton). Many deregulated crops such as GE Alfalfa and GE Sugar Beet, being planted in 2011, have the ability to destroy the organic industry.

People are asked to participate in or organize a rally in their area.

MAIN EVENT: Washington, D.C., 1600 Pennsylvania Ave, The White House Sidewalk (The White House Sidewalk is the sidewalk between East and West Executive Avenues on the South side of Pennsylvania Avenue NW) 11am- 3pm

Dates for ALL locations is Saturday March 26, 2011 and include (alphabetically):

Ann Arbor MI, Southeast corner of Catherine Street and N. 4th Avenue, just south of the A2 Farmers Market and Kerrytown Shops 12pm – 3pm
Albuquerque NM, UNM 12pm – 3pm
Atlanta GA, Around Centennial Olympic Park across from the CNN Bldg. 11am – 4pm
Austin TX, at The Capitol 12pm – 3pm
New York City, City Hall steps, between Broadway and Park Row 12pm – 1pm
Colorado Springs CO, Acacia Park 11am – 1:30pm
Hollywood FL, Open Air Bandshell Theatre on Hollywood Beach Boardwalk, 100 Johnson Street and North Ocean Drive/A1A 11am – 2pm
Indianapolis IN, 200 W. Washington Street #220 12pm – 2pm
Kansas City MO, The Plaza Downtown Kansas City 11am – 3pm
LA CA, Los Angeles (Westwood) Federal Bldg, 11000 Wilshire Blvd. 11am – 2pm
Maui HI, in front of Long’s streetside on Ka’ahumanu Ave in Kahului  8am – 11am
Milwaukee WI, Water and Wisconsin 11am – 2pm
Montpelier VT, Outside CITY HALL 11am – 3pm
Nashville TN, Nashville Farmers Market, 900 Rosa Parks Boulevard (Eighth Avenue North) 10am – 1pm
Queen Creek AZ, Safeway Food Store, Queen Creek, Arizona East valley Power and Queen Creek road 12pm – 1pm
Saint Paul MN, Minnesota State Capitol Building – South Mall, 75 Rev Dr. Martin Luther King Jr Blvd 12pm – 2pm
Salem OR, 900 Court St. NE, Salem, Oregon 97301 12pm – 3pm
Seattle WA, Westlake Park 12pm – 2pm
Tampa Bay FL, Downtown 11am – 2pm

Visit: www.facebook.com/rallyfortherighttoknow2011 for more information.

Savvy growers, instead of reaching for the chemicals, look to a cue from Mother Nature in their search for effective biological products that can prevent and treat certain fungal diseases. The most notable are a specific group of naturally occurring bacteria that can be used to prevent and control fungal infections. These bacteria are called Bacillus subtilis and Bacillus pumilis.

So what are these strange Latin names and, most importantly, how can we use these bacteria to help us grow healthier, happier, and more productive plants? We asked Emily Walter from Agraquest, a provider of biological and low-chemical pest management solutions, to give us the lowdown on our friendly neighborhood fungal disease controllers.

Fungal diseases are a common issue among gardeners. And some of the more common diseases that gardeners struggle to control are powdery mildew and botrytis. Mildew can cause significant damage on some plants. It’s a common, but rarely fatal disease which affects many different types of plants. Most gardeners resort to removing infected plants, but often, the best strategy combines control and treatment.

So What Exactly Is Powdery Mildew?

Powdery mildew is a fungal disease that causes patches of white to gray powder on leaves, stems, fruits or flowers of infected plants. These patches can grow to cover the entire surface on both sides of leaves. Different strains of fungi cause the disease on different plants, but they are all similar in appearance. On some types of plants, the mildew will cause leaves to yellow and prematurely drop, or can cause stunted or deformed plant growth, and eventual plant decline. Mildew thrives in cool, damp conditions with poor air circulation. Indoor and greenhouse growers listen up!

What about Botrytis?

The dreaded botrytis or ‘gray mold’ is a fungal disease that infects many annual and perennial plants. There are several species of the fungus botrytis which can cause significant plant damage; the most common is Botrytis cinerea. Botrytis infections are favored by cool and humid conditions, and are most common during rainy spring and summer weather when temperatures hover around 60°F (15°C). Gray mold can take hold and spread rapidly if your indoor garden sustains long periods of high relative humidity, or outdoors when rainy, drizzly weather continues over several days. Botrytis can affect leaves, stems, crowns, flowers, flower buds, seeds, seedlings, bulbs and just about any other part of a plant with the exception of the roots.

[Left] Scanning Electron Micrograph (SEM) showing a healthy fungal spore on the surface of a leaf. [Rigth] SEM showing a destroyed fungal spore after foliar application of the beneficial bacteria Bacillus subtilis strain QST713. The Bacillus bacteria are the small rod shaped organisms around the top of the picture.

Steps Towards Prevention

Good cultural practices can help prevent and control the spread of fungal issues. The first and most important step toward prevention is to select healthy plants in the first place; these will be more likely to resist fungal attacks.

Plant breeders often select specimens that show resistance to common fungal diseases. This has lead to many different varieties of fruits, flowers and vegetables that have an ever increasing resistance to fungal diseases.

If you have no choice but to use susceptible types of plants outdoors, make sure they are in full sun and will receive a minimum of six hours of sun each day. Isn’t UV radiation great? Indoors, however tempting as it may be, never overcrowd your plants! Allow plenty of fresh air to circulate around your plants, this will discourage disease. When growing indoors, it’s absolutely crucial to focus on maintaining adequate ventilation.

Carefully remove infected fruits, flowers or mildew covered leaves. It is best not to do any removal of diseased plant when they are wet with dew or rain since this could spread fungal spores during conditions which favor infections. Likewise, avoid overhead watering or misting plants especially if fungal disease has been troublesome in the past.

If you encounter a heavily infected leaf, fruit, or flower and are worried about spreading spores around your garden, carefully cover the moldy item with a plastic bag before attempting removal. This way, spores end up in the bag rather than all over your garden!

Always throw away infect plant debris instead of placing it on the compost pile. Spores can overwinter on diseased plant material. New spores can be carried by the wind, so destroying the infected plant parts are essential to help stop the spread of plant disease pathogens.
In an effort to keep fungal diseases at bay, it’s good general practice to keep your indoor garden as clean and tidy as possible. Avoid leaving yellowing or dead leaves hanging from plants, and never keep piles old leaves and trash bags in or near you indoor garden.

Fungal Control Options

There are many chemical controls on the market but they do have some drawbacks. Some controls have temperature and timing restrictions impacting applications or harvest of your crops. Some diseases become resistant to certain chemicals over time as well. If you are using IPM (Integrated Pest Management) in the garden, you will want to preserve beneficial insects, which can be impacted by some chemical controls. Additionally, not all chemical fungicide treatments are acceptable for consumable plants. Some chemicals can only be used when the plant is dormant or cannot be used when the plant is close to harvest time. Carefully read fungicide labels to discover which is right for your particular need.

Beneficial Bacteria – Bacillus as a Fungicide

Another way to control plant diseases is to use products based on beneficial bacterial, specifically Bacillis subtilis or Bacillis pumilis. Both of these bacteria are common found in soil and have been used in horticulture and agriculture for many years.

Bacillus subtilis are naturally-occurring soil borne bacteria, fist characterized in 1835. Over the years varying strains of B. subtilis have been widely used for industrial processes (like detergents or waste water treatments). Bacillus subtilis strains produce extremely photo – and temperature – stable bacterial spores, making them ideal for gardening applications. B. subtilis is also Generally Regarded As Safe (GRAS) by the EPA.

Some strains of Bacillus subtilis are active ingredients in highly effective, broad-spectrum contact fungicides and bactericides. The Bacillus subtilis in these products produce lipopeptides, which are anti-fungal metabolites and anti-bacterial compounds. These lipopeptide compounds that Bacillus subtilis produce kill fungal spores and they are highly stable, resistant to elevated temp and pH extremes.

Lipopeptides are small peptide rings with a lipid (fat) attached. One end of the lipopeptide is negatively charged, the other is “greasy”. A fungal cell membrane can be compared to a sandwich – with hydrophilic (water-loving) surface and a lipophilic (fat-liking) core. The lipopeptides insert into those fungal cell membranes and create small holes in a fungal spore. As, they puncture the cell membrane, cell contents leak out and the fungus is killed.

Some B. subtilis products rely on prolonged wet periods on the leaf surface for the bacteria to become active, produce lipopeptides and then out-compete the fungal spores for leaf surface area. This is not the case with all products – the specific Bacillus subtilis strain QST 713 is unique in that it does not require time to activate, since the bacteria have already done their job producing the lipopeptide metabolites during production. Information about the active ingredient and how it works should be found on the container label of the product you decide to use.

Some Bacillus subtilis strains also illicit plant health and growth promotion in treated plants.  When applied, these strains can trigger the plants’ internal defenses and physiological responses. The effect is systemic – responses are triggered throughout the plant even when a small area is treated.

Products based on Bacillus subtilis are widely used by gardeners and commercial growers since they offer broad spectrum control, have little potential for resistance, have no temperature or time restrictions for application, are non-toxic to beneficial insects (including honey bees) and can be used up to and including the day of harvest. Some products based on B. subtilis are approved for organic production. Since Bacillus subtilis are non-toxic to beneficial insects you can use predatory insects for pest control and beneficial bacteria for disease prevention.

Products based on Bacillus pumilis strains are useful for gardeners for similar reasons. While products based on B. subtilis destroy fungal cell membranes, products based on B. pumilis instead focus on fungal cell walls. The compounds produced by B. pumilis compete with fungal diseases for amino sugars needed to build cell walls, effectively making it impossible for fungal cells to build and grow. B. pumilis does not control bacterial diseases. Instead, it is strongest against rust and mildews. B. pumilis is typically used by a gardener when targeting a specific type of fungal infection that is better controlled by this specific bacteria over the more broad spectrum approach of B. subtilis. Also, B. pumilis strains, like those of B. subtilis, have been shown to trigger plant’s natural defenses.

Both of these beneficial bacteria are best used when applied to plants in a preventative disease control program or at the very first sign of disease. Beneficial bacteria can be used in conjunction with other gardening products. Bacillus subtilis and Bacillus pumilis can be applied every seven days up to the day of harvest if needed. Beneficial bacteria can be applied more often if needed such as every four days during heavy disease pressure. When applying either type of bacteria as a foliar spray one should spay the leaves, shoots and new growth until the plant is dripping wet. Run-off spray will not affect beneficial soil fungi like mycorrhiza. When a gardener is planning to use beneficial bacteria or an organic gardening product to prevent or control fungal and bacterial diseases they should scout the garden often to look for any signs of disease. Strains of these beneficial bacterial can also be found in some compost teas since it can promote plant health and growth promotion.

Practical Tips:

When Do I Use It?

Most Bacillus subtilis or pumilus products can be sprayed as a preventative measure or be used as a curative control. They can be applied early on in the plant’s lifecycle on established cuttings or seedlings, and as late as the day of harvest on mature plants. Most growers freak out at the mere idea of spraying mature flowers or ripe fruit, but these natural Bacillus products are safe for human consumption and actively kill fungal growth.

Spray timing

When using outdoors, it’s best to spray in early morning or late afternoon when light intensity is not too strong. Sunlight contains a natural broad spectrum microbe inhibitor, Ultra Violet light. If applied during strong sunlight, the UV may prevent some Bacillus products from working effectively.
When spraying indoors, it’s also good practice to spray in low light. This may mean raising your grow lights up high before spraying, or spray just before the lights come on or go off.

Spraying the plants

The best fungal control is achieved when the plants are thoroughly wet, and run-off spray is dripping from the leaves. It’s a good idea to use a wetting agent for increased coverage. Avoid adding other foliar additives or nutrients as this may interact negatively with the beneficial bacteria. Spray the underside and top side of the leaves as well as any exposed stems. Sprays can be repeated every 3-4 days if plants are heavily infected, or every 7-10 days as a preventative.

What products contain Bacillus subtilis or pumilus for foliar fungal disease control?

Most good quality compost teas will contain some Bacillus subtilis and pumilus strains, so regular spraying can help with disease prevention. For a more targeted fungal control, the patented Bacillus subtilis strain QST 713 can be found in the commercial product ‘Serenade.’

Other Bacillus subtilis strains are used for root disease control, these include strains GB 03 found in the microbial inoculant ‘Companion’ and strain MBI 600 found pre-mixed into the substrate ‘Pro Mix MX with BioFungicide’.

Until the 1950s, most plant pots you could buy at your local gardening store were made of terracotta clay—then along came plastic—a substantially cheaper more durable and lightweight product. However, not all gardeners were convinced, and for good reason. Unglazed terracotta pots insulate the root zone from hot and cold temperatures and, because clay is porous, the pots are able to ‘breath’—albeit with only a small amount of air that’s able to pass through the clay pot, many old school gardeners claim this as the main reason they can produce better plant growth than with plastic pots.

It’s pretty obvious why plastic pots with solid sides are now the norm; they’re cheap, more practical and durable than clay and, of course, featherweight in comparison. Also, although they restrict air, there’s no arguing that they work, and in most cases they work pretty well. However, as we can see, plastic pots are far from perfect which means, of course, that there’s room for improvement. It turns out that, with a few design tweaks, many of the fundamental problems associated with standard plastic pots can be reduced, if not eliminated.

So what’s the problem with standard containers?

Remember, Mother Nature didn’t create plant pots. Humans did! In normal plastic plant pots, roots grow until they hit the inner edge—invariably the roots start circling around the pot. Now, in this case, being at the fringe of the action isn’t such a good thing. Those plastic pots can get fairly warm, especially under grow lights or if exposed to direct sunlight. Remember, roots like cool and moist conditions. Roots that are circling around a pot are more susceptible to the negative effects of excess heat (because there’s no media to provide insulation,) drought (the edge of your growing media tends to dry out first) and disease (unhealthy roots that are suffering in these conditions are more prone to disease.) One thing’s for sure—these outer roots are certainly not taking advantage of all the water, nutrients and beneficial biology that may be present within the growing media.

So how do you get the roots to concentrate their growth within the growing media? The answer actually lies in providing a consistent restrictive environment for root growth at the pots edges. This can be done in a few ways, but the most common techniques are air pruning and root trapping. Understand how these techniques work, and you’ll understand how plant pot design can be vastly improved!

Air Pruning

Essentially air pruning is a physical technique that inhibits root growth from extending beyond its growing media, or circling around its container, by exposing the root tips to relatively dry air and stopping their growth. As these roots now have nowhere else to grow, it stimulates further growth of secondary roots that branch out from them within the growing media. These secondary roots will spread throughout the pot until they reach the sides and bottom and get air pruned again, stimulating more root growth and more root hairs. More root hairs = more root tips. More root tips = more water and nutrient uptake. The overall effect of this growth and pruning cycle is the establishment of a well-developed root system in a relatively short space of time throughout the entirety of the growing media.

Root Trapping

This may be a new concept to some growers; it involves a more mechanical approach in comparison to air pruning. With root trapping the root tips become physically trapped in the pot material, which is made from coarse felt or other fabric materials. When a root tip grows in to the material at the edge of the pot it becomes trapped, preventing horizontal and vertical growth around the edge of the pot. I know, I know, words like “trapped” and “preventing” don’t sound good. But, because the root tip is unable to grow any further at the pots edge, it’s forced to branch and grow secondary roots within the growing media. This all adds up to a more effective root zone.

Parallels with the above techniques can be made with the plant growth we observe above the ground. Most gardeners know that pruning a lateral branch or terminal (uppermost growth tip) can create a more productive plant. You cut and remove the tip to encourage lateral branching and in this way create a fuller, bushy plant with more branches. The same can be done for the root structure, air pruning and root trapping is all about encouraging lateral root branching.

Clever Containers in Action

This illustration shows how air pruning works in a breathable fabric pot.

1 – Shortly after the cutting/seedling is planted into the pot, primary roots grow towards the sides and bottom.

2 – The fabric sides of the pot allow to breath, allowing air to get to the growing media. This air is drier than the root zone environment within the pot, so as the roots start to grow out of the growing media the relatively dry air prevents further growth, and stimulates secondary roots to branch out within the pot.

3 – The root branching and pruning cycle keeps occurring, creating a plant with an abundance of healthy well branched roots within the growing media.

Key Benefits

• Stronger, healthier starts.
• Elimination of root circling in pots.
• Less growing media needed.
• Decreased risk of transplant shock.
• Improved overall root structure (more root tips.)
• Better use of water and nutrients.
• Promotes the activity of beneficial biology.
• Quicker growing times.
• Fewer transplants required.

There are many containers in grow stores and garden centers that have adopted air pruning, root trapping or a combination of both into their designs to help improve results. These can be classified to two general categories, fabric and plastic containers. Here’s a list of clever containers with and brief description of how they work.

Fabric Containers

Generally, fabric containers are relatively inexpensive, can be used with a variety of growing media, and are suitable for hydroponics systems (ebb & flow and drip irrigation), as well as basic hand-watered application.

High Caliper – Smart Pot

Made from black custom non-woven, polypropylene material, Smart Pots use a combination of root trapping and air pruning; the root tips grow into the fuzzy fabric of the pot and become trapped, the fabric is breathable causing the root tip to become air pruned. The black fabric helps to warm the growing media (outdoors in the early season) and also helps heat escape via the breathable material and evaporative cooling action in summer. Smart Pots are highly durable—see if you can rip one—and can be re-used over several grows.

Sizes Available: 1 2 3 5 7 10 15 20 25 30 45 65 100 200 300 400 (Gallon)

10 Gallon MSRP: £5.95

Aurora innovations – Root Pots

Made from 100% recycled materials, the Root Pots certainly have an authentic recycled look to them. The breathable fabric allows air pruning of the roots to occur, preventing root circling. This fabric pot helps with thermal insulation during cold temperatures, but also allows evaporative cooling during hot conditions. Root Pots are re-useable for between three and five years, but are also bio-degradable.

Sizes Available: 1 2 3 5 7 10 15 20 30 45 65 100 150 200 250 300 400 500 600 (Gallon)

5 Gallon MSRP: £4.00

RootMaker – RootTrapper II

These containers are made using thick felt, and as the name suggests, utilize root trapping to encourage root branching. The felt is lined with an outer white plastic layer that is designed to keep the internal temperature of the container cool as well as prevent evaporative moisture loss. The white outer coating also reduces the risk of roots completely dying on sides that are exposed to direct sunshine, which can happen with black containers. Water use can be reduced because there are no large drain holes at the bottom or evaporative sides. The base is made from a slightly different material that allows for adequate drainage. They are reusable, but trapped root tips will remain in the fabric.

Sizes Available: 1 2 3 5 7 10 15 30 45 60 100 150 400 500 (Gallon)

5 Gallon MSRP: £7.25

Square Root Aeration Containers

Utilizing a slightly different approach, theses containers have a space saving square design. The soft breathable fabric provides adequate drainage at the base and aeration through the sides, allowing air pruning to occur. The black fabric helps to keep the substrate warmer during cold temperatures and reduces substrate temperatures during high temperatures.

Sizes Available: ½ 1 3 5 7 10 20 30 100 (Gallon)

5 Gallon MSRP: £5.95

Plastic Containers

These high tech plastic containers are more expensive than the fabric, but are more durable and can be reused time and time again. Like the fabric pots, they are suitable for use with many types of growing media and indoor and outdoor gardening applications.

Air-Pots

Air-Pots have a somewhat unusual design, the sides of the pot are made up of inward and outward pointing cones, much like an egg box, and the bottom is plastic mesh. The inward pointing cones are solid whereas the outward pointing cones are open ended. The purpose of these cones is to firstly deflect the roots and stop them from circling within the pot, but more importantly, to direct the roots towards the outward pointing cones and allow the root tips some direct exposure to air, causing air pruning.

Sizes Available: 0.3, 0.8, 1.2, 1.5, 2, 2.4, 3.4, 4.3, 5.2, 6.5, 8, 10, 12, 45(gallon)

5 Gallon MSRP: £10.00

RootMaker II – Propagation Containers

These plastic propagation cell trays have either 32 or 60 cells. Within each cell there are tree tiers and in the corner and sides of these tiers are small holes. These holes allow air pruning to occur during the initial propagation stages, preventing root circling.

Available Sizes: 32 Cell Tray & 60 Cell Tray

RootMaker II – Injection Molded Containers

Larger versions of the propagation cells, these plastic pots have a tiered design with multiple small holes on each tier to allow air pruning to occur and stop root circling around the pots sides. These are available in square and round variations in the 1 gallon size, but are only available with a round design for the 3 and 5 gallon containers. The Root Makers are made from largely recycled plastic.

Sizes Available: 1 3 5 (gallon)

5 Gallon MSRP: £8.95

RootBuilder II

These pots have a similar design to Air-Pots. The walls are assembled around a bottom disk to create either a 3 or 5 gallon container. The walls of the containers have outwardly projecting funnels with a hole at the tip. Root growth is directed toward the holes at the end of these funnels, where the roots get air-pruned.  The shape of the containers is designed to direct the roots to the air holes but also creates shade keeping containers and root zone cooler which will also help to improve plant growth. The Root builder II containers also have solid root directing bottoms which direct the roots towards the edges of the pots. .

Sizes Available: 1 2 3 5 7 (gallon)

5 Gallon MSRP: £12.95

Clever Containers – Grower Feedback and Tips

Quick Establishment

The quickest way to see the benefits of air pruning containers is to use them in the early stages of propagation and vegetative growth when plants are establishing their root systems. Growers using air pruning containers observe quicker establishment into new pots (whether these are larger sized air pruning containers or larger normal pots,) improved root growth and overall plant vigor.

Reducing the Chore of Transplanting

Whilst it’s important to match pot size to plant size, transplanting can be a chore! One of the great benefits most growers can achieve with root pruning containers is the reduced amount of necessary transplants, particularly when growing with potting soil. Many commercial nurseries have experienced time and labor saving benefit for years, and now many indoor growers are taking advantage of some of these same benefits.

When growing in standard pots and potting soil, most growers would go through three to five (or in many cases more) potting stages, for example; propagation cube > 0.3 gal > 1 gal > 3 gal > 5 gal.

With root pruning containers this can be significantly reduced, with most growers only having to use two potting stages, for example; propagation cube > 0.5 gal > 3 gal.

Smaller volume

Plants grown in root pruning containers have shown the ability to cope with being containerized for longer, in comparison to plants of a similar age in the same volume standard pots. This means you could potentially step down the size of your containers without the risk of the plant becoming root bound, saving floor space and reducing the need for so much growing media. However, if you do reduce the volume of your pot, an increase in water requirements should be expected.

Water Consumption

Of the majority of growers we spoke to, all found the growing media to dry slightly quicker than usual. Most said this was not as significant as they thought it would be, with the average reporting a 10-20% faster drying time.

When growing in standard pots if the growing media is allowed dry more than usual, it can become difficult to re-saturate and water can run straight down the sides. The same goes for Air-Pots and RootBuilders, but instead of water running down the sides, it will run out the outward pointing cones. To get around this instant run-off when the growing media becomes too dry, you need to re-saturate with small amounts, and water slowly.

Tip: Consider installing a drip irrigation system to water your plants. These are an excellent way to deliver water slowly in order to achieve an even and steady re-saturation.

Moving Pots

One of the advantages of growing in any pots is their ability to be moved around the garden to suit your needs. Obviously, this is still possible with all root pruning containers but the fabric pots need some extra care. Lifting any fabric pot using the rim while they are wet and heavy will cause the sides to stretch, this often causes the root tips to rip, which can be felt as the pot is lifted. So, while lifting or moving fabric pots its a good idea to support the bottom.

Filling Technique

A few growers we spoke to using Air-Pots and RootBuilders reported that they had to spend more time during the potting up stages adding the growing media to the pot. The growing media in these pots needs to be slightly more compacted than in normal pots, and frequent tapping down of the during filling is absolutely crucial to ensure all that growing media settles in all of the outward pointing cones/funnels. Some growers tip the pot on its side whilst filling with growth media to ensure that it fills every nook and cranny—very important!

Growing Media

Most growers using root pruning containers are growing with potting soil and hand watering. However, other growers are choosing to use clever containers for automated growing applications, particularly drip irrigation systems. Growing media that is more prone to drying out faster, like rockwool and clay pebbles are much more suited to automated irrigations.

Nearly all types of growing media are suitable for use in root pruning containers. One minor issue we heard about is from growers using clay pebbles in Air-Pots in automated drip systems. These growers are happy with the improved growth of their plants, but found that some of the outward pointing cones can become blocked with pebbles when filling. To get around this they found that taping the sides of the pot and poking the obviously blocked holes sorted things out.

General Air-Pruning Tips

Air pruning can be applied to any stage of plant growth, however, most growers avoid air pruning roots of newly rooted cuttings or seedling grown in small propagation cubes or plugs. Cuttings and seedlings are quite a tender stage of a plants life, so a sensible approach would be to wait until the next propagation stage to begin air-pruning, where plants are grown on in larger rockwool blocks or low volume root pruning containers.

Season variations in climate should be taken into consideration when choosing the growing media or potting soil mix for short cycle plants in air-pruning pots to help you deal with over- and under-watering issues. During winter when average temperatures are lower, the growing media can be lightened up with less absorbent media like perlite, clay pebbles or coarse coco chips. During summer when water requirements increase, the mix can be made heavier by reducing the previously mentioned amendments. These seasonal variations will help you achieve the maximum potential when using air-pruning techniques.

The relative humidity of the air in the growing environment will determine the severity of the air-pruning. In humid conditions, roots may stop growing at the surface of the media and produce secondary roots with the media, but the tips may not completely dehydrate. Although we do want the roots to stop growing in response to contact with drier air, we don’t want to stress our plants by trying to grow them in an environment with low humidity (below 50%). Experimenting with different relative humidity for your species and variety of plants and growing media is highly recommended. Try varying the humidity between 55-80% to see what effect is has on your air-pruning.

Got an air-pruning experience you want to share? Email us at: rant@urbangardenmagazine.com

However, it turns out that lots of indoor growers (especially those growing short-cycle plants) choose a different route. In short, they reuse their growing media! And before you think this is just the preserve of penny-pinching hippies, it turns out that it’s not all about saving a few dollars – it could increase your yields too!

Aha, there we go … increased yields … that’s all we needed to say wasn’t it?

What is Coco Coir?

Grab some coco coir out of the bag and, at first glance, it looks like soil. But it isn’t.

It’s actually a bi-product comprised of the fibrous husk of … you guessed it … coconuts. From this husk three main horticultural coir products can be acquired; coir chips, coir fiber or coir pith/dust. The latter dust retains water well while the fibers and chips help with air space and drainage. Many mixes and grades of coco coir are on sale in grow stores, variations of coir media exist to suit the irrigation strategy or hydroponic system of the grower.

Coco coir dust is the major constituent of most coir products and is composed of millions of capillary micro-sponges that absorb and hold up to nine times its own weight in water. It has a natural pH of around 5.7 to 6.5, plus a good cation exchange capacity or ‘CEC’ (how easily it gives up nutrients to the plant’s roots), making it ideal for hydroponic cultivation.

Plants grown in coir can develop large roots, stems and blooms. Unlike regular potting soil, which can easily become compacted, coco coir has plenty of air spaces for plant roots, giving rise to a healthy aerobic rhizosphere—essential for favorable nutrient and water uptake. Coco coir has a naturally high lignin content which encourages favorable micro-organisms around the roots and discourages decomposition, making it an ideal growing media for reuse.

Buffered and Non-Buffered Coco Coir

Coco coir in its natural state contains a lot of sodium ions, which cling to the coco coir like a magnet on the cation exchange sites, and is also rich in potassium. In order to make coco coir suitable for use as a growing media it must be pretreated or ‘buffered’ before use. The buffering process involves pre-soaking the coir for 12-24 hours with a buffering solution high in calcium; this displaces the sodium and balances the naturally occurring potassium. After the soaking period the media is washed with water, this removes the displaced sodium, leaving the calcium in the coir. This buffering process prevents unwanted draw down or ‘lockout’ of calcium and magnesium, and avoids sodium toxicity issues. Luckily for us home growers, most pre-packaged coir products in grow stores are buffered at the point of manufacture and will be ready to use, however; it doesn’t hurt to check the packaging before use!

In the early days when coir was first introduced into the hydroponic market, the pretreatment process was overlooked. Young non-composted and non-buffered coir products were sold without instruction and many growers suffered major nutrient issues and lost crops. Although these days are behind us, this initial introduction to coir tarnished its reputation as a quality growing media for many years.

It’s worth pointing out that not all growing media is suitable for re-use. So first, here’s what you should factor into your evaluation:

1.            Structure stability

2.            Nutrient retention

3.            Practicality

Now let’s look at coco coir in these three terms. Coco coir, as a soilless growing media, is usually a mix dust and fiber, but some mixes can also contain larger coir chips.

1.            Structure

Good quality, buffered coco coir, will keep most of its attributes throughout its useable life. However, the structure of steam sterilized coco coir will degrade faster than its un-cooked counterpart. For the purpose of this discussion we will assume that the coco coir is soft water washed, unpasteurized and chemically buffered; this represents the majority of coir available to hydroponic growers. Coco coir’s miniature “sponges” will become misshaped and smaller towards the end of their life, resulting less air space between particles and an overall higher water holding capacity. Even though this is a slow process some adaptation in watering may be required. After using coir for short cycle crops, amendments with 10-20% fresh coir or perlite may be required when being reused for the 3^rd and 4^th cycle. Care must be taken with the irrigation regime and nutrient program to insure coir has an adequate life span. Principally, good watering practices and monitoring run-off EC (keeping it within optimal range) will permit seamless re-use.

2.            Nutrient Retention

Buffered coco remains relatively chemically stable throughout its life, particularly when used with a coco coir specific nutrient; formulated to complement the unique cation exchange properties of the media. Coco coir can be easily EC controlled by monitoring the EC of the run-off.  Watering with a low EC nutrient solution will reduce its EC without rinsing off the famous buffer.  If plain water is used in excess, the coir may be rendered chemically imbalanced and may create problems in subsequent culture.  On the other hand, coir reacts quickly to low EC rinse and thus it requires much less run-off than peat mixes.  Unpasteurized coco coir is also a very hospitable substrate for its natural beneficial fungal inhabitant trichoderma, making it a very disease resistant and root protective growing medium.

3.            Practicality

The widely held belief in the gardening industry is that coir may be used for up to one year, or three to four crops for short cycle plants, without any compromise on crop quality. Others growers claim that they have successfully re-used coir for years. The amount of times that coir cam be utilized ultimatly depends on the initial quality of the coir and the steps taken to prepare the media between each use. The first thing that must be done is the removal of dead cellulose e.g. root matter left over from previous plants. To remove the large roots the coco coir can be broken up, passed through a ¼ inch soil sieve and larger roots can be discarded. Enzyme products (e.g. CANNAZym, Hygrozyme / Grozyme, or Multi Zen) when applied in the latter stages of the crops cycle will do a sufficient job of cleaning up the residual decaying material. It is not advisable to have lots of dead roots remaining in the media because they can contribute to an anaerobic (low oxygen) environment. Once the root material has been disposed of, coco coir should be flushed with water or a low EC nutrient solution to bring the nutrient levels back down to an acceptable range.

Preparations and Considerations

Once the media is ‘clean’, the addition of beneficial microbes is highly recommended. Coco is an ideal environment for beneficial bacteria and fungi, in particular, the introduction of trichoderma and mycorrhizal fungi will help maintain good growth and disease resistance. Inoculating coco coir with beneficial fungi also has great benefits when re-using the media, as fungal colonies improve with time.

The key component to how long coco may be reused all has to do with how far it has decomposed naturally. Coir does decompose when wet over a period of time. Unfortunately, fungus gnats thrive in the presence of decaying organic matter, and coir is a perfect environment for them. Making sure that all the dead roots are removed, the coir isn’t over-watered and a using dry mulch of coir chips or clay pebbles on the surface of the media will all help to prevent fungus gnats. Utilizing certain “drench” products definitely controls gnat populations, along with sticky traps and the natural predator Hypoaspis miles.

IMPORTANT: You should not reuse coco coir if you encountered any pathogenic or root insect issues during a cycle.

Conclusion

Coco can often produce better results on the second or third use; this can be due to a number of factors.  Coir can get better after the first successful crop because there will be a stable balance of ions on the cation exchange sites, leading to subsequent crops starting life with an improved root environment. Another reason growers often see improved results is due to the beneficial microbes present in media, these take time to develop and flourish; particularly mycorrhizae and Trichoderma, which can reach much higher potentials for growth improvement over longer time frames. However, an alternate explanation might be that the original coir coco was too young in decomposition first time round and may have degraded in a favorable way after reuse.

Crops that went through a flush period at the end of a crop cycle fair better because salt levels are reduced during the leaching process. Salts are constantly given off by coco coir as it decomposes, mainly potassium and sodium. Since the medium decomposes throughout its life, this process is continuous. Washing the media out well before planting should mitigate any negative effects. Reusing coir that has not been flushed often results in nutrient imbalance and over-fertilization issues. However, it should be noted that the presence of some of these ions is what buffers the coco. If you lose this buffer you return to calcium and magnesium lockout and pH issues of untreated coco.

In summary, coco has great potential as a reusable media, but to what extent is dependent on the motivation of the gardener. Should a gardener decide that the preceding is too much trouble, coco may always be reused as a soil improver for outdoor plants as well as a ‘brown’ high carbon addition to compost piles.

About the authors:
Robert Hunt is the owner of Rocky Mountain Hydroponics in Golden and Edwards, CO and of Evergreen Garden Center in Portland, ME. Zac Ricciardi is the products trainer for Rocky Mountain Hydroponics in CO.

Everyone’s talking about a revolution. Some even say it’s being broadcast on Al Jazeera. But didn’t any of you listen to a word Mr. Warhol said? The real revolution occurs in a place where cameras cannot film. Can you think where? There really is no need to bother signing a petition on Facebook or writing to your congressman. We have been trained for millennia to defer our responsibility to others. And look where that’s got us!

Nobody is in control—not the government, the Federal Reserve, the Catholic church, the Freemasons, the Jews, the Nazis or the Neocons—not even the shape-shifting grays and their international banking cartel. These are merely “epistemological cartoons” as my friend Terence once said. In other words, it’s all in your head! Protesting, blogging, arguing back and forth or even hurling bricks through Starbucks’ window just affirms your ardent belief in these fictions. Get back to your gardens.

It’s not going to be easy. Humans have been bred, just like modern vegetables, to such an extent that life outside the garden gates of the industrial food system seems impractical, even backward. It’s easier for us to play the disempowered fool and ignore the atrocious wars that feed our parasitism than to break through our conditioning and start taking responsibility for ourselves.

So, if you’re ready to get your hands soiled, read on. You’d better be! Let us know what you think of the new layout and super geeky articles within! Here’s hoping that this incredibly dirty issue of Urban Garden provides some inspiration for a true revolution!

Peace,

Everest

“We must cultivate our own garden. When man was put in the Garden of Eden he was put there so that he should work, which proves that man was not born to rest.”

~ Voltaire

If you really want to learn about organic growing, why not pick the brains of world-renowned experts—if you get the chance? Turns out, you’re in luck! Recently we were fortunate enough to be able to eavesdrop on some highly enlightening Q&A sessions between two Ph.D. wielding friends of ours, Drs. Carole Ann Rollins and Elaine Ingham. The insights revealed will blow your mind and can well be put to use in your garden today! Make sure you check this out!

CAROLE: Can you explain in simple terms how a plant goes about obtaining the different nutrients it requires from the soil in a regular outdoor setting?

ELAINE: In different parts of the growing cycle the plant needs different nutrients, so the plants sends out food to certain microbes that it “knows” (a process of selection has happened over the course of millennia) will result in the nutrients it needs being made available at that particular time of its growing cycle. The plant feeds the organisms it needs, changing pH by altering fungal or bacterial foods to grow bacteria or fungi, thus producing the pH it needs to have more or less of this or that nutrient solubilized by bacteria or fungi. The increased bacteria and fungal populations then attract protozoa, nematodes, microarthropods and/or earthworms to eat those bacteria and fungi. So, the right nutrients, in the right amounts are released in the right place, i.e., right around the roots. The plant is in control of its own nutrient requirements, and it knows, way better than people do, what it needs.

CAROLE: Okay, let’s say the plant needs more nitrate, which requires alkaline conditions to be made. What will the plant do in order to get more nitrate around its roots?

ELAINE: The plant puts out the exudates (sugars) that will encourage the bacteria that produce alkaline byproducts in order to make sure the pH shifts to alkaline. The plant then feeds the particular foods to stimulate the nitrifying bacteria, who make the enzymes to take the hydrogen ions from the ammonium molecule, so nitrate is made in a two step process.

CAROLE: So you’re saying that the microbiology around the roots actually relies on food from the plant?

ELAINE: Pretty much all organisms around the roots rely on the plant for food in one way or another. Additional foods that help supplement what the plant directly provides is contained in general organic matter.

CAROLE: Why do we apply compost or compost tea then?

ELAINE: To supply the organisms that are missing from your soil or plant surfaces, and to add additional foods so those organisms have something to eat when the plant isn’t specifically feeding them.

CAROLE: So is it a good idea to feed the organisms in the compost before you spread the compost or make it into compost tea?

ELAINE: You would want to feed the compost so the balance you need between the organisms is right. Part of the trick is to look at what is currently in your soil, and then make sure that the compost and/or tea contains the missing organisms. The compost doesn’t need to supply all the organisms. It just needs to supply the missing ones. Diversity in compost is probably more important than getting the balance in the compost adjusted perfectly for your plants. The fine adjustments of balance will happen in your soil. Just make sure the plants you are growing are the ones you want, and not plants that grow because the nutrient concentrations are all out of whack, and set for weed growth, and not crop growth.

The plant will fine-tune balance of species, or function, if it has the organisms that do the various things it needs. Thus, diversity is a really important thing for growers to focus on and maintain, along with keeping the soil habitat aerobic. It is easier to increase the organisms missing in your soil by adding compost than to try to add the specific foods or mineral nutrients to the soil and hope they get to where you need them to be to help your plant. REMEMBER: Organic matter is plant material that has partly decomposed. All nutrients except carbon are therefore concentrated as compared to the original plant material, as long as the process remained aerobic. Properly made compost should therefore contain all the nutrients a plant needs, in higher concentrations than the plant actually needs. The limitation in most soils is the lack of organisms to do the work of cycling the nutrients from plant not-available forms to plant available forms.

CAROLE: Is it the case that soils growing plants that are diseased, or that show signs of lack of nutrition, just need a boost with the balance of organisms? Would it be safe to say that organic fertilizer is not needed in soils if you’re applying good quality compost before planting?

ELAINE: You should add any organism group that is lacking in diversity or balance, or is below the minimum thresholds to produce adequate yields. How many bacterial or fungal species, or foods, or protozoa, or beneficial nematodes are needed? First, assess these groups in your soil to determine what is lacking. (For more information on identifying beneficial microbiology see Urban Garden Magazine Issue 6, pgs. 62-65) Check the balance of bacteria and fungi in the soil, and then in the compost. Enhance your compost with any group that is too low in biomass, activity or diversity. Then apply that compost, and check, about two weeks after application, that the life in the soil is changing in a beneficial direction.

Compost is classified by some people as an organic fertilizer. But possibly we need to use that term fertilizer with a degree of care. To many people, the term fertilizer implies inorganic, salt forms of nutrients. To others, fertilizer means anything that benefits plant growth. The question being asked might actually be whether any other form of amendment is needed if the compost being used is good compost and provides the nutrients and biology the soil needs. The answer would be, no other amendment would be needed, other than the plant residues that will grow.

But, if the compost is lacking something, then other amendments would be needed. Those other materials, like microbial inoculants, humic acids, kelp, green sand, etc might be needed if the compost isn’t really up to par.

CAROLE: So if we add food to the compost to get more organisms growing, what exactly is compost?

ELAINE: Compost is the mix of plant materials, the more kinds the better because then more of the foods needed to grow a huge diversity of microbes will be present, and the organisms that decompose that plant material. Where do the organisms come from in compost? They were on the surfaces of the plant material the pile was made from, so again, the more types of plant materials added, to greater the diversity of organisms in the pile.

CAROLE: Would you class kelp as an organic fertilizer?

ELAINE: Kelp is plant material from the sea, that has been dried and ground up. Kelp has not been through the composting process so it cannot be labeled compost in any way, but it contains many plant nutrients, whatever was in the kelp as it was growing. Thus it is an organic fertilizer as long as we do not limit the definition of fertilizer to inorganic salt forms. .

CAROLE: How do we make the nutrients in kelp available to the plant?

ELAINE: Bacteria and fungi would need to grow on the plant material (i.e., decomposition must occur), the bacteria and fungi have to be eaten by protozoa, nematodes and microarthropods in order to release the nutrients in a plant usable form. That’s what is going on in a composting process. Kelp is plant material used because it contains high levels of certain nutrients.

CAROLE: Do bacteria or fungi convert or release any nutrients directly without being eaten by protozoa or nematodes?

ELAINE: Care must be taken with the word, “release”. What is really meant? Release would require that the organism take up the nutrients into the biomass of the organism, and then processed to release those nutrients in a different form. When enzymes alter substances outside the body of the microbe, real uptake is not performed, and thus release is not involved.

Consider Carbon to Nitrogen ratios (C:N). Bacteria (C:N around 5:1) have to concentrate N because they consume, or eat things that have a wider C:N, say on average around 30:1. Bacteria therefore cannot release any N, they have to hold onto all of it, or they would die from too low N levels. Presumably, to the best of our knowledge, the same is true for P, K, S, Ca, etc. Bacteria have to hold all other nutrients except of C, because all their food resources are too high in C, or too low in other nutrients. Given that bacterial enzymes are much, much better than fungal enzymes for competing for the simple, easy-to-use substrates or foods, fungi get stuck having to make do with the wider C:N ratio foods, like wood, sawdust, corn cobs, standing dead grass material. That means they too do not release any nutrient on their own, they must concentrate it. Fungal foods are generally C:N 100:1 or higher, while fungal biomass is 20:1. No release from fungi or bacteria on their own. They are retainers, holders and sequesterers of nutrients.

CAROLE: Do fungi release any Nitrogen?

ELAINE: No, fungi are retainers of nutrients, even carbon, because they leave carbon behind in their hyphae, rather like railroad tracks, which the fungi can re-use if they need. This is unlike bacteria, which release copious amounts of carbon as CO2. Bacteria are the real problem when we look at elevated carbon dioxide in the atmosphere. Humans have enhanced so many bacterial decomposition processes, to the detriment of fungal decomposition that the imbalances are even being seen in the atmosphere of the planet.

CAROLE: Humic acid is a good fungal food, does it therefore have a C:N 100:1?

ELAINE: Some humic acid products have C:N around 30:1, mainly because of the perception that the only way to grow plants is to add the inorganic forms of N the plant needs. As soon as people realize this is only necessary if the nutrient-cycling life in the soil has been destroyed, by tillage, toxic chemicals, a lack of adding foods for the microbes back into the soil, then people will get off the kick of adding inorganic salts to everything. Humic acid should have C:N ratios more in the 60:1, or 150:1 to 200:1 ratio, because humics are made of long, long, long chains of carbon, with long side chains of mostly carbon, many ring structures, and unusual bonds. Humics are highly condensed, with many, many branches and complex binding within the molecule. .

CAROLE: What about sea kelp?

ELAINE: The first flush of kelp growth after a dormant period has a high concentration of N, around a C:N of 10:1. As that first flush is diluted by photosynthesis proceeding rapidly, GREEN plant material has C:N of 30:1. Kelp, if harvested green has C:N around 30:1 like any other plant. If harvested after it becomes dormant, then the “standing dead” material, which easily breaks off and washes up on shore, will have a C:N upwards of 150 to 200.

CAROLE: What happens if the kelps dries? Will the plant material lose any nutrient content?

ELAINE: If the drying process is rapid, within a few hours to days, and stays aerobic through that whole process (no loss of nutrients by volatilization), it should not lose any nutrients except water… Distinguish drying from burning to make charcoal, for example, which is a totally different process.

About the Authors

Dr. Elaine Ingham is President of Soil Foodweb Incl, an international laboratory system that assesses the balance of bacteria, fungi, protozooa, nematodes, and mycorrhizal fungi in all materials. The major emphasis of her work is to return health to soil, so that natural nutrient cycling and disease suppression mechanisms are present, allowing the desired plants to grow without requiring use of pesticides or inorganic fertilizers.

Contact Info: Sustainable Studies Institute, 1750 S.W. 3rd St., Suite C, Corvallis, OR 97330, 541-752-5066, website address: www.sustainablestudies.org, email address; info@sustainablestudies.org

Dr. Carole Ann Rollins is co-owner with her husband of Nature Technologies International LLC located in Novato, California, producing organic alternatives to toxic pesticides and synthetic fertilizers; Nature’s Solution brand of compost tea, ancient humate, sea kelp, mycorrhizae, worm castings, compost tea brewers, solution ingredients, and books. She has co-authored and compiled several books, manuals, posters and articles with Dr. Elaine Ingham.

Contact Info: Nature’s Solution, P.O. Box 1519. Novato, CA 94948, 415-898-5895, website address: http://www.nature-technologies.com, email address: naturetech@earthlink.net

Seriously, there has to be a good reason why fish fertilizer has been used for thousands of years. So we called in organic expert and gardener extraordinaire Jeff Lowenfels to give us the lowdown on the various products available that are derived from our aquatic friends.

American kindergarteners are taught the story of Squanto, a Native American who showed the Plymouth Rock pilgrims how to use fish to fertilize their corn plants. Egyptian children learn about their ancestors using fish to feed plants along the Nile, and Peruvian youths are taught that their pre-Columbian ancestors put a kernel of corn into the mouth of a fish and planted the whole thing.

My Grandfather, an avid gardener and fisherman, was my Squanto. He taught me to bury fish guts and too-bony-to-eat-fish in the rose garden and beneath the tomato plants. The results were outstanding. I’ve been hooked, if you will pardon the pun, on fish as great fertilizer ever since.

What is Fish Fertilizer?

Obviously, fish fertilizer is fertilizer made from fish or fish parts. However, not all fish fertilizers have the same characteristics. In fact, there are actually three different categories of fish fertilizer, so don’t just walk into a store and pick up whatever is on the shelves without doing a bit of homework first.

Each category of fish fertilizer is made using a different process and the products that result, contain varying amounts of nutrients. There are also best uses and special problems, so it is important to know a bit about fish fertilizers before you wade into the water (sorry, I can’t help myself!) and start using them.

In sum, the three categories of fish fertilizers are: fish meals, fish emulsions and fish hydrolysates.  Fish meals are made by grinding fish carcasses after a heating process has removed much of the oils. Wastewater left over from making fish meal can be concentrated to produce fish emulsions. Finally, fish digested in vats using enzymes instead of heat produces fish fertilizers called hydrolysates.

Large Tank of Fresh Fish Hydrolysate

The word “fish” can refer to both a single fish or plural when referring to fish in general or to a quantity of fish of the same kind; the word “fishes” is a special kind of plural used to refer to a quantity of various types of fish.

What types of fish are processed into Fish Fertilizer?

Virtually any kind of fish can be made into a fertilizer. However, fish are usually divided into two groups. The first are fish harvested for human consumption. These include tuna, salmon, catfish, halibut, bass, anchovies and sardines. Fish processed specifically to make products for plants and animals make up the second group. These include pollack, menhaden and herring.

What are the advantages of Fish Fertilizer?

Fish fertilizers have several advantages over their chemical counterparts. First, they can be totally organic with all the benefits associated with improved soil structure, increased microbial life and better plant health. Second, fish fertilizers don’t burn plants as readily as chemical fertilizers. Fish fertilizers generally have slower release rates and they don’t need to be applied as often. Moreover, fish fertilizers are not readily leached from the soil, rather they are held in the bodies of the microbes that turn then into plant food. Finally, they often contain trace nutrients not found in chemical formulas.

Characteristics of Fish Fertilizer

The characteristics of a fish fertilizer are based on the way it is processed as well as what is in the fish used. Processing methods are either listed on the label or implied by the name of the kind of fertilizer.

Fish Hydrolysates

These fish fertilizers are made from whole fresh fish, or fresh fish scraps, which are digested using special enzymes that break down the large proteins in fish meat and bones. Enzymatic digestion is known as hydrolysis, hence the name hydrolysates for the liquid mixtures that result. These liquids are like thick fishy milkshakes. Phosphoric acid is added to the mixtures to halt the digestion process. As a result, the pH of hydrolysates is usually lower than other kinds of fish fertilizers. Also they don’t smell nearly as bad.

Generally, fish hydrolysates have an NPK analysis around 2:3:0, 2:4:1 or 2:5:0. Because no heat is involved in making the fertilizer, and nothing is removed from the fish, hydrolysates contain more of a fish’s proteins, hormones, trace elements and vitamins than do other kinds of fish fertilizers. Application requires dilution to about five or six teaspoons per gallon of water. Fish hydrolysates can be used in all stages of growing.

Finally, unlike the other two kinds of fertilizers, hydrolysates contain all of the fish oils. These oils are excellent beneficial fungal foods, which make fish hydrolysates a good nutrient source for maintaining and increasing soil fungal populations.

Hydrolyzed fish is widely considered to be the “high-end” fish fertilizer product. It doesn’t have a highly objectionable odor like fish emulsion and it’s also highly water-soluble, so it’s great for drippers and foliar applications. It also contains higher levels of phosphorus than fish emulsion products.

Fish Meals

Fish is often heated to remove fats and oils to use in various products. The lean carcasses that remain are ground up into a meal and sprayed with phosphoric or sulfuric acid for stabilization and deodorization. Unlike hydrolysates and emulsions, fish meals are not liquid. They have more protein than emulsions, but less than hydrolysates.

Fish meals usually have an NPK analysis around 10:6:2 or 12:6:2. The high nitrogen obviously makes them good for vegetative growth and the relatively high phosphorus content makes fish meals good for root development, too. The down side is that fish meals have a strong odor.

Fish meals are granular or powder in form, and are usually applied at a rate of 5 to 10 pounds per 100 square feet. They continue to smell for a few days and are therefore usually buried into the root zone. They are not recommended for indoor use because of their odor, but if you can stand the smell, they can be mixed into soils where they act as a slow release fertilizer.

Fish meal is a good soil conditioner for use early in the outdoor growing season—it’s ideal in new vegetable or flower beds because it will help root development. Although most fish-meal fertilizers will last for 6-8 months, most of the benefits are realized in the first few months.

Fish Emulsions

After oils, fats and proteins are removed from fish, a liquid slurry is all that remains. This slurry can be concentrated by evaporating up to half of its liquid, resulting in a syrupy emulsion suitable for use as a fertilizer.  Some phosphoric acid is added to stabilize and deodorize things. This lowers the pH of the emulsions, which is still not as low as that of hydrolysates.

The cooking segment of the fish emulsion manufacturing process destroys a lot of the fish “goodies” such as the vitamins and hormones so useful to plants and microbes. There is much less protein in emulsions, and fewer solids, but the upside is that fish emulsion is more soluble than other fish fertilizers and cheaper, too.

Fish emulsions have an NPK analysis of 5:2:2 or 5:1:1, even though they are known for their micronutrient content. As the most soluble fish fertilizers, they are good for foliar feeding.

The fish used to make emulsions are usually “trash” fish, which are harvested only for this purpose and not for consumption by humans. They often contain toxics. Menhaden, for example, spend part of their lives in waters that are heavily polluted with metals. Some freshwater fish that can’t be eaten because they are polluted are also often processed into fish emulsions.

Moreover, if the steam employed to strip oils from the fish is from a municipal source, it usually contains chlorine. When the final liquid is concentrated, so is the chlorine—reportedly up to as much as 50%. Chlorine can be harmful to plants and beneficial soil microbes, so you might want to review product MSDS reports to make sure what you buy isn’t too loaded with chlorine.

Application rates of fish emulsions generally run about five or six tablespoons per gallon of water. Fish emulsions are often used in mixtures made up of kelps, other seaweeds and crab shells. They sometimes contain additional materials to raise the NPK. These may not be bad, but you need to take into account what they provide before using these fish fertilizers on your plants.

The nitrogen contained in fish emulsion is released more gradually than in many other non-fish-based fertilizers. Fish themselves naturally contain about 2.3% nitrogen.  However, some fish emulsion products contain synthetic sources of nitrogen, such as urea, to boost the nitrogen percentage. Be sure to check with the manufacturer to find out if their fish emulsion product is comprised only of organic inputs.

Hydrolysate and Emulsion Process (image credit - Dramm Corporation)

Common Objections to Fish Fertilizers

There are some basic objections to using fish fertilizers, which may help you decide to use one versus another.

It Stinks!

One of the biggest concerns about using some fish fertilizers is their smell. Fish meals, for example, smell horrendously. The odor goes away after a few days but using the stuff inside might be problematic, even for those growers with the largest carbon filters! Fish emulsions can also have a strong, offensive odor even when deodorizing agents are added to them. Generally, hydrolysates have much less, if any, offensive odor.

While humans may take offense to the smells of fish meals and emulsions, many pets and pests find the odor attractive. Cats, dogs and raccoons love to eat fishmeal and some dogs like to roll in it. If you are concerned about animals disturbing your plants, take protective action.

Toxins

Adding to the problems caused by high concentrations of chlorine in the steam water used to cook some fish fertilizers are the existence of other toxins. Some fish fertilizers contain heavy metals like mercury, which are found in fish living at the top of food chains. Concentrating solutions when making emulsions also concentrates these toxins. However, these fertilizers may still be fine for inedible plants.

Unfortunately, the amount of toxins in a fish fertilizer is not going to be listed on the label. However, you can look up individual fertilizers by—to determine any heavy metal content—on a great website maintained by the Washington State Department of Agriculture.

Sustainability

No one should ever buy fish fertilizer made from endangered or depleted fish stocks and some argue that there are good reasons not to buy any fish fertilizer made from “trash” fish. For the most conscientious growers, only waste fish and fish wastes from human consumed fish are acceptable.  Again, a little snooping around on the Internet can provide you with the valuable information needed to make a rational purchasing decision.

In this day and age, there are other sustainability considerations. Packaging, energy resources spent on processing and transportation, as well as additives used are all inputs to making a choice as to which category or brand of fish fertilizer to purchase. Again, a little research is worth it in terms of environmental, plant and human health.

Suitability for hydroponics and foliar applications

Fish emulsions and fish hydrolysates can be used in hydroponics systems because they are liquid in form. Emulsions are more soluble and some of their nutrients are plant useable without beneficial microbiology, but both work best in organic systems with microbes. Odor is a concern, especially with emulsions, and toxins may be as well. If you use a filter in your system, fish hydrolysates may need straining to prevent clogging the filter’s fine mesh screen.

All of the major hydroponics companies sell fish based hydroponics fertilizers. They also supply lots of information to promote them, but read labels carefully and fish (ouch!) for the necessary information to make an informed decision. You can also request MSDS (material safety data sheets) from these companies.

Fish fertilizers as a catalyst for beneficial biology

Organic fish fertilizers excel at supporting the microbe herd that is at the base of the soil food web. They all provide some NPK and most, at least those made from sea fish, also provide trace elements, micronutrients and other good stuff.

Fish hydrolysates, in particular, come about as close to duplicating the practice of burying a whole fish. Only the hydrolysis process makes the fish more available to microbes, breaking down large molecules into tiny ones. Microbes can and do happily feed off the organic matter and proteins from the meat and guts. Calcium from the fish bones is also retained in hydrolysates. And, as noted, the oils in hydrosylates make great fungal food for those plants that prefer fungal dominated soils: perennials, trees and shrubs. For this reason, hydrolysates make great fungal food for compost teas.

Fish meals, too, support loads of microbial activity. They contain tremendous amounts of protein and are great foods for bacteria, and annuals and vegetables that prefer a bacterial dominance in their soil. Covered with bacteria, fishmeal added to a compost pile gets the pile cooking due to its high microbial metabolism. In addition, flies (and their larvae) love it, which in turn attracts other members of the soil food web.

Fish Fertilizers: Be an educated consumer

Not all products sold as fish fertilizers are made just from fish. Some contain non-fish additives as previously mentioned—primarily seaweed and crab shell. The seaweeds are full of micronutrients, auxins and cytokinins; crab shells provide chitin found in the cell walls of fungi. Sometimes, however, non-organic materials are added to boost NPK, so always read the labels on fish fertilizers.

The right fish fertilizers, or combinations thereof, can be great for your plants. Fish hydrolysates provide more nutrients and vitamins, hormones and micronutrients. Fish meals are slower acting, more suitable for outdoor use and larger areas.  Fish emulsions are ideal for quick-acting foliar sprays.

However, while fish fertilizers can be extremely useful, do your homework before buying. Research the web, read labels and know what to ask for and you won’t go wrong.

Words: Jeff Lowenfels – author of the best selling gardening book “Teaming With Microbes: The Organic Gardener’s Guide to the Soil Food Web” from Timber Press.
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