I invite you to come along with me on my quest for natural sources of both macro and micro-nutrients. Each of the sources quoted are worth reading in their entirety, but Ill present them as I search for the answers.
I have taken to Earthan Beds which are dirt filled wicking beds connected to a bioponic or aquaponic system. Urine (humonia), weed tea, and compost supply much of my bioponic gardens needs. But one of the most difficult minerals to supply during my experimentation with Soil-Less Bioponics and Aquaponics was iron (Fe
2+) in an available form. For this one mineral I may have to give in to purchasing a product. The following describes my pursuit, but first here are some interesting facts you should know
Common chelated forms (iron-EDDHA, DTPA and EDTA) differ in their ability to hold onto the iron (and therefore keep iron soluble and available to plants) as the media pH increases. Between a media pH of 4.0 to 5.5, any form of iron will work (including iron sulfate) at supplying iron to the plant. However, as the media pH increases above 7.0, only the iron from Iron-EDDHA has high solubility. Research has shown that the ranking of iron forms from most effective to least effective at supplying iron at high media pH is Iron-EDDHA > Iron-DTPA > Iron-EDTA > Iron sulfate. If iron is applied in a form that is not soluble because of high media pH, then most of the nutrient will not be available to plants until media pH is lowered. - http://www.greenhousegrower.com/uncategorized/understanding-plant-nutrition-fertilizers-and-micronutrients/
Now that we know what forms of iron are available how do we go about finding a natural source for our garden? It should be noted that iron, manganese, zinc and copper all require chelation in order to be available to your plants. Generally manganese, zinc and copper chelates are only found in the EDTA form, but Zinc sulfate is generally used because Zinc chelate is too expensive to use at rates needed to increase zinc levels in the soil.
"The worms digestive enzymes (or, properly, those produced by bacteria in the worms intestines) unlock many of the chemical bonds that otherwise tie up loose materials and prevent their being plant available. Thus vermicastings are as much as seven times richer in phosphate than soil that has not been through an earthworm. They have ten times the available potash; five times the nitrogen; three times the available magnesium; and they are one and one half times higher than calcium (thanks the calcium carbonate added during digestion). All these nutrients bind into organic material in the fecal pellets." - .
Teaming with Microbes: The Organic Gardeners Guide to the Soil Food Web, Revised Edition (2010) by Jeff Lowenfels & Wayne Lewis.
Sadly iron is not mentioned as one of the micronutrients made available by worms, but the benefits are obvious an even though Lowenfels and Lewis did not specifically mention iron it may still be one of the benefits.
The balance of evidence suggests that earthworms increase metal mobility and availability but more studies are required to determine the precise mechanism for this - http://www.sciencedirect.com/science/article/pii/S0269749109000979Iron plays an important role in enzyme functions and is a catalyst for synthesis of chlorophyll. Plants deficient in Fe may exhibit pale leaves and/or yellowing of leaves and veins. Nickel has only recently been recognized as an essential element. It is required for the urease enzyme to break down urea into usable nitrogen and for iron absorption. - http://www.aglearn.net/isfmMod2.html
Clearly its not just iron we need but instead a full spectrum of nutrients, and worms provide many of these. Also note that most macronutrients are mobile within the plant, most micronutrients are immobile, and so a constant supply is needed for the duration of the crop. A healthy soil web with worms is crucial to maintaining the constant availability of these nutrients.
If your soil is lacking in certain elements, the best way to add them is through the compost pile. Add colloidal phosphate (organics) or superphosphate for phosphorus and wood ashes for potash. Composted organic materials can also be used as a cheap iron chelate (a slow-release source of iron) to remedy the adversities of iron chlorosis, i.e., yellowing plants. Gardeners can make a "synthetic chelate" in their compost pile by mixing 1 cup of iron sulfate (copperas) for each bushel of moist compost. Particles of iron will adhere to the surface of the compost material and will be released for plant use as the material decomposes while it is being used as a mulch around plants or when incorporated into the soil. - http://aggie-horticulture.tamu.edu/archives/parsons/earthkind/ekgarden11.htmlThis gives me some hope of finding a practical method of creating available iron. Iron sulfate is readily available and inexpensive, but my quest for natural and available sources has not been satisfied. Some plant material high in iron include artichokes, spinach, collard greens, lentils,
mushrooms, and soybeans, so compost these whenever possible.
Below are some relative values I calculated from Healthaliciousness.com
I dont throw many nuts away, but they contain a lot of iron. Some common nuts such as pine nuts, hazelnuts, peanuts, almonds, pistachios, and macadamia contain about 0.061%
Beans are also a good source - soybeans, lentils, kidney beans, garbanzo beans, and lima beans, navy, black beans , pinto,, and black-eyed peas contain about 0.037%
Leafy greens - Swiss chard, turnip greens, kale, beet greens contain about 0.036%
Grains &
Seeds - pumpkin seeds, squash seeds, oats, barley, rice, bulgur, buckwheat, millet contain about
0.015%How did our ancestors garden without store bought soil amendments? Were they just lucky to be the first to plant in the nutrient rich soil before it was depleted? The natural production and distribution of iron is a process of volcanic action where sulfur and iron are spewed forth along with many other micro nutrients into the jet stream and ocean currents. The ocean contains most of earths natural minerals which are spread out by strong air and water currents.
Kelp contains enzymes, a lot of potassium, and many other minerals essential for plant growth, making it a perfect garden supplement with about 22% iron. Ill admit I dont know if that 22% is in an available chelated form. Kelp also contains cytokinin which promotes resistance to bugs, and allows for faster cell division. You may recall that one of the benefits of insect frass is cytokinin, but I do not wish to diverse.
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| Kelp Forests |
I am not lucky enough to live near an ocean, but kelp is a natural product with many benefits. As much as I would like to curtail my dependence upon commercial products it may be that some products such as iron sulfate or kelp will have to be purchased in order to achieve outstanding results. Azomite, BT, and Spinosad are a few others I have come to rely upon, but my quest for independence will continue.
It seems that ferric iron is generally present, so the better solution might be to simply make it available as ferrous iron by adding plenty of organic acids in the form of humus.
Many of the components of humus are heterogenous, relatively large stable organic complexes. They function to give the soil structure, porosity, water holding capacity, cation and anion exchange, and are involved in the chelation of mineral elements. - http://www.humates.com/pdf/ORGANICMATTERPettit.pdf A plant-excreted chelate forms a metal complex (i.e., a coordination compound) with a micronutrient ion in soil solution and approaches a root hair. In turn, the chelated micronutrient near the root hair releases the nutrient to the root hair. The chelate is then free and becomes ready to complex with another micronutrient ion in the adjacent soil solution, restarting the cycle. The process works like this: A chelate is exuded from a root to the soil solution. The chelate complexes a micronutrient (e.g., iron) from the soil solution. The chelated micronutrient is carried to a root hair, where it is released. The chelate goes back to the soil solution and starts another cycle.- http://edis.ifas.ufl.edu/hs1208Humic acid, humate and folic acids are mined, and sold, but what if compost can provide the same benefit. It is known that Earthworms (Eisenia foetida) produce several bioactive humic substances which are found in earthworm compost.
The chelating action of humic acid is sometimes used to produce chelated iron products. Without the addition of a nutrient such as iron, the claim is often made that humic acid has the ability to solubilize micronutrients already in the soil. This is a valid claim,but one has to realize that turfgras roots themselves excrete organic compounds that solubilize micronutrients. - http://aggie-horticulture.tamu.edu/newsletters/hortupdate/hortupdate_archives/2002/jun02/art4jun.html.I may be reading too much into this but I think Ive found the answer to my my quest for natural sources of chelated iron
- Earthworms (Eisenia foetida).Along with the bioactive humic substances which produce chelated iron; earthworms and their compost also provide enzymes, that promote hormonal activity, and make chemical reactions millions of times faster. Microbes make organic plant food from minerals and dead stuff with the enzymes they produce.
Mart Hale sent these to me. Liquid Grass Clipping Fertilizer
Plant Based Tea Fertilizer Ingredients
Weed Tea / Fertilizer
Gather some herbs from the list below and put in a large container such as a bucket or barrel. Fill with water. Infuse for at least two weeks. This is best to prepare with the new moon and strain and fertilize around the full moon, although it can be done whenever it is convenient.
Nitrogen:
Alfalfa, Clover, Soybeans, Field Beans, Vetch, Comfrey, Kelp, Licorice Root leaves, Nettles
Magnesium:
Bladderwrack, Carrot leaves, Coltsfoot, Comfrey, Dandelion, Dulse, Horsetails, Kelp, Meadowsweet, Mistletoe, Mullein, Parsley, Peppermint, Primrose, Willow bark, Skunk Cabbage, Watercress
Potassium:
Braken fern, Borage, Carrot leaves, Chamomile, Chickweed, Chicory, Clover, Yellow Dock, Eyebright, Fennel, Lambs Quarters, Nettle, Mullein, Oak bark, Parsley, Peppermint, Pigweed, Plantains, Comfrey, Toadflax, Watercress, Yarrow, Orange and Banana skins
Phosphorous:
Barley, Buckwheat, Calamus, Caraway, German Chamomile, Chickweed, Clovers, Dandelion, Yellow Dock, Garlic, Lambs Quarters, Lemon Balm, Licorice root leaves, Lupine, Marigold flowers, Meadowsweet, Mustard, Pigweed, Purslane, Savoy, Sorrel, Vetches, Watercress, Yarrow, Comfrey
Boron:
Gopher Spurge, Cardboard boxes, Beetroot leaves
Copper:
Coltsfoot, Dandelion, Nettles, Plantains, Valerian, Yarrow, Parsley
Manganese:
Chickweed, Lambs Quarters, Watercress
Sulphur:
Coltsfoot, Eyebright, Fennel, Garlic, Meadowsweet, Mullein, Mustard, Nettle, Plantain, Shepherds Purse, Watercress, Cabbage leaves, Onions
Iron:
Sarsaparilla, Bladderwrack, Dulse, Iceland Moss, Kelp
Silicon, Oat Straw, Plantains, Valerian, Borage, Comfrey, Dandelion, Horsetail
Calcium:
Chicory, Comfrey, Dandelion, Nettle, Perilla, Watercress
Willow Tea:
Used for rooting transplants or cuttings. Infuse leaves from a willow tree in water as if you were making an herbal tea for yourself. Once cooled, water the plants that you wish to root with this mixture.
Here is another article that I found quite interesting.
http://www.appropedia.org/Bacteria-rich_liquid_fertiliser
First I had an old falling down building that I took apart and used what wood I could salvage to build a table. I built it 3 feet deep and 4 feet wide by 3 feet tall. I built it that tall because I wanted to be able to have easy access to the fish, and I measured the 100 gallon stock tank that I want in the future and it was 2 feet. 
The fish tanks is next. I come down about 3 to 4 inches and drill 2 holes that are 1 inch.
The pump I use is just a simple submersible fountain pump that you can find at Harbor Freight or Big garden centers. The one I found was actually from lowes that was on clearance when the season started to get cold. I use a half inch hose to connect the pump to a half inch pvc that then goes to my bedding trays. You can skip that step and just run the length of hose strait to the bedding tray if you like. But since I plan on putting valves to control the flow later, I chose PVC.
I am using Lava rock for the first base and then will add expanded clay to the last 3 inches of my bedding trays. I could have went to the creek and got some creek pebbles, but It was just easier to go to the garden center.
The system was then filled with water and ran for a couple days to make sure the chlorine was out and it was going to work ok before I placed the fish. For testing purposes and it was also going into winter I decided to go with local fish to start and then change them out to Tilapia come spring. You can read how to properly cycle your fish here on the blog if you are wanting to do it correctly.
