- Organic Gardening
Garbage in, Garden Out, Humic Substances. Ten Ideas About Humic Substances, humic acid, etc.
Testing Himc Acid, Greater San Diego Science and Engineering Fair 2002
Humates, humic acid, and humus
Humates are a huge group of carbon molecules as well as groups of huge carbon molecules, that break down from a specific fiber in plants called lignin. Plants build carbon dioxide into larger and larger molecules and then build these into plants structures. When they break down into smaller molecules there are hundreds of them we will simply call humates, from humus, or mulch, if you will.
Humates are important enough to warrant their own segment in this book.
What are they? Simply put they are complex groups of phenyl molecules. To envision this, just draw a hexagon, a six sided box. Now add another one and another one and make as many of these as you like, you will be close to drawing at least one of the humates. Yes, it is a little more complex that this, but never the less, this is a good illustration.
Think of them as the same shape, but very much smaller, similar to the face of a honeycomb but where some of the pieces are missing. So in places they are in contact wall to wall like the honeycomb in other places one or more carbons are missing so there are five sided loops where nitrogen may replace one or two of the carbons. In other places there are just different molecules like oxygen, sulfur or others connecting these hexagons and pentagons.
Of course, this illustration is only one layer deep for our honeycomb. Then cut that face into hundreds of pieces of differing sizes, twist them here and there, then think about thousands of these compounds and you are starting to get the picture.
Simple compound might have 6 to 42 carbon atoms. Complex ones have thousands of molecules and they come in all shapes and sizes.
They form gels that help hold water, since they are mild acids they attach to alkali metals in the soil increasing ion exchange and help carry those metals into the plants via the root and the leaves. They interconnect and form large molecules that do not break down easily and so stabilize the soils and help to nourish the soil for long periods of time. Microorganisms take them up, use them for energy and also for structural components, and so preserve the various carbon compounds in different forms for longer periods. With heavy metals they form insoluble complexes that prevent the plant from absorbing them. They stimulate the growth of all types of soil microorganisms.
The large molecules always break down into smaller molecules which is consistent with our two laws.
Using humus, humates, and “tea” made from them will increase the health of your soil, the organisms in it, the health of the plants, the productivity of the fruits and vegetables and increase the effectiveness of fertilizers of all kinds.
They do the same in water for fresh water plants. My son tested this for a science fair project and by using a spectrometer we could see that all minerals useful to plants experiences increased absorption using humates but toxic heavy metals were blocked. They are also algaecides, that is they kill algae but no other plants in the aquarium, pond, or lake.
Don’t be confused if you hear that it takes thousands or tens of thousands of years for humates to develop. This was caused by their discovery in lignin coals and a gross misunderstanding of where the term comes from. The term comes from humus, decomposing organic matter.
Humates are that collection of organic compounds that result from the deterioration of organic matter.
Just remember, there are hundreds of these and all useful in the soil and water. Let’s look at some of the ways they are made and the uses in your garden.
Bugs as Humic Recyclers
Think of bugs, pill bugs, worms, beetles, larvae and the like as small humate recyclers. They break down plant materials into smaller compounds that either are easier for bacteria and fungi to then digest, or they ingest them where the bacteria and fungi digest those compounds. Either way, bugs in the garden are for the most part, your friend. You didn’t know you had so many friends, or things working on your behalf!
Elsewhere we talk about fruit and other things in the surface of the ground or in the ground and you might think that the bug is eating the nutrients from those and walking away. If you have flies around the yard, that is true but other than fruit flies, you really don’t want things that attract flies, so bury those things. But other bugs simply don’t move that much that you would be concerned about the missing nutrients, so the bug may simply be delaying or flattening out the nutrient supply curve until it dies and is recycled into the soil.
Think of it as the difference between something breaking down in the soil that is simple verses something that is complex. Just as it took time and energy to make simply nutrients into complex nutrients, so it will take nature a little longer to break down the complex nutrients, in this case, bugs, than it does to break down simple nutrient in, say, a piece of fruit or a carrot.
Newspaper is the better of the papers for use in the garden because they do not wash out all of the lignin. That is what gives it the soft and slightly tacky texture.
Because of this, newspapers can be broken down faster than other paper sources when there is sufficient moisture.
Cut up newspaper in the compost, soak in ammonia first of you have the time to add some nitrogen, the bacteria will convert this to usable ammonium and help speed up the humus production.
Cut up newspaper in worm bins and moisten it. The worms can eat the paper as can many other bugs, returning the carbon to the soils where it came from originally.
Make paths in the garden from newspaper. It discourages weeds, hided bugs, and feeds them at the same time that is breaks down slowly into humates.
Making Humic Acid
We have a large Ash tree in our yard and under this I had a small fish and plant pond. Just a few fish to keep the mosquitoes out since the goal was to raise Louisiana Iris. This was one of those small pond liners you buy at the garden shop, but the pond was being overrun by algae. Long green string algae had invaded and taken over my pond. Just as the weather changed and the leaves started to fall we had a dry Santa Ana wind come through and nearly all the leaves fell from the tree in literally 2 or 3 days. By the time I got into the garden, you could not even see the pond. Had just enough time to dig the pond out to the surface then realized the leaves had saturated and sunk all the way to the bottom of the pond. No big deal, it was only 18 inches at the deep spot, but I just didn’t have the time to deal with it, so I left it as a chore for the weekend.
Come the weekend I went back to the pond and the water was brown like tea. There was no algae in the pond. I scratched my head, called one of my kids and said, “Well, science begins with observation. I observed the algae died when the water turned brown from the leaves. Does this brown substance make an algaecide?”
The next step in science is to formulate a question then develop a testable hypothesis. The observation certainly seemed to support the hypothesis that this brown stuff in the water was an algaecide, all the algae was dead!
My son did a science fair project on that. He took a 50 gallon barrel, filled it with leaves from the ash tree, filled it with water and left it for several days to soak. He tested the pH and our normal water pH being about 8.5, lightly alkali and in three days, it was 6.5, slightly acid, but that was a significant change in pH.
Since I keep aquariums, I have a lot of different kinds of plants from various mosses to Java fern, and even rooted plants.
He put this humic substance into a group of water plants which included algae which we collected at our nearby water reservoir. He took small plastic cups and made groupings for the different plants, weighed each plant before he put it into the cup, numbered the cups. We made a barrel of water using tap water then simple aquarium chlorine remover and let it sit overnight. Then he took a measured amount of that water and put it into each cup. All this was set up in the garage to create a controlled environment under fluorescent lights with a timer on them. Doing this inside prevents something like a bird adding fertilizer to some of the plants and screwing up the test.
This brings the great philosopher Yoda to mind from Star Wars telling the young Luke Skywalker, “Control, control, you must have control!”
So the plants that had just the water were, of course, the control group. That is, what happens if there is nothing added to this water? What is the baseline growth expected in this environment?
He then added a certain number of drops of the humic acid to each group of cups.
Lo and behold, just like in the pond, the algae died, all the other plants thrived.
He upped the ante and did this with large groups of cups many plants, the results were quite clear. Of course, he won first place in the science fair. That didn’t hurt.
So my daughter wanted in on the act. Let’s test to see if this newly discovered substance (at least as far as we knew) which we then knew helped water plants grow, would help other plants. But where do you get a plant that you can control all the substances that are in the dirt to ensure you have a good control group?
It seems to me you only have two alternatives: 1) start from scratch with new pots, a soil mix you design, or at least all from the same bag, start with seeds or cuttings and grow your own, or 2) use a plant that doesn’t grow in soil.
Well, I just happen to grow Spanish moss in the back yard with other Tillandsia (“air plants”). So we took Spanish moss and broke it into small groups, weighed each, and hung them on paper clips which in turn hung on clothes hangers. For the control group we sprayed them with purified tap water and used that water to make the humic acid. The test groups we sprayed with various concentrations of humic acid. All were sprayed at the same time several times a day.
Again, outstanding results. The Spanish Moss sprayed with the humates grew 40% faster than those receiving water only. She also won at the Science Fair. Second place I believe.
So then we knew we had a good, organic algaecide that actually helped other types of plants.
Since we have slightly alkali water here in San Diego, this becomes a great way to balance the soil. My ferns, fuchsia, and other acid loving plants love it.
If you keep aquariums, you can now find humic acid supplements to feed your plants, or, you can now make your own.
The Good, the Bad, and the Mosquitoes
In the experiments above we had a lot of humic acid left over which we left in the large container for a week or so and I noticed mosquito larvae in the water. Since we have West Nile Virus in the area, this is not a good thing. I fed the larvae to my fish and even put fish into the water to eat the rest of them and for the fish to breed during the warm summer months.
I started to wonder if it were not humates and gasses given off by them that attract mosquitoes.
Swaps are, of course, famous breeding grounds for mosquitoes and are also famous for giving off various gasses from carbon dioxide (they are the largest producers of CO2) to methane and other carbon containing gasses because waste from both plants and animals decay in the bottom and there are their natural by products of fungal and bacterial degradation. Are mosquitoes attracted by these gasses? Specifically, are they attracted by the gasses given off by decaying leaves?
So, I did another test. I took some of the clean humic acid mixture out and put it into several glass bottles, took some other water from my fish tank so it was a clean biologically active water that did not smell of chlorine and left them out on the wall to see if there was a difference in the mosquito larvae, watching them closely.
Sure enough, a few days later the humic acid groups had mosquitoes in them, but not the water from the aquarium sitting right next to them.
So, humic acid off gasses some mixture of methane and carbon dioxide and/or other gasses and this attracts mosquitoes.
But think about this.
Doesn’t this make sense?
Stagnant water with decaying plant material attracts mosquitoes. Of course, those were disposed of, but the brief experiment had a most interesting result.
If you intend on keeping humic acid around for future use as a fertilizer or acidifier for your tropical plants, a few drops of olive oil on the surface will kill mosquito larvae, or you could put it into jars to preserve it.
If you simply use the humic acid up and leave no water standing, the problem is gone and your plants will love you also.
If you want to keep the humic acid but kill the mosquitoes, add a few drops of olive oil to the water. Mosquito larvae use a siphon tube to breath and it cannot penetrate the oil because the oil has a greater wicking action, that is, it clings to the siphon tube and smothers the larvae. Your really don’t want them becoming pupae, the stage where they roll into a little ball because that is the stage where they metamorphose into an adult and you will very shortly have mosquitoes in the yard.
Acid Loving Plant Love Organic Carbon Based Acids
Acid Loving Plants
So called house plants are usually tropical plants that appreciate a mildly acid soil. Acids help chelate or pick up minerals and bring them into the plant through the root tips.
Humic acid fits the bill for this purpose.
After making your humate solution place your houseplants into a tray, then add humic acid and allow the plants to soak for several hours. This will neutralize the alkali built up in the soils from tap water and help the plants absorb nutrient. After soaking, let the water drain off then place them back in their places. Be careful not to sunburn the plants which are probably acclimated to less sunny locations. Humates seem to work by helping to transport minerals into plants at the root level and at the leave level where this is appropriate. If you use foliar sprays (to spray the leaves), add some humic cid to the mixture to help absorb the nutrients.
Since plants need there mineral for growth, this helps keep the plants healthy.
Remember those mineral salts on the outside of the pot can be used by the plant if they are in solution since most of those salts are calcium carbonate.
Very few plants appreciate alkali soils which result from the way we treat our water for sanitary purposes. All will likely appreciate a good soaking in humic acid for a few hours unless it is simply too strong of a solution. For the ground in general, everything we have tried it on responds well to humates, or humic acid, again, this helps to root system absorb and transport minerals, something much harder for the plant to accomplish in an alkali environment because it must then generate its own acids, which it does, but then uses resources to do so.
In a soil that is slightly acidic, these minerals are readily available.
Tillandsia, Air Plants
We discussed above the fact that Spanish Moss grew at an accelerated rate when sprayed frequently with humic acid.
Real life is somewhat different than testing, so you don’t have to run out on a set regimen to spray your plants every few hours, but even an occasional spray with humic acid will help them speed up their growth and reproduction, or at least vegetative reproduction.
Of course, reproduction has two aspects that benefit you if you like these plants, the first is vegetative reproduction, simply producing more small plants. With Spanish Moss (well, we just lost all the people from Georgia to southern Texas and below) and many other Tillandsia simply produce small offshoot from their leaves or their base. All blooming plants have sexual reproduction, and so produce seeds and this kind of reproduction is encourages weakly through the use of humic acid.
Frankly, much of what we have discussed and will discuss in this book relates to composting materials in a low intensity or distributed composting situation, particularly those where you dig some organic material into the soil.
Composting proper is the subject here.
What exactly is compost?
Compost is the result of the rapid biodegrading of organic materials resulting in a nutrient dense mixture of carbon molecules, minerals, and soil nutrients that can be applied to plants areas and pots that enrich the soil with organisms, nutrients, and carbon.
What is composting?
Composting, done correctly, involves the mixing of different plant and/or animal products together to create compost. Done correctly, this will take about two weeks to convert, say, a pile of leaves and grass clippings into rich, dark, organic compost that improves the soils wherever it is used.
What can go wrong?
We mentioned animal products above. If you get carried away and use, say, meat in the mixture, you may end up with a smelly mess that attracts flies, rats, or other animals in the area and makes your neighbors wonder what is going on.
Or, let’s say you just get the carbon-nitrogen ration wrong (call this the dried plants to green plant ratio), you could end up taking a bit longer than two weeks to break down the material. But then again, if you started with two day old grass clippings and some dried leaves, turned in every other day and kept it moist, you could reduce the time also.
But this really is a simple thing to manage. Just follow some simple tips.
The carbon-to-nitrogen ratio isn’t all that precise, but just think about it while you are making the initial compost pile or bin. Layer dried organic material, hopefully chopped finely, and add freshly cut green materials in different layers. Newspaper will do, and, if run through a grinder, or simply regular office paper (not coated papers such as magazines) does quite a good job.
I tend to use larger green materials from my yard that I cut up with garden shears directly into the compost bin. The add leaves, more green material, and so on. Alternatively, if you have a large pile of green material, just add the dried material and turn it to mix and get the needed oxygen into the pile.
What we are really doing here is creating an environment where microorganisms can thrive and multiply rapidly. Many of the things we have talked about adding to your garden can be added here as well, especially cooked plant materials like spinach from your dinner, or salad. Just be careful not to create a pile that attracts animals. Milk products break down quickly and might attract a cat for a day or two, but this is not a problem and the added nitrogen can boost the pile’s heat production. Cultured milk, like kefir or yoghurt even better.
A boost to the compost is gained by adding manures from horses or cows which already have huge numbers of microbes, is partly broken down, and has a good mixture of carbon and nitrogen.
If you live near the beach, bring home some seaweed, wash it, break it up and add it for super minerals for your soils. If you like near a pond, use algae, and, you don’t need to wash it.
If you are in a cold location, try insulating the pile during the winter. Even covering it with black plastic can help heat the pile by sunlight, but bins are likely a better way to compost in a cold winter.
Once the recipe for your compost is thrown into the pot it will start to cook itself.
When I was young, my family made our annual trek to Yosemite where we would stay in rented private cabins. Walking past the ranger station on a hike I noticed smoke or steam coming from a pile of ground up leaves and bark. Not understanding that this was from bacteria and fungi heating up the pile as it degraded the materials, I thought maybe there was a fire smoldering beneath. Wanting to help and not see a full fire start, I climbed to the top of the 8-foot pile and browsed around to check for ambers. Not seeing any I plunged my hand into the pile to be sure it was as moist, and therefore not in danger of bursting into flames, as it looked at the top few inches.
The only thing that burst into flames was my hand! I learned very quickly that a mulch pile can reach temperatures of 160 degrees! Ouch!
This heat is the result of microbes in the soil that digest organic compounds. They need carbon, nitrogen, moisture, and oxygen, so, keeping the pile moist (not wet) and mixing the pile every two or three days will accelerate the compost, killing weeds and creating a rich additive to your soils.
Here is another tip: If you want, but don’t have a compost bin, find three wooden shipping pallets and nail these together in a “U” shape and make your pile in the center. For piles with sufficient mass, this works very well, especially in moist conditions. It doesn’t work as well in the southwest because of the dry conditions as this allows for more moisture to escape, so you need more water and water is at a premium.
Remember that making compost “cooks” down the materials. The materials lose mass in the process, and this is the way of nature. Living things die so other living things can continue to grow.
Another tip mentioned above: If you have, say, a pile of hay, or just dried leaves, but want to make compost, build your pile and moisten it for a day or two, then add some ammonia and water to the pile and turn it. In the wet environment are microbes that can convert the ammonia into ammonium, nitrates, and nitrite, all useful to those other microbes to meet their nitrogen requirements and heat up the pile. Do this every third day, two, or maybe three times, as needed to heat up that pile and break it down. But you can also add grass clippings, green leaves, and cooked vegetables. Remember, everything can be returned to the soil. If you add materials when it is hot, it will keep the fire burning, as it were, but if the pile is starting to cool down, you will interrupt the organic processes. Treat it as if it were a new pile, mix dry and green materials, and so forth. This, being a new pile, will take a few weeks before it is ready.
When you are ready to use the compost you can use it as mulch, that is, a top dressing, but it is better mixed into the soil. Just remember, it is mostly carbon, and so recycles into the soils and air and will eventually be gone. This means, if you use half compost and half soil in a pot, the level of soil in the pot will drop every year and in two or three years, you will need to add more or repot the plant.
If you have houseplants, take some compost and put it in a fine cloth like a tea towel then soak it in water to extract the nutrients. When done, just put the compost in the garden and use the water to either water the houseplant soil, or use as a foliar spray for directly feeding the plants. Remember, most living things can absorb things directly through their outer covering, including human skin.
You have to feed your worms
Pitty your worms
Have you ever thought about feeding your worms before?
Pity the Poor Worm
Have pity on your worms! They would enjoy your coffee grounds or tea leaves. How about that pot of soup that sat out all night? Why poor it into the sink when your garden would benefit from it?
You feed your pet, or your kids, or your neighbors and friends, feed your worms.
Become an environmental activist for your garden! You think about your family, have they eaten today? Think about your worms, nasturtiums, and don’t forget the fungi and bacteria!
OK, we are getting silly here, but you get the idea. Ask yourself before you throw something out, how your garden might benefit from its use. Why throw out 100 pounds of food waste then buy fertilizer for the garden when you can dig that food waste into the garden and maybe forget the fertilizer?
What is mulch and how is it different from compost?
Mulch is (usually) organic materials on top of the soil. Mulch helps reduce weeds by making it too hard for the sprouts to reach the surface. Mulch helps reduce erosion, reduce heat, and preserves water. Note that all these things are more or less mechanical. But, like compost, it tends to improve the soil itself if it is organic and there is moisture present.
So, the term mulch has to do which where the material is. Compost is biodegraded material, so it is what has happened to the organic material.
Since these are not contradictory concepts, compost can also be mulch. Mulch can be subjected to composting either rim place if the environment is right, or it can be collected and added to compost, but again, mulch describes where it is, on top of the soil.
As stated, not all much is organic. Some municipalities have taken to using inorganic mulches in areas where they may want water penetration but not plant growth, or around trees where they want to prevent weeds but, again, want some of the mechanical benefits of mulch.
How does the presence of mulch cool the surface of the soil?
Sunlight hits the surface of things and heats them up, of course, so, when it hits mulch, the mulch is heated, but much of this heat is lost to the air around the mulch. Hot air rises, and carries that heat away from the ground.
If the sunlight hit the ground, most of the heat would simply be conducted deeper into the ground.
Biologically filtered aquariums
Leaves under soil in potting plants
We have a little crustacean in the yard, we call pill bugs (these roll into small round pill shapes when bothered, sometimes called roly-poly bugs). These are small grey anthropoids.
They tend to make openings in pots into exit vents for potting soils, and thus can kill a potted plant, so I have always looked for ways to prevent that without using poisons.
One of those ways is to fill the bottom of a new pot with leaves, which, when compressed seem to be a barricade to the bugs.
Why did I call these a crustacean? It really is, and it is the only crustacean that can live its entire life on land.
Leaves though also help the plant to grow well in a pot. They prevent water from draining to quickly, allow roots to grow between the leaves, and slowly shrink away allowing both for plant growth and for removal of the plant when needed. They also provide some ongoing food for worms in the pot.
Mulch aquarium waste
I keep aquariums, really nice aquariums filled with green, and some red plants. Keeping an organic, a bio-filter for an aquarium is really easy, relaxing and fruitful. The only problem is, what to do with waste.
Waste in aquariums comes in two forms. If you keep a standard aquarium you should do regular water changes to keep algae from growing in the tanks and waste from killing your fish.
The water used in the aquarium is rich in nutrients and in biology and so does quite well in the garden or on your houseplants.
If you are like me and simply change a little water once a year (yep, once a year is all that is needed), then the problem will be what to do with all those plants?
You have three choices, throw them in the trash (not good), or sell them back to the fish store for store credit, or use them as compost or mulch.
Remember, these are water plants and most of them are so filled with water that they can be added directly to a new potting soil mixture, put directly into the mulch in the garden, or directly into the worm bin or compost pile.
Potted plants as mulch (pots on top of leaves speed breakdown, preserve water)
A pot as mulch?
Surely you must be kidding.
As Professor Neilson would say, I am not kidding, and don’t call me Shirley.
Sometimes there are areas you just don’t want to plant directly. This may be under a tree, or in a particular spot that is resistant to rapid soil improvement.
Potted plants can serve as a kind of mulch in these areas. I have a small spot which seems to resist all the soil amendments I put into it including a whole fish buried there, pots of soup, and other things. The soils is nice and dark, but there must be sand soils below because it drains quickly and nothing will grow there.
It makes a fine place for a pot.
Another zone is very dry and I am considering making this into its own bromeliad garden. In the mean time, I have pots covering those areas not yet planted.
What we mean by the term “mulch” is that it covers the area and helps prevent water from evaporating which improves the soil. Also, when you water the pot it slowly releases water into the soil below so you make double use of that precious water.
© 2015 Ronald A Newcomb