Humic Acid as a Compost Accelerator

Humic Acid as a Compost Accelerator

Adding humic acid can accelerate your compost pile when it doesn’t seem to be doing anything. There are a number of reasons why your compost pile may not be decomposing and I’ll go over them. But first, let’s look at what a compost pile is made of.


A compost pile decomposes into dark-rich soil with the aid of microorganisms. But that process can happen in an accelerated manner only if the compost and microorganisms have 4 things: water, air, carbon, and nitrogen – all in the right amounts.

Carbon and nitrogen are supplied by the organic matter you pile to compost. They have to be in the correct ratio for microorganisms to be the most effective. You need a ratio of 20:1 to 40:1 of carbon to nitrogen for rapid decomposition. As the microbes decompose your compost, they will decrease the amount of carbon in the pile so watering with a dilute humic acid mixture (if it needs moisture) acts as a compost accelerator to give the microbes a boost.

You need greens and browns in a compost pile. Greens materials are vegetation such as vegetables that are past their prime to serve your family, fruit and food scraps (except dairy and meat), excess biomass, and grass clippings. Greens supply nitrogen to your compost. Browns are straw, fall leaves, and stalks of harvested crops such as corn or wheat. Browns add carbon to your compost. Be sure all the materials you use for compost are free of synthetic chemicals, which will kill the microbes in your compost pile.

Remember that 20:1 to 40:1 ratio of carbon to nitrogen? That means you must have 20-40 times more browns in your pile than greens. Where are you going to get 20 times the amount of browns for efficient microbial activity? Humic acid has a carbon content, adding it benefits your C:N ratio and stimulates microbial activity. When you add humic acid as a compost starter, your compost pile will start rapid decomposition.

If your C:N ratio is above the optimal range, in other words, too much nitrogen, the microorganism reproductive process will increase. More microorganisms mean they use the available oxygen at a faster rate. If there isn’t enough oxygen, the compost pile can quickly turn to anaerobic.

Turning your pile to incorporate oxygen and adding some extra fruit wastes is particularly effective because aerobic bacteria decompose simple sugars very effectively, increasing the population of microbes. More aerobic bacteria means accelerating the decomposition of your compost pile. Piling on woody material will slow down bacterial activity. The lignin in wood is more difficult for bacteria to digest. But it increases the fungal community. You may end up with a few pieces of wood in the finished product but you’ll have a strong and diverse microbial community which includes both bacteria and fungi.

Oxygen is necessary for aerobic decomposition. When there’s not enough Oxygen in your compost it starts to smell. That’s when you know it’s gone anaerobic. That means species of microorganisms that can handle anaerobic conditions have moved in and are decomposing your pile.

Anaerobic bacteria are much slower at decomposition than aerobic microbes. Pathogenic bacteria are predominantly anaerobic so oxygen is crucial for a healthy compost pile. To get it aerobic again just turn it. If you have a small compost pile, use a pitchfork. If you have a large farm with livestock and windrows of organic matter decomposing use the front-end loader of your tractor or a compost turner.

Water is a necessary ingredient for decomposition of organic matter. This doesn’t mean your compost pile is soaked (in which case the anaerobic bacteria take over and your pile smells). Your compost pile should have between 40-50% moisture so that it feels like a wrung-out sponge. Give your compost the “sponge test” by taking a handful where it’s wettest and squeezing it. If you can squeeze out an appreciable amount of water your compost is too wet. When a compost pile is too wet there isn’t room for oxygen and it will become anaerobic.

Although aerobic bacteria need water to live, they are actually found in a thin film on the surface of compost particles. There has to be enough water for chemical reactions to take place and enough oxygen for the microbes to live. The best way to achieve this balance is to turn your pile periodically, every week or two. Turning creates a balance of water and air pockets for rapid microbial decomposition of your compost.

If it’s still too wet after turning, put a tarp over your pile, this way you will protect it from getting wetter. Keep an eye on it and when it passes the “sponge test” take the tarp off.

Hot Compost Pile Means Active Microbes

Throughout the process your compost pile will heat up. You’ve seen steam coming off a compost pile or manure pile in the middle of winter, that’s from the heat in the interior caused by microbial activity. Isn’t it amazing how microbes can be invisible yet cause such obvious changes to organic matter? How a compost pile can be 5-foot x 5-foot x 3 foot tall with chunks of vegetables and leaves and over a period of a few months shrink 70-80%? And those chunks become dark rich sweet-smelling soil.

The interior temperature of a well-functioning compost pile can and should reach above 130o F in a few days. That’s hot enough to kill most weed seeds and pathogens, but it’s only happening in the core of the compost pile, that’s why turning your compost pile is so important. On the outside of your compost pile those same weed seeds and pathogens are alive and well. Turning your pile regularly will kill the weed seeds and pathogens and give you beautiful soil.

The Best Way To Start a Compost Pile?

There’s no “best” way to make compost. It depends on how quickly you want it, how much time and equipment you devote to it, adding humic acid as a compost accelerator, and how much you value that compost for farm fertility. The care you give your compost also determines the quality of your compost soil.

humic acid as a compost accelerator

Why Is My Compost Just Sitting There?

The #1 reason

You don’t have the correct ratio of carbon to nitrogen in your compost.

Composting For Your Garden

A pile of fall leaves will decompose given enough time. It takes more time because they’re primarily carbon and microbes take longer to use the excess carbon to create the correct C:N ratio before it looks like anything has happened. Even though you can’t see it a lot is happening in that pile of leaves you raked up.

When you raked you got some grass and grass roots so there’s a little added nitrogen. The larger the leaves the longer the decomposition time. Shredding the leaves increases the surface area giving microbes more space to populate.

Accumulating leaves in the fall, stockpiling them by the compost bin, and adding them in layers of browns and greens- lasagna fashion- makes it easier to have all the materials on hand.

A helpful hint: I bag (using paper bags) and stack as many leaves as I can in the fall and have them by the compost bin. As I add greens, I open a bag and remove what is needed to cover the green layer. When the bag is empty, I rip it up and it goes into the bin because its carbon!

Have a covered bucket next to your compost bin and when it’s full add the contents to the compost bin. It will smell terrible. That’s because the covered bucket is an oxygen free environment and its contents have already started decomposing with anaerobic bacteria. When you add it to your aerobic compost bin, oxygen is introduced to the waste and anaerobic bacteria are replaced by the aerobic microbes. The anaerobes will go dormant and become part of the soil. Be sure to add a layer of brown over the smelly greens or – it’ll smell.

Composting Manure On The Farm

If you’re piling manure and waiting for it to decompose, it probably has too much carbon in it. Very seldom will you have “pure” manure, it will almost always be a mixture of manure and bedding. Pure horse manure is almost the perfect C:N ratio for microbial action and rapid decomposition, according to the Univ. of Missouri Extension Service.

It depends on the bedding how high the carbon ratio will be in the mix. If wood chips are used as bedding the carbon can be as high as 300-500%, whereas oat straw will only be 70-75% carbon. Adding grass clippings, excess biomass, or kitchen scraps to your manure pile will speed decomposition. Chicken droppings, on the other hand, are high in nitrogen and must be composted or aged to prevent burning your plants. Adding humic acid to chicken manure acts as a compost accelerator.

The #2 reason

There is either too little or too much water. If there is too little and your compost pile is dry, microbes slow down their activity. If too much water, your compost pile will lack oxygen, anaerobic microorganisms will take over. They also cause your compost pile to smell, so if that happens, you know it’s too wet.

With any animal manures it’s critical the proper water and air conditions are met so the microbial activity heats up the compost pile to above the 130oF. Most pathogens and weed seeds in the manure are killed if this temperature is maintained for a number of days. Turning moves the material from the exterior of the pile into the interior, and vice versa. For more information on composting animal manures this guide is very informative.

How To Speed Up Composting

If your compost pile isn’t “settling” very fast you don’t have very active microorganisms in your pile. Adding humic acid to a compost pile, preferably as you build it, will activate microbes that are already in the ingredients you’re putting into your pile. If your pile is already built but is on the dry side (after doing the “sponge test”) water it down with humic acid to accelerate decomposition. Humic Land, an organic humic acid, stimulates microbial activity. It also acts as a chelating agent for N & P, stabilizing N and increasing the availability of P in the finished compost “soil”. It’s best to add ingredients in amounts necessary to maintain the C:N ratio so if you’re adding kitchen scraps (excluding meat, dairy, and fats) and don’t have quite enough, either wait until you have enough or add some grass clippings or other greens such as weeds that haven’t gone to seed at the same time. Making a lasagna layering of greens and browns then watering the browns with humic acid water will speed decomposition considerably.

Humic Acid Speeds Up Composting

Humic acid isn’t a fertilizer, it’s a biostimulant. It gives microorganisms the extra nutrients needed to rapidly decompose your pile. When you’re creating your compost pile think of humic acid as a compost accelerator because watering your pile with a dilute humic acid water stimulates microbial activity. It also adds long-lasting carbon to your compost soil, increases the CEC, creates higher water holding capacity, and helps to make nutrients more plant available.

Humic acid is not only a compost accelerator but when incorporated into your soil can dramatically increase yields. Because it stimulates soil microorganisms it helps plant roots receive water and nutrients.

Our product, Humic Land™, is an ecofriendly humic acid derived from peat. It’s not mined, so it leaves no deep scar on the face of the earth. It comes in a gel form that is easily diluted in water and can be applied with sprayers, irrigation systems, or a sprinkling can. Don’t you think your farmland and pocketbook deserve the benefits of Humic Land™? Contact us to find out more.

Posted in: Gardening, Humic Acids

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