Tag: microbes

Soil-The Living Layer of Earth


A noted French theologian once said that “man is the living layer of earth.” He was referring to the spiritual realm, I’m sure. Because there is another “living layer of earth” right below our feet – the soil.

That’s because good soil is alive with millions, billions, trillions – countless mega trillions of living creatures which are born, live, procreate and die every second. A teaspoon of good soil would contain millions of living creatures, while a shovel-full would hold billions. An acre would contain more living organisms than there are starts in our galaxy… perhaps in the entire universe.

These organisms are part of the complex nature of soil – which is different from dirt. I’ll call good soil simply soil in the rest of this article.

I have already written about how soil is formed. Here is a deeper view. Once the tiny bits of grains have deposited and some organic material begins to grow and die, bacteria, single-celled animals and fungi begin to colonize the growing soil and mineral mixture.

Picture yourself in a forest. A tree sheds its leaves. Those leaves, now on the ground, begin to decompose. It’s not a process that just happens. The organic compounds in the leaves are being consumed by living microscopic creatures (and some larger ones). A single bacterium lives about 12 hours, after which it divides. In 7 generations, that single cell with become more than 16 million duplicates of itself. You could see that, in a year, the total bacteria population would completely cover the earth.

However, there is a failsafe, which contributes to the soil being enriched. Bacteria in the soil are being consumed by larger single-celled animals, like amoebas and protozoans. And while these cells are dividing, they are being consumed by even larger creatures.  Now, while all these microbes and macro-organisms are going through their life cycles, microscopically fine threads of symbiotic fungi are making their way from root to root.

It’s not over yet. Larger creatures – earthworms, pill bugs, beetles and other detritus-eating plants, munch away at the larger pieces of debris that the microbes did not finish consuming. The earthworms are especially adept at this, and they do more. By passing the detritus through their gut, they inoculate the particles with beneficial bacteria, which they then excrete back into the soil. Worms also make vertical tubes, allowing air and water to penetrate the soil.

Spiders, bug-eating beetles, ants, and other predators begin feasting on the earthworms and their helpers, adding their carcasses or depositing it as excretion onto the ground.

Now, even larger creatures come into the soil – like moles and birds. These predators love the other creepy crawlers and provide a useful purpose.


Every time I turn my compost in the spring, a robin perches near me waiting for worms. Since my compost is usually full of worms, except during the coldest days of winter, I don’t mind sharing them with this friendly avian. She waits until I have tossed four or five wriggling ones her way, she daintily picks each one up with her beak until she has all of them captured. Still holding them in her beak, she slams the worms against the crushed granite walkway until she has them dazed enough to her satisfaction. A quick flit to her next in a nearby oak, a couple of minutes there, obviously feeding her chicks and she’s back waiting for a more worm largesse. Occasionally, I’ll find her on top of my compost pile, scratching on her own – which is okay with me. I’ve got plenty of earthworms.  


This is the natural flow of things making up the living layer of earth and an essential part of the planet’s recycling process.

Advertisements

What is Soil? It’s not just dirt!


Plants obtain water and nutrients from the soil surrounding their root systems. Plants also use the soil to anchor them physically, allowing them to stand upright.

Soil is made up of weathered rock fragments which contain minerals, the decaying remnants of plants and animals, including micro-organisms, and the secretions from the plants and animals living in it. It contains varying amounts of air, water and micro-organisms.

Good soil is made up of about half solids and half pores or open spaces between the solids. The solids consist of minerals and organic matter. The minerals consist of a myriad of particle sizes, from those that can be seen with the naked eye to those so small that an electron microscope is needed to view them.

These minerals make up about 45 to 48 percent of all the solid matter in soil. An additional 5 percent is made up of organic matter – decaying plants and animals.

An ideal soil would consist of the above concentrations of minerals and organic matter and the other 50 percent would include 25 percent air and 25 percent water in the porous areas.

The air and water provide sustenance for plant roots. The organic material allows microbes to grow. The microbes in turn, help the plant retrieve minerals and nutrients from the soil.

For more information on soil, please click here.

Are you connected to Earth’s Natural Internet?


Are you connected to Earth’s Natural Internet?

By Bob Dailey

There is a fungus which grows in the soil on and around plant roots that is absolutely essential for plant health. In fact, this fungus is so important that some plant species cannot exist without it. Named mycorrhiza, which literally means “root fungus,” this organism creates a symbiotic relationship with plants. The amazing properties of this root fungus has prompted scientists to call it “Earth’s natural internet.”

If one digs into leaf mold, or into really good soil, tiny white filaments resembling spider webs can be seen spreading through the soil or leaves. This is mycorrhiza. Though deceptively small, a teaspoon of good soil can have eight or nine feet of the tiny strings.

Mycorrhizal fungi create a symbiotic relationship with plant roots, taking in minerals from the soil and delivering it to the plant, in exchange for sugars produced by the plant. Plant biologists have estimated that 95 percent of the plants investigated are either partially or completely dependent on these fungi- a testament to their importance. Orchids, for instance, are so dependent on mycorrhiza that even their seeds cannot germinate without it.

Once attached to plant roots, this fungus sends out tiny threads which extend out much further than the roots can extend.  Though they look like plant roots, these white filaments are what absorb nutrients. Since they have a great deal more range than the plant roots themselves and have significantly more surface area, they are able to find and take in significantly more water and nutrients than the plant roots can. Scientists have also discovered that mycorrhiza can store up nitrogen when it is plentiful, and then release it to the plant when there is a lack of nitrogen in the soil.  These fungi can also store water, which it releases to the plant in times of drought.

Plants that are not aided by these fungi may not be able to take up important nutrients such as phosphate or iron – which can lead to iron chlorosis or other plant deficiencies. Mycorrhiza can also play a protective role for plants in soils with high heavy metal concentrations, such as acidic or contaminated soils. These fungi are also suited for colonization of barren soils.

Soil-borne diseases (such as take-all patch and brown patch) are also serious problems for plants. Unfortunately, many residents are quick to apply fungicides at first signs of take-all or brown patch. While these fungicides will kill the bad fungi, it will also kill the mycorrhiza. A better method may be to inoculate the lawn with organic material that has high concentrations of mycorrhiza.

Studies are showing that plants colonized by mycorrhizal fungi are much more resistant to these and other diseases.  Scientists have also now determined that mycorrhizal fungi can also transport nutrients and water from plant to plant through extensive underground networks.

Operations like tilling can also kill mycorrhiza, although aeration prior to adding organic matter will do relatively little damage to it.  For floral or vegetable gardeners, many experts are recommending “no-till” methods.

Making black gold


Autumn carries more gold in its pocket than all the other seasons.

~Jim Bishop

Although golden autumn colors are great to behold, those beautiful leaves also possess another type of treasure – black gold, which, when coaxed out, recycle earth’s bounty. “Black gold” is what gardeners call compost, that rich mixture of nutrients and decayed matter that works wonders on all plants.

Leaves contain nutrients that the plants have taken out of the ground through their roots, pumped up their stems and trunks, up to the organs that make food for them…the leaves. The leaves fall and decay. Those nutrients that were trapped in the leaves return back to the earth, where they are reused again by plants.

In a forest, it takes about two years from when the leaf hits the ground to when it becomes part of the soil. A backyard gardener, using a well-managed compost system, can make a fairly large amount of good, rich “black gold” in about three months.

The decaying process is carried out first by microbes. When you see smoke rising from a compost pile in the winter, it’s not because the sun has heated it. The reason is that billions of bacteria are actually dissolving the materials and it is they who are creating the heat. A well-constructed compost pile can heat up to 130 F or more.

Carbon

The microbes feed on the leaves  and other sources of carbon. This could be shredded newspaper, shredded cardboard, old hay, sawdust, small ranches and twigs and pine needles to name a few.

Nitrogen

The microbes need another ingredient – nitrogen –  to grow and reproduce. Nitrogen sources vary: coffee grounds, tea bags, grass clippings, kitchen scraps (but no meat or dairy), aged manure, alfalfa pellets (yes the same used as rabbit food), and cottonseed meal are a few.  Manure from chickens or herbivores is okay to use if it is aged, but carnivore or omnivore manure (pigs, dogs, cats) should be avoided as they may carry pathogens that the composting process will not kill. Weeds should also be avoided, unless they do not have seed heads.

Carbon-Nitrogen Ratios

Although there is a complicated formula to measure the exact  amounts of carbon and nitrogen materials required to start a compost operation, the general rule of thumb is equal weight of carbon and nitrogen. These should be mixed well – a cake mix, not a lasagna.

Water and oxygen

Since all living things need water, add water while mixing the materials. When finished, the compost pile should have the wetness of a wrung-out sponge. Now, it’s ready to start cooking. In two weeks, the compost should be ready to turn. A compost fork is the best way to turn it.

Turning the pile fluffs up the material and adds more oxygen to the mix. To turn, just take forkfuls from one pile and dump them into a second pile. Some gardeners like two or three compost bins to turn one into another. Remember to add water if needed.

After this, turn the pile every week or two. Now, the other, larger organisms will come into your compost pile: earthworms, pill bugs and other detritus-eating animals, further breaking down the materials.

In three months, all these materials will end up as good, organic compost, or black gold.

Types of bins

There are numerous compost bins on the market. Wire bins or bins that are open at the bottom seem to work best because they sit directly on the ground.  That way, earthworms and other organisms can access them. Additionally, open bins allow the air to circulate more freely. Drum bins work, but not as well as open bins.

The benefits of compost:

  • It recycles nutrients back into the soil. One of the things that make plants different from animals is that they make their own food. In order to do this, plants need essential elements like nitrogen, phosphorous, potassium, calcium and others.
  • It improves soil structure. Adding compost helps create “aggregates,” or tiny clusters of soil particles. Soil with a large amount of aggregates is full of tiny (some microscopic) channels and pockets, through which air and water can pass or accumulate in small amounts. Compost also helps with silt or clay soils, breaking them up so air and water can penetrate and plant roots can expand.
  • Compost conserves water. It’s a simple fact. Soil which has compost in it holds more moisture. Soil with five % organic matter can hold up to three quarts of water per cubic foot. Composted soil acts like a sponge. The compost helps soak up moisture. A pound of heavily composted soil can hold almost two pounds of water. Compost also inhibits evaporation of moisture in the soil. In drought conditions, composted soil continues to provide moisture to plants.