Amendments To The (Soil) Constitution

Did you know that fall is the most important season of the year for improving your soil?

You should be adding three things:  finished compost, raw organic matter, and organic nutrients.

Whether you are using your own homemade compost, or are purchasing compost in bags or by the truckload, stock up early with as much as you can afford. I use up a couple of yards of compost each fall (besides what I make in my own bins).

As you remove dead organic matter from your garden, apply at least a 3″ to 4″ layer of compost. While soil temperatures are still warm, the nutrients and organic matter in the compost will stimulate microbes and other beneficial organisms. Tired, end-of-season soil will be refreshed and renewed when spring comes around

Planting new shrubs, trees or other landscape plants?  Mix a few shovels of compost with the soil that goes back into the planting hole.

Raw Organic Matter

The soil in your vegetable garden will probably be laying fallow over the winter months (unless you’re lucky enough to garden year-round). To boost the amount of organic matter in your soil— beyond what you can get from finished compost— consider incorporating raw organic matter directly into the soil.

There’s just one thing to keep in mind when you’re adding raw organic matter to your soil. The beneficial soil organisms that will help decompose this material, require nitrogen to do their work. This means that if you don’t add some additional nitrogen along with the organic matter, the microbes will start using up the nitrogen in your soil. To avoid this, you can either add some nitrogen-rich manure along with the raw organic matter, or sprinkle on some granular organic fertilizer.

Shredded leaves are my top choice for raw organic matter. Use a leaf shredder if you have one. If not, just mow over the leaves several times with your lawnmower.

Animal manures (but not from dogs or cats) are great for the soil. You can gather it in buckets, plastic trash bags, feed bags, or in the back of a pickup truck. A good thing about adding animal manures in the fall, is that it doesn’t really matter if the manure is fresh or aged. Over the winter months, the caustic ammonia will dissipate, leaving behind valuable nutrients and organic matter.

Organic Soil Amendments

Most organic fertilizers release their nutrients slowly over many months, so applying them in the fall helps ensure they’ll be available to your plants next spring. If you can get your hands on some kelp meal,rock phosphate, or bone meal, do so. Because it’s the end of the season, your local garden center may even have some broken bags they’ll be willing to sell you at a discount. You can mix these organic materials right into your garden (or side dress around plants), along with the shredded leaves, manure and compost. Breaking down organic material requires some nitrogen.

If you suspect that your soil pH may need adjusting, autumn is the time to correct it. It’s best to raise or lower soil pH slowly, over a three- to six-month period. Add lime in the fall to raise the pH level of your soil. Add acidifiers like pine needles, peat moss and elemental sulfur if your soil is too alkaline. Remember that unless you already know that your soil is too acidic or too alkaline, you should always do a soil test to determine the pH level before taking corrective measures.

Better Soil — Better Garden

Improving the soil in your garden makes a huge difference in its ability to retain water, support healthy plant growth, and help your plants fend off diseases, pests and other stresses. Whether you’re new to gardening, or a seasoned pro, building better soil is the single most important thing you can do to improve your gardening success. And fall is the best time to do it!

The Nitrogen Cycle

All Life depends upon the chemical element nitrogen.

An atom of nitrogen lies at the heart of all amino acids, which are not only the building blocks of protein of which muscles and many other of the body’s parts are made, but also the basic constituent of DNA, which carries the genetic code for all living things.

Nitrogen atoms are also present in the molecules which enable energy transfer during photosynthesis. Without nitrogen, life as we know it would not exist.

Though about 78% of the Earth’s atmosphere is nitrogen, plants and animals don’t necessarily have an easy time getting all the nitrogen they need. Green plants can’t use the nitrogen that’s free in the atmosphere. Nitrogen must be “fixed” before it is usable by most living things.

NITROGEN FIXATION

The process of chemically altering unusable, free atmospheric nitrogen into a form usable by organisms is referred to as nitrogen fixation. In nature, there are two main ways of “fixing” nitrogen:

FIRST WAY: Lightning. If you’ve ever been close to a lightning flash and right afterwards smelled an ammonia-like odor, that was lightning-fixed nitrogen you smelled. Only a relatively small percentage of nitrogen gets fixed in this way, however. Nature’s main nitrogen fixers are…

SECOND WAY: Special microorganisms living mostly in soil and water.

Nitrogen-fixing microorganisms, existing abundantly but practically invisibly nearly everywhere, include a few forms of bacteria, the blue-green algae, and some fungi. Some nitrogen-fixing bacteria live in nodules, or small, bag-like growths on the roots of certain plants, especially members of the Bean Family.

NITROGEN-FIXING NODULES ON BACKYARD CLOVER

In many backyards, nodules can be seen on the fine, wiry roots of clover, a member of the Bean Family, and considered a weed by those who don’t know its importance.

The image below is a much-magnified section of the roots of the clover in the above photo. The brown, baglike things hanging on the larger roots are nitrogen-fixing nodules.

USABLE NITROGEN, STEP BY STEP

Typically, nitrogen-fixing microorganisms do not fix free atmospheric nitrogen to a usable form in one step. Usually one set of organisms converts free nitrogen(N2) to ammonia (NH3). This ammonia is accompanied by its ammonium ion (NH4+), which some plants can use. However, most flowering plants need nitrogen in yet another form, which microorganisms provide by converting the ammonia to usable nitrate (NO3-).

Already you see that various organisms must work together to accomplish this profoundly important job. However, it’s even more complex than what’s described above! The process of converting ammonia to nitrate, callednitrification, is usually accomplished by two different sets of bacteria working one after the other.

POINT TO PONDER

The point of all this is not to convince you that nitrogen is wonderful stuff, although it is. The point is that nature is composed of a huge number of interrelated parts, and nitrogen with all of its jobs is just one tiny, usually ignored part.

When we dump toxic chemicals (insecticides and oil pollution,for instance) into the Earth’s air, water, and soil, we are upsetting vital life-enabling processes by killing organisms that are profoundly important to the continuance of Life on Earth.