eGarden © 2005 Ed Mues

From The Garden of Ed. Submitted for publication in The Towne Crier on October 19, 2005

It's Not Just Dirt, It's Our Soil Connection.

In my Labor Day column I suggested fall was a great time to plant trees, shrubs, bulbs including garlic, and also, a great time to fertilize lawns and established plants in anticipation of next years growth. The tops won't grow any more this year. A couple of hard frosts have put the plants to rest, so to speak. However, the roots will continue to grow until the ground is frozen.

Well, I got to thinking about this garden calendar of sorts, and it occurred to me that I have not once mentioned soils in any depth. Believe it or not, the thought struck me from a more recent column on the drought that followed the floods. Both are the results of extremes. I've come to the conclusion that sometimes it's a matter of asking," Can too much of a good thing be a bad thing?"

In considering the state of soil health and plant nutrition, it's not just about fair and dry weather, or rainfall, but the three elements needed for both gardeners and their plantings to be successful. Nitrogen (N), phosphorous (P), and potassium (K). These three are the most limiting elements related to plant growth. They are the three most important constituents of fertilizers. When any one of these in out of balance, there is trouble. N is needed in the greatest amounts for proper plant function. In a nutshell, Nitrogen is needed to produce lush green growth, chlorophyll, and comprises 18% of protein. Phosphorous is important for flowering and and fruiting, root growth and development, and plant maturity. Potassium is essential to balance the previous two elements , is needed in starch and chlorophyll formation, adds tone and vigor to plants, and confers some resistance to diseases.

There is an incredibly complex dance that takes place here. For our immediate purposes, let's remember that plants are a special life form in that they are autotrophs and manufacture their own food. I've said it before and I'll say it again. Photosynthesis may be the most important chemical process taking place on the planet.

So, what good thing could possibly be a bad thing, too? Nitrogen. One would think it would be blameless, since it's the most abundant element in our atmosphere, nearly 80 %. From this alone, one might think plants would always and forever have more than enough nitrogen. The problem is that atmospheric N isn't available to plants (think forests, as well as corn and tomatoes) until it becomes mixed with oxygen and hydrogen and forms nitrates and ammonium, respectively.

This natural process is part of that dance. It's performed by soil bacteria and microorganisms that live in the first few feet of our soils, just where the roots of most plants also live. There they are able to absorb the gaseous nitrogen and form ammonium which plants can now take in and make use of. Both bacteria and their companion microorganisms became known as "nitrogen fixing" because of this important ability. One extra, an important bonus, awaits. Many of these have symbiotic relationships with plant roots, most famous being the legumes (peas, soybeans, alfalfa, etc.). Their nitrogen fixing powers are nothing short of extraordinary. These can add hundreds of pounds of N to a field. What a dance!

Nitrogen is also "fixed" in the soil when we add chemical fertilizer. This, of course, is not a natural process, but a very common one, at home and especially on golf courses and some farms. I'll stick to homes and gardens.

In January of 2004 I wrote about the value of snow as a carrier of atmospheric N to earth where it is absorbed by the soil and then fixed as a free fertilizer, courtesy of Mother Nature. Lightning, with its intense heat, also makes a big contribution by allowing atmospheric N to combine with oxygen and fall to earth dissolved in rainfall. This is a form of the notorious "acid rain".

Any precipitation that has a pH lower than 5.6 is regarded as acid rain. It is usually a dilute form of nitric acid, and the N can come from decomposing vegetation and as a by product of blue-green algae which have the ability to fix N. Acid rain can also be a form of dilute sulfuric acid, a result of air pollution from industry and volcanic activity.

Acid rain where we live here in the Catskills is more the norm than the exception. Here is a closer look at "... how too much of a good thing might be a bad thing?" For a couple of summers, I measured rainfall pHs on a regular basis. More frequently than not, the pH ranges were between 4.8 and 5.3. Acid rain has negative impacts on growing plants. It clogs leaf stomata (the pores of the plant that allow for gas exchange) and this, of course, interferes with photosynthesis. To complicate the dance, the dilute acid dissolves and speeds up the leaching of important soil nutrients, in particular potassium, magnesium and calcium, especially around the root zone. To add insult to injury, this same process frees aluminum and other metals that hinder the plants ability to absorb the same three nutrients, now in short supply.

The result is that nitrogen begins to build and build, and the other nutrients become less and less available to a point where there is a collapse in the delicate balance necessary to maintain a healthy root environment.

In addition, runoff presents possible problems to life in aquatic habitats and to our drinking water. With all the excess N in the soil, we witness stimulated growth too late in the year. This can play havoc with both winter hardiness and pest resistance. Many of these symptoms are visible in the canopies of our forest trees. Look and see.

Traditional agriculture has promoted the repeated and continued application of N fertilizers. This has contributed to the gradual but continued acidification of our soils. The standard remedy was to lime to correct the soil pH. The resulting killing off of the beneficial bacteria and microorganisms was never contemplated, nor was the reduction in the plants ability to absorb vital calcium, magnesium and potassium. Several studies equate this to aging the soil at a rate twenty to fifty times normal.

What does this mean? If we allow this state of decline to continue, we lose. Big time. The nutrient content of our foods, fruit and vegetable, as well as the flesh of animals we consume that feed on these, has been decreasing at alarming rates. Research done by Dr. Philip Barak, Soil Chemistry and Plant Nutrition, University of Wisconsin, led him to suggest that the damage done to our soils in the last fifty years might be equal to thousands of years of normal aging.

Don't lose hope. There is a bright and shining light on this issue. It began a long time ago and has won many advocates. Robert Rodale and countless other followers bent on straightening out the ills of modern agricultural practices have led the way for a congregation of believers. I wrote about organic gardening in my June 18, 2003 column. Local organic and sustainable farmers and their markets are legend in all areas of the state.

Home gardeners who want to know more are above average, are environmentally aware and organically inclined. Visit these farmers' markets, talk to the local producers, and learn because you care. Fortunately for you, the home gardener, there is a different bottom line.

You can feed your soil and the habitat of your plants' roots. You care about what you put into your body and those of your friends and loved ones. It's about a respect for all life, including the life in the soil that nourishes. This is a bottom line, too. Different from that of the agro-industrial complexes. The tide is changing at an encouraging rate. Learn, spread the word and celebrate all life! You know it's not just dirt. It's your connection to the earth that sustains in so many ways.

From The Garden of Ed. Submitted for publication in The Towne Crier on October 19, 2005

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