Henry Homeyer: What Are The Benefits Of Organic Vs. Chemical Soil Treatment?

One cold, snowy day, I stopped to reminisce about a conference I attended a few years ago, hosted by the Organic Agriculture Association in Pacific, California. There have been many hearings from scientists presenting research that confirms what organic gardeners have always known; There is even data showing that organic practices can reduce weed pressure. I dug through my notes so I could share what I learned.

Larry Phelan, a research scientist at Ohio State University, explained that he wanted to see if organic crops attract insect pests differently than those grown using conventional methods. He collected soil from two farms opposite. The reasons are the same, except for the caution of recent years. One organic farm, the other traditional.

The gardener. Are you worried that your flower bulbs are already blown? This is what you need to know

Henry Homer. How to make a simple plant support for planting seeds indoors

To mitigate the other variables, Phelan put the soil back in the greenhouse and planted it in a large pot. He then grew corn in pots, adding chemical fertilizers to some, fresh cow manure to others, and organic manure to others, using two types of soil for each method. When the corn was the right size, throw the corn digger into the greenhouse and see what happened.

Not surprisingly, corn borers prefer conventionally grown corn. Not only that, but the long-term history of the Earth is also important. Organically cultivated soils contain higher levels of organic matter and are always less attractive to diggers, even when treated with chemical fertilizers.

Why is organic soil better than chemical fertilizers?

Why does this happen? Phelan explained that plants have evolved over thousands of years to obtain their nutrients through the soil's food web, depending on a symbiotic relationship between plants and microorganisms. Chemical fertilizers are not suitable because they provide nitrogen for rapid growth, but often give too much nitrogen or too much at the same time. Soil rich in organic matter provides nitrogen and other essential nutrients in a slow, steady flow, just as Mother Nature does.

When plants get too much nitrogen, he said, the excess is stored as amino acids, which are the building blocks of protein. For insects it is like candy for children. they can spot it and go to the source.

Henry Homer. Saving traditional vegetable seeds

In another experiment, Phelan grew his soybeans hydroponically, varying the amount of available nutrients. Soybean caterpillars prefer plants that are nutritionally imbalanced, but it's not just nitrogen that matters. Iron, boron and zinc levels are also important. Of course, these elements are not found in ordinary fertilizers. Chemical fertilizers provide only nitrogen, phosphorus and potassium. A good, well-fertilized soil should contain everything your plants need.

How organic soil helps plants fight fungal diseases

Otar Mato, an employee of the US Agricultural Research Station in Beltsville, Maryland, also gave interesting results. He compared the health of tomatoes grown using chemical fertilizers on black plastic with the health of tomatoes grown organically with hairy pea mulch, an annual cover crop. It has been found that tomatoes planted with a hairy puppy are much better at combating fungal diseases, especially those that turn black and drop leaves, which is often the gardener's bane.

Mattu explains that peas fix nitrogen as they grow, meaning they take nitrogen from the air and convert it into a form that plants can use. It is pruned before flowering and allowed to remain on the soil surface, creating enough biomass to feed soil microorganisms.

Compared to chemical fertilizers and black plastic, Mattu found a 25-30% increase in yield using peas. He explained that organic tomato plants will eventually develop a fungal disease, but for the first 84 days after transplanting (late August for us), there were almost no black leaves. At the same time, traditionally grown tomato plants suffered a lot of damage.

Henry Homer. Plan a backyard vegetable garden now!

He attributed many of the changes to hormonal signals. Antifungal proteins can be produced when certain leaf defense genes are activated. He explained that depending on environmental conditions, certain genes are turned on or off. He was able to demonstrate this by imaging specific genes in tomato leaves to see their size and thus their level of activity. There seems to be something in the peas that causes the tomatoes to produce these anti-fungal proteins.

This shows that there are many benefits to being an organic gardener and scientists are getting the results. So consider avoiding chemical fertilizers when planning your spring garden projects. There are many organic fertilizers that are made from natural, biologically derived materials, such as oyster shells, peanut shells, cottonseed meal, and natural minerals such as rock phosphate and greensand. Of course, compost is a great way to increase biological activity in your soil.

Henry Homer's blog appears twice a week at gardening-guy.com. Write to PO Box 364, Cornish Flat, NH 03746. Include a self-addressed, stamped envelope if you wish to reply by mail. Or email henry.homeyer@comcast.net.

This article originally appeared in The Providence Journal; Henry Homer.