How Chemicals Affect Your Soil And What To Use Instead

Chemicals Harm the Soil Ecosystem

[Guest post by Phil Nauta]

Without a diverse soil food web, our garden gravitates toward being a desert.

The soil food web refers to the organisms living in and on the soil. While this includes plants and animals, we especially talk about microorganisms.

Having a healthy, diverse soil food web is critical if you want a healthy, vibrant garden. They do the work of creating excellent soil structure, making nutrients available to plants and even protecting plants from predators.

For example, there are special bacteria that take nitrogen out of the air and convert it into a form plants can use. There are special fungi that can get phosphorus out of the soil and bring it to plants, something plants have a difficult time getting themselves.

In return, the plants send a huge amount of carbohydrates produced during photosynthesis down into the soil to feed these beneficial microorganisms.

We definitely need these organisms in our gardens.

There are many reasons people have been so outraged by the potential Scotts-NWF collaboration. What I’d like to cover is the effect of chemicals on the soil food web. Importantly, this means both pesticides and chemical fertilizers.

How Pesticides And Chemical Fertilizers Impact The Soil

You may already know the problems with pesticides. “Cide” means to kill. That’s what pesticides are for. Herbicides, for example, are designed to kill plants, but they also have a big impact on non-target organisms. They kill or at least injure plants and microorganisms at the same time. Same goes for all pesticides.

It’s important to realize chemical fertilizers are extremely harmful to soil life as well. In the soil they undergo chemical reactions that can produce acids with a pH lower than 1.2 or bases with a pH above 11. These are toxic to pretty much everything.

Even without these reactions, the fertilizers are salts that interfere with the cell walls of microorganisms, hurting and killing them.

Consistent applications of synthetic nitrogen-phosphorus-potassium fertilizers at the expense of the dozens of other nutrients that are needed creates an imbalanced soil environment unsuitable for a healthy soil food web, leading to compaction, weeds, pests, plant sickness and a whole host of problems.

Then there’s the sewage sludge and toxic heavy metals that are included in many chemical fertilizers as filler.

What To Use Instead

This effect on the soil is one important reason we want to avoid chemicals in our gardens. We absolutely need a healthy soil food web in order to have a healthy garden. That means no pesticides and also no chemical fertilizers, especially the N-P-K brands.

When we start thinking of our garden as an ecosystem, we understand that we need to work with nature. Our job is really just to provide little tweaks to the system so nature can do what it does best, which is increase in diversity and abundance.

For fertilization, that means we add organic matter in the form of compost, mulch and plants, plus the occasional fertilizers and biostimulants to fill in the gaps.

For pest control, it means creating plants which are so healthy that plant predators won’t attack them in the first place (insects and diseases need nutritionally imbalanced plants).

And we create an ecosystem. That means things like compost and compost tea to improve the diversity of the soil food web. It means providing insects, butterflies, birds and other animals with water, food and shelter.

The soil food web organisms will take care of the rest as long as we give them what they need and avoid harming them with toxic chemicals.

What do you do to encourage your soil food web? Let me know below.

[Phil Nauta is a SOUL Certified Organic Land Care Professional and author of ‘Building Soils Naturally’, to be released by Acres U.S.A. this spring. He has taught for Gaia College and been a director for The Society For Organic Urban Land Care. He holds a Certificate In Organic Landscape Management from Gaia College, a Certificate In Sustainable Building And Design From Yestermorrow, and a Permaculture Design Certificate. He ran an organic landscaping business and an organic fertilizer business before starting Smiling Gardener to teach others innovative methods for organic gardening, especially in the vegetable garden.]

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  1. says

    Phil, thanks so much for contributing your thoughts to our discussion here. People seem to forget about the whole ecosystem of a garden under the soil, but in many regards a healthy soil ecosystem is the most important part of any garden, because without that, all else may be pointless. Soil science and the soil food web is a fascinating subject, which I’m just beginning to learn more about. Talk about a wildlife garden! The amazing array of wildlife who live in our soil is just astounding :)
    Carole Sevilla Brown recently posted..A Love Letter to Wildlife

  2. says

    Phil, excellent piece and much appreciated. So well said and a great addition to our cause, promoting true wildlife gardening . . . where we’re hoping to get people to stop & think before practicing the same old, same old . . . and often hazzardous . . . gardening practices.
    Pat Sutton recently posted..Mourning Cloaks in the Garden

  3. says

    Carole thank you for having Phil post. This is one of the best posts that speaks so clearly as to why we need to garden naturally. I can relate to the desert effect; the poor soil and plants. I had no idea of the chemistry and biology of what I had done to my garden with chemicals, but I could see it and feel it. It feels good to know why what i am now doing is the right thing.

    Phil, thank you for this incredible post. I do many things to help the soil food web including compost, compost tea, native plants, leaving the leaves and plants to decay naturally. I provide water through bird baths and a pond and food through native plants for wildlife. I have been rewarded with lots of wildlife in one year of change from a naive chemical user (although it was limited) to a natural gardener. I appreciate learning the why of what I know is the right thing to do…I love to learn and you have taught me so much!!
    Donna@ Gardens Eye View recently posted..The White Garden Revealed

  4. says

    Very helpful information Phil. I’m a big fan of whole-system thinking, and the facts you give us about soil chemistry add nicely to our understanding about what’s going on in our landscapes. Thanks!

  5. says

    Phil, You’ve managed to make the topic of the importance of healthy, living soil and the soil food web and make it so accessible. If we could all remember this one simple idea, our gardens would be so much healthier — “Our job is really just to provide little tweaks to the system so nature can do what it does best, which is increase in diversity and abundance.”
    Debbie recently posted..Just Say NO ~ 5 Ways To Break Up With Your Lawn

    • says

      I have read studies of health side effects of spraying BT. It’s especially a huge issue now that it’s genetically modified into crops. I don’t know much about milky spore.

      Either of them may be helpful for rescue, but they should not be used every year as a matter of course. Whether synthetic or natural, pesticides are just a band-aid for crops that are so nutritionally deficient that they are not really fit for us to eat anyway.
      Phil (Smiling Gardener) recently posted..Today I Define Humus And Why It Rocks My Pants Off

  6. says

    Phil, You’re preachin’ to the choir.
    I read the book “Teaming with Microbes” when it was first published… It discussed the soil food web in detail. While there is some controversy over the compost tea philosophy that was endorsed by the book, respecting the soil community is important…

    I’ve also been learning about development of landrace cultivars. Apparently there’s controversy there as well… but developing plants that thrive in local conditions seems like an integral step toward a thriving garden.

    I think that there’s got to be a way to leave all the garden kritters be… let them all sort things out…

    I am still looking for predator that targets squash bugs, though…

      • says

        I wasn’t sure if you were familiar with the controversial aspect of compost tea.

        The book by Jeff Lowenfels & Wayne Lewis suggests that compost tea needs to be aerated when made… That the aeration encourages the good microorganisms.

        The latest controversy is over whether there’s a health hazard in consuming produce grown with compost tea, and whether there’s a ground water danger.

        I’m not especially convinced by the argument, but it’s important to know what people are saying…

  7. Dee says

    Excellant post!
    So many gardeners need to change their mind set & their way of thinking. They think they are doing a good thing fertilizing everything in sight. They believe by applying fertilizers they are replenshing essential nutrients back to the soil, when in fact they are killing everything in the soil. I had no idea how bad chemical fertilizers are, but I never used them because I didn’t know if they would harm the cats and butterflies. I had no idea they are so toxic!
    I have a special receipe I use for soil. Composted manure, peat, worms & coffee grounds from the local coffee shop. I call & they save the grounds for 3 days, I get a large heavy bag. I top it off with much. This year I’m going to make compost tea.
    I have learned so much from this web site! I am so grateful to all of the authors who have shared their knowledge!

  8. says

    Nice write up Phil. Thanks for spreading awareness about ‘Cide’ part of pesticides and chemical fertilizers.
    They hurt soil most of the time as well as breaks ecosystem of soil.
    Not only they are harmful for soil but most of them toxic to Pets and Childrens. I can recall a incidence where pet of one of my friend died after ingesting toxic fertilizer when my friend was working in his garden.

    I think going organic is much better way to save ecosystem as well as to brings healthy plants growth.
    James recently posted..Fertilizer Numbers – Understanding Fertilizer Numbers, Its Meaning & How To Use Them


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