[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.
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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