In my recent column (“One Solution to Climate Change Lies Right Beneath Our Feet,”) I described how our planet’s soil, air and water are in serious trouble. Soil is one of the earth’s largest carbon sinks, and it functions best when it has lots of carbon in it. But far too much carbon has been released into the atmosphere in the form of carbon dioxide. Where do we put that vast amount of carbon wreaking havoc on our planet?
Part of the solution can be found in our own yards and gardens. Here’s how:
Avoid synthetic chemical pesticides and fertilizers
These harm the soil organisms that digest and sequester carbon to support healthy plant growth. With the intention of buoying plant growth, home gardeners and commercial farmers alike add chemical fertilizers and nitrogen to the soil. However, easily half of this nitrogen is unused by the plant and is released into the air as nitrous oxide, a greenhouse gas. The production of chemical fertilizers and pesticides also contributes to greenhouse gases. Use of these products on soil contributes to nitrogen run-off which pollutes waterways, creating dead zones in the oceans and algae growth in ponds and lakes. Synthetic fertilizers actually reduce the fertility of the soil, leaving plants more vulnerable to pathogens and our homegrown veggies less nutrient-dense.
Increase organic matter in your soil
Add compost to your gardens, and if you really get hooked, make your own. Leave grass clippings on your lawns, and rake fallen leaves into your garden beds. More organic matter on and in your soil attracts and nurtures soil organisms and prevents soil compaction. Don’t forget to compost your kitchen scraps and food-soiled paper to the city’s compost program, by adding them to the yard-trimmings cart. This keeps food out of the landfill and goes a long way towards reducing methane, a potent greenhouse gas.
Don’t leave your soil naked
When you cover your soil with compost, mulch, straw, leaves, and chopped crop residue, it acts like a cozy, nutritious and protective blanket. Leave the leaf litter on your soil. It adds more carbon for the soil organisms and also helps prevent soil loss and compaction. Happy soil is soil you cannot see.
Maximize living roots in your soil for as long as possible
One of the important and positive changes that regenerative farmers are making is to plant cover crops to prevent weed growth, to protect the soil and to keep living roots in the ground year-round. Remember that plants feed the soil organisms, which return minerals to the plants from the soil. It’s a very collaborative relationship down there, under our feet. Growing plants, including cover crops, increases the amount of organic carbon and pore space in the soil. Living roots allow rain and water to infiltrate deeply where moisture is retained, reducing the need for additional water.
Consider plant diversity
Look at your yard and garden. Do you have different types of plants and trees growing? Diversity above the ground means a diversity of soil organisms below the ground delivering a variety of benefits to your plants. Diverse plants attract a variety of beneficial insects and pollinators. And there’s more! Different plants have different root structures, some broad and bushy, others drilling deep into the ground. Perennial plants and trees that live for decades establish root systems that hold stable organic carbon undisturbed deep in the soil.
Remember when we were told to double-dig our garden beds and rototill until the soil was fine and loose? Not anymore. Scientists are learning how the soil community functions. Let soil organisms do the hard work. First the bacteria, then the fungi, and afterward, the worms will finish tilling and digging your soil for you. We don’t want to break up those communities, or the soil aggregates they create. These aggregates enable our soil to hold together in heavy rains and winds, minimizing loss of topsoil and erosion. Many large-scale regenerative farmers avoid tilling soils entirely by growing plants and cover crops year-round, greatly reducing fossil fuel use as well.
Practice judicious water management
Try building a swale in a lower area in your garden or on a hillside to catch run-off, so the water and topsoil don’t end up miles away, down the river and in the Bay. Barrels to catch rainwater from the roof, drip irrigation to maintain a measured amount of water in the right place (this also minimizes weeds) and clustering plants with similar water needs will save on water use. Keeping soil covered with plants or mulch retains moisture longer, and the ground temperature stays far cooler, minimizing evaporation. Increasing the organic matter in the soil also increases the soil’s ability to hold water.
Move on from gas-powered tools
Exchange your gas-operated blowers and trimmers for rechargeable battery tools. Use an electric lawn mower if you still have a lawn. These battery-operated tools make a lot less noise, too. Make sure garden lighting is LED or solar-powered and purchase plants locally to avoid transportation costs.
There are more living organisms in a teaspoon of healthy soil than there are people living on the earth. By partnering with these soil organisms, we can grow more productive plants to feed our growing population. We will also be helping to address climate change by pulling a significant amount of carbon out of the atmosphere and putting it back in the soil where it belongs.
More actions you can take:
— Vote for candidates committed to addressing climate change. Follow League of Women Voters Candidate Forums: https://www.lwvnapa.com
— Watch the documentary “Kiss the Ground,” a hopeful and informative film about practices to heal our earth. On Nov. 12th from 7-9 pm, UC is sponsoring a screening, including local growers and gardeners to talk about their climate friendly, regenerative soil practices. https://ucanr.edu/ucmgnapa/
— Join UC Master Gardeners’ Zoom workshop on “Soils and Climate Change” Saturday, February 20, 2021, 10-12 noon. This group can also speak to your organization. Check the website calendar to register. See https://ucanr.edu/ucmgnapa/for information on this and other events.
Carol Glaser has lived in the Napa Valley for 43 years. She is a Master Gardener and member of Napa Climate NOW!, heading up the Carbon Farming Campaign.
Napa Climate NOW! is a local non-profit citizens’ group advocating for smart climate solutions based on the latest climate science, part of 350 Bay Area. Find us at Facebook or through http://napa.350bayarea.org
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