- (Public Value) UCANR: Protecting California's natural resources
by Carole Kent
The power of caring and acting, and I emphasize EVERY action to care for the Earth (capital E) and earth (small e) is necessary and important. Greta Thunberg, the young climate activist from Sweden puts it this way, "no one is too small to make a difference".
Climate change is obvious and it affects everything. We can all work to stop and reverse this damage, and it all begins with soil. We can cultivate an attitude of caring and relationship with soils as we understand more about the life of the soil.
Healthy soil is teeming with life: approximately 8 billion microorganisms live in 1 tsp. of soil. Healthy soil has highly complex and organized relationships where everything is connected. Carbon is essential to all life and carbon use and sequestration is out of balance. By improving the health of our soil we help correct the imbalance, at the same time strengthening plant's ability to withstand increasing heat. Plants draw down and sequester carbon, carbon helps feed the microbial life in the soil which helps feed the plant, a true win (slowing climate change), win (feeding the microbes), win (feeding the plant).
There are many ways to increase soil health with innumerable benefits:
- Increase soil organic matter: All types of soil benefit:sand, clay & silt, because organic matter increases water retention,4" of compost can decrease water use by 40%, and compost attracts and feeds soil microorganisms.
- Keep soil covered: It can reduce soil temperatures dramatically, reduce evaporation, reduce weeds, reduce compaction and erosion.
- Practice judicious water use: Water in early morning and use drip irrigation, it reduces evaporation and places water next to roots
- Avoid chemical fertilizer and herbicides and pesticides: Chemicals kill the life in the soil, birds, bees, beneficial insects, leach into streams and lakes, contaminating water sources
- Maximize living roots, plant cover crops: Soil organisms need to be fed carbon, carbon comes from plants roots, roots enable carbon sequestration
- Increase plant diversity: Nature loves diversity, monocrops invite pests and disease. greater diversity above ground increases diversity below ground
- Minimize soil disturbance-no till: Disturbing the soil destroys the life in it and breaks up the soil food web, requiring rebuilding of fungal hyphae that link plants sharing water, nutrients and warnings of pest invasions. It breaks up aggregates and releases carbon into the atmosphere, allows water to evaporate and brings up weed seeds and creates hard pan
- Avoid soil compaction-don't walk on soil: It squeezes air out and soils have less ability to hold water, and thus can cause erosion
Our future depends on us taking action. Taking action depends on knowledge, caring and being aware that everything is connected. We are part of, not apart from this magnificent web of life. Deborah Koons Garcia, a documentary filmmaker says, "soil is one of the true miracles of the planet and we treat it like dirt."
Our calling is to change that.
Napa Master Gardeners are available to answer garden questions by email: mastergardeners@countyofnapa.org. or phone at 707-253-4143. Volunteers will get back to you after they research answers to your questions.
Visit our website: napamg.ucanr.edu to find answers to all of your horticultural questions.
Photo credits: Opensource image
Information links:
UC ANR Healthy Soils for California https://ucanr.edu/sites/soils/
Healthy Soil Basics https://ucanr.edu/sites/soils/Soils_101/
Tips to improve your garden soil https://ucanr.edu/sites/soils/Soils_for_Homes_-_Gardens/
Soils and Nutrients https://ucanr.edu/sites/Soils_and_Nutrients/
- Author: Jane Callier
This is the fifth post in this series following concepts and information from UC Master Gardeners of Napa County presentation, “Soil is the Solution, healing the earth one yard at a time,” https://www.youtube.com/watch?v=JqA8DqBtRuo . The presentation describes practices we can learn and implement about soil to help slow and ultimately reverse the damage humankind has done and slow global warming. Previous posts were May 24, June 7, June 28 and July 19, 2021.
Another feature of robust, healthy soil is a diversity of plants. Not only does this make an area of the landscape interesting; it means it's part of a healthy biosphere, working as nature intended allowing microscopic and larger organisms in the soil to achieve their full potential. Having a diverse natural system translates to stability in that system. Having a greater diversity above the ground also means a greater diversity below the ground.
Does this mean we rush out and buy plants and put them in the ground willy-nilly with no thought as to whether or not they are invasive, or their water and other cultural needs? For our mediterranean climate, California native plants are a good choice, plus there are many perennials and bulbs from other summer-dry mediterranean climates of the world that greatly increases our palette. There are many excellent plant lists to consult before a mission of diversifying a landscape. A combination of trees, shrubs and perennials are ideal. When planting food crops, plant starts of cold season crops as summer crops fade. This idea is called interplanting.
The discussion also needs to include the welfare of pollinators. Their importance can't be stressed enough. Without pollinators there would be no food, hence no life and we couldn't have a discussion at all. For now, as we think about plants for the landscape, keep in mind pollinators and plants they favor. Just as our tastes range from sandwiches to ice cream cones, so do pollinators appreciate a variety of plants. Plant a stand of flowering plants three to six square feet to make it easy for them to find. Provide fresh water and house them according to their needs, so they can feed, live and raise their young.
For safety in fire prone areas, non-combustible mulch should be used for areas less than five feet away from structures and shouldn't have plants. Live plants, even when irrigated, can ignite. For mulched areas between five and thirty feet from structures, large bark nuggets and composted wood chips can be used in non-contiguous areas.
Our takeaways are these:
A diversity of plants builds into a healthy system of root varieties, greater soil activity and carbon sequestration.
Appropriate plants for our climate are best.
Take care of our pollinators.
Napa Master Gardeners are available to answer garden questions by email: mastergardeners@countyofnapa.org. or phone at 707-253-4143. Volunteers will get back to you after they research answers to your questions.
Visit our website: napamg.ucanr.edu to find answers to all of your horticultural questions.
Photo credits: Creative Commons (CC BY-ND 2.0)
https://www.ebmud.com/water/conservation-and-rebates/watersmart-gardener/watersmart-plants/
https://ucanr.edu/sites/fire/Prepare/Landscaping/Mulch/
https://anrcatalog.ucanr.edu/pdf/8498.pdf
- Author: Jane Callier
Sadly, the damage doesn't end there. These conditions change weather patterns and impact water supplies. It's no wonder bare soil is another element in global warming. I remember my first-grade teacher discussing an article the class had read in “My Weekly Reader” about farming and the notion of leaving a field fallow for a season or two to rebuild fertility. Such was the thinking in the 1950s, and I thought the notion sounded perfectly reasonable. Of course, nothing could be farther from the truth. Unplanted bare soil degenerates and the carbon cycle stops working.
Alternatively, the process of photosynthesis is a cooling, or endothermic activity as plants make their carbohydrates. There is a net water gain if land has a continuous population of plants. The conventional agriculture practice of tilling renders a net water loss. If the soil is planted with a cover crop, water can keep infiltrating the soil, and life beneath the surface keeps functioning and staying healthy. Legume cover crops like fava beans and clover are good choices because they return a significant amount of nitrogen to the soil. This is achieved when the plants are chopped down and left on the soil. Using fast-growing buckwheat for a cover crop will feed pollinators. Mustard and brassica will fumigate the soil for nematodes. Grass roots hold soil in place and help keep the ground cool. All of them attract beneficial organisms, pull down carbon from the atmosphere and help retain water.
Mulching is another good practice to keep the ground cool. Two inches of compost should first be laid down, then three inches of mulch. Straw is an excellent, organic cover for garden beds. Mother nature can help by using leaves to mulch if we can get past another unuseful habit (besides tilling the soil) of demanding our gardens be perfectly manicured. It's always a good idea to spread compost, but the reason we do it before we mulch is that some mulches, such as wood chips, can leach nitrogen out of the soil. If we apply compost first, the effect will be buffered.
If we follow these practices, we will improve the tilth of the soil, promote soil organic matter (SOM), retain moisture in the ground, prevent leaching of soil minerals, attract soil organisms, and improve the yield and nutritional value of our fruits and vegetables.
Our takeaways are these:
Bare, tilled soil contributes to global warming.
Cover the soil with living plants.
Use cover crops.
When this isn't practical, add compost and mulch.
*This is the fourth post in this series following concepts and information from UC Master Gardeners of Napa County presentation, “Soil is the Solution, healing the earth one yard at a time,” https://www.youtube.com/watch?v=JqA8DqBtRuo . The presentation describes practices we can learn and implement about soil to help slow and ultimately reverse the damage humankind has done and slow global warming. Previous posts were May 24, June 7 and June 28, 2021.
Napa Master Gardeners are available to answer garden questions by email: mastergardeners@countyofnapa.org. or phone at 707-253-4143. Volunteers will get back to you after they research answers to your questions.
Visit our website: napamg.ucanr.edu to find answers to all of your horticultural questions.
Photo credits: Pixabay
- Author: Jane Callier
Healing the Earth by Healing the Soil – Maximize Living Roots, Minimize Soil Disturbance
This is the third post in this series following concepts and information from UC Master Gardeners of Napa County presentation, “Soil is the Solution, healing the earth one yard at a time,” https://www.youtube.com/watch?v=JqA8DqBtRuo . The presentation describes practices we can learn and implement about soil to help slow and ultimately reverse the damage humankind has done. Previous posts were May 24 & June 7, 2021.
It's easy to see how a healthy mass of roots benefits a plant, but there is a lot more going on with roots than making a healthy plant. Roots need carbon to grow and plants have the capability of drawing carbon from the atmosphere. Carbon dioxide, of course, is a major contributor to greenhouse gas and global warming.
What we're looking at when we inspect healthy roots is not just roots themselves. Through photosynthesis plants create carbon sugars to feed their own growth and deliver it to the soil via their roots.
As roots exude carbon sugar, mycorrhizal fungi are drawn to them, and the active chemistry and microbiology that happens between them in this narrow area around the roots is called the rhizosphere. Part of the mycorrhizae are their hyphae, garden hose like structures that can extend 300 yards. They attach to roots, creating an immense root system. Mycorrhizae metabolize more root sugar, plants grow, pull down more carbon from the atmosphere, and roots transfer minerals absorbed from the soil into the plant. Both plants and soil structures benefit from the interaction.
We're looking at a soil biome that we might compare to a bustling city: busy freeways, construction workers and lots of food trucks and bistros. What happens when we don't have plants, roots and microorganisms creating all this life in the soil and performing this scientific, yet magical dance? As one of the presenters commented, “without (it) we just have geology.”
Organically grown food from a biome we just described has a higher nutritional value. Several minerals are present in significantly higher amounts that contribute to overall health and help combat inflammatory ailments like Alzheimer's and heart disease.
Holding it all together
We have already learned that tilling the soil grinds up the soil biome, destroys microorganisms in our bustling soil community and leaves us only dirt, or, as mentioned above, “geology.”
The soil fungi hyphae in healthy soil make a protective coating called glomalin that literally holds the soil together, making soil into an aggregate. A healthy biome without aggregated soil cannot exist. A demonstration in the presentation made this easy to understand. One plate had a mound of flour on it representing tilled soil. Next to it was a plate with a piece of bread on it representing aggregated soil. Water poured on the flour ran off, penetrating nothing. The bread absorbed the water as does aggregated soil, keeping carbon, nitrogen and minerals in the ground. Aggregated soil has been likened to a “carbon sponge.”
We can create aggregated soil to maximize living roots by planting perennials and trees, both having roots that stay in the ground for a long time. A vegetable garden can be intercropped, that is, planting seedling cool season vegetables beside mature warm season crops that are nearing the end of their harvest. Becoming more and more popular is the practice of planting perennial fruits and vegetables. Common ones are artichokes, asparagus and strawberries. The goal is to have roots in the ground year-round. Our soil has degenerated to such an extent that the establishment of more plants and their roots can be a lifeline as the earth's climates heat up.
We need to overcome the habit of tilling the soil. As much as possible, we need to leave soil intact. Soil is made up of sand, silt or clay, water and air. Only 5% of soil is made of organic matter. Of this 5%, only 5% is made of living organisms. This is indeed a precious commodity, and most of it occurs in topsoil, the top two inches of soil.
Our takeaways are these:
- Protect our soil biome and the rhizosphere.
- Keep the soil aggregate intact and functional.
- Retain healthy topsoil and protect it from erosion.
Napa Master Gardeners are available to answer garden questions by email: mastergardeners@countyofnapa.org. or phone at 707-253-4143. Volunteers will get back to you after they research answers to your questions.
Visit our website: napamg.ucanr.edu to find answers to all of your horticultural questions.
Photo credits: Pixabay
- Author: Jane Callier
Use compost, not chemicals
This is the second post in this series following concepts and information from UC Master Gardeners of Napa County presentation, “Soil is the Solution, healing the earth one yard at a time,” https://www.youtube.com/watch?v=JqA8DqBtRuo . The presentation describes practices we can learn and implement about soil to help slow and ultimately reverse the damage humankind has done. The first post was May 24, 2021.
Using a military analogy, a reconnaissance mission is our first task. Once a pest has been properly identified, determine the number of pests and the extent of damage they are causing. Next, deploy a combination of biological, cultural, mechanical, and chemical management tools into combat. IPM almost always uses a combination of management techniques instead of dependence on only one method. While one of the goals of IPM is to reduce chemical applications, there are times where the best strategy involves the use of pesticides, but careful timing and the amount applied is critical to reduce the impact to non-target species and environmental degradation. For more complete descriptions of IPM's management tools see http://www.ipm.ucdavis.edu/
The use of chemical fertilizer gets us nothing as we endeavor to improve our soil. We might get plants that we can liken to a weightlifter pumped up on steroids, but take that away and we have some mediocre to sickly looking plants. Plants grown in healthy soil sustain themselves. It can be argued that on a molecular level, the primary nutrients of nitrogen (N), Phosphorus (P) and Potassium (K) are the same in both chemical fertilizer and in natural fertilizer. True, but if we leave out the fundamental operation that healthy soil provides to plants, (remember we get healthy soil by applying compost, whose organic elements nurture microorganisms,) we short circuit the natural process that mother nature has used for millennia. Instead of feeding plants, we need to feed the soil. From there, what nature intended will take over and the soil will feed the plants.
In the presentation, a convincing example illustrated how composted soil is the best nourishment plants can have. The experiment showed the biomass of root systems of borage plants grown using different methods of fertilization. The first example was the control, plants grown not using any product, had a root system that looked pretty good. Example two used synthetic fertilizer and there was almost no root system at all. The third example used an organic product; its roots looked about the same as using nothing at all. The fourth example was grown in composted soil. This plant's root system was the lucky winner. The roots formed an impressively large, healthy looking mass. That's what nature intended.
Master Gardeners are following recommended social distancing guidelines that keep everyone safe, Napa Master Gardeners are available to answer garden questions by email: mastergardeners@countyofnapa.org. or phone at 707-253-4143. Volunteers will get back to you after they research answers to your questions.
Visit our website: napamg.ucanr.edu to find answers to all of your horticultural questions.
Resources:
Photo credits: UC IPM video https://www.youtube.com/watch?v=UJeEVQm-9uE