(music begins) - [Narrator] On this edition of Bay Area Bountiful.

- [Karen] Sediment is brought in with the tide floodwaters into wetlands, and then the plants capture it and becomes part of the soil.

So if there's less being delivered, then the soil doesn't build up enough.

- So to maintain, you know, the healthy soil food web, that's how we recognize that, you know, an organic farming method is one of the where that, you know, you maintain a healthy ecosystem.

- Well, it's not all about quote unquote carbon farming, it's about, it's about what's good for the community, what's good for the land, what's good for the animals, what's good for the environment and, how all of those things can come together to make something that's longer term and regenerative.

- [Narrator] Bay Area Bountiful is about agriculture.

It's about feeding us.

It's about land, and water.

It's about the health of our planet.

It's about stories that matter.

(upbeat music) Bay Area Bountiful, cultivate, celebrate, connect.

(music begins) - [Narrator] Bay Area Bountiful is made possible in part by Rocky, The Free Range Chicken and Rosie, The Original Organic Chicken.

The Sonoma County Agricultural Preservation and Open Space District.

Made Local Magazine and Sonoma County Go Local, and through the generous support of Sonoma Water.

(music ends) (music begins) - [Narrator] So much of life on earth begins with soil.

Soil is where we grow our food, it's what makes up the land, and it's teeming with activity, above and below ground.

(music) In the tidal marshes at San Pablo Bay National Wildlife Refuge, scientist Karen Thorn and Chase Freeman study how quickly sediment accumulates in the marshland over time.

They use a surface elevation table, a device that measures elevation change to track soil buildup.

- [Karen] It's really important to monitor what the wetlands are doing because we want to know, are the soils building?

so they can keep pace with sea level rise, meaning that they can build their elevations at the same rate that they get flooded with the oceans, but if the oceans rise too quickly, then things start to submerge or get drowned.

And so we can measure how much the soil is building, how much the plants are growing, both above and below ground.

And these wetlands are really important because they provide habitat for endangered plants, and animals, and birds, and they also provide flood protection, so during storms or high tides in San Francisco Bay, they can absorb that water like a sponge and really prevent our highways and roads and towns from getting flooded, so they're very important part of the estuary.

- [Narrator] The US Geological Survey installed four surface elevation tables at the refuge in 2013.

Karen and Chase take new measurements periodically to monitor any changes.

(weed sound) - [Karen] This is the pickleweed I talked about, it's pretty cool, it's a succulent, native succulent, and you can see the red tips of all the salt from the soil that it collects over a growing year, and then drops it in the fall.

And if you were to taste it, it tastes salty.

The surface elevation tables is a really common approach, so we have them, like we have some in the Petaluma River, and the San Francisco Bay Delta, farther up river, but they're also all over the world and throughout the United States and really just globally, so it's a standard approach that people all over the world can be... (laughs) (indistinct) So, people can... can use... everywhere, and it's all comparable cause we're doing the same thing.

(indistinct) - [Karen] I think I got everything.

This shows the four corners of the plot, and then we'll walk on this, so we don't disturb the plot.

(Indistinct) - [Karen] Sorry, I was trying to be helpful, is that helpful?

(Indistinct) - [Chase] This is basically a benchmark that we have out in the marsh, and then here's our service elevation table reader, it has a little notch right here that slides into the monument benchmark, the receiver and tightens down, and once it's completely tight, and all these are tight, we know that it's been in the same position as every other time that we've read it.

Once it's level, we have nine pins and we're just going to slowly drop them to the soil surface, and sometimes you got to get the vegetation moving a little bit, so you can actually see the surface, and then you can just go ahead and start dropping them down.

(wind blowing) Okay, so now that all the pins are down, we are going to measure from the arm of the reader to the top of the pen.

We will be able to look at that measurement over time, if it's going up, measurement's getting bigger, then we know that the marsh's moving upwards.

If it's the measurements going down, we know the marsh is moving downwards.

So pin one is 2,2,5, (Karen repeating) 2,2,9, (Karen repeating) 2,3,0, (Karen repeating) and 2,2,9.

- [Karen] So we were here in November of 2020, and based on his measurements, they've gone up, so we've gained elevation or the wetland has built sediments since then, so that's good news.

- [Karen] Sediment is brought in from the rivers, from our Delta and also from the tides from the ocean, and it gets brought in with the tide floodwaters into wetlands, and then the plants capture it and it becomes part of the soil, so if there's less being delivered, then the soil doesn't build up enough, so it's flooded underwater too much in a day.

So the plants out here are adapted to being flooded, but if they get flooded too much, they will die back and get stressed out.

And so this is a pretty natural but complicated process, but, you know, nature has been dynamically responding to sea level rise over time, just the question is how fast it's currently happening, and if our wetlands can build up fast enough to kind of keep pace with that.

- Each set has four corners; we have the A corner, B corner, C and D. The A, B and C have feldspar marker horizons, and feldspar is basically just the clay the hardens when wet and as sediment gets brought into the marsh, it'll basically create onto that feldspar marker horizon, and then when we take a plug, we can measure the accretion above that marker horizon, which then relates to the elevation change that we're measuring with the pence.

This is the B corner at feldspar marker horizon for the set, and if you come down here, basically what we did was we put out feldspar powder between these four posts, and over time you can see sediment has come in, but also this biomass has also broken down and become part of the surface, so what we're going to do is we're going to move some of that away, and we are going to cut a little bit of the plug out of here so that we can measure the feldspar layer.

So you can see a white areas, the feldspar, and that was the marsh surface before when we put it out, and this is the marsh that has created on top of it.

This is how we're going to be able to tell what is actual accretion versus the elevation change.

It's important to know both of those... have both of those measurements, and basically be able to tell what is above ground and what's below ground surface movement.

- [Karen] Here in California, there's tectonics, right?

So we're always sort of, you know, the land is always moving about up, down, right, left, but there's also sinking or land subsidence, where we have lost elevations of the land because of land use or some other reason, you know, a water extraction or something.

So when the land is sinking, what it requires is that wetland to build its elevation even faster, so it has to accommodate the rising sea levels, but also the sinking of the lands, so it's actually something we call relative sea level rise, which means it's a local rate because of sinking land and rising seas together.

It's an important thing to understand because right now most of our wetlands are keeping pace with sea level rise, but the current projections are that it's going to continue to increase over time, and so kind of tracking how things are doing out here is really important.

- [Narrator] While scientists studying marshlands are examining soil accumulation, certified master gardeners in California are looking very closely at soil content.

Though each receive a minimum of 50 hours of training, Sajeemas ''Mint'' Pasakdee credentials go way beyond that.

- [Mint] So we are part of University of California cooperative extension of the UCCE.

We have demonstration gardens, located in the South San Jose.

We have open houses throughout the years.

our program educate the public about how to become a better gardener, so gardening is not only get successful garden products, but also be able to garden with environmental friendly ways that minimize the impact to the environment.

I came here as a graduate student and I went to UC Santa Cruz for my PhD, and my research was on soil fertility and management and agroecology.

- [Narrator] Studying soil fertility and agroecology led Mint to learn more about what would become her passion, the soil food web.

- [Mint] Soil food web is an amazing world that is beneath us, so the complexity and the interconnection among those microorganisms is actually giving us a healthy soil.

And just to give you an idea, in one teaspoon of healthy soil, has about 1 billion microorganisms.

So it can be that many that you need the microscopic level to look into it.

- [Narrator] The soil food web is a model that helps explain complex biological activity in soil.

Healthy plants stay healthy when a key list of nutrients and organisms are present in their soil.

- [Mint] We define soil food web as a interconnection of living things that some of them you can see with the naked eye and some of them, you need to look under microscope.

One organism consumes another, all these nutrients it releases, it will become the important nutrient that feeding back to the plants, that's how we keep healthy plants that way.

- [Narrator] Mint is one of many proponents of the soil food web, another is Margaret Lloyd.

- [Margaret] Everything grows out at the soil, it's where all the nutrients come from, that is where nutrient exchange happens, it's where the soil microbes get their food, and where the soil microbes really thrive, so it's really the foundation for agriculture.

- [Narrator] In this drama, each actor plays a specific role.

- [Mint] Bacteria.

Bacteria is the microscopic single cell organism that they are also an important member of the soil food web.

So you see what we call nodules, these little dots, so this is where the bacteria will be able to bring the nitrogen from the air and store it in the soil, and then that's how the plant keep growing bigger and bigger without additional fertilizer, Rhizobium bacteria, so that's one group of them.

Another member of soil food web is Protozoa, and they are actually animals, including amoebas.

For example, the earthworm would eat them, so they become earthworm food and when the earthworm excretes the worm casting 'cause they are actually contribute to like, you know, giving nitrogen to the soil.

(music) So most of us would recognized Fungi, as part of the mushroom family.

So fungi is neither plan no animal.

So they are that unique group of living organism, they help with decomposition process.

What they do is they turn, you know, the fresh fruit or veggies to be the rotten food and veggies, you know, so the plant can use that as a part of the growing process.

(music) Another member of soil food web is called Nematodes, and some of you might recognize them as they uh, look like little worm.

It actually very hard to see with naked eye, you know, sometimes you can't spot them, but they are also beneficial nematodes, and also bad nematodes or bad guys.

So the next member of the soil food web is Arthropods.

- [Narrator] Arthropods, also known as bugs.

- [Mint] This group, you know, you'll be able to identify them, you know, with naked eyes.

As a little kid call ''roly polies'', which is a pill bugs.

And then this tiny spider that also live in the soil, you know, so they are also part of this group as well.

They consume the organic material, and when they excrete, that become a nutrients for the plants.

We recognize Earthworms, there are several species out there, so they are part of the decomposing organism that maintain the healthy soil biology.

And they do that thing on the soil surface, you know, the consuming the organic material on the soil surface, and turn that into the nutrient that would feed the plant, and worm castings have about four times higher nitrogen content than regular compost.

- [Margaret] All of these organisms from the microbes, to the earthworms, to the ground dwelling beetles, they're all working in this web of life, and above ground you have things like birds eating insects and worms from the soil.

They're moving nutrients around in a cycle.

(music) - [Mint] If you want to see beautiful flowers, or big tomatoes, you know, you need to have those soil food web members living out there.

I like to share my knowledge with the public, you know, and I love to garden myself as a scientist, you know, I love to talk about things that scientific support.

(leafs crushing) So there are a number of activities that, you know, could damage the soil food web.

(music) Adding chemical-base fertilizers, so you have to be careful with that.

So another factor that, you know, could actually damage the soil food web is about, you know, disturbing the soil or, you know, how you till the soil.

- [Narrator] We till the soil when we dig it up.

- [Mint] Extensive tillage can actually, you know, damage those microorganisms in the soil.

We would recommend you to minimize those, you know, activities that, you know, you dig deep into the soil.

(music) The option for organic farmers to have a good and healthy garden, you should actually maintain or recycling nutrients by adding compost, you know, as I would recommend, you know, adding compost and making your own compost.

(music) - [Narrator] Compost is the perfect addition to promote diversity in the soil food web.

- [Margaret] Biodiversity is key because we need to recruit all of the roles and benefits of all these different microbes, and we really need all of these skillsets, so to speak, to make that healthy soil.

- Soil is a living, breathing thing, and people are trying to rebuild their soils around the world, and it's the foundation for agriculture.

You know, the old adage, feed the soil, let the soil feed the plant, that's kind of what we're all about.

My partner, Brian O'Toole actually came up with the idea, he said, we're not in the worm business, really we're in the microbial business.

- [Narrator] TerraVesco specializes in raising composting worms, which produces nutrient rich soil called vermicompost.

Before the worms can create vermicompost, the food waste they're going to eat must be processed properly.

- [Margaret] Worms often are introduced a little bit later in the composting process, so when material first gets added to a compost pile, it can first go through these really thermophilic processes where it gets really hot and there's a lot of active decomposition happening, and that's really driven by microbes.

So once you sort of go through this like really hot process, and then it starts to cool down, then it can become ready for the earthworms.

So most composts stops after that first phase, and so vermicomposting takes that compost material and further degrades it.

- [Narrator] These composting worms called Eisenia fetida, thrive within and feast upon soils with high levels of organic material and manure.

- [Jack] The worms are consuming a composted dairy manure, we take that and we compost it into individual bins.

We will feed about an inch, to an inch and a half of material on top of the beds, and we have about a million and a half worms per 130 foot bed.

So they're turning that compost into vermicompost, and what comes out the bottom of the bed is a finished material, much more finished than what goes into the bed.

Those beds are alive.

We did a test, 528 different microbial species come out in our vermicompost, so there's a lot of life down there.

- [Narrator] West Marin Compost is also in the microbial business, they produce high quality and fertile compost, full of life.

- When we apply compost to the soil, we're actually applying microbes.

There are millions, and billions, and trillions, depending on the quantity of compost of living organisms in the compost.

Compost is important for a number of reasons; it feeds soil microbes, it jump-starts the soil, creates a state change in soil, so the microbes are healthy, therefore the plants are healthy.

They photosynthesize more, they create healthier food, more nutrient dense foods.

- [Narrator] Not only does compost benefit plant life and the quality of produce, it can also be a tool to capture atmospheric carbon and store it in the soil.

- [Kevin] Compost can facilitate carbon sequestration in our range lands in ways that we didn't imagine, the incredible piece is that it creates this state change in the soil.

All the activity, the living activity in the soil comes alive and the plants begin to thrive.

So as the plants thrive, and they're photosynthesizing more, they're bringing more soil carbon in, and they're sequestering more carbon.

- [Narrator] West Marin Compost provides UC Berkeley silver lab with compost to assist in the university's research on emissions, soil health, and carbon sequestration.

- [Kevin] So our compost is actually being delivered throughout the state, and being tested in different climates, and different soils, so that we really are getting some very interesting data about the benefits of compost.

To see the potential, the vast potential of, as this gets put onto our soils, these studies, and these are really in-depth peer reviewed studies that are measuring carbon, that's being sequestered from this one, small operation is incredible.

The number, the thousands and thousands of metric, tons of CO2, atmospheric CO2, that is being sequestered into our soil forever is making a difference.

- [Narrator] Ranchers like Loren Poncia see the value in carbon sequestering through compost application.

After partnering with the Marin Carbon project, Poncia continues to implement ecologically sound practices at his ranch.

- [Loren] So at Stemple Creek Ranch, we've tried to do the dance with mother nature for years and years, and do the right thing, and before I started with the Marine Carbon project, I thought that, you know, we're grass farmers and the grass would grow, and I didn't really pay much attention to the top foot of the soil, but really what I've realized in the last 10 years or so, and put a lot more focus on is, the financial health of our land, and the financial health of my family, and the high quality cattle; really is depending on high quality soil.

It's not all about quote unquote carbon farming, it's about what's good for the community, what's good for the land, what's good for the animals, what's good for the environment, and how all of those things can come together to make something that's longer term or regenerative.

The whole thing that drives carbon farming is photosynthesis, so in order for photosynthesis to have happen, you have to have a living root in the ground, and the plant has to be healthy enough to capture the rays of the sun, to pump liquid carbon into the soil.

So the processes that we use for carbon sequestration are really focused around a few main things, one is keeping soil cover, so we don't want to graze their grass or forb until there's no soil cover.

We use a lot of compost on our pastures and hill grounds.

We source our compost from a few local companies, and then we actually make some here on farm.

- [Narrator] Through conscious environmental efforts, Poncia is proud of what Stemple Creek Ranch has been able to accomplish.

- [Loren] I'd say the most rewarding part about carbon farming is seeing the cycle of life and watching how much forage, and how much biodiversity we grow here on the ranch when the seasons are right, and actually seeing positive results, and seeing that dark chocolaty, beautiful, healthy soil layer, knowing that our management, and the practices that we're doing are actually helping create more of that, because it's really, it's not real easy to see CO2 coming from the atmosphere and storing it in the soil.

It's not easy to see, it's not even easy to measure, but it's... when it feels right, and you see that you're producing high quality forage, and nutrient dense food for communities, it feels like the right thing to do, and just let's keep doing this over, and over, and over again.

I know that much about soil health and carbon sequestration, but I know a lot of what I won't do in the future, and a lot of what I will do more.

I don't want to speed up time, but I'm super excited to see what this land looks like in 10 years, because I think it's going to look totally different than it does now.

I hope, so we'll see.

(music ends) (upbeat music)