Typically, people connote soil with the ground.  When thinking about soil and plant life, everyone always seems to look downwards at their feet.  As we go further into the twenty first century, this image is going to be changing as people are going to have to look up to find soil.  Yes, there will always be soil at our feet, but now there is a huge push towards green roofs, or gardens on top of buildings.  As urbanization continues to increase, so will the growth of urban gardens on rooftops.  As this change occurs, one question will be how this soil above ground is different from that below our feet?

To some, the idea of a green roof may be a newer or foreign concept, but here in Charlottesville, they are very present.  In the University of Virginia community itself, there are green roofs popping up on the newer buildings.  In 2012, the University made it a goal to receive a Green Seal Certification by combing advanced technology with environmentally conscious practices.  The green roofs popping up around grounds are part of this initiative.

Rouss Hall Green Roof

Our initial plan was to take observations and soil measurements at the green roof on top of the new school of commerce building, Rouss Hall.  The layout of this green roof is a grid of 4 by 4 plastic panels deep enough to plant sedum in between each one.  The soil and sedum plants help serve as a layer of insulation for the building by absorbing heat and also protecting from the cold.  The choice of soil and sedum plants also holds waterfall to release it slowly and prevent flooding.

Green Roof on Ruth Caplin Theater

We later decided on using the green roof on the Ruth Caplin Theater to observe the soil.  This garden is a green roof hidden in plain sight.  The ground has a very thin layer of soil covered in a thin layer of gravel.  This helps to absorb water.  Around the outer edges of the garden are rosemary plants, while in the middle were a variety of sedum plants.  This garden is separated by pathways, so the public can easily walk around it.  Building this green roof was part of the initiative for helping UVA gain its Green Seal Certification.

Gravel Soil and Sedum Plants on Ruth Caplin Theater

Gravel on Ruth Caplin Theater Green Roof

The common factor between both roofs was the gravel combination with the soil and the use of sedum plants.  Sedum plants can be both low growing or grow tall.  The low growing sedum plants only grow to be a few inches off of the ground and are usually planted in rock gardens.  High growing sedum grow to be a couple of feet tall and are usually used as a border between flowers.  These sedum plants are so common on the rooftops because they are low maintenance and do not require frequent watering.  They also do not need shade and can be in direct sunlight. Another benefit, is sedum plants attract butterflies.  The low maintenance of these plants and ability for them to form the basis of a garden community explain why they are so common as the main plants used in green rooftops.

As urbanization and the push to be more sustainable increases, green roofs will become more common.  Green roofs will become more familiar and we will become more acquainted with the idea of sedum plants and gravel soil as we look up to the gardens, rather than down.

Sources

http://www.cavalierdaily.com/article/2005/04/green-roof-to-atop-new-comm-school

http://www.fm.virginia.edu/docs/annualreportFM/2012-2013AnnualReport-FM.pdf

http://www.garden.org/plantguide/?q=show&id=2059

Post by Danielle Danzing

“More respect is due to the little things that run the world.” – E.O. Wilson (Beatley, 35).

Whether it be for studying, relaxing in the shade, having a picnic in the grass, attending a social event, or participating in a walking tour, the Gardens of UVa are popular destinations for visitors, students, and faculty alike.  As the BioGrounds Team tasked with investigating life in soils, we have asked ourselves the following questions: How often do visitors to the Gardens pay attention to the living organisms that exist just below their feet?  What life forms actually exist within the soils of these mixed-use spaces?  And, how can knowing what life forms exist in the soil better connect us to the Gardens with which we have already become so familiar?

Observations and Findings

From the time that we entered the Gardens, specifically Pavilion Garden II, I felt as though we had entered another world.  Though we arrived to measure soil pH, water moisture, and search for signs of macro-invertebrates living in the soil, being in the Gardens instantly enriched day’s experience as I was overcome with awe in being surrounded by such a nature-full space.  We suddenly found ourselves away from the hustle and bustle of daily University life and surrounded by trees, shrubs, flowers, grass, butterflies, bees, and a brick wall.

Since the Gardens are well maintained and experience increased foot traffic in the spring-time, I was initially concerned whether we would find many life forms in the soil.  However, we were pleased to find ants, earthworms, centipedes, millipedes, beetles, slugs, tiny spiders, and what appeared to be barely-visible soil mites.  The presence of these many organisms indicate that, despite these gardens being manicured and well-maintained spaces, its soils are full of life that is necessary to promote healthy plant growth (both directly and indirectly), as well as serve sources of food for other organisms higher up in the food chain (Moravec and Whiting, 2014).  For example, in addition to being a food source for birds, earthworms help to add nutrients to the soil when they consume microorganisms and organic matter to produce nutrient-rich excrements.  As these worms create burrows within the clay soils of the gardens, they also facilitate the infiltration of water and help to oxygenate the soil for healthy plant roots.  Lastly, earthworms do best in soils with a nearly neutral pH, and higher moisture content, which is consistent with our findings (Card, 2011).

Earthworm

Millipede

Slug

Ant

Centipede

Experiences: The Healing and Restorative Power of our Gardens

While in the Gardens, I took some time to sit on a bench, clear my mind, and take in the surroundings.  As I looked out and scanned over the Gardens, I noticed how safe, happy, and at peace I felt.  I definitely felt a connection with this space after having a better understanding for what tiny life forms exists in its soils.  Realizing how much I did not know made me more appreciative of these organisms as they all serve important roles in helping to provide us with the healthy gardens that we have today.  For this reason, I think that the life in the soils of our gardens deserve much more respect and attention than they currently receive.

I later found myself making connections to what we learned in class regarding the concepts of “prospect,” “refuge,” and gardens as “healing spaces.”  The Gardens at UVa are perfect examples of spaces with good prospect.  A space with good prospect must have the ability to look out across a vast area.  I was able to look over several of the multiple-tiered levels of the Gardens to not only see the space in its entirety, but also see parts of the University.  Prospect is meant to foster feelings of openness and freedom, as well as safety and control (Browning and Ryan, 2014).  A space with good refuge, away from University-related activities, and demonstrated by the brick walls, is also meant to foster feelings of safety and security and allow for healing and restoration (Browning and Ryan, 2014).  Therefore, it should be known that the Gardens of UVa are not only habitats for many macro-invertebrates and arthropods, but also incorporate several biophilic elements that are relevant to our course.

Concept of Prospect

Concept of Refuge

So the next time you find yourselves in the Gardens, look down and see what living organisms might be co-inhabiting the soils of our University underGROUNDS.  Then, take a moment to walk around, or sit on a bench, and experience their therapeutic and restorative powers for yourself!  I certainly will.

Sources:

Beatley, Timothy. Biophilic Cities: Integrating Nature into Urban Design and Planning.

Washington, DC: Island, 2011. Print.

Browning, William, and Catherine Ryan. “14 Patterns of Biophilic Design.” 14 Patterns

of Biophilic Design. Ed. Alice Hartley. Terrapin Bright Green, 12 Sept. 2014. Web. 08 Apr. 2015. <http://www.terrapinbrightgreen.com/reports/14-patterns/>.

Card, Adrian. “Earthworms.” Earthworms. Colorado State University, 2011. Web. 8 Apr. 2015.

<http://www.ext.colostate.edu/mg/gardennotes/218.html>.

Moravec, Catherine, and David Whiting. “The Living Soil.” The Living Soil. Colorado State

University Department of Horticulture & Landscape Architecture, 2011. Web. 10 Apr. 2015. <http://www.ext.colostate.edu/mg/gardennotes/212.html>.

Post by Chantal Madray

On an overcast, stickily-humid April day, the Gardens taskforce of the Life in Soils team traipsed across the Lawn to the even-numbered Gardens lying between the Pavilions and East Range. There, we settled on Pavilion Garden II, a tiered landscape featuring a diverse spread of edible plants, including a large pecan tree, blueberry bushes, grape vines, four varieties of heirloom plums and crabapple trees. The garden is also home to daylilies and a magnolia tree. This garden would be the site for our data collection of soil moisture and pH measurements in order to test the soil quality and therefore extrapolate on the health of the Gardens. We then moseyed around, surveying the soils in each patch of landscaped shrubbery and plants. We came to choose three sites within the garden with which to average our data on soil moisture and pH. The first (1) was a mostly bare patch of soil, with some onions and what looked to be tulips poking out of the ground nearby. The second (2) place was a spot beneath a number of plants nestled around it. The third (3) was nearer to the Rotunda side of the garden, and therefore closer to the construction work that is still underway, right next to a large tree.

Area (1)

Area (2)

Area (3)

Why do soil moisture and the pH level of soil matter?

First, let’s talk about what each measurement means. Soil moisture content tells you how much water is in the soil, usually as a percentage, representing what percentage of total ‘volume’ of soil is moisture. The amount of water that’s in the soil is of fundamental importance to many hydrological, biological and biogeochemical processes. It determines how much water is available for surrounding plants to take up and is a key variable in controlling the exchange of water and heat energy between the land surface and the atmosphere through evaporation and plant transpiration. Soil moisture, then, plays an important role in development of weather patterns and the production of precipitation. It also directly affects topsoil and nutrient runoff into nearby streams and rivers, resulting in pollution and ecosystem health implications. Soil moisture information can be used for reservoir management, early warning of droughts, irrigation scheduling, and crop yield forecasting.

Soil pH, on the other hand, is an indication of the acidity or alkalinity of soil and is defined as the negative logarithm of the hydrogen ion concentration. The pH scale ranges from 0 to 14, with 7 as neutral. From pH 7 to 0 the soil is increasingly more acidic and from pH 7 to 14 the soil is increasingly more alkaline or basic. Soil pH has a significant effect on the solubility of essential minerals and nutrients that plants need to obtain from soil. Before plants can use a nutrient it must be dissolved in the soil solution. Most minerals and nutrients are more soluble or available in acidic soils than in neutral or slightly alkaline soils. However, a soil that’s strongly acidic can also be toxic to the growth of certain plants. A pH range of approximately 5.5 to 7.0 promotes the most readily available plant nutrients for most plants. Additionally, soil pH can influence the activity of beneficial microorganisms, affecting plant growth. Bacteria that decompose organic matter are hindered in strongly acidic soils, resulting in a lack of available nutrients, particularly nitrogen, for plants to use to grow effectively.

Testing the soil moisture content

Testing the pH level

The data we collected is as follows:

Soil Moisture

(1) VMC (volume moisture content) 55%

(2) VMC 58%

(3) VMC 34%

* Average soil moisture content: 49% *

pH Level

(1) 6.84

(2) 6.76

(3) 4.47

* Average pH: 6.02 *

Conclusions drawn from the data:

The soil moisture content average at 49% indicates that the soil in the gardens is most likely at an optimal water content level in order for plants to transpire maintain normal plant growth. In area (3), the soil was composed of more clay and was located right next to a large tree, which could account for the less soil moisture content recorded there.

The average 6.02 pH level we recorded is classified as a moderate acid, which is in the range that is optimal for most plant growth, indicating that the nutrients and minerals in the soil are able to be dissolved in the soil solution and taken up by plants. At this level, it is most likely that the soil is rich with the nutrients plants need to grow and thrive. It is interesting to note however, that area (3) had a noticeably lower pH than the other two locations. The higher acidity found here is most likely due to its proximity to the construction that was occurring right on the other side of the undulating brick wall.

Final thoughts + musings:

So why did we, a group of busy college students with meetings to attend and essays to write, take the time out of our day to go out into the gardens and measure some components of soil? Besides the fact that we were assigned this project, we have truly come to realize how important it is to measure soil health because of the impacts and implications soil has on the ecosystems and nature it supports. Soil is one of the fundamental components of natural systems and fluctuations in the nutrients, minerals and water that composes this vital substance can affect biological functioning, environmental quality, and plant and animal health. Understanding the interactions between soil properties and management will ensure the adoption of appropriate practices to improve and maintain the health of our soils. And ultimately, the health of our soils determines the health of us as individuals, contributing to our happiness and overall wellness. Every time I step outside, I look down to the soil at my feet and feel gratitude and awe for the often-overlooked substance that provides the wondrous opportunity for growth and life.

References:

http://mea.com.au/soil-plants-climate/soil-moisture-monitoring/learning-centre/soil-moisture-content-in-the-field

http://wwwghcc.msfc.nasa.gov/landprocess/lp_home.html

http://www.esf.edu/PUBPROG/brochure/soilph/soilph.htm

http://www.extension.colostate.edu/SEA/News%20Releases/2012/Why%20Should%20We%20Care%20about%20Soil%20Health_Trujillo_5.14.12.pdf

Post by Allie Arnold

No visit to Grounds is complete without a jaunt in Jefferson’s extensive and well-planned gardens. All ten contain unique plant life complete with charm and character. Jefferson intended for the gardens to be a place to study and be studied. Contained by famous serpentine walls, the gardens remain largely empty nowadays except for the occasional evening event or brilliantly sunny day when locals walk their dogs or children fence to fence through squares of lawn, flowers, shrubs, and trees.

Jefferson also left many of details of the garden to be decided by Pavillion inhabitants. Residents were allowed to plant whatever they liked, so each plot assumed a very different personality and changed often. In earlier days, beans, peas, cabbage, and fruit trees served as ornamentation and livelihood. A historical restoration of the gardens occurred in 1950, and more maintenance took place in the 1980’s. By 2003, the gardens were dramatically different from their original composition.

A brief summary of the individual gardens:

Garden I is divided by a serpentine walk bordered by azaleas, purple leaf plums, and a sweetgum tree. The garden was once bordered by fruit trees and full of rectangular beds for vegetables and herbs.

Garden II contains a diverse spread of edible plants. A large pecan tree stands amongst grape vines, blueberry bushes, four varieties of heirloom plums, and crabapple trees. The garden is also home to daylilies and a magnolia tree. The trees were planted between 1915 and 1953 by the resident of Pavillion II, Dean Ivy F. Lewis, professor of biology.

Garden III is the largest of the garden, complete two Biltmore ash trees to shade the extended lawns. Other plantings in neviusia, a goldenrain and silverbell tree.

Neviusia 

Garden IV contains descendants of French marigolds planted by Jefferson. It was restored to its late eighteenth century style in 1916 by the Albemarle Gardening Club. The design included tree peonies, rose blossoms and Southern magnolias.

Garden V is dotted with two “Albemarle pippin” trees in the center of each square that defines the bottom half of the garden. The upper area is sprinkled with purple hostas and pink crepe myrtles, and defined elegantly with green boxwoods.

Albemarle Pippin Trees

Garden VI is modeled after an orchard in the middle terrace. The upper terrace is a small lawn bordered by boxwoods. Its contains a famous feature, the Merton Spire (built in 1491 and donated to the University in 1928), which was carved for Oxford’s Merton College Chapel. It can be said that VI contains the most wilderness due to its native trees and shrubs, which include sweetbay, rhododendron, and mountain laurel.

Rhododendron

Garden VII has a smaller area due to several additions. Its serpentine pathways are dotted with romantic roses.

Garden VII

Garden VIII’s main blooms of crepe myrtle, rose of sharon, and chaste trees occur during the summer. Intimate flower gardens hide behind large boxwood while oakleaf hydrangeas and roses line the walkways. A small formal orchard is home to apples, plums, and walnuts.

Garden IX also contains a wide variety of edible plants. “Cox orange” and “pippin” trees line the lower wall, pomegranate shrubs border the edges, and a large fig sits in the center. The garden was originally designed around the McGuffey ash, which stood for one hundred and fifty years before sucombing to disease in 1989. Other plants include Persian lilacs, peonies, viburnums, amelchancier, and clethra.

Amelchancier

Garden X is reminiscent of popular Southern styles of the eighteenth century. Kentucky coffee trees and a collection of boxwoods create an old-world atmosphere. An oval lawn is strapped with “elephant ears” and large hollies left over from an earlier garden.

Soil, in many ways, serves as a record for the activities that occur on its surface. Layer upon layer of minerals, organic matter, water, and air document and preserve the past, both of the land and the people. An analysis of the soil is thus a chronicle of history above the ground and a self-preserved record of underground life. The gardens are as integral to Jefferson’s vision of the University’s layout as the Lawn and architecture that frame it, and therefore their histories, as documented by the soil, are equally as important.

Post by Kendall King

Sources

http://www.virginia.edu/uvatours/gardens/gardensExplore.html

http://www.vahistorical.org/collections-and-resources/garden-club-virginia/colleges-and-universities/university-virginia

http://www.virginia.edu/uvatours/gardens/

http://www.c-ville.com/secret-gardens-uvas-pavilion-gardens-harbor-history/#.VRQ1VxDF_K0

http://www.virginia.edu/uvatours/gardens/gardensHistory.html

Picture of the Neviusia: http://www.southeasternflora.com/view_flora.asp?plantid=521

Picture of the Albemarle pippin tree: https://www.willisorchards.com/product/newtown-pippin-apple-tree#.VRcy4BDF_K0

Picture of the rhonodrenon: http://www.almanac.com/plant/rhododendrons

Picture of the amelanchier: http://commons.wikimedia.org/wiki/File:Amelanchier_lamarckii_bloeiwijze.jpg

When I was in grade school, my science teacher (who was coincidently my mom) played a song for us called Dirt Made My Lunch by The Banana Slug String Band. While I have forgotten most of the lyrics, I remember the main and key theme. We have a lot of gratitude to express to Earth and its soil. Soil sustains us and helps us build life. All soil, however, is not the same. Soils can be affected by what the land is used for and how frequently the land is visited. As the Life in Soils team, we look forward to exploring the biodiversity of these soils and learning more about under Grounds.

As a group, we chose to test three types of sites. We will test some of the gardens in the back of Pavillions, the lawns’ of different frat houses and the green roof on top of Rouss Hall. We hope to see how different social settings, use and ability of access will affect the biodiversity of the soil at these sites.

Garden of Pavillion V

To help us determine the biodiversity, we will both test for signs that show the health of the soil and observe for life. We plan to test soil for its pH levels, moisture content and observed life in the soil.

But what exactly is soil? And why does the pH and moisture content of the soil matter? And why does biodiversity of soil matter?

 Fraternity Houses at UVa and their lawns

Well, soil is a general term, which refers to Earth’s outermost layer. Sand, silt and clay compose soil in different proportions. Clay is a key component of the red soil that is very typical of Virginia. The color of soil gives us more information about soil, such as the moisture content and make up of the soil. As bedrock breaks down, this becomes a key component of soil. As well, organic matter is a key component of soil.

pH measures the concentration of hydrogen ions, and the pH scale runs from 0 to 14, with 7 being neutral. The zone of the pH scale that is most conduciveto plant growth would be something from 6 to 7. To determine the pH of soil, a pH meter is used. Over time, soil can become more acidic. One way to help solve the problem of acidic soil is to add lime to the soil. Not only does lime help to raise pH, but it also provides calcium and magnesium, two key elements of soil. Additionally, lime makes phosphorous more readily accessible for plant growth. Lastly, lime helps break down organic matter, which makes more nitrogen available for plant growth. Soil moisture conditions influence how plants will absorb the water from the soil.

Rouss Hall Green Roof

Lastly, biodiversity is important for soil healthy. At the same time, the biodiversity in the soil, shows us the health of the soil. Soil, it is important to remember, is filled with living organisms. These organisms could be microscopic, like bacteria, or the organisms could be larger, like earthworms. This living organisms help to break down the organic matter and make healthier soil. These organisms help to keep the carbon cycle of soil constantly going.

Soil is extremely important. Our team hopes to examine soil at each site and see how it has been affected. By measuring pH, we hope to see what life the soil could provide. Testing the moisture content of soil will help us see how this plays into life in soils. As well, we will keep our eyes open for signs of life by each site. By examining these aspects of soil, we will begin to see the life of soils.

Post by Robert McCarthy

Sources:

https://www.soils.org/discover-soils/soil-basics

https://www.soils.org/discover-soils/soil-basics/what-makes-soil-soi

https://www.soils.org/discover-soils/soil-basics/how-do-soils-form

http://www.esf.edu/PUBPROG/brochure/soilph/soilph.htm

http://www.soils4teachers.org/biology-life-soil

http://www.agriinfo.in/?page=topic&superid=4&topicid=274

Images:

Rouss Hall Green Roof – http://www.greenroofplants.com/projects/viewproject/?projectid=268

Now that we’ve established the composition and components of soil, and described a brief history of soil in Virginia, we can expand on what properties in soil promote growth. We can do this while examining different soils from around central grounds. Three areas we will highlight are Observatory Hill Field (Figure 2), Fayerweather Hall (Figure 3), and the Lawn (Figure 4).

Organic matter

Organic matter broadly alludes to the assortment of dead plant and animal material in the soil. This includes everything from ground-up leaves to compost. Organic matter is essential to soil for its wide range of benefits that it provides. These benefits include being able to “supply nutrients for plants by providing surfaces where nutrients can be held in reserve in the soil, facilitate better drainage by loosening soil structure, store water in soil, help increase air drainage, and increase the activity and numbers of soil microorganisms” (organic matter). The optimal level for organic matter in soil is about 5 to 6 percent. From Figure 1, we can see that most places meet this level, or come close to it. Interestingly, Observatory Hill Field has the lowest level or organic matter listed, measured at just 1.33% (Refer to Figure 1 for all measurements). Desert areas have around 1% so its possible that this soil sample was taken when they were reconstructing the field, and did not have any grass there at the time. On the other hand, Fayerweather Hall, with 7.83%, had the highest recorded percent of organic matter. While this may initially seem like a very good situation for growing plants, it has been ascertained that too much organic matter can actually be detrimental. It can heighten the levels of phosphorus to the point where it becomes poisonous for plants, and can also “over stimulate microorganisms, which then consume so much nitrogen and other plant nutrients that soil fertility temporarily declines” (organic matter). Between the two extremes, is the lawn, with all flats retaining an organic matter percentage of 4.65-5.59%. Since the Lawn is iconic to UVa, there may be more of an effort put into regulating this area, which would explain the good levels of organic matter. However, overall, the majority of sites around grounds have recorded mainly optimal percentages.

pH

Another key determinant of soil fertility is pH, which is important because it allows plants to easily dissolve nutrients in the soil. The pH scale goes from 0 to 14, with 7 being perfectly neutral. Anything below 7 is increasingly acid, while everything above 7 is increasingly alkaline. Like organic matter, there are damaging effects if the pH is too low or too high. For example, plants nutrients rapidly leach out of soils, bacterial activity “that releases nitrogen from organic matter and certain fertilizers” does not take place, and the overall texture of the soil changes to make it difficult to cultivate (Perry). Specifically, when the pH falls below 6, nitrogen, phosphorus, and potassium are leached more rapidly. When it is above 7.5, iron, manganese, and phosphorus are not easily absorbed (Understanding PH). Therefore, a good range for pH is about 6-7.5. Every plot recorded on grounds fell within this category, with 6 being the lowest pH and 7.2 being the highest. Observatory Hill Field had a pH of 6.8, Fayerweather was recorded as 6.1, and the Lawn flats ranged between 6.2 and 6.6. These pH levels are consistent to Virginia’s natural levels based on the amount of rainfall and vegetation.

Although these are just two predictors, they can adequately show the health and growing potential for the soils around grounds. If you wish to further examine other predictors, they can be found in the Turfgrass soil summary table in Figure 1.

Works Cited:

Websites:

“Organic Matter.” Organic Gardening. Web. 27 April. 2014. http://www.organicgardening.com/learn-and-grow/organic-matter

Perry, Leonard. “Department of Plant and Soil Science.” PH for the Garden. Web. 22 April. 2014. http://pss.uvm.edu/ppp/pubs/oh34.htm

“Understanding PH.” What Is Soil PH and What Does It Mean?: Organic Gardening. Web. 22 April. 2014. http://www.organicgardening.com/learn-and-grow/understanding-ph

Images:

Fayweather Hall. 2006. Charlottesville. Office Architect UVA. Web. 22 Apr. 2014. http://www.officearchitect.virginia.edu/GroundsPlanWebsite/GPNEW/CaseStudies/GPCaseStudiesWilsdorfHall.html

Observatory Hill Dining Hall. 2006. Charlottesville. SaylorGregg Architects. Web. 25 Apr. 2014. http://www.saylorgregg.com/projects/uva-ohill.htm

The Lawn. 2010. Charlottesville. Web. 22 Apr. 2014. http://en.wikipedia.org/wiki/The_Lawn

UVA Turfgrass areas soil results. Charlottesville. 9/13/2013. April 19. 2014.

Post by Merrill Hermann, First-Year, Undecided

Superstar sustainable beyond-organic farmer Joel Salatin of Polyface Farms sums up the diversity of life under our feet when he proclaims in his book, Folks, This Ain’t Normal, that more individual life exists in one double handful of healthy soil than there are people on the face of this earth! He imagines the microscopic universe inhabiting the very soil that nourishes our plants and forms our landscape:

“A six-legged grazing microbe, lollygagging along on hairlike cilia, comes into view. Without warning, a nautilus-looking four-legged predator rockets in form two o’clock, impales the grazer with the saber-like spear affixed to its head, and sucks out the juices from the soft belly of the grazer. Before the hapless grazer microbe can fall to the hairy pasture, however, another predator enters the viewscape from ten o’clock and lops off the grazer’s head, devouring it contentedly as the now-decapitated and fluid-deflated carcass hits the ground. Within moments, other smaller scavengers enter the viewscape and polish off the carcass crumbs.”

As Salatin imagines, beyond the earthworms macroscopic enough for us to see with our naked eye, an entire world of microbes makes its home in the damp, dark earth. Bacterial decomposers called actinomycetes lend the soil its trademark earthy odor. Microbes called azotobacter fix nitrogen from the air into the soil to provide nutrition for plants. Mycorrhiza refers to the relationship between fungus and plant roots in the soil that results in stronger plant immune systems.

Soil, the earthy medium in which all plants grow, must be full of nutrients to support healthy plants. In agricultural systems, soil health proves even more important not only because the plants grown in the soil directly nourish our bodies, but because careless agriculture can actively destroy the soil. However, with sound agricultural practices, sustainable gardening and farming can actually improve the health of the soil beneath us. One method to enhance the nutrient-fixing capacity of the microbes already present in the soil is composting. Composting is the process of breaking down organic material like food and plant waste into a nutrient-rich soil supplement that greatly increases the viability and nutritional content of the crops it nourishes. Rerouting food waste into composting systems saves key nutrients from ending up in the landfill, where they decompose into a greenhouse gas called methane that is about 25 times more toxic than carbon dioxide. Instead, those nutrients create compost that works as an effective fertilizer by lightening the soil, which allows for better air and water filtration. It improves the soil structure, which combats erosion, and allows for the formation of stronger root systems by imparting nutrients and minerals.

Composting can take many forms, but vermicomposting takes advantage of organisms that thrive in soils: worms! Patricia Boudier of Peaceful Valley Farm and Garden Supply touts the benefits of incorporating worms into composting systems. Worm manure contains five to 11 times more nitrogen, potassium, and phosphorus than regular soil, negating the need to dump environmentally harmful chemical fertilizers into the earth. Vermicompost has more micronutrients than regular aerobic compost that doesn’t use worms, potentially enhancing the nutritional content of the plants we eat.

What types of worms work best for vermicomposting? Several types of earthworms prove suitable, and they go by common names like red worms, red wigglers, tiger worms, branding worms, and manure worms. Several species such as Eisenia foetida, Lumbricus rubellis, and Lumbricus terrestrius work particularly well.

This spring, the University of Virginia Community Garden saw the establishment of its own new vermicomposting system! Previously, the garden used an aerobic composting system that lacked efficiency, so the incorporation of worms will enable quicker compost creation to enhance the microbiotic activity in the soil. Engineering Students Without Borders has designed and constructed a wooden structure the size of a regular garden bed with eight compartments to allow for various stages of food waste decomposition. After the finishing touches have been added, the new vermicomposting system will use Lumbricus rubellis, a worm particularly effective at both composting organic matter and working the soil, or Eisenia foetida. Clearly, the life beneath our feet, from the micro to the macro scale, proves incredibly beneficial and necessary to the nutrition of our plants. Protecting the health and biodiversity of soil life, those miniscule organisms we often don’t appreciate due to their invisibility, should be a top priority as we plan our cities for a more sustainable future!

Works Cited

“Decentralized Composting.” Waste Concern. United Nations Economic and Social Commission for Asia and the Pacific, n.d. Web. 24 Feb. 2014.

Patricia Boudier. “Vermicomposting.” Online video. YouTube. YouTube, 20 June 2012. Web. 21 Apr. 2014.

Salatin, Joel. Folks, This Ain’t Normal: A Farmer’s Advice for Happier Hens, Healthier People, and a Better World. New York: Center Street, 2011. Print.

“Vermicomposting: Composting with Worms.” CalRecycle. California Department of Resources Recycling and Recovery, 22 July 2011. Web. 21 Apr. 2014.

Post by Love Jonson, Second-Year, Urban and Environmental Planning Major and Global Sustainability Minor

Soil faces a number of threats, both natural and manmade, which can compromise its physical structure and chemical composition. And since soil is the vital foundation of most life, it is important to understand the processes that affect it. If the soil is not healthy and stable plants, animals, and microbes will not be able to survive. One of these primary forces of change in the realm of soil is erosion.

Soil is formed in place by the erosion of bed rock and the introduction of organic matter. The horizons of soil previously mentioned in the other posts will develop in undisturbed soil. Often though the soil is transported by wind or water and deposited elsewhere as sediment; this constitutes the process of erosion. Small scale erosion is normal and can even be beneficial for the dispersal of nutrients. However, large drastic events of erosion can cause damage to the soil structure and other aspects of the environment.

Erosion may seem like a simple, inconsequential process. After all, it is just the movement of dirt from one location to another. But the process takes on a new significance when you consider the fact that it takes millennia for an inch of soil to form and only decades for that inch to erode. Soil is a valuable resource that is not replaceable on a human time scale, meaning that we must take better care to preserve it.

Erosion is a process that not only impacts the well-being of soil; it also has a great effect on the human environment. We need to work with soil to maximize our interactions with the natural world and avoid unnecessary difficulties. This may involve the integration of new soil management practices. One such technique for improving soil quality is the use of agroecology. This practice emphasizes a shift away from viewing soil as a chemical system toward perceiving it as a biological network. It describes soil as intricate web of plant, animal, microbes, soil, and water interactions. By having a more specialized, in-depth understanding of the soil in a specific area, productivity can be increased. This improves the growth of plants, which helps prevent erosion, and it maintains better soil quality by not draining the soil of vital nutrients.

The importance of preventing erosion and maintaining soil quality is especially important here at the University of Virginia since there is so much opportunity for soil disruption. Many vegetated areas are heavily trafficked by students and other pedestrians, which can kill groundcover in those places, leaving the soil vulnerable to erosion. (Fig. 1) There are around 14,000 undergraduate students attending UVA, most of who walk to class, and in some areas the sidewalks simply cannot accommodate that many pedestrians. Grass along these paths is worn away and the topsoil erodes quickly, leaving hard, compacted ground that is not conducive to life. In addition, UVA has many buildings and landscape areas that are under construction. The grass is often removed and sometimes the top layer of soil is stripped away. This leaves the soil unprotected for long periods of time. Barriers are put it place in an attempt to help control erosion, but precipitation and wind still carry away a lot of the exposed soil. Rain water seeping into the soil leeches away more mineral s and nutrients than normal, slowly degrading the soil quality because it lacks the insulation of topsoil and grass. Once the structure and quality of the soil has been damaged it can take a very long time to restore it. Depending on the extent of the damage, it could take years or decades to return the soil to its original state, which further demonstrates our need to protect the soil.

Bibliography

Montgomery, David R. Dirt: The Erosion of Civilizations. Berkeley and Los Angeles, California: University of California Press, 2012. Print.

Post by Jessica Hawkins, Second-Year, Environmental Science

The interface between soil and the atmosphere is extremely dynamic as it represents the marriage of the physical and biological worlds contained within an ecosystem. The physical environment of the leaf litter and topsoil combined has a tremendous effect on the type and diversity of organisms able to survive there. Human interactions with the soil layer can vastly change the life present. Buildings, construction, pollution and many others have the power to change the landscape.

There are multiple ways to uncover this hidden world of smaller organisms through sampling of soil. Luckily for our group, the grounds of the University provide a plethora of diverse sites for soil sampling. From the natural settings of the Dell Pond and the trails of Observatory Hill to the heavily traveled areas of the Lawn and Nameless Field, the grounds present different habitats, each with varying degrees of human interaction. Having these numerous locations all in one place lends itself to increasing the amount of biodiversity present here.

When looking at the life in soils, it is important first to characterize the physical environment of the soil because it has such an impact of the type and diversity of species able to live there. Soil can be sandy, made of mostly clay, silty, or a any mix of these together. The make up of the soil can be tested using the ribbon finger test where a small amount of the soil in question is doused with a couple drops of water then rolled between fingers to form a ribbon (Figure 1). The length of the ribbon produced gives information about the type of soil. Another important factor is the depth of the organic matter layer. The O layer and the connection to plants were described in our first soil blog post but it is crucial for the habitat and livelihood of microorganisms living in the soil. Finally, another parameter commonly measured in soil testing is the bulk volume of the sample. This is a measure of the volume of dry soil in a total volume of soil, which provides information on the amount of pore space available for creatures to survive in and how easy it is for the roots of plants to penetrate the soil.

However varied the soil types are around the world, the diversity of organisms living in these habitats are even more diverse. Biota commonly found in soils can range from the microorganism scale such as bacteria and fungi to the macro organism scale represented by earthworms and small insects in the organic layer. The most common sampling method for looking at the biotic facet of the soil is by using Berlese funnels (Figure 2). This set up requires that a small amount of alcohol is set up in a graduated cylinder with a funnel full of a soil sample is placed at the top. A light is then shown directly on the soil sample for usually a day. As the arthropods are sensitive to light, they travel down into the funnel tube and eventually fall into the alcohol. Once there, they can be classified and recorded.

The invisible life in soils is often times disregarded as unimportant and forgotten in the midst of conserving large mammals or keystone species. However, these mighty microbes contribute hugely to the biogeochemical cycling of the earth, recycling organic material for reuse, and convert nitrogen into the available form for plant growth. I think this section of the underground world would benefit greatly from increased research and appreciation.

Post by Emily Blanton, Third-Year, Environmental Science, Minor in Urban and Environmental Planning

As a gardener (and member of the UVA Community Garden), I am intimately familiar with soil and the need for healthy soil to grow healthy plants. In the past several years, I have learned quite a bit about Virginia soil and how to coax productive plants from it. Naturally, Virginia soil is very high in red clay; the predominant soil order in Virginia and the rest of the Southeastern United States is ultisol. Ultisols are acidic red-clay soils that are suitable for forestry, but don’t have enough natural fertility to support agriculture. Ultisol soil is strongly leached and lacks many essential agricultural minerals and nutrients, like calcium, magnesium, potassium and sodium. To make the soil suitable for agriculture, fertilizers and lime must be added to the soil to boost fertility. We have also learned in class that healthy soil should contain significant numbers of microorganisms that can be added to soil in the form of organic matter like compost. Soil that contains ample amounts of nutrients and microorganisms may be considered healthy.  Having healthy soil is important for a number of reasons, not the least of which is the efficient production of fruits and vegetables for human consumption. Healthy soil also encourages farmers to use less artificial soil additives (unnecessary if the soil is already fertile), healthy soil is better at holding water, and encourages good practices to maintain the health.

As a member of the community garden, I have seen the soil change and improve over the last several years as we have been taking care of it. Each growing season, we make a point to condition the soil with a large dose of compost – the garden does not use synthetic fertilizers, pesticides, or herbicides. We take care to leave cover crop or existing plants in the beds over the winter so the roots can help prevent erosion and soil runoff, which is another tenet of maintaining healthy soil. We keep the soil and plants properly watered to maintain good hydration. Our efforts have noticeably paid off and in the last few years, the soil has gone from hard packed, mostly clay to rich, brown-red soil that produces healthy plants. The difference was particularly noticeable at a recent workday when I compared the soil at the two different plots that belong to the community garden. The main plot by Observatory Hill Dining Hall has been steadily worked for several years and now has fertile, compost-augmented soil that is brown to deep red. In contrast, the plot behind Gilmer Hall which has not been worked consistently has packed soil that is a much brighter red. When the ground is no longer frozen, our group may look into examining the differences between nutrient and microorganism content between the two plots. We also plan to examine the benefits that compost brings to our soil. Currently, we get our compost from Black Bear Composting but we want to build our own composting system to become a self-sustaining garden. Our next blog about the garden will examine compost more closely and how it benefits the soil.

In regard to soil’s capacity to sustain life and perform as a home for creatures micro and macroscopic, Virginia clay soil has much potential. In regard to microbial biomass, microorganisms need moist soil and organic matter to consume. One huge benefit to clay soil is that it holds water well, creating a hospitable environment for microbes. Adding organic matter (through compost) to clay soil not only benefits microscopic organisms but ones that are plainly visible to the human eye as well. Take, for instance, worms. Vermicomposting is a well-known and popular method of composting that uses worms to aid in the decomposition of organic waste. Worms are also a huge benefit to soil in general for their aerating and casting-enriching capabilities. This is especially important in clay soils where worms help to loosen the easily compacted soil and enrich it with their castings.

http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/survey/class/?cid=nrcs142p2_053609

http://www.nrcs.usda.gov/Internet/FSE_MEDIA/stelprdb1237749.pdf

http://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1049061.pdf

http://sci.windwolf.org/soil/orders11.htm

http://www.britannica.com/EBchecked/topic/613380/Ultisol

Post by Ida Yu, Fourth-Year, Computer Science and Psychology, Global Sustainability Minor