Welcome to the Soil Biota Service Learning Project Blog!

Soil Biota Team!

The Soil Biota Team!

 

We're as cool as Colepotera.

Soil Biota, the Direct Connection to Soil.

One of the most important aspects of soil, are the organisms within. They breakdown organic matter, supply nutrients to plants and other organisms. Nutrient loses are also prevented by being stored in the organisms. Soil organisms maintain good soil structure. As you can see, many soil characteristics are determined from soil biota.

Some of the most abundant organisms found in our soil, litter, and compost samples were of the Acarina order. These are the soil mites. They are considered predacious, feeding on other invertebrates along with plants and fungi.

Photo courtesy of Ray Norton, www.fcps.edu.

Of the second most abundant order are the Collembola or springtails. Springtails feed on fungi, and dead plant tissues. Springtails can also be predacious, feeding on other smaller invertebrates.

Photo courtesy of Drees, insects.tamu.edu.

As each of the different types of organic matter had a wide variety of organisms in each sample, some of the other common orders are Araneida (spiders). All spiders are predators.

Photo courtesy of soilbugs.massey.ac.nz.

Coleoptera (beetles). Beetles feed on fungi or are predators of other small arthropods.

Photo courtesy of eppserver.ag.utk.edu.

 Diplura (japygids). Japygids are predators.

Photo courtesy of soilbugs.massey.ac.nz.

Pauropoda (pauropods).  Pauropods feed on fungal hyphae and well-decayed plant tissue.

Photo courtesy of Tom Murray, bugguide.net.

Of the less common orders found are Chilopoda (centipedes). On centipedes, the first pair of legs is modified into hollow, piercing fangs that are used to inject digestive enzymes into their prey.

Photo courtesy of Cryptops sp, soilbugs.massey.ac.nz.

Diplopoda (millipedes). On Millipedes feed almost exclusively on dead plant tissue however, some are predators.

Photo courtesy of colocalders.com.

Pseudoscorpiones. Pseudoscorpiones feed on tiny arthropods.

Photo courtesy of Tom Murray, bugguide.net.

Annelida (ringed and earthworms), earthworms are responsible for aerating and enriching soils.

Photo courtesy of jiaekingdomanimalia.wikispaces.com.

Nematoda (round worms), many are parasitic and some are predators of soil nematodes. Isopoda (isopods).

Photo courtesy of www.shadesofgreensa.com.

Soil Maps, Series, and More!

Oak Creek Center for Urban Horticulture

Oak Creek Center for Urban Horticulture

         Kim took the liberty of collecting our samples from her neighborhood, Oak Creek Center for Urban Horticulture and from the side of the intersection of the 22 and 99 highways in 10 miles west of Salem. These are the locations in Soil Map Form!!

Salem

Salem

The major soils at Kim's neighborhood, Oak Creek and the Salem locations were Dayton/Willamette, Bashaw/Dayton, and Cove/Coburg respectively. 

Kim's Neighborhood

Kim's Neighborhood Soil Stats!!

Soil Stats	Dayton Silt Loam	Willamette Silt Loam
Color	10 YR 3/1	10 YR 2/2
Texture	30.4% clay 7.3% sand 62.4% silt	26.2% clay 6.3% sand 67.4% silt
Structure	Moderate medium and fine subangular blocky	Weak medium subangular blocky
Organic Matter Content (%)	0.64%	1.24%
Drainage	Poorly drained	Well drained
Hydraulic Conductivity (mm per second)	5.8662	8.3671
CEC (milliequivalents per 100 grams)	26.6	22.6
Bulk Density (g/cm^3)	1.34	1.4
Assumed Particle Density (g/cm^3)	2.65	2.65
Water Holding Capacity (cm per cm)	0.19	0.2
Available Water 0-100 (cm)	17.88	20.45
Susceptibility to Compaction	Low resistance to compaction	Low resistance to compaction

Oak Creek Soil Stats!! 

Soil Stats	Bashaw Clay	Dayton Silt Loam
Color	10 YR 3/1	10 YR 5/2
Texture	60.7% clay 5.7% sand 33.6% silt	30.4% clay 7.3% sand 62.4% silt
Structure	Moderate medium and fine subangular blocky structure	Moderate medium granular structure
Organic Matter Content (%)	2.04%	0.64%
Drainage	Poorly Drained	Poorly Drained
Hydraulic Conductivity (mm per second)	0.2	5.8662
CEC (milliequivalents per 100 grams)	45.2	26.6
Bulk Density (g/cm^3)	1.2	1.34
Assumed Particle Density (g/cm^3)	2.65	2.65
Water Holding Capacity (cm per cm)	0.16	0.19
Available Water 0-100 (cm)	15.95	17.88
Susceptibility to Compaction	Low resistance to compaction	Low resistance to compaction

Salem Soil Stats!!

Soil Stats	Coburg Silty Clay Loam	Cove Silty Clay Loam
Color	10 YR 3/2	10 YR 3/1
Texture	37.8% clay 10.5% sand 51.7% silt	52.4% clay 17.1% sand 30.6% silt
Structure	Weak medium subangular blocky and moderate medium granular	Moderate fine subangular blocky
Organic Matter Content (%)	1.94%	3.05%
Drainage	Moderately well drained	Poorly Drained
Hydraulic Conductivity (mm per second)	4.5	0.5684
CEC (milliequivalents per 100 grams)	22.5	41.2
Bulk Density (g/cm^3)	1.3	1.26
Assumed Particle Density (g/cm^3)	2.65	2.65
Water Holding Capacity (cm per cm)	0.19	0.17
Available Water 0-100 (cm)	19	16.81
Susceptibility to Compaction	Low resistance to compaction	Low resistance to compaction

What We Takeaway In The Big Picture:
 Dayton Silt Loam- Fine, smectic, mesic Vertic Albaqualfs. Alfisols. Low bulk density means high porosity. High porosity means well aerated soil.  Low organic matter means poor nutrient and water supply in this particular soil.
Willamette Silt Loam- Fine-silty, mixed, superactive, mesic Pachic Ultic Argixerolls. Mollisols. Low bulk density means high porosity. High porosity means well aerated soil. Well drained means roots can easily get oxygen which means plants would do well in this soil.
Bashaw Clay- Very-fine, smectic, mesic Xeric Endoaquerts. Vertisols. Low bulk density means high porosity. High porosity means well aerated soil. High CEC means high clay content. High clay content means generally higher amounts of organic matter. More organic matter means more nutrients and water for the soil.
Coburg Silty Clay Loam- Fine, mixed, superactive, mesic Oxyaquic Argixerolls. Mollisols. Low bulk density means high porosity. High porosity means well aerated soil.
Cove Silty Clay Loam- Fine, smectic, mesic Vertic Endoaquolls. Mollisols. Low bulk density means high porosity. High porosity means well aerated soil. High organic matter means good supply of nutrients and water to soil.

These are the soils at the locations we got our soil biota from, however most of the biota came from compost piles, and leaf litter above the soil/in the Oi horizon. Here are some pictures from the Oak Creek Compost Piles...

Briana, our fearless leader, by the compost piles

Straw compost

Wood chips next to compost

Finished compost

What is the broader impact of the project that we helped with?

 The broader impact of the project we helped within the soils is to understand that without biota we would not be where we are today. Without the consumers and decomposers the cycle of soil would not continue. To get the soil we have we need soil biota. If there were no microorganisms in the soil, soil would not be broken down and thus the plants would not get the nutrients needed. When there is an abundance of microorganisms the soil is well aggregated which also means that there are good infiltration rates and plant growth. Without soil biota we would not have the soil we have and thus we would not have habitat because soil is habitat!

The broader impact of the project for this class was a service project because we prepared samples for in the soils lab sections. We labeled and sorted the samples so that they would be easy to access by members of our class. Because we prepared the microbiota beforehand, the labs could discuss other aspects of soil biota, such as the earthworm count per square foot and the respiration rate of the soil. Because the samples were already in cleaned preserved solutions the lab groups could easily find the microbiota. This service helped facilitate the learning experience in lab.  

Looking at Soil Biota under the microscopes

Image through microscope lens.  The large specimens are an archid and Colembola.  We were amazed at the different scales of biota in the samples!

Is there a way that soil management changes could improve this project?

     In class we had discussed that good soil management needs to have stable aggregates, low bulk density, and lots of macropores. We also know that the soils need to have organic matter added to them as well. In our compost piles, it was noticed that the straw, wood chip piles, and the deciduous litters all had high numbers of biota contained within them.

This finished compost appears to have a diversity of pore sizes, and a lot of macropores, this is a quality of good soil management.

    When it came to the finished compost pile, there were very low numbers of biota within them, and it was also noticed that there were more predators and macrofauna within the finished compost pile. 
This was probably due to the fact that the pile was “finished” with decomposition, which also means that the smaller decomposing microfauna were done with their "job."  Since their food source was depleted, they either died or moved elsewhere.  As the microfauna die or move out the larger biota will eventually die or move out too as their food source diminishes.  We predict this is the stage that the soil ecology is currently at in the finished compost.  If there was more organic matter added to the finished pile it would give the decomposing biota more food so they would remain in the pile.

This predator prey relationship explains the ecological stage the finished compost is at

     It’s important to observe these biota to fully understand their role in the ecosystem, and how they can impact the soil function. It is known that soil biota are important for the regulation of organic matter dynamics, as well as enhancing the soil physical structure and the water regime. This chart below shows the relationships between the biota and their functions within the food web.

       Since there are diverse roles that different biota serve in soil decomposition, good soil management would facilitate diverse populations of biota.  The diversity and type of species present in a soil could be an indication of how "healthy" the soil is, and if the soil is being managed well.  Comparing the species present and the diversity of species in soil samples with a treatment of good soils management and poor soils management would have been an interesting component to this project.




http://www.nature.com/scitable/knowledge/library/the-soil-biota-84078125

What we did, how we did it, and what we learned!

    Our project was the collection of soil biota for the week 8 lab of the Soil 205 class. We began our journey at the entomology lab on the 4th floor of Cordley Hall. As we stood in utter confusion, our valiant coordinator stepped into the hallway to rescue us all! Kim Townsend was her name, and bugs were her game. We first learned that she had already collected the six samples we would be using and set up eight Berlese Funnels with six samples that were to be used the labs.

 

Berlese Funnels with lights on and mason jars secured

 

Attaching the mason jars to the Berlese Funnels, these funnels are the catch system for the soil biota.

   If you didn't know, a Berlese Funnel is a curious contraption that you place a sample of soil into, and place a heat lamp over the top to drive the bugs down into a container of observation. either they went into an ethanol bath to quickly, humanely die or a moist environment to keep them thriving for live observation. It takes at least forty-eight hours to drive the majority of biota down into the holding containers, though some come out very fast.

Inside the Berlese Funnel, a mesh cover prevents the litter from falling into the biota samples collected in mason jars

Lauren and Briana fill the Berlese Funnels with the soil samples

   We initially sorted the bugs under a stereoscope, trying to classify the bugs by their phyla, and observe their physical characteristics. We quickly realized that it would be more effective not to classify, but to provide diverse samples for each lab. One really interesting way that we learned to classify the biota is by identifying their purpose in the ecosystem of the Oi horizon. For example, by looking at the physical characteristics of millipedes and centipedes we found out that centipedes are the predators because they are fast like soil sharks and millipedes are decomposers because they move more slowly and break down litter like a sloth on a hot day. Other attributes include; the millipedes have a defense mechanism where they release a chemical compound (cyanide) when touched by a perceived predator. Here is a picture to further show their differences.

    Another interesting fact that we learned during our project was that during the last ice age, most of the native earthworms were wiped out and were no longer around in american soils. The earthworms that exist in our soils today are mostly not native and were brought in from Europe unintentionally in soils used for ship ballast on cargo ships. They quickly moved across the new world and are the most common earth worms today. 

Katie fills the Berlese Funnels with soil