Resource Hub
Personal resources
If you are interested in a presentation from Dr Shannon Cappellazzi, the following are ideas for presentations that can be put together with options on how much/what is covered relative to the interest of the group. We welcome feedback on presentations that seem interesting or relevant to you, and if a topic is missing please reach out!
Presentations
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Oregon Climate and Agricultural Network OrCAN Panel on Climate Resilience
12 October 2022
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Can cover crops break through restrictive soil layers
2 August 2022
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Carbon Indicators in Soil Health Assessments
23 February 2022
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Soil Health Measurements for Scale
23 February 2021
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Soil’s Capacity to Function: It all Depends
15 February 2021
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Framework to quantify the functions of soil: An approach to soil health assessment interpretation
8 September 2020
Publications
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Soil health benefits of compost persist two decades after single application to winter wheat
17 October 2024
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No-tillage, surface residue retention, and cover crops improved San Joaquin Valley soil health in the long term
1 May 2024
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Evaluating common soil health tests for dryland wheat systems of inland Pacific Northwest
19 December 2023
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Long-term agro-management strategies shape soil bacterial community structure in dryland wheat systems
25 August 2023
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An evaluation of nitrogen indicators for soil health in long-term agricultural experiments
23 May 2023
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Use of Phospholipid fatty acid analysis as phenotypic biomarkers for soil health and the influence of management practices
May 2023
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A minimum suite of soil health indicators for North American agriculture
May 2023
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Evaluation of Aggregate Stability Methods for Soil Health
15 December 2022
Video Outreach and Education
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Dude Where’s my N
12 October 2023
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GO Seed Research update 2023
12 October 2023
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Does annual ryegrass increase soil pH
14 June 2023
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Soil Bulk Density and Carbon Stock with Dr. Shannon Cappellazzi
8 May 2023
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Measuring Carbon Sequestration in Falcata Alfalfa Soil Pit with Dr. Cappellazzi
8 May 2023
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Why are worms slimy? Dr. Cappellazzi knows!
8 May 2023
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Research Update: Roots Break Barriers
9 February 2022
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In 1 minute: How do Plants Fix Nitrogen
8 February 2022
TIPS
Soil Sampling Demonstrations
Our soil sampling demonstrations will continue to be uploaded as new information becomes available, check back or let us know if there something you are interested in seeing!
Soil Health Interpretation
Soil Health Indicators
The following three indicators form the SHOCD minimum suite, aligned with the essential suite detailed by the Soil Health Institute work on indicators that I was a part of (NAPESHM; Bagnall et al. 2023, Soil Security). Together they assess whether a soil is moving toward regeneration generally.
| Indicator | What it measures | Why it matters | Methods Accepted |
|---|---|---|---|
| Soil Organic Carbon (SOC) | Total carbon feed available to soil microbes. Represents organic matter pool. | Controls nutrient cycling, water holding, aggregate formation, and microbial activity. | Dry combustion (preferred). OM by loss on ignition × 0.5 ≈ SOC. Record lab and method. |
| CO2 Burst (respiration) Potential C mineralization | CO2 released from rewetted dry soil. Indicates microbial activity and biomass. | Shows whether organisms are using the carbon. Highly responsive to management changes. | 24-hour incubation preferred. 72- hour and 96-hour also accepted. Record hours and lab. |
| Aggregate Stability | Percentage of soil aggregates that stay intact under water force. | Reflects physical + chemical + biological soil structure. Related to erosion, infiltration, and habitat. | Cornell Rainfall Simulator, Slakes app, or wet sieve. Record method and lab performing |
Soil health indicators cannot be interpreted in isolation. Results depend on inherent soil properties and climate. A high CO2 result in a Willamette silt loam means something different than the same number in a Walla Walla silt loam or a Quincy sand.
- At minimum, know your: soil texture, pH, and local climate for interpretation.
- For SHOCD purposes: GPS coordinates drive automatic lookup of inherent properties (SSURGO) and climate
(AgriMet, PRISM) — this is why GPS is required for every sample.
[Video embed coming soon]
Bookend Sampling
Bookend sampling is the cornerstone of SHOCD soil health interpretation. The goal is to find the lowest and highest soil health values you can expect for a given soil type in a specific ecoregion. This gives you a context specific scale for interpreting any production field sample. CAUTION: CRP land is often inherently poor soil and not typically good for either bookend.
| Sample Type | What to look for |
|---|---|
| Low Bookend | Soil that has NOT had soil health practices for at least 10 years. Likely paler in color, hard to get a shovel in, low in organisms and roots. Could be a high traffic path, or a research field. Talking with farmers who have just purchased previously degraded ground is a good way to find these without insulting producers. |
| High Bookend | Area with long-term grass or a mix of perennial plants, minimal disturbance, some really well managed grazing areas. Relatively darker soil, soft to the touch, smells rich, teems with life. Native prairie remnants, well-managed pasture, fence lines, parks, or other native habitat. |
| Production Sample | our farmed field. Same soil type (SHSG) as your bookends. Compare to see how far you have come and where your upper potential is. |
[Video embed coming soon]
Field Sampling Protocol
The Soil Slice Method
Repeat the following sequence 6 times to create one composite sample:
- Place the sharpshooter perpendicular to the soil surface. Push straight down — aim for at least 8 inches (20 cm) deep.
- Wiggle side to side along the blade edge to create a clean slice.
- Rotate 90 degrees. Place the sharpshooter so the slice meets the corner of the previous cut. Repeat for a full square.
- Place the sharpshooter an inch back from one edge and push in at an angle. Use this as leverage to pop out the cube of soil (~6×6×6 inches).
- Pull the cube out. Smell it, feel it, look at it. Start your observations. Set it aside.
- Use the hori hori to take a slice about 1 inch thick from each of three sides of the hole. A hand on the inside helps keep soil on the knife.
- Take a photo of the representative knife slice, then place the soil in the bucket for mixing
After 6 holes: Mix the bulk soil in the bucket with the hori hori. Pour into the quart-sized bag. Keep cool immediately.
Push Probe Method
Use when time is a constraint. Take 15 soil cores from across the EU, use the top 6 inches (15 cm) from each core, composite into one bucket, mix gently, and pour into a quart bag. Keep cool.
⚠ NOTE: The push probe creates artificial clods that can skew aggregate stability measurements. Use the soil slice method whenever aggregate stability is a priority measurement
[Video embed coming soon]
Visual Soil Assessment
Visual Soil Assessment (VSA)
Observation is the first step in the scientific process. You can use the visual soil assessment (VSA) as a standardized form to record your observations. This helps minimize memory bias, and creates a free assessment to track changes over time. The more detail in the observation columns, the richer the dataset.
The VSA is collected for the bookend samples so we can create a frame of reference for those who will do their own VSA measurements on their own farm to track soil health on a regular basis with less frequency than lab analysis. Using senses to evaluate soil is one of the early ways humans used data to make decisions. The more areas of your own property you can evaluate with the VSA the better you can gauge the relative changes caused by your management practices and the landscape. This can be used as a start point tool and adapted to your own preferences.
[Video embed coming soon]
Field Measurements
Water Infiltration – Single Ring Method
Measures how quickly initial water enters the soil. Do this 3 times per composite sample area.
- Measure the inner diameter of a cylindrical tube (minimum 2 inches long, 3+ inches diameter).
- Calculate volume for height 1 cm of water: V = r² × π × h (result in cm³ = mL). Example for 3-inch tube: V = (3.81)² × 3.14 × 1 = 45 mL.
- Remove surface biomass, live or dead from the area, trying to minimize disturbance of mineral soil.
- Use a block and mallet to insert the tube at least 1 inch into the soil.
- Line the tube with a small piece of plastic, pour the measured water in, remove the plastic, and start the timer.
- Observe until all small pools between aggregates are gone. Record time in seconds.
- If there is high variability within your EU, repeat to better capture average. I consider 1 min and 5 min as highly variable. 1 min and 2 min are not highly variable.
- If the infiltration takes more than 10 minutes for 1cm of water, I record > 10 min.
Record: time, tube diameter, soil moisture condition, whether the surface had residue or was bare.
SATURO Soil Infiltration Test
Penetrometer
Indicates compaction. Only useful when soil is moist (ideally 3 days after a saturating rain event — near field capacity). Not recommended for cross-site comparison — use as a relative indicator within one site.
- Use the ½-inch penetrometer tip.
- Push consistently and smoothly into the soil, perpendicular to the surface.
- Record the depth (cm) when PSI reaches 200.
- Record the depth when PSI reaches 300.
- Record the depth when PSI drops back below 200 (if it does — indicates hardpan is past).
- If you hit a rock: discard and move to another spot.
- Alternatively, you can record the PSI at 6 in depth and 18 in depth to align with the Cornell methods.
- Record the average of 3-5 pushes per sampling area. Stop at 3 if results are consistent; take more if variable.
⚠ NOTE: Penetrometer results are strongly affected by soil moisture. Always record soil moisture condition. Do not compare across sites or dates unless soil moisture is the same.
Bulk Density
Additional External Resources
The following websites have useful resource catalogs of their own that may be of interest: