Sample soil health report from the State of the Soils Assessment
Fall 2022
Your farm’s results below
Thank you for being a participant in our State of the Soils Assessment. This work would not be possible without your collaboration and input.
Over the past three summers, WSDA, WSU, conservation districts, and agricultural professionals traveled across Washington to sample nearly 700 fields in more than 50 crops. We are excited to share with you some preliminary results with data from your fields.
The goals of our project are to 1) Evaluate the current soil health status and priorities for crops across Washington; 2) Calibrate soil health scoring curves relevant for Washington’s soils, climates, and cropping systems; and 3) Further understand how soil management affects important soil functions.
Project Team:
| WSDA | WSU |
|---|---|
| Perry Beale, NRAS Manager | Deirdre Griffin LaHue, Asst. Prof, Soil Health |
| Dani Gelardi, Senior Soil Scientist | Teal Potter, Postdoctoral Scholar |
| Leslie Michel, Soil Scientist | Molly McIlquham, Extension Coordinator |
| Jadey Ryan, Data Scientist | Kwabena Sarpong, Graduate Student |
Measurements
Biological |
Physical |
Chemical |
| Permanganate Oxidizable C | Water Holding Capacity | Total N and Total Organic C |
| ACE Soil Protein | Bulk Density | pH and EC |
| Potentially Mineralizable C | Aggregate Stability | Cation Exchange Capacity |
| Potentially Mineralizable N | Texture | Plant Available Nutrients |
What are these measurements?
Potentially Mineralizable Carbon (MinC, frequently referred to as “Soil Respiration”) measures the release of carbon dioxide (CO²) from soil under controlled conditions. Soil microbes produce CO² as they decompose soil organic matter and residues, and higher MinC represents greater potential biological activity.
Permanganate Oxidizable Carbon (POXC, frequently referred to as “Active Carbon”) measures the amount of soil organic matter that is oxidizable in the presence of potassium permanganate. This test is an estimate of the amount of C that microbes can easily access for energy and can indicate how soil organic matter is stored in your soil. For more information, check out this WSU Extension Publication.
Potentially Mineralizable Nitrogen (PMN) represents the amount of organic N that can be converted (or “mineralized”) to plant-available nitrate or ammonium. This measurement is done in lab incubations over four weeks and can allow producers to estimate how much available N the soil may release. Additional information on measurement and interpretation of PMN can be found in an OSU Extension Publication.
ACE Soil Protein represents a fraction of soil organic matter that contains proteins from organisms. ACE stands for Autoclavable Citrate Extractable, meaning the method extracts the proteins using sodium citrate. ACE is an indicator of biological life in the soil and a predictor for N availability because proteins contain N and are an important source of plant-available N.
Bulk Density is an indicator of soil compaction. It is calculated by measuring the dry soil weight within the volume of the sample taken. It may seem simple, but it can vary greatly depending on soil texture and structure, and can affect aeration, water infiltration, and root growth.
Aggregate Stability measures the resistance of soil aggregates to disintegration. A soil aggregate is a group of soil particles that are bound to each other more strongly than to adjacent particles. Aggregates are formed when soil particles associate with plant roots, mycorrhizal fungi, and other microorganisms in the soil. Water and wind can break down unstable soil aggregates, while stable aggregates can reduce erosion and increase water infiltration, drainage, and storage capacity.
Water Holding Capacity (WHC) is the amount of water a soil can hold. WHC indicates how the soil will supply and store water during high rainfall events and times of drought. WHC varies by soil texture (sandy vs. clayey) and bulk density, and can be greatly impacted by management.
Total Organic Carbon (TOC) is a measure of the C contained in organic matter in the soil. This includes both stable and “active” forms of soil organic carbon (SOC). This value measures only organic forms of C and does not include any C from carbonates, which are common in some arid soils. Organic C has large effects on almost all other soil properties and thus is often used as a primary indicator of soil health. You can estimate soil organic matter content by multiplying total organic C by a factor of 1.72.
Total Nitrogen is a measurement of both inorganic (plant-available nitrate and ammonium) and organic (typically not plant-available) N in the soil. Having sufficient total N in the soil is key for promoting mineralization, or the process of changing the N to a form that the plants can use.
Cation Exchange Capacity (CEC) is a measure of the soil’s ability to hold onto essential nutrients, and provide a buffer against soil acidification. CEC varies based on the minerals in your soil, the soil texture, and the quantity of soil organic matter (SOM).
Your fields
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Interaction with this map is disabled for this sample report.
Tip: Click on the points to see the field name and crop.
Project Results
Below are tables and graphs for texture, soil health indicators, and soil fertility tests. Each point represents a sample in this project. Take a look to see how your fields compare to others in the project. All samples were collected from 0 to 12 inches.
Texture
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Soil health indicators
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Fertility tests
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Download your data
Looking forward
We hope you find this preliminary soil health report informative. Please remember this is the beginning of a long-term project. Ultimately these data will be used with the management survey to better understand how soil health indicators are linked to soil functions such as disease suppression, yield maintenance, and carbon sequestration. Your data is critical to developing crop-specific and region-specific decision support tools, currently under development.
For project updates, funding opportunities, or to further get involved, visit our website or go to agr.wa.gov and type “Soil Health” into the search box.