Regulated soil sample is a term used at ALGL to identify a soil sample the requires special handling to avoid the spread of unwanted pests and diseases. These soil samples can originate inside or outside the continental US.
ALGL maintains a USDA Animal and Plant Health and Inspection Service (APHIS) permit to import soil and plant samples from outside the continental United States. These samples are allowed to flow through customs with an inspection, when accompanied by the correct permit. These permits are not to avoid import duties, rather they are part of a bigger effort to control the spread of pests and diseases. Regardless of trade relations with a country, these permits are required when shipping samples to our lab.
These permits are more than a piece of paper. They represent documented protocols as to how the lab will contain and dispose of these samples, in accordance with USDA/APHIS guidelines. These processes and procedures are created to avoid introduction of an undesirable pest or disease into the US. Within the ALGL lab there are separate sample preparation facilities for these materials. These facilities and protocols are inspected by USDA/APHIS on a regular basis. These samples incur an additional handling fee.
While USDA-APHIS permit addresses the introduction of pests from outside the continental US, there are federal domestic soil quarantines within the continental US. These quarantine areas are designed for the same reason, to slow the spread of pests and diseases. The map below shows the areas of concern and is updated by USDA-APHIS regularly. The current map can be found at: https://www.aphis.usda.gov/plant_health/permits/organism/soil/downloads/Fed-SoilRegs.pdf
Here at ALGL we process samples from quarantine counties the same as soils from outside the continental US. These samples also incur an additional handling fee.
While shipping address on an inbound box help identify soils potentially from these areas. The origination of the soil sample may not align with a shipping address with the larger regions being covered by our customer today. We do ask if your soil samples originate from the areas marked in green or yellow that you indicate on your soil submission form that the soil originated from a quarantined county. If the soil samples originate from a county marked in orange, please contact the USDA before shipping the sample.
In modern agriculture, maximizing crop yield while minimizing input costs takes precedence. Soil sampling techniques play a crucial role in achieving this balance by providing valuable insights into soil fertility and nutrient levels. There are two primary sampling strategies when setting up a field: grid and zone sampling. Each method has its benefits and drawbacks, and understanding the difference is essential for farmers to make informed decisions about their soil management practices.
Variability is a key factor in determining which sampling strategy to utilize. It influences most in-field decisions including what, how and when to sample. To understand what types of variables are present they can first be placed in two different categories.
Temporal variability in agriculture fields refers to the fluctuations and changes that occur over time in various aspects such as crop yields, soil conditions, pest and disease outbreaks, and weather patterns. These variations can be influenced by seasonal changes, climate variability, and agricultural practices. Some in-season temporal changes could include nitrification or volatilization of applications, or plant nutrient availability due to seasonal changes. A perfect example of this is fluctuating potassium levels in the soil profile. Levels in corn acres are typically higher in spring samples, compared to fall, due to crop uptake. The plant must wilt then decompose and return these nutrients to the soil causing fluctuations.
Spatial variability refers to the differences in one location to the next. These differences include soil properties, nutrient levels, moisture content and slope typically within the same field. This variability can result from factors like soil type, topography, drainage patterns, and management practices. Many times, these variations can be seen as surface features such as a low, waterlogged area to a high, sandy hill. Other times they can be hidden within, or below the soil surface such as a previous lime pile site. This variability would create a false representation of the grid area, or zone, by having increased calcium and/or magnesium levels.
Variability is unavoidable. How we as farmers, applicators and agronomists understand/utilize this variability can have lasting impacts. With modern technology, variability has never been more documented. Often referred to as “big data”, it can be broken down into simple data sets. These are commonly called data layers. A data layer can be added, recorded, noted or submitted through an incredible number of avenues. A few examples are planter ride quality, seeding population, hybrid placement, aerial imagery, nutrient placement, yield maps, even applicator name and contact information.
The soil sample and nutrient maps are the most crucial data layers to sift through when making management decisions. They have the most return on investment, when utilized properly, and can have lasting effects for years to come. To fully encapsulate variability in a particular field, sampling strategy plays a large role. The two textbook practices mentioned before are grid and zone sampling.
Grid sampling is the most straightforward strategy in the soil realm. This type of sampling assumes the nutrient levels throughout the field are random. Historically grid sampled fields have been fertilized in build up programs and masked the natural nutrient discrepancies across the working acreage. Imagine a transparent checkerboard lying on top of a field. These square, or grid, sizes typically range from 1-5 acres. Within each square are, preferably, georeferenced sample points. As mentioned above, variability is everywhere and repetitive sampling, in the same relative area, is the only way to get a respectable data layer.
Grid sampling can offer these precise values to an operation through accurate representation and repetitive sampling but has its setbacks as well. It is usually more time and labor intensive. More samples will be taken from a field set up as grids. This means it will also take much more time to do this job and that creates more costs. However, in uniform fields the zones are much too large to get an accurate representation of an entire area and grid sizes are simply made larger.
Zone sampling is utilized in more stable environments. Several of these areas are naturally occurring, and the spatial/temporal variability has been present for many years. These sampling zones are created from these variabilities through many ways. Yield monitors are a great indicator layer, when calibrated correctly, but only offer one piece to the puzzle. To create proper zones, one must take all factors into consideration. The natural variations of a field are recorded, and documented, using the yield monitor, aerial imagery, and soil tests (to name a few) to determine where zones differentiate. These zones include waterlogged areas, slopes, and soil types. Once zones are established, they can be used for much more than soil sampling. Seeding/fertilizer rates, hybrid/variety type and even tillage/seeding depth can be adjusted according to zones.
All these factors can be isolated through other forms of data layers like scouting, soil sampling, aerial imagery etc. and made into its own zone. This reduces the sampling costs by having larger sample areas but may have a higher start up cost due to the technology required and subscriptions used.
Georeferenced sampling uses GPS, global positioning system, to mark a specific area. This is important when sampling in a grid or making zones. A common mistake is to place a sample location in an area where ag lime was piled before application. If it is a referenced area, it is simple to find this location and see why certain outliers were present in a soil analysis report. Another important reason to have georeferenced sampling is variability, as discussed above, is inevitable. Nutrient variability is highly common, hence why frequent and repetitive sampling is required.
Grid sampling is still frequently used even though variability may move some points within a grid section. To overcome this, some agronomist practice kriging. Kriging is mostly used in grid soil sampling to predict values of unsampled locations based on spatial variability, such as slopes and hills, and nearby sampled locations. If variable rate technology is not being used, it is wise to move points away from areas that will change application rates drastically.
When deciding which sampling technique to use, all these factors must be taken into consideration. If the field is a new addition to the farm, a grid style sampling technique is highly recommended, with a small grid size, to determine where variability exists. If the results show drastic nutrient levels, an even smaller grid size is required at the next sampling date to determine what is needed, or not needed, and where.
While grid sampling provides precise data for targeted nutrient applications, it can require more time and costs. On the other hand, zone sampling offers a more practical and cost-effective solution for large scale operations but may sacrifice precision. The choice between grid and zone sampling should be based on factors such as field size, budget, goals, and the level of detail required for effective soil management practices. By selecting the most appropriate soil sampling method, farmers can optimize nutrient use efficiency, enhance crop productivity, and sustainably manage their soils.
Your ALGL sales agronomist can help determine with method is right for you.
Editorial Comment: The weather in late 2023 and early 2024 has been a roller coaster of temperatures to say the least. However, up to this point 2024 has been relatively dry. The warm temperatures could have certainly led to the nitrification of some of the nitrogen, but fortunately there may not have been enough precipitation to leach it from the soil. The weather over the next two months is likely to be the greatest determinant of nitrogen loss, and at this time appear to be above average in temperature with average rainfall. If you are planning to plant corn into a fall manured field, a pre-sidedress soil nitrate test is the best tool to assure that you have adequate nitrogen. For more information regarding sampling procedure and data interpretation, please see our fact sheet.
Original article posted February 2020
Manure applications can be a valuable component of a nutrient management program but timing those applications to maximize the utilization of nitrogen can be challenging. Manures generally contain two forms of nitrogen, ammonium and organically bound nitrogen. Ammonium is immediately plant available and relatively immobile in the soil because it is a positively charged ion that held by the cation exchange capacity, like potassium. Organically bound nitrogen is also immobile in the soil, but it is not plant available until the organic matter is microbially decomposed, mineralizing the nitrogen.
In an ideal situation, manure applications would occur either into an actively growing crop or shortly before a crop is planted to gain the most benefit from the nitrogen. Unfortunately, our cold wet soil conditions in the spring and the types of application equipment we have available often do not allow for spring or early summer application. As a result, much of the manure in our region is land applied following harvest in the fall and early winter leaving several months for potential nitrogen loss.
The first step to maximizing the benefits of manure is to keep it on the field and in the soil profile. The most obvious potential loss of nitrogen when manure is fall applied is surface runoff. Runoff can be minimized by avoiding applications on saturated, frozen, or snow-covered ground; incorporation with tillage; or subsurface injection.
Once the manure has been incorporated into the soil profile, there is still the potential for substantial nitrogen loss to occur before the next crop can utilize it. The two potential mechanisms for loss are leaching and denitrification. Leaching has the greatest potential to occur on well drained soils during periods of heavy precipitation. However, for significant losses of nitrogen to occur due to leaching, the nitrogen needs to have been converted to nitrate prior to the precipitation. The conversion of ammonium to nitrate is a microbial process that will only occur when the microbes have adequate temperature and aeration in the soil to be active. Denitrification is the conversion of nitrate to gaseous forms that can be lost to the atmosphere. This is a microbial process that only occurs when soils are saturated, and the microbes are in an anerobic environment. Microbial activity is minimal when soil temperatures are below 50 degrees. If soil temperatures remain cold after application, the chances of significant nitrogen loss are minimized.
The winters and springs in this region are generally cold enough to keep most of the nitrogen in the soil profile. However, over the last few years this has not always been the case. The spring of 2017 was unusually warm with February and March temperatures reaching 70+ degrees. In one situation, using a soil nitrate and ammonium test, we were able to confirm the loss of nearly all the nitrogen following a fall hog manure application that was subsurface injected and treated with a nitrogen stabilizer. The grower in this situation had to supply a full rate of nitrogen fertilizer though sidedress to sustain his corn crop. The next season, following the very cold spring of 2018, the same grower in the same exact situation was able to confirm that no additional nitrogen was needed to produce his crop.
The winter season provides many of our customers with the opportunity to stay inside and review and work on different aspects of the business or operation that is not possible to accomplish during the rest of the year. Whether driven by curiosity, new products seen at tradeshows, or a need to upgrade, a common inquiry lately has been about what soil sampling software options are available. Below is a list of software companies with links to their websites that we at ALGL have experience with receiving and exporting data to. This is by no means a promotion for any of these companies, nor is a complete list of options in the market.
Proagrica (formerly SST Summit) https://proagrica.com/
Soil Test Pro https://soiltestpro.com/
When selecting a new software package there are many features to be considered that really do not impact data flow to and from a soil testing laboratory such as, compatibility with equipment and other software, scouting options, local or cloud-based data storage, billing and invoicing options, customizable soil fertility recommendations, and the list goes on. What is important to the soil testing lab is communicating what program you are using once to have selected the one that fits your needs. While many software companies are adopting a common data format, the steps involved in delivering the data are different, and your lab account needs to be set up to accommodate this to make data transfer as easy as possible. When contacting the lab to make a change in software, this is the opportunity to make other updates to your account such as the units that are being reported (ppm vs. lb/ac), Mehlich-3 vs. NCR data, and selecting who electronically receives the data.
We get inquiries for a wide variety of tests, some of them we do not perform. So how do we as a lab determine what tests to offer? There are two main criteria for ALGL.
Is there a business case to offer the test? While that seems rather cold, like our customers we are a business and need to be profitable. We must determine if we can generate enough revenue to cover not only the materials and labor to perform the test, but also the operational costs. We need to develop the procedure, train staff, maybe purchase equipment that requires building space, maybe make building alterations to support the equipment, and the list goes on. Often there is a lot of publicity about a given test, but the sample numbers generated don’t always reflect that market excitement.
Does the test provide value to our customers? A valuable test provides data that can within in a reasonable level of accuracy and stability track progress over time. Ideally the test will also provide some level of predictable outcomes in the future based on prescribed actions. This means there is enough understanding of the system to interpret the data to make informed prescriptive management actions.
A simple example is the fuel gauge in your vehicle. If the fuel gauge shows half full, what does that mean and what decisions can you make with this information?
The gauge reading of 50% or 0.5 is only data. However, though knowledge of the tested system you know the fuel tank has a 40-gallon capacity, now we know there is 20 gallons of fuel in the tank. If though observation you know that the vehicle gets 20 miles per gallon, you now know that you can travel 400 miles on that tank of fuel before running out. If through related research you know that your destination is 300 miles away, you can travel to your destination without stopping for fuel but will need to refuel within 100 miles after leaving that location. Our understanding of a simple fuel gauge is far greater than many of us consider. The greater understanding, the more informed decisions can be made.
Like the fuel gauge, a test value on a lab report is of little value until additional interpretive knowledge is gained. New tests are being developed regularly and the key to their long-term success is interpretive data. The staff at ALGL are regularly tracking new and developing tests to see what offerings make business sense for us and our customers.
In the ever-evolving world of agriculture, precision is key. Farmers and agronomists continually seek ways to optimize crop yield and resource efficiency. One often overlooked but critical tool in this journey is the soil probe. Selecting the right soil probe can make a significant difference in gathering accurate data, leading to informed decision-making and improved agricultural practices.
Soil probes come in various shapes and sizes, each designed for specific purposes. The classic push probe is simple and affordable, suitable for routine soil sampling. However, for more in-depth analysis, hydraulic or electric soil probes offer greater depth penetration and precision. These advanced probes can access subsoil layers, providing a comprehensive understanding of the soil profile.
On the ALGL website, https://algreatlakes.com/collections/probes-replacement-tips, one can find various probes and tips available for purchase. With many items, and practices, in farming there is not a “one size fits all” category for soil probes. There are different types and configurations that will increase efficiencies, and decrease fatigue, while pulling soil cores.
Described above is just one example of a soil probe. Others may include various replaceable parts, such as handles, footsteps and even replaceable tips. Replaceable tips are a great tool when sampling fields with drastic spatial variability. Sandy soils are abrasive and may need a dry tip that can be replaced once dull. A normal soil tip will be the best place to start, for any sampler, and will cover a wide range of soil types. A wet tip is designed for use in clay, mud or very wet soils. There is a lip on the inside of this tip which prevents the soil core from sticking to the bottom of the sampled area and keeps it in the soil tube on the probe. All these options can be selected depending on usage frequency, soil type, sampler physique and budget.
A self-sharpening probe can be purchased instead of replaceable tips. The sampler will not have to worry about potentially losing a tip in the field or having it rattle off during transportation. While self-sharpening probes are generally less expensive, there is only tip design available for all soil conditions.
With all sampling technology, precise and consistent sampling are the priorities. Each piece of equipment has its own advantages and disadvantages. Choosing the right soil probe involves a thoughtful consideration of soil types, depth requirements and a budget in mind. If you need help selecting the right soil probe for your needs, please reach out to your ALGL sales agronomist.
As 2023 comes to a close, 2023 has brought a wealth of challenges and successes. It seems that each year that passes, unique challenges seem to follow. While 2023 was marked with a cold spring bringing planting delays, a dry summer bringing us crop nutrition challenges and led to higher than desired grain moisture for much of the ALGL region, let’s take a moment to reflect on the positive aspects of 2023.
Despite all of the challenges this growing season, yields were good to excellent in most areas, but better than expected everywhere. The dry weather showed us where our weak links might be in our fertility plans to help us make improvements for next year. While we all might not have had the number of staff members we would like to have, the work still got done.
For ALGL, 2023 marks new records. A record number of soil, plant, and manure samples were processed at the laboratory this year, including the highest number samples processed in a month for two of the three sample types. This is the second time records have been set in these all three of these sample types in the past two years!
While sharing these facts may seem boastful, the intent with sharing these facts is not. These achievements could not be possible without a hardworking laboratory staff partnering with each other to get the work done, nor without the samples sent to the lab by our partners in the industry. To each partner of A&L Great Lakes, we extend our heartfelt gratitude. Your trust in our expertise, your commitment to improved soil and crop management, and your passion for cultivating growth is the driving force behind our success.
As we celebrate a New Year, we are energized and inspired to continue expanding our capabilities and knowledge. The road ahead is filled with exciting opportunities, and we are eager to embark on new challenges, and enhancing both existing and new partnerships.
To our amazing team, loyal customers, and everyone who has been a part of our journey to this point – thank you. Your dedication, hard work, and passion have made ALGL what it is today and into the future.
We raise a virtual toast to a phenomenal year, let’s look forward to many more years of shared growth, collaboration, and success.
Here’s to another year of cultivating excellence together!
Dates and locations are set for the 2024 Soil Fertility Workshops. The goal of our workshops is simple: we provide a general overview of fundamental agronomic principles and current university research so our attendees are better able to make nutrient management decisions for their customers or for their own operations. Today’s producers are inundated with information regarding crop inputs and practices. By applying the fundamental principles of agronomy to these inputs and practices, a consultant, agricultural retailer, or producer can evaluate and decide which of those are most applicable for achieving both the short-term and long-term goals of a specific operation.
The workshops are developed and presented by A&L Great Lakes Laboratories’ Agronomy Staff comprised of Certified Crop Advisers, Certified Professional Agronomists, and Certified Professional Soil Scientists whom have a wide range of experience in the agricultural industry.
We will be presenting six workshops in January and February in Illinois, Indiana, Michigan, and Ohio. Registration can be completed online, or by mail/email. Click here for more information and registration.
February 6, 2024 - Fort Wayne, IN
February 8, 2024 - Frankenmuth, MI
February 13, 2024 - Grand Rapids, MI
February 14, 2024 - Rockford, IL
February 20, 2024 - Perrysburg, OH
February 22, 2024 - Fort Wayne, IN
When soil sample location or depth change, so can the soil test data. Often when calls come into the lab about inconsistent soil test values overtime, the responding agronomist will look at the impact of sample location and depth first. If the soil sample is collected in a consistent manner including same depth, same time of year, same location/pattern, following the same crop, the values soil test values should be relatively stable over time. There also will be a gradual trend upwards or downwards depending on the nutrient management focus. If the value of the soil organic matter (SOM), phosphorus, or CEC change dramatically, i.e. 30-50% in 2-4 years, further investigation is in order.
Calcium and magnesium are relatively consistent with soil depth. If calcium and magnesium change by more than 20-25% then it is likely that the sample location has changed, or an aggressive application of lime or gypsum has been applied. Since the primary values used in calculating CEC are calcium and magnesium, the CEC should be relatively stable if the sample is collected in the same location.
If the CEC is stable, but the SOM changes by 0.5% or more in soils with SOM levels below 4-5% then most likely the sample depth has changed. Most of the organic matter is near the soil surface and shallow samples concentrate SOM in the sample leading to a higher relative higher SOM. The same is true for phosphorus to a lesser degree. Soil test phosphorus can be more variable naturally in the soil by small changes in locations that may not be indicated by the calcium and magnesium values.
If the samples are sampled using GIS location, be sure to compare individual sample points and not the field averages. Field average can skew what is taking place with individual sample points if all the sampling points are not impacted the same.
Editors Note: During the 2023 fall sampling season we have noted a large number of small soil samples. Some samples represent less than one sample core of soil. While smaller samples might seem desirable to reduce shipping costs, the greater risk is the negative impact on data quality. Special handling of small samples may result in an additional prep fee.
Originally posted 1/29/21
Most commercial or university soil testing laboratories provide soil sample bags to you at little to no cost. Every lab designs its sample bags with its own logo and contact information in the hope that a sample will be collected, placed in that bag, and sent back to the lab for analysis. While each lab’s sample bags may look unique, most sample bags have one common feature, a line or some other indication of how much sample should be put in the bag. So why is sample volume so important?
The most obvious reason that a lab indicates this volume of soil, is that we need enough material to process and analyze. We also like to have some extra in case a component needs to be reanalyzed for quality control purposes or should the customer request additional testing.
The less obvious, but possibly more important reason to fill the sample bag to the indicated line is to obtain a valid representation of the area sampled. Soil nutrient levels can vary greatly even in a very small area. By collecting enough cores to fill the bag, your results are more apt to represent the true average of the area sampled. Research has shown that a minimum of 8 individual soil cores need to be collected to make a single sample. Collecting fewer than 8 cores increases the potential that a single unusually high or low testing core will skew the results. Taking a subsample of the collected soil in the field can bias soil test data, whenever possible send all of the collected soil providing it does not exceed the soil fill line on the bag. A lab dried and ground sample mixes and homogenizes much better than field moist samples. 8 soil cores from a 6" to 8" sampling depth fit in the soil bag.