March 04, 2022

Soil Sampling Depth - A Critical Piece of the Puzzle

When formulating a quality soil sampling plan, our focus is often directed toward parameters such as grid vs. zone, sample point locations, number of acres per sample, or number of cores per sample. However, a critical parameter that is often overlooked is sampling depth and the consistency of hitting the target depth every time. Cores that vary in collection depth by 1/2” – 1” or more can greatly impact the resulting data which translates straight to the bottom line when it is time to purchase and apply fertilizer inputs.

Nutrient concentration can vary greatly throughout the soil profile, especially under long term no-till conditions.Therefore reliable, consistent results can only be achieved when sampling depth is closely controlled. If you have employees or others helping in your sampling operation, make sure this topic is included and discussed in any training and instructions that you provide.

We often receive questions at the lab regarding sample collection in wet soil conditions.  Proper sampling can continue if good depth control can be achieved.  When the probe is placed into the soil, look in the top of the collection tube and ensure that the top of the soil core being collected is very near to the soil surface.  Under extremely saturated conditions the tip of the probe will not accurately cut through the profile and will push into the ground like a stake while compacting the soil around it resulting in inaccurate sampling depth.

Recommended sampling depth under varying cropping conditions are normally 4” in lawn and turf, 6” in no-till cropping and 8” in conventional tillage.  When choosing your desired sampling depth it is critical  to make your best choice for your conditions  and consistently sample at the same depth over time.  Most samples are collected every 2-4 years and the sampling depth must remain the same so that nutrient concentrations can be compared across collection dates and trends can be established.

 

Depth

OM

Soil Test P

Soil Test K

0-2”

3.9

82

154

0-4”

3.4

47

133

0-6”

3.2

33

109

0-8”

3.1

28

101

Long term no-till. LOI, Reported as Bray P-1, ammonium acetate K. Source ALGL 2021

As seen in the data table above, phosphorus, potassium and soil organic matter tend to decrease as sampling depth increases.

If you would like assistance with any of your sample collection plans, please contact our agronomy staff.

March 04, 2022

We Need Your Photos!

The ALGL customer photo calendar is becoming a tradition! This past year we celebrated the 5th issue of the calendar built by you. Over the past years it has been amazing to see how beautiful the world around us truly is though the eyes of our customers. Once again, we are reaching out to the best customers a business can ask for.

Do You have photos to share?  Please share with us pictures of those things in the life sciences that speak to you and show how amazing the world around us truly is. We want to see pictures that illustrate what fuels your passion for life sciences and customer service. When you get that picture captured, send it to news@algreatlakes.com along with your name, address, and brief note about the picture(s). Please submit your pictures in the highest resolution possible before September 15th. Then we will select our favorite pictures, then we will be letting our followers on Facebook vote on their favorite, to be on the cover of the 2023 calendar. Follow us on Facebook for voting details.

 Photo criteria 

  • Landscape oriented photos preferred, but not required.
  • Please share the highest possible resolution photo.
  • Please try to avoid company logos and easily identifiable faces.
  • No dangerous or illegal activities.

Rules 

  • Photo submission deadline is September 15, 2022
  • One entry per person, however you may submit more than one photo.
  • Must be 18 years or older to enter.
  • Need not be present to win.
  • No purchase necessary.
  • Submitting a photo gives A&L Great Lakes permission to use the photo for promotional use.
  • Employees of A&L Great Lakes Laboratories, Inc. and their immediate families are not eligible for prizes, but may submit photos for consideration in the calendar.
  • Use of images in promotional items does not increase your odds of winning a prize.
  • Contest decisions and/or judgements by A&L Great Lakes Laboratories, Inc. are final.
March 04, 2022

Basics of Lab Data Files

The lab data generated by ALGL is delivered to clients in a variety of formats for the use in software. One key distinction about these data files is that it is lab data only. There are data file formats that are dedicated to the spatial representation of lab data. We at the laboratory do not generate these files. In most cases the GPS coordinates of the sample location is not shared with the lab.

The most common data files are CSV files. They are identified by their file extension, .csv and are commonly called “comma delimited” files. These are basic text files in which the data for a given sample is contained in a single line of text, and each piece of data is separated by a comma. These files can be viewed, opened, modified in spreadsheet programs like Excel and text applications like Notepad, but must be handled within specific parameters to maintain the integrity of the file structure. Often critical metadata, which is information that provides context to allow the data to be understood by the end user, is not contained in the data file. This metadata includes such information as the type of data being presented (analyte), units, and extraction method. This is especially true because not all software packages require this information to be explicitly given within a data file.  

A growing data file format is the Modus-xml file. Modus is a standardized system of defined terminology, metadata, and file structures that has grown from a need to manage and exchange agricultural testing data. The file format follows an XML structure, which is essentially a coding language. The Modus files have a standardized data structure and use a preset list of codes to identify all parameters of the sample such as lab method and units.

We often get requests for shape files. This is not a single file, but rather a set of files, that are often grouped in a ZIP file. Each data set is contained in three identically named files with different file extensions of .shp, .dbf, and .shx. Each file contains an aspect of the complete data set. These files are specific to GPS/GIS mapped data. The GPS coordinates of the sample location are required to generate these maps.

Often software companies electronically share data about a soil sample or set of soil samples before they arrive at the lab. This data can be as simple as a grower/farm/field, or very detailed, and is often determined by the software’s data flow. In most cases a unique identifier (serial number) is assigned to the sample or set of samples. That unique identifier accompanies the samples to the lab and is used to link the electronic data that was sent by the software ahead of time to the physical sample.  This can also provide more efficient data entry for the customer and the lab.

When the lab results are released, they are sent to the customer in a couple of ways. Some data is simply emailed to the customer for manual import. Some data is emailed to a server, and the server automates the uploading of the data to the software. Data can also be sent directly from our server through an automatic interface that processes the data and imports it into the software platform.

March 01, 2022

Fall Applied Manure. Will the Nitrogen Still be There?

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.

Following a relatively cold winter in 2022, nitrogen losses from fall applied manure should have been minimal so far. 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.
January 31, 2022

Testing Soil Carbon

In this newly emerging world of carbon credits, carbon markets, and carbon banking, the need to quantify and document soil carbon content is becoming more and more important. The challenge with this new market is that the testing methods for soil carbon have not been standardized across the industry. Carbon can be analyzed by several different methods and each method can give you different results.

At A&L Great Lakes Laboratories, soil carbon can currently be analyzed by 3 different methods; loss on ignition, combustion, and Walkley-Black oxidation.

The loss on ignition method is the quickest and cheapest method for estimating soil organic carbon. The process is fairly simple. A portion of the dried and ground soil sample is weighed, then put into an oven to burn off the soil organic matter. The sample is then weighed again, and the change in weight is equal to the organic matter content of the soil. From the organic matter content, the organic carbon content can be calculated by assuming that 58% of the organic matter is carbon.

The combustion method is a way to determine total soil carbon. The simplest explanation is that a weighed portion of the soil sample is heated to the point that both the mineral and organic fractions of the soil combust and the gases are then analyzed to determine the total carbon content. While this is a very accurate method, there is no way to determine whether the carbon originated from the organic matter in the soil, or the mineral fraction. The liming materials that are generally used consist of calcium and magnesium carbonates, and this test will detect this form of carbon also.

The Walkley-Black method determines the organic carbon content of a soil by measuring amount of carbon that is oxidized in a reaction with dichromate through a back titration. While this method is generally considered the most accurate method to determine soil organic carbon, it is also the slowest and most expensive. It also requires the handling of hazardous materials, so it is generally the least preferred method for occupational and environmental safety reasons.

As the carbon farming industry continues to evolve, the methods for analyzing carbon are likely to change as well. When comparing results from separate sampling events, be sure that you know what sampling procedure and method were used so a fair comparison can be made.

January 31, 2022

2021 Soil Test Data Summaries Are Available

The 2021 annual soil test summaries are available on the ALGL website at https://algreatlakes.com/pages/2021-soil-test-summaries. Your regional ALGL sales agronomist has access to regional trend graphs that show the change in soil test values from 1996 to 2021 for the Great Lakes Region, and individual states, that they can share for use in presentations and meetings as needed.

Soil Test Phosphorus levels 1996 - 2021

For those customers accounts that analyze more than 20 soil samples a year, soil test summaries are available for the account. Those summaries can be found on eDocs at https://docs.algreatlakes.com/login.aspx. Be sure to adjust the eDocs’s data filters to include “Summary” as the document type and the time filter to span December 31, when the reports were posted.

These same customers will also find a trend graph of these summaries over time, and a soil sampling history report that summarizes all the field that were sample in that given year. These soil sampling history reports are a great tool when routinely sampling on a 2-, 3-, or 4-year standard rotation. For example, when preparing to soil sample in 2022 on a 2-year cycle, go back to the 2020 Soil Sampling History Report for a list of fields that are due to be resampled in 2022.

December 30, 2021

Crop Removal Soil Fertility Done Right

For rented cropland, applying phosphorus and potassium fertilizer based on crop removal is common and simple, or so it seems. Theoretically if you apply as much nutrient as is removed in the harvest of grain and/or biomass, soil fertility levels should remain steady. This works well in a cash rent scenario. The soil fertility is maintained at over time for the landowner, and the tenant farming the land is not building up a soil fertility that they may not have access to in the future.

The crop removal fertilizer rate is calculated by multiplying the yield times the nutrient removed per unit of yield. Often this is done without routine soil testing to keep input cost down, further compounding potential issues. Actually, there are three main inputs into the crop removal fertility methodology, the crop removal factor, yield, and soil test values. Let’s look at how each factor can impact the results of a crop removal soil fertility plan.

Often book values are used for crop removal factors, these tend to be slightly higher than actual crop removal in many cases. The nutrient removed per unit of grain can vary quite a bit, biomass harvesting can vary even more. Most book values are identified so that 2/3 to 3/4 of all the values in the dataset fall below the single published value. In most cases using book values for crop removal factors will slightly overestimate the actual crop removal, this helps avoid a short fall in fertilizer application rates. For corn the nutrient removed per bushel often declines with increasing yields. When corn yields increase because of a larger corn kernel, the majority of that kernel is starch comprised of carbon, hydrogen, and oxygen. The germ of the kernel that contains nutrients like nitrogen, phosphorus, and potassium stays relatively the same size. This reduces the concentration of nitrogen, phosphorus, and potassium in the grain. Crop removal can also be impacted by growing conditions and variety. To improve the accuracy of the crop removal values, biomass and grain samples can be sent to the lab for analysis.

The value used for the yield input can be the source of the greatest errors. Yield is not defined in soil fertility calculations as past measured yield or future predicted yield. Measured yield is usually more accurate than predicted. Often the field average yield or an average of several past years of yield are used for this value. This assumes that the yield is stable from year to year and that the yield is uniform across the field. Often this is not the case. The picture below is a simple example of both issues. This field has a 4-year running average of 198.7 bpa corn, and a realistic yield goal of 200 bpa corn. However, in 2021 the field average yield was 235 bpa. If 200 bpa was used in the calculation, the calculated fertilizer rate could be 15% under actual average crop removal. For this same field if a uniform 200 bpa was to be used, 18% of the field would receive more fertilizer than was removed, and 52% would receive less fertilizer than was removed. Using a flat yield value would lead to excessive fertilizer inputs for the low yielding areas and put the high yielding regions at risk for lost yield potential. While arguments can be made about the accuracy of yield maps, they will identify regions of above average and below average yields. There is an application for variable rate fertilizer application even in a crop removal fertility program.

While soil tests are often seen as a way to predict or prescribe fertilizer application rates, they can also help monitor changes or the results of the fertility management. Soil testing this field after many years of flat rate crop removal revealed that the low yielding areas of the field did not require any fertilizer and the high yielding areas of the field had very low soil fertility levels. Soil fertility maps can be used in conjunction with yield maps to further define fertilizer application rates in a variable rate crop removal fertility plan.

December 30, 2021

The Key to Nitrogen Management

While high nitrogen prices are a common topic in the media, the key management strategies are nothing new. The key is increased nutrient use efficiency, and for most of our region that means reducing the risk of nitrogen loss. There is a wide continuum of nitrogen rates from 1.4 pounds of nitrogen per bushel of corn to 0.7 pounds of nitrogen per bushel of corn, the difference is the efficiency of nitrogen use.  

Ways to increase nitrogen use efficiency:

  • Using nitrogen stabilizers delays the conversion of nitrogen to forms that can be lost to the environment. 
  • Avoid preplant applications of nitrogen. The wider the time gap between nitrogen application and crop uptake, increases the chance of nitrogen loss. In some cases, fall applications of nitrogen, commercial or manure, can take place 7-10 months before the nitrogen is taken up by the crop.

 Read more about fall applied manure:

  • Split applications of nitrogen throughout the growing season brings the application closer to use and reduces the amount of nitrogen subject to loss at any one time. Split applications also allow for rate adjustments based on the growing season. 
  • Incorporate all forms of nitrogen if possible. Nitrogen left on the soil surface is subject to volatilization though more than one mechanism. These loss mechanisms are in addition to loss mechanisms the nitrogen is subject to in the soil. 

Read more about nitrogen loss mechanisms:  

  • Apply sulfur. While the application of sulfur does not always increase yield, it often maintains yield at a lower nitrogen rate. The application of sulfur can increase the plant’s efficiency to utilize of nitrogen. 
  • Avoid situations where high C:N crop residues or livestock bedding material might reduce nitrogen availability to the crop. 

Read more about nitrogen release from organic residues:

  • Plant crops requiring supplemental nitrogen on fields with higher organic matter contents. The mineralization of nitrogen from soil organic matter can provide a significant nitrogen contribution.

 Read more about ENR:

  • Use soil nitrate and ammonium tests for manured fields and late nitrogen season applications. For manured fields, early spring weather can have a huge impact on nitrogen loss. PSNT testing can help determine supplemental nitrogen rates for manured fields. For late season split application of nitrogen in corn, nitrate and ammonium testing can dial late season application rates based on in season crop observations and realistic potential yield.

 Read more about PSNT in manured fields:

Read more on late season commercial nitrogen rate determination:

  • Focus on maximum profit rather than maximum yield. Often with high fertilizer prices focusing maximum yield or apply a bit extra nitrogen as a “insurance policy”, can be rather expensive management strategies. The MRTN model can help evaluate your options. This year it is very important to complete a crop budget ahead of the growing season.

 Read more on MRTN:

  • Tissue tests can monitor nitrogen levels in the plant through the growing season.

 Read more about collecting plant tissue samples:

December 16, 2021

Is Reality Becoming Stranger than Fiction?

Editorial by Agronomist Jamie Bultemeier

For the past few years, just prior to the yearend, I have been looking back and reflecting on the happenings and lessons learned as the year comes to a close. So, what did the 2021 growing season show us?

The spring planting season had some minor rain delays, but overall went smoothly. Field operations, while slightly delayed for some, still progressed better the previous few years. Strong commodity prices led to an increase in plant tissue sampling through the season. Overall, the first half of the crop season was good. As the season progressed some challenge began to appear with extended wet or dry weather and the appearance of disease. Harvest started earlier and the soil sample volume to ramped up earlier than normal. Shortly after the strong start of fall harvest, the fall rains began and made harvest a challenge. Unfortunately, there are producers in the region still trying to finish harvest. The fall rains resulted in fields scarred with ruts from harvest that will impact crops for the next few years. Through all of these challenges there were numerous reports of exceptional yields.

During the fall of 2020, the stage was being set for increased fertilizer demand leading to increased fertilizer prices. The fall of 2020 was dry, and yields were good. There was a notable amount on pent up fertilizer demand due to previously low commodity prices, and pent-up soil sampling demand due to several sequential wet fall and spring sampling seasons preventing sample collection. Fall of 2020 set soil sample number and fertilizer application volume records. The record pace of fertilizer consumption and soil sampling continued into the spring of 2021. Early in 2021, the shipment delays of fertilizer began as well. Very good crop condition, with favorable commodity prices, led to strong in season fertilizer use. This kept the demand and supply pressure on the fertilizer market and the market was unable to recover before the fall of 2021.  This time last year it would have been reasonable to anticipate increases in fertilizer prices. But how many people forecasted and planned for a 2 to 4 times increase in fertilizer prices occurring in 2021? Now we are preparing for the 2022 season making plans to address the reality that the supply of fertilizer, especially nitrogen, may be limited. We have seen high fertilizer prices before, but widespread supply shortages, that is a new challenge for most of us in agriculture.

We need to be making alternate plans in the event any given input is unavailable or increases in price 10-fold. Producers and suppliers need to be asking themselves, “How do I produce a profitable crop if “x” is not available/accessible?”  These kinds of shortages are not impossible in agriculture, they have occurred. During the 1973-74 energy crisis, and WWII, fuel was in short supply. Agricultural supply shortages are something we have not experienced in recent years. Some herbicide chemistries are also looking to be in short supply for the coming growing season. Tires and machinery parts may continue to be a concern as well.

Each year as I write this article I sit for a moment and think, what challenges might next year bring. What challenges and opportunities lie in store for producers in the coming year based on the outcomes of the current year?  As a producer, and a professional agronomist, I try plan for the extremes and the worst-case scenario when developing and executing a nutrient management plan. Drought and excessive rain are always in the plan. Then there is planning for the unexpected, that seems to be growing more difficult each year. Maybe even to a point beyond what is conceivable in the planning process. Two years ago, I did not contemplate the impact of a global pandemic, and last year I did not consider the impacts of a widespread global supply chain disruption. Maybe my planning for 2022 should include the evaluation of what impact an alien encounter would have on crop production.  Anything is possible.  It almost seems that reality becoming stranger than fiction.

November 26, 2021

Don’t Overlook Manganese

Manganese (Mn) is a nutrient that is often overlooked in the Great Lakes region since it rarely tests as low or deficient in our soils. In fact, nearly 90% of soils tested at ALGL test at adequate or higher levels. However, this is not the case for corn and soybean plant tissue tests. It is quite common for plant tissues to test low or deficient in Mn.

Manganese Deficient Soybeans

Where does this discrepancy between soil and tissue tests come from? The simple answer is that just because the Mn is present in the soil, does not mean that it is in a form that the plants can uptake. Manganese availability is highly dependent on soil pH, it is most available when the pH is around 6.5. As the pH approaches 7.0 or higher, the availability is greatly reduced. Another factor that reduces the availability of Mn is organic matter. Manganese is highly reactive with organic matter and forms bonds with it making it impossible for plants to access it.

The good news is that there are options available to manage Mn. The best option is to maintain your pH around 6.5. However, this is not always possible, many areas in the Great Lakes region have naturally alkaline soils. In these areas, both soil applied, and foliar applied Mn fertilizers can be used successfully. In areas with high organic matter, foliar applied fertilizers tend to be more successful. If the pH and the organic matter are both high, a chelated form of Mn is the best option to maintain availability.

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