Pioneer Water Testing Laboratory. A MESSAGE FROM THE PRESIDENT George W. Mitchell, President/Agronomist

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1 Pioneer Water Testing Laboratory Spring ADDRESSING THE NEEDS OF AGRICULTURAL PRODUCERS AND PLANTING THE SEEDS FOR A SECURE FUTURE. Agri focus A MESSAGE FROM THE PRESIDENT George W. Mitchell, President/Agronomist Welcome to our newsletter, Pioneer Water Testing Laboratory s, Agri Focus. Our main objective with publication is to keep you informed about recent developments in our industry and shine the spotlight on laboratory equipment, software, personnel and quality control. Our newsletter will cover a wide range of topics; ones that will explore new and exciting ideas both here in our laboratory and throughout our industry. Education is the key to our future! Here at PWTL, we pride ourselves on the fact that we are always trying to learn more! We continually strive to make consistent laboratory improvements, educate ourselves to stay on top of the latest technological advances and research, and are always looking to ensure the utmost quality control for you, our valued customers. We are seeing unprecedented change in our industry. Milk price is at an all time low, fertilizer commodities are in unfamiliar territory, and feed commodity prices hit an all time high not long ago. I welcome this as a new beginning. I welcome the challenge. Everyone here at PWTL is working hard to streamline processes and to find efficient ways to use technology. We will partner with you to listen and understand your needs! PWTL is on your side as your business copes with these uncertain economic times. As always, our goal at PWTL is to provide the best analytical results possible while continuously being mindful of your needs and treating you, our customer, with the highest regard. Thank you for your patronage, George EQUIPMENT SPOTLIGHT Near Infrared Reflectance Spectroscopy (NIR) Jeff Foster, Owner/CFO Near Infrared Reflectance spectroscopy (NIR) is a complicated analytical method for quickly determining nutrient structure. Utilizing spectral properties of the forage, multiple nutrients are determined simultaneously. The NIR was first utilized for forage and feed analysis in the late 1970's. Its popularity has blossomed over the last 25 years to make it our most popular service. NIR is recognized by the Association of Official Analytical Chemists (AOAC) as an official method of analysis. We continued to enhance our computer hardware and software which has contributed to progressive improvement of the technology. The NIR is calibration dependent. Historically, our calibrations were developed for common sample types by analyzing hundreds to thousands of samples. The chemical information contained in these samples is correlated to spectral properties and a calibration is born. As the need for additional elements such as Fat and Ash were asked for by our customers, we were able to expand our calibrations. As the need for Starch and Sugar was apparent, we worked with the University of West Virginia to expand our calibrations. We are also able to expand calibrations through being a member of the NIRS Consortium. As you know, we have an extensive Wet Chemistry Laboratory here at Pioneer Water Testing Laboratory. If you prefer Wet Chemistry results or the NIR is unable to read a sample and tells us to run the sample in our Wet Chemistry Lab, we are able to do so. We take pride in providing you with the best analytical results.

2 Agri Focus Spring Page 2 Soil ph, Buffer ph and Principles of Determining Soil Lime Requirement Using the Mehlich Buffer Tim Hoerner Agronomist/Feed & Forage Support Manager Maintaining a neutral or near neutral soil ph through the addition of finely ground limestone to the soil provides most agronomic and horticultural crops with an optimum environment in which to grow. The roots of these crops can perform their functions best when the soil ph is optimum. Not only is the movement of essential nutrients into the roots impacted by the soil ph but so is the release of these essential nutrients from other soil constituents such as clay and organic matter. What is Soil ph? From our laboratory perspective, Soil ph is a measure of the acidcausing elements present in a mixture of water and soil. This mixture of soil and water is referred to as the soil solution. The soil solution contains not only the acid-causing elements but also a multitude of dissolved elements, many of which are essential for plant growth. On a soil test report this value is listed under the heading Soil ph. Soil ph is not a measure of the total soil acidity. More information on this later in What is Total Soil Acidity. What is the source of Soil Acidity? The elements that produce most of the soil acidity are hydrogen and aluminum. Hydrogen is the main source of soil acidity in agricultural soils. Aluminum does not contribute significantly to the measured soil acidity until the soil ph drops well below ph 6. Hydrogen and Aluminum must be in their oxidized or ionic form in order to produce acidity. This means the hydrogen or aluminum had to be a part of another substance prior to breaking away and entering the soil solution. Where do Hydrogen and Aluminum Ions come from? Hydrogen, the primary source of soil acidity, comes from numerous sources. These can include the breakdown of crop, manure, and other organic residues by soil organisms, the addition of certain fertilizer materials, the conversion of ammonia-nitrogen to nitratenitrogen, and the loss through leaching of basic chemical compounds. Aluminum is part of the particles that make up soil, especially clay. Its contribution toward soil acidy is not significant until a very large pool of hydrogen ions accumulate in the soil and depress the soil ph below 5.5. When aluminum reacts with water at these low ph s, some of the hydrogen in the water is released, adding even more to the soil acidity. Is all of the Soil Acidity located in the Soil Solution? Only a portion of this aciditycausing hydrogen can be present in the soil solution at one time. The remaining hydrogen ions become attached to soil particles and fragments of organic matter. These points of attachment are called exchange sites. Additional exchange sites become available to hydrogen ions when nutrients such as calcium, potassium, and magnesium move into the soil solution from the soil particles to replace nutrients removed by the plant or through loss by water moving through the soil. What is Total Soil Acidity? Total Soil Acidity is the sum of the hydrogen ions in the soil solution plus the exchangeable hydrogen ions on the exchange sites. To neutralize a soil requires knowing more than just the Soil ph. It is necessary to know how much acidity is stored on soil exchange sites. On a soil test report, the Total Soil Acidity is listed under Acidity and expressed as milliequivalents of acidity per 100 grams of soil or simply meq/100g. Think of Soil ph as the air pressure in a tire and Total Soil Acidity being the size of the tire. A truck tire and a bicycle tire can have the same pressure (ph) but the truck tire (clay soil) holds a lot more air (acidity) than a bicycle tire (sandy soil). How do we eliminate Total Soil Acidity? By applying limestone to the soil in sufficient quantities and mixing it throughout the root zone, all of the soil acidity is eliminated or more correctly, neutralized. What happens in the Soil when Limestone is applied? Limestone is composed of calcium carbonate, a chemical that slowly dissolves in water and soil solution. When limestone dissolves in the soil solution, it separates or dissociates into two separate ions: calcium, which is positively charged and carbonate, which is negatively charged. Through a chemical reaction, it is the carbonate ion, not the calcium that reacts with the hydrogen ion in the soil solution to form a new compound. The hydrogen in this new compound is bound and is no longer available to contribute to the acidity of the soil solution. This effectively neutralizes the acidity of the soil solution. What about the Exchangeable Hydrogen ions? This is where the calcium from the limestone plays a large role. As the hydrogen ions in the soil solution become bound to the carbonate ions from the limestone, more hydrogen ions are released into the soil solution from exchange sites on the solid soil particles - the reserve acidity. Article continued on page 3

3 Agri Focus Spring Page 3 These hydrogen ions also react with the carbonate ion and no longer contribute to the soil acidity. While this is occurring, the calcium ions are attaching to the exchange sites formerly occupied by the hydrogen ions. The huge number of calcium ions in the soil solution help push more of the hydrogen ions from the exchange sites through a phenomenon called mass flow. Within about 6 months, all of the finely ground limestone will have dissolved into the soil solution, replacing all of the acid-causing hydrogen ions on the soil exchange sites with its calcium, and will have reacted with and effectively removed the hydrogen ions from the soil solution, resulting in a neutral ph soil. How is the Soil Limestone Requirement Determined? Researchers and people with a lot of time on their hands can determine the soil limestone requirement by splitting a large soil sample into many smaller subsamples, adding increasing amounts of ground limestone to each moist subsample, incubating all of these subsamples in a warm oven for several weeks, and then measuring each one s ph with a ph meter to see which amount of limestone raised the soil ph to the desired level. Need your limestone recommendation a tad faster than that? Next is a very rapid procedure that is calibrated to perform as well as this time-intensive method! The Soil-Buffer Method As seen above, soil and limestone take weeks or months to react. That is the reason we don t just add limestone to soil samples in the laboratory and immediately measure the ph. The reading would keep changing until all of the limestone was dissolved and reacted with the soil acidity. Instead, soil is added to a buffer solution and the rapid change in the buffer s ph that occurs in minutes indicates how much acidity is present in the soil and therefore how much limestone is required. A chemical buffer is a substance that resists change of some sort. A ph buffer is a solution that resists changes to its ph even as foreign materials are added to it. By creating a ph buffer that responds quickly in a way that resembles soil when limestone is added to it, a laboratory test can accurately predict, in short order, the amount of limestone that will be needed to change the ph of a soil. Just as limestone is added to soil to raise its ph over time, soil is added to the buffer to see how much the buffer s ph drops as a result of any acidity in the soil. The lower the buffer ph, the greater was the amount of acidity in the soil. If the buffer ph does not change at all, then the soil contains no acidity. Seems simple, right? Not really. Chemicals can be combined in millions of ways to create millions of ph buffers that react in different ways. Which one is right for our soil testing needs? Finding the Right Soil Buffer The right soil buffer to use depends on the nature and characteristics of the soil to be tested. Some buffers are great indicators of large amounts of soil acidity in clay-based soils but fail to respond with clarity to the small amounts of acidity in sandy soils. A buffer that responds well to the low acidity in sandy soils may underestimate the acidity in more acid soils. By understanding the various processes that create acidity in soils, specific chemicals that react to each process can be added to the soil buffer solution. Buffers used in soil testing include the Woodruff buffer, SMP buffer, Adams-Evans buffer, Mehlich buffer, and the Moore- Sikora buffer. Each one works well under specific soil conditions. For decades the SMP buffer has been used on silt loam and clay loam soils in the eastern United States with good success. Why switch to another Soil Buffer? The SMP buffer contains two chemicals that require special handling and disposal procedures. In an effort to remove chemicals such as these from routine laboratory use and the waste stream, other common soil buffers were evaluated to replace the SMP buffer. The Mehlich buffer mentioned above is very similar to the SMP buffer in the way it responds to soil acidity but it too contained an environmentally unfriendly chemical. Unlike the SMP buffer, a substitute chemical was found to replace the problem chemical in the Mehlich buffer that does not change its buffer properties. Limestone recommendations based on the SMP and Mehlich buffers are almost identical for a given soil sample. Additional benefits to using the Mehlich Buffer The Mehlich buffer responds better than the SMP buffer to low soil acidity levels that require one ton of limestone or less to neutralize, such as those from frequently limed clay soils and sandy soils with few exchange sites. Because of the difficulty and expense of applying small amounts of limestone to fields, we do not provide limestone recommendations of less than one ton per acre. What may change on the Soil Test Report? Using the Mehlich buffer, we are able to report Acidity values less than 2.0 milliequivalents (2.0 meq/100g soil) on our soil analysis report. Low Acidity values were not reported using the previous SMP buffer even though up to one ton of limestone may have been recommended. Using the Mehlich buffer, the Cation Exchange Capacity or CEC may be slightly higher on soils with low acidity than when the SMP buffer was used on those same soils. This is due to the reporting of low acidity values when using the Mehlich buffer. This CEC is likely a better representation of the soils exchange capacity. Continued on page 4

4 Agri Focus Spring Page 4 A slight increase in the CEC will cause a corresponding small decrease in the reported percent base saturation of potassium, magnesium, and calcium. Although minimal, these decreased saturations may result in slightly more potassium and magnesium being recommended. The reason for this is that our baseline soil levels for potassium and magnesium are based on specific base saturation levels for these two nutrients. If the percentage of the CEC made up of potassium and magnesium drops (which happens when more acidity is added to the CEC total), additional potassium and magnesium will be recommended to meet the desired baseline levels. Does anyone else use the Mehlich Buffer? In addition to the soil laboratory at Pioneer Water Testing Laboratory, other laboratories using the Mehlich buffer include Penn State University, Virginia Tech, Dairy One, University of Maine, and North Carolina Department of Agriculture. USING PLANT ANALYSIS AS A TOOL TO MONITOR NUTRITIONAL STATUS Lisa Dreibelbis, Agronomy Service Manager Plant growth and productivity in agricultural growing systems is almost always below its maximum potential. Factors influencing this statement involve genetics, environment and nutrition. Genetics are controlled thru the use of cultivars, the environment can be managed to a degree by using practices such as: irrigation, fertigation, plasticulture etc.. Nutritional deficiencies/toxicities that are limiting growth can be diagnosed by utilizing plant analysis. Plant analysis (also referred to as leaf analysis) determines the elemental content of a particular plant part for 14 essential plant nutrients. The approach to using plant analysis can be viewed reactively or proactively. The reactive approach is when a plant analysis is sent to the lab to verify visual deficiency/toxicity symptoms. Unfortunately, when this approach is used it is often too late; plant growth and yield goal are already detrimentally affected. Over the past several years plant analysis for most growers has switched to the proactive philosophy. The proactive grower will use a sequence of plant analysis to track and log the nutritional status of the plant throughout the growing season. This weekly monitoring of nutritional status allows the farmer to correct on the grow. The results of the plant analysis findings are used to determine if soil fertility level and applied fertilizers are high enough to meet the crops requirements. This monitoring allows for adjustments and supplements to be added to the fertigation process resulting in stronger plants and increased yields. Spring is just around the corner and it s time to be prepared for the coming growing season. Test your soil to determine soil health and fertility prior to planting. If you are applying manure have it analyzed also, with the high cost of fertilizer these two simple tests could put money in your wallet. Finally choose your approach to plant tissue testing, will it be reactive or proactive?

5 Agri Focus Spring Page 5 ECONOMY WATCH: The Agriculture Industry Greg Zimmerman, Feed and Forage Service Manager Everywhere we turn these days it is hard to avoid the news of companies announcing layoffs, plant closures, and/or financial losses. The economy has taken a turn for the worse and the future of most industries is cloudy. Uncertainty and fear has gripped its hold on the world. Despite the recent news, the agricultural related fields have remained steady as the demand for food does not decline with the slide of the stock markets. We can all be thankful to be weathering the storm in a relatively safe environment. That is not to say that agriculture has not seen any effects: commodity prices have fallen; milk prices have fallen; farms have had to scale back in size; but there is a strategy for industry to ride the waves and come out on the other side with minimal damage. Blessings can be found if one looks hard enough: with the plummeting oil prices, the demand for ethanol fuel has fell along with it and has led to closures of ethanol facilities leading to a surplus of corn on the market, thereby bringing feed prices down that just last spring were of so much of a concern. There are reasons for hope. Here at Agri Analysis, we are also looking to the future with the attitude of being right there with you through these hard economic times; working with you to provide the testing needs that fit into your financial budget. Also at this time, we are still working to improve our methods and expand our testing capabilities. We appreciate any input that you, our customers, have on what you would like to see available. If you are just finding out about us and would like to know more, or a current customer looking to improve or refine your testing, please contact us today. I m sure we have a package available that suits your needs and budget. AGRI ANALYSIS INC. a division of PIONEER WATER TESTING COMPANY, INC. ANALYZE TWO FEED AND FORAGE SAMPLES & TEST THE 3 RD SAMPLE FREE! **Complimentary test must be of equal or lesser value. ** Must include coupon with samples to be tested to receive this offer. **Limit 1 per customer Agri Analysis, Inc. 280 Newport Road P.O. Box 483 Leola, PA Phone: Website: