PRODUCT MANUAL

The Science Behind SO4

Calcium Productscalciumproducts.com | SO4 Product Manual | 1 May 18

00447_CP_SO4_ProductGuide_8.5x11_JC_April18B.indd 1 5/14/18 3:31 PM TABLE OF CONTENTS

What is SO4? Page 3

The Need for Sulfur Page 4

Comparing Sulfur Sources Page 6

SO4 Application, Handling and Storage Page 8

Soil Amending Page 10

Selling SO4 to Growers Page 12

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00447_CP_SO4_ProductGuide_8.5x11_JC_April18B.indd 2 5/14/18 3:32 PM WHAT IS SO4?

SO4 SO4 Fertilizer Ca Ca Ca S Superior Sulfur Release S 1 14 SO4 is the superior sulfur source that S 7 delivers the right amount of sulfur pH perfectly matching plant needs for yield-maximizing plant growth. Superior Sulfur Release pH Neutral Application Flexibility

• Superior Sulfur Release. SO4 Product Specifications What is gypsum? supplies a strong initial release Guaranteed Analysis Gypsum is a soft mineral, of sulfur followed by a steady Calcium:...... 21% chemically composed of calcium supply throughout the growing Sulfur (sulfate):...... 17% and sulfate, and two molecules season, perfectly matching plant Moisture (max):...... 1.0% of water (CaSO4 • 2H2O), called needs. Ammonium sulfate (AMS) Calcium sulfate dihydrate:.... 92% calcium sulfate dihydrate. is 300x more soluble than SO4 Variations of calcium sulfate occur (Haynes, 2014), releasing sulfur Average Particle Size Before naturally, such as anhydrite (CaSO4) too quickly, while elemental Pelletizing but it has lower solubility compared sulfur releases sulfur too slowly, 4-mesh: 100% passing to dihydrate gypsum due to the neither meeting the crop’s 8-mesh: 100% passing lack of bound water in its crystalline complete needs. 100-mesh: 80% passing structure. • pH Neutral. SO4 is pH neutral, which means it will Production Details How did SO4 get its name? not acidify the soil, while other • SO4 pelletized gypsum is The chemical formula for sulfate is sulfur sources. Proper soil pH 2- manufactured SO4 and served as the inspiration maximizes a plant’s utilization of from mined gypsum in Fort for the founder of Calcium nutrients promoting good plant Dodge, IA. Products to give the brand name of health and optimizing yield. • The binding agent used is SO4 to his pelletized gypsum. • Application Flexibility. SO4’s calcium lignosulfonate consistent pellet size allows it and is a byproduct of the paper SO4 is OMRI Listed® to be blended and applied with milling industry. SO4 is the only pelletized gypsum other dry fertilizers and makes approved for use it the smart choice for any Pellet Physical Characteristics in certified organic application scenario. Size Guide Number (SGN) production. It is Averages: certified by the SO4 is mined and pelletized from a < 200: 3% Organic Materials Review gypsum vein in northwest Iowa, one 200-280: 37% Institute (OMRI). of the purest sources in the world. 280-400: 40% The mined gypsum is finely ground > 400: 20% to a powder, 80% passing a 100- mesh screen, and then pelletized to Average SGN: 300 achieve ideal reactivity and pellet Uniformity Index (UI): 50 strength. Compression strength: 9.0 pound- feet (LBF) Bulk density: 61 lbs/ft3

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00447_CP_SO4_ProductGuide_8.5x11_JC_April18B.indd 3 5/14/18 3:33 PM THE NEED FOR SULFUR

The Fourth Major Nutrient It is widely understood that plant growth is impacted by the three primary macronutrients – nitrogen, phosphorus and potassium. Many agronomists consider sulfur, a secondary macronutrient, to be the fourth major nutrient because of the critical role it plays in healthy plant growth.

The Benefits of Sulfur Sulfur is an essential component of plant growth. Key functions of sulfur in the plant include chlorophyll formation, protein production and activation of enzymes. Amino acids such as cysteine and methionine may be deficient in plants where

Sulfur is Needed Throughout the Growing Season

Sulfur uptake in corn has been presumed to be similar to Sulfur uptake in soybeans is similar to corn, with more nitrogen. However, a University of Illinois study indicated than one-half of sulfur uptake occurring after the that more than one-half of sulfur uptake occurs after the reproductive phase has begun (Bender et al., 2013). transition from vegetative to reproductive processes has Alfalfa would have a very similar, although greater begun. This suggests that a season-long supply of sulfur is overall, uptake pattern for sulfur. critical for corn nutrition (Bender et al., 2013). CORN SOYBEAN 26.0 100 100 18 22.8 ) )

-1 S -1 15 S 80 19.5 75 al (%)

16.3 12 t 60 13.0 50 9 9.8 40 ent of To

6 c 6.5 25 S Uptake (kg ha S Uptake (kg ha

20 Per 3.3 3

0.0 0 200 400 600 800 1000 1200 1400 GDDC Days After Planting

VE V2 V4 V6 V10 V14 VT/R1 R2 R4 R5 R6 Planting V2 V4 V7 R2 R4 R5 R6 R8 Growth StageGrowth Stage Grain Grain Flowers, Pods Flowers, Pods Stem, Petioles Stem, Petioles Leaves Leaves

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00447_CP_SO4_ProductGuide_8.5x11_JC_April18B.indd 4 5/14/18 3:31 PM sulfur is lacking, negatively impacting instead of a lack of adequate sulfur in the youngest leaves of the the food or feed quality from these (Datnoff et al., 2007). corn plant first, while nitrogen plants. Sulfur is also important in deficiency appears in the older nodule formation in legume crops, Recognizing Sulfur leaves first. The difference is where it aids rhizobia bacteria in Deficiency related to how each nutrient is converting atmospheric nitrogen into 1. Look at leaf color. Plants with mobilized in the plant. plant usable forms (Marschner, 1995). pale green appearance should be inspected closer for nutrient 3. Utilize a tissue test. Sulfur Sulfur deficiency can result in the deficiency symptoms. Both deficiency can be visually inhibition of protein and chlorophyll sulfur and nitrogen deficiency misdiagnosed, even by seasoned synthesis. Sulfur deficiencies can be are marked by yellow striping agronomists. Collecting tissue difficult to determine from visual between the veins of the leaf from the growing plant and observation as symptoms resemble (interveinal chlorosis), which submitting it for laboratory nitrogen deficiency. Sulfur deficiency can cause confusion when analysis is an excellent way occurs in younger leaves, causing diagnosing sulfur vs. nitrogen to positively identify nutrient them to turn light green to pale deficiency. The photo(above) deficiencies and provide yellow. Many plants have their shows sulfur deficiency. quantitative values for any growing point at the top of the plant, needed corrective actions. Your which can often lead to a visual 2. Inspect plants’ youngest testing lab can provide threshold misdiagnosis of nitrogen deficiency leaves. Sulfur deficiency appears tissue test values.

A Rising Need for Sulfur

Agronomically, plants have always needed sulfur. of the amount of sulfur today compared to 30 years ago. Historically, much of the sulfur need was satisfied from atmospheric deposition of sulfur as a result of coal burning Additionally, modern fertilizers are highly concentrated industries. Amendments to the Clean Air Act in 1990 and contain less sulfur than in the past. Compounded targeted sulfur dioxide emissions and the resulting “free” with declining organic matter, less sulfur is naturally atmospheric sulfur decreased dramatically. Many areas of available while crop yields continue to climb, resulting in the central and eastern Midwest receive less than one-half more opportunities for sulfur deficiency to occur.

SULFATE ION WET DEPOSITION, 1985 SULFATE ION WET DEPOSITION, 2016

• •• • •• • • !! • •• • •• !!!! ••• •• •• • •• •• • • •• • • • • • • •• •• • • • • • •• • •• • •• •• • !! •• • • • • • •• • •• •• • • • • • • • • • • ••••• ••••• • • • • •• • • • •• ••• •• • • • • • •• • • • • •• • • • • • • •• •• • • • • •• •• •• •• • • ••• • • • •• •• •• •• •• •• • • • • • • •• •• • • •• • •• • • • •• • ••• • • •• • • • • • • • • • •• •• •• • • ••• •• • • • • • • •• • •• • •• • • • •• • •• • •••• • • • •• • • •• • •• • ••• • • •• •• ••• •• •• •• •• •• • • •• •• • • • • • • • • ••• • •• •• •• • • • • •• •• • •• • •• •• • • • • •• • •• • •• •• ••• • • •• •• •• • • • •• • • • • •• •• • •• • • •• •• •• • • • • • • • •• •• •• •• •• • • •• •• •• •• • •• •• 2- •• • • 2- • • Sulfate as SO4 • • • • Sulfate as SO4 • • •• •• • • ••• •• • •• •• • • (kg/ha) • • ••• • • • • (kg/ha) •• •• •• •• •• •• •• • ••• • •• ••• • •• •• •• ≥ 24 ••• ≥ 24 • • • • • •• • • •• •• •• !! 20 • • • • 20 •• •• • • •• •• •• 16 • • • • •• • •• • • • 16 •• •• •• • •• • • • • • • 12 • • 12 • • •• •• •• •• • •• • 8 • 8 Sites not pictured: •• ! • • •• ! 4 • • • Argentina 01 4.0 kg/ha • 4 •• •• • • Alaska 01 1.0 kg/ha 0 0 Alaska 02 3.0 kg/ha • •• • Alaska 03 <1 kg/ha Alaska 97 2.0 kg/ha Puerto Rico 20 19.0 kg/ha National Atmospheric Deposition Program/National Trends Network Saskatchewan 20 2.0 kg/ha http://nadp.isws.illinois.edu Saskatchewan 21 2.0 kg/ha Virgin Island 6.0 kg/ha

National Atmospheric Deposition Program/National Trends Network http://nadp.isws.illinois.edu

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00447_CP_SO4_ProductGuide_8.5x11_JC_April18B.indd 5 5/14/18 3:31 PM COMPARING SULFUR SOURCES

Side-by-Side Comparison There are several dry sulfur sources available on the market today and comparing them can be a complex task. There are differences to consider such as included nutrients, rate of sulfur release and soil acidification.

Pelletized AMS MAP + AMS + Synthetic Elemental Elemental Sulfur Gypsum Sulfur

Nutrition Total Sulfur 17% 24% 10% 16-18% 90% Plant Available Sulfate 17% 24% 5% 17% – Nitrogen – 21% 12% – – Phosphorus – – 40% – – Calcium 21% – – 21% –

Solubility Rate of Sulfur Release Ideal Rapid Rapid then Slow Slow to Moderate Slow

Soil Acidification Amount of 98G needed None 120 lb/A 100 lb/A None 80 lb/A to neutralize the acid from 25 units of sulfur/A

Approved for Use in Organic Farming OMRI Listed® Yes No No No Yes

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00447_CP_SO4_ProductGuide_8.5x11_JC_April18B.indd 6 5/14/18 3:31 PM Rate of Sulfur Release In 2017, a study was conducted in Study Results the Calcium Products laboratory 450 to evaluate the sulfur release rate of several sulfur sources. Analysis 400 of sulfur release was completed by 350 Midwest Laboratories in Omaha, NE. 300

Study Findings AMS 250 MAP + AMS + elemental sulfur • SO4 supplies the best balance of SO4 initial sulfur release and steady 200 Pelletized synthetic gypsum supply throughout the growing Elemental sulfur season perfectly matching plant 150 Sulfate concentration (ppm) needs. 100 • Ammonium sulfate (AMS) has an extreme initial release of nearly 50

all its sulfur, leaving it susceptible 0 to leaching throughout the March April May June July August September remainder of the growing season. AMS is 300x more soluble than SO4. released sulfur from the AMS is to predict exactly when sulfur • Sulfur release of ammonium then susceptible to leaching in will be fully released from thiosulfate (ATS) would be similar subsequent months. elemental sulfur due to several to or greater than the sulfur • Products containing AMS and environmental factors. release of AMS. elemental sulfur also degrade • Synthetic pelletized gypsums • Products combining AMS and soil quality by acidification due to include additives and extra elemental sulfur provide an nutrient transformations. binding agents, slowing initial initial release from the AMS but • Elemental sulfur needs significant breakdown and preventing full very little, if any, further release time to release its sulfur. Very solubility during the growing from the elemental sulfur. The little sulfur was released from season. They can also contain elemental sulfur in this study. heavy metals not suitable for Further, it is nearly impossible land application.

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00447_CP_SO4_ProductGuide_8.5x11_JC_April18B.indd 7 5/14/18 3:31 PM SO4 APPLICATION, HANDLING AND STORAGE

Application Timing and Rate as a rescue application, a response volume of soil being impacted SO4 can generally be applied spring to SO4 can be expected within a compared to a broadcast application. or fall, depending on soil type, week, provided adequate moisture is Rates for strip-till or banded making it a flexible sulfur source in present. application are often determined fertilizer recommendations. by the capacity of the equipment Another option for applying SO4 being utilized, in combination with The application rates in the table post-emergence is to topdress SO4, frequency of desired refill. This often are general recommendations. at V4-V7. A common SO4 topdress results in a rate from 50 to 100 lbs/A. Application rates are best rate is 100 to 150 lbs/A. determined by either: 1. Incorporating equations from Strip-till or banded application of Calcium Products into your SO4 is appropriate in many instances, precision software, or although this will result in a small 2. Using the SO4 application rate calculator on our website - http:// www.calciumproducts.com/ag- products/ag-calculators

Application Timing on Corn Pre-emergence As you can see from the table Application 1 3 4 7 T R1 R6 (below) , SO4 can be applied to corn Topdress in the spring pre- or post-emergence. application If you identify a sulfur deficiency post- occurs 4 - emergence and need to apply SO4

Application Timing Application Rate Coarse-textured Sandy soils Other soils Fine-textured soils All soils soils

Fall/Spring 100 lbs/A 150 lbs/A Spring • Pre-emergence – Corn (17 units S) (25 units S) • Post-emergence

75 lbs/A 100 lbs/A Spring Fall/Spring – Soybeans (12 units S) (17 units S)

Spring and/or 175 lbs/A total: summer, • After first cutting, applied prior to or apply 100 lbs/A after first cutting (17 units S) – – – Alfalfa and additional • After third applications cutting, apply after subsequent additional 75 cuttings as desired. lbs/A (12 units S) The sulfur rates above are based on recommendations from Iowa State University.

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00447_CP_SO4_ProductGuide_8.5x11_JC_April18B.indd 8 5/14/18 3:31 PM Mixing Best Practices SO4’s consistent pellet size allows it to be blended and applied with other dry fertilizers. To best maintain the integrity of the SO4 pellet, there are a few best mixing practices to keep in mind. 1. SO4 pellets will begin to break down or degrade after contact with water or other liquids. While this is a desired trait after soil application, it can create problems where liquid materials are present, such as impregnation of pesticides into mixtures containing SO4, or when improper application of nitrogen or phosphorus Pre-emergence stabilizers occurs prior to or Application 1 3 4 7 T R1 R6 during blending with SO4. Topdress When labeled rates, directions application and mixing practices are occurs 4 - followed, problems should not arise. In cases where application volumes exceed labeled rates and carryover wetness contacts Handling and Storage Best Minimizing exposure to SO4 pellets, breakdown can Practices moisture from rain or snow occur and cause gumming or To best maintain the integrity of the will aid in maintaining product buildup on the application SO4 pellet, there are a few handling integrity. SO4 does not absorb and/or blending equipment. and storage best practices to keep moisture from the atmosphere, If higher than normal rates in mind. unlike many other fertilizers are expected, we recommend 1. Handling equipment such such as urea, which are a small scale blend test to as conveyor belts or bucket hygroscopic. determine how these rates will elevators (legs) are conducive 3. Product should be stored as affect SO4 breakdown and to maintaining good product close to the receiving location subsequent problems. quality. Augers and drag and equipment as practical. 2. While no adverse or damaging conveyors are not ideal for This will result in less interaction effects have been noted product handling, as they create with the handling equipment between SO4 and other numerous opportunities for due to shorter distances and pesticides, additives, etc., abrasion and wear between time. it is the responsibility of the the material and handling end user to consult with the equipment. Maintaining all manufacturer of other products handling equipment and on any concerns or questions keeping it in good repair regarding product efficacy, will result in satisfaction with product interactions, etc. product quality and less downtime due to breakdown. 2. Product should be stored in facilities kept in good repair.

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00447_CP_SO4_ProductGuide_8.5x11_JC_April18B.indd 9 5/14/18 3:31 PM SOIL AMENDING

Improving Soil Drainage Sodium remediation Magnesium remediation Gypsum has been used for • Soils with sodium levels in • High levels of magnesium, which hundreds of years in remediating the range of 3% to 15% base are less problematic than sodium and amending soils, particularly saturation are prone to negative but more widespread, can also sodic soils. Through ion exchange, effects from sodium. Geography lead to adverse effects on soil calcium displaces sodium from the influences what level of sodium structure. soil colloid, allowing the sodium warrants action, so make sure • Magnesium levels exceeding to leach and the clay particles to to check with local extension 20% base saturation can aggregate. guidelines to determine baseline negatively impact soil physical thresholds. properties. However, there is Using variable rate equations • Irrigation water quality should no established rule regarding to calculate SO4 rates for be monitored and analyzed a threshold magnesium soil amending needs is highly regularly for the presence base saturation value that recommended. We have worked of sodium. This is often a warrants corrective action. with several software providers to significant contributor to sodium We recommend partial field include specific parameters and accumulation in the soil. applications to determine product recommendations in their • The addition of soluble calcium effectivity before widespread systems. aids in maintaining good soil application. structure and offsetting the Soil testing combined with variable negative effects of sodium. rate technology will result in the most accurate and cost-effective application of SO4.

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00447_CP_SO4_ProductGuide_8.5x11_JC_April18B.indd 10 5/14/18 3:31 PM Soil structure, tilth and quality effects • Due to the complex nature of IMPORTANCE OF CALCIUM soil chemistry, it is often difficult to predict which soils will benefit A Needed Macronutrient from SO4 application. However, Calcium is categorized as a secondary macronutrient, along with soils that are prone to surface sulfur and magnesium. It plays a major role in the plant through crusting, are difficult to till, don’t the formation of cell wall membranes, which provide stiffness and maintain proper soil moisture rigidity. Calcium is an activator of several enzyme systems in protein levels and/or exhibit poor soil transfer and carbohydrate transfer. It also acts as a detoxifying agent structure can be considered by neutralizing organic acids in plants (Marschner, 1995). for SO4 application to improve these problems. • SO4 is a versatile tool for use CA CLAY CA CA CLAY CA + + + + in many difficult soil conditions. + + + + CLAY CLAY CLAY CLAY There are many other tools such as cover crops and no-till that CA + + CA CA + + CA + + + + can also be used. CLAY SILT CLAY SILT CLAY + + + + CA + + CA CA + + CA

CLAY CLAY CLAY CLAY + + + + + + + + CA CLAY CA CA CLAY CA

Calcium in the Soil Calcium in the soil flocculates clay particles, promoting soil porosity. Good soil porosity improves soil aeration, which provides an environment for adequate drainage and root growth (Brady and Weil, 2008).

Calcium and sodium have opposite effects on soil structure. Calcium is beneficial to good soil structure, providing flocculation and aggregating very small soil particles into loose aggregations. Sodium is detrimental to soil structure, causing soil particles to disperse, which can clog pathways for air and water to enter and exit the soil easily, leading to difficult growing conditions (Brady and Weil, 2008).

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00447_CP_SO4_ProductGuide_8.5x11_JC_April18B.indd 11 5/14/18 3:31 PM SELLING THE VALUE OF SO4 TO GROWERS

CALCIUM PRODUCTS RESEARCH BRIEF Iowa Research Maximize Yield Plant-Available Sulfur Summary At the end of the day, we all know When the Plant Needs It growers are looking to maximize Not only is the sulfur in SO4 YIELD RESULTS yield. Ask your Territory Sales already in the form the plant uses – Average yield increase of 16 bu/A vs. no sulfur Manager if we have SO4 yield data sulfate, the release pattern of SO4 Overview A series of trials have been conducted to evaluate the effect of in your area. perfectly matches plant needs. SO4 SO4 on corn yield as a sulfur source compared to no sulfur. Background supplies the best balance of initial • Conducted by Iowa State University • 53 trials in 21 counties • 2006 to 2016 From 2006 to 2016, Iowa State sulfur release and steady supply • Various soil types tested • Average application rate of Iowa counties where SO4 research trials have been conducted. 100 lbs/A (17 lbs Sulfur/A) • Trials included pre-plant and post- emergence applications University conducted 53 trials throughout the growing season. 2016 TRIAL IN HANCOCK COUNTY in 21 counties comparing SO4 Background SO4 Increases Corn Yields 250 • Iowa State Northern Research Farm 200 Location: Hancock County, Iowa • 212 at 100 lbs/A to no sulfur. The pH Neutral • Silt loam soil type present 150 bu/A • Visual sulfur deficiency 182 bu/A • SO4 Rate: 150 lbs/A at V5 100 trials’ average yield increase was SO4 is pH neutral, which means it YIELD RESULTS 50

0 Yield increase of CONTROL 16 bu/A. See the full SO4 Iowa will not acidify the soil, lowering No sulfur 30 bu/A vs. no sulfur SO4 applied applied at 150 lbs/A Yield Summary Research Brief for soil pH, like other sulfur sources.

calciumproducts.com July 17 more details. Research briefs are Proper soil pH maximizes a plant’s available for other states and crops. utilization of nutrients promoting good plant health and optimizing yield.

Literature Cited

Bender, R., Haegele, J., Ruffo, M. and F. Below. 2013. Modern Corn Hybrids’ Nutrient Uptake Patterns. Better Crops 97:2013-1. Brady, N. and R. Weil. 2008. The nature and properties of soils. 14th ed. Pearson Education, Inc. Upper Saddle River, New Jersey. Datnoff, L., Elmer, W., and D. Huber. Mineral Nutrition and Plant Disease. The American Phytopathological Society. St. Paul, Minnesota. Haynes, W.M. 2014. CRC Handbook of Chemistry and Physics. 95th ed. CEC Press LLC, Boca Raton, Florida. Marschner, H. 1995. Mineral Nutrition of Higher Plants. 2nd ed. Academic Press, Inc. San Diego, California.

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