General Information about the tool

ISOFAST is a web-based interactive tool to visualize and summarize historical on-farm replicated strip trial data conducted by farmers working with the Iowa Soybean Association. The tool’s capabilities for each study include:
• Describes on-farm study rationale, specifies trial locations, field management and weather.
• Shows dynamic graphics to better communicate statistical summaries, variability and uncertainty in yield differences within and across trials.
• Provides break-even economic analyses using cost and price inputs provided by users online.
• Summarizes key scouting, soil and tissue observations for tested treatments.
• Provides short summaries for aid in decision making for farmers and agronomists.

Process

Farmers apply treatments and collect yield observations using yield monitoring equipment and GPS. All the trials used have two treatments: treated and control. Yield and as applied spatial data of the studied fields were cleaned of errors and outliers guided by aerial imagery and information from farmer equipment such as combine speed, grain moisture, harvest date and field scouting. Treatment averages were combined with weather observations from the Iowa Environmental Mesonet, field management, digital soil information, and scouting data.

Data analyses

The effect of treatments is shown as average yield differences (bu/acre) or yield change (%) for individual trials and across trials in different years. Uncertainty in averages is shown by 80, 90 and 95% confidence intervals. The treatment effects are meaningful if the confidence intervals for the averages do not cross the zero-yield response line. Yield differences are correlated with observed rainfall, growing degree days and yield level of the control or control strips.

How to use the tool

Navigate through Tabs on the left to select a crop and trial category of interest. Read the trial description, check trial locations, observed weather and view results. You can select or deselect years by checking boxes on the legend. You can hover to see data values on the plot. Scroll under each graph to view more information or explanation. General conclusions for each trial type follow the graphic information.

Disclaimer

The information contained in this website is for information purposes only. The information is provided by the Iowa Soybean Association and while we endeavor to keep the information up to date and correct, we make no representations or warranties of any kind, express or implied, about the completeness, accuracy, reliability, suitability or availability with respect to the website or the information, products, services, or related graphics contained on the website for any purpose. Any reliance you place on such information is therefore strictly at your own risk.

Contact

For any information, or to report a technical issue, please send an email to Anabelle Laurent alaurent@iastate.edu or Fernando Miguez femiguez@iastate.edu or Peter Kyveryga @ pkyveryga@iasoybeans.com

What was done

Rationale

Cyst Nematode (SCN) is a plant parasitic nematode that can cause significant yield loss in soybean. The primary management of SCN is using resistant soybean varieties. In recent years, nematicide seed treatments have become available to control and manage SCN.

The objective of this study was to evaluate the Clariva Complete Beans biological seed treatment for its effectiveness in reducing SCN reproduction and increasing soybean yield across diverse soil and weather conditions in Iowa.

The Clariva seed treatments were compared to a control, Cruiser Maxx Advanced plus Vibrance, which was a background for both treatments.

Trial Locations

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Information

The map of Iowa shows county lines (black) and landform regions (gray): Northwest Plains, Des Moines Lobe, and Iowan Surface, from west to east across the northern half of the state, and Southern Iowa Drift Plain across the southern half of the state.

Conclusions

  1. Of the 32 trials in 2014, 2015 and 2016, only 3 trials had significant positive yield responses of 1.2, 1.4 and 2.2 bu/acre on soybean.
  2. Across three years with a 90% confidence interval, Clariva nematicide treatments increased yield on average by 0.4 bu/acre, from -0.1 to 0.8 bu/acre.
  3. There was no significant difference in egg counts between the spring counts and the fall.
  4. Only three trials had SCN counts larger than 1,000 eggs per 100 cubic centimeters of soil
  5. Clariva slightly decreased SCN egg counts in a few trials.
  6. With soybeans at $10.00 per bushel and Clariva nematicide application at $18.00 per acre, the breakeven yield response is 1.8 bu/acre. The probability to exceed the breakeven is 0% and the average expected profit exceeding cost is $-14.13 per acre.

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What was done

Rationale

Sudden death syndrome (SDS) is caused by the fungus Fusarium virguliforme resulting in significant soybean yield loss. Another yield reducing pest is soybean cyst nematodes (Heterodera glycines). The objective of this on-farm study was to evaluate the efficacy of the seed treatment ILeVO (fluopyram) to control SDS and soybean cyst nematode (SCN) and the effect of these pests on yield soybean yield across diverse soil and weather conditions in Iowa. Fifteen two-treatment on-farm replicated strip trials were conducted in 2015. The two treatments had a base fungicide and insecticide seed treatment (Poncho/Votivo) with and without ILeVO. Soil sampling for SCN was conducted in the spring and fall, SDS severity ratings were taken in early September. Georeferenced yield data were collected by farmers' combines equipped with GPS.

Trial Locations

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Information

The map of Iowa shows county lines (black) and landform regions (gray) to clarify trial locations and general topographical attributes. The bulk of Iowa’s landmass falls primarily into 4 regions: Northwest Plains, Des Moines Lobe, and Iowan Surface, from west to east across the northern half of the state, and Southern Iowa Drift Plain across the southern half of the state.

Conclusions

  1. Of the 26 trials on soybean in 2015 and 2016, 11 trials had significant yield responses of 0.7, 0.9, 1.0, 1.0, 1.3, 1.3, 1.4, 1.6, 2.2, 3.0, and 3.3 bu/acre.
  2. In 2015 and 2016, ILeVO seed treatments increased yield on average by 0.6 bu/acre, with a 90% confidence interval from 0.2 to 1.1 bu/acre .
  3. ILeVO significantly increased soybean yield in about 40% of trials, but the majority of the3se increases were relatively small.
  4. With soybeans at $10.00 per bushel and Ilevo application at $20.00 per acre, the breakeven yield response is 2.0 bu/acre. The probability to exceed the breakeven is 0% and the average expected profit exceeding cost is $-13.40 per acre.

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What was done

Soybean often yield higher when planted in narrow versus wide row spacing. While the evidence of yield benefits from narrow row spacing is well documented, many farmers are hesitant to switch to narrow row spacing due to required investment in new planters and the higher risk of soybean disease in narrow rows. These on-farm trials were designed to document the benefits of narrow row spacing by planting 15-inch row replicated treatments using a 30-inch row planter. The 15-inch row treatments were planted twice using autosteering or GPS guidance systems with a 30-inch row planter.

Trial Locations

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Information

The map of Iowa shows county lines (black) and landform regions (gray) to clarify trial locations and general topographical attributes. The bulk of Iowa’s landmass falls primarily into 4 regions: Northwest Plains, Des Moines Lobe, and Iowan Surface, from west to east across the northern half of the state, and Southern Iowa Drift Plain across the southern half of the state.

Conclusions

  1. Of the 18 Row Spacing trials on soybean between 2010 and 2016, only 3 had significant yield responses of 2.7, 3.8 and 9.0 bu/acre.
  2. Compared with 30” row spacing, 15” row spacing treatments increased yield on average by 0.7 bu/acre, with a 90% confidence interval from -0.6 to 1.9 bu/acre.
  3. Responses to 15” row spacing tended to be greater when May-June rainfall was above average.
  4. The trial with largest, 9 bu/acre, yield difference had hail during the growing season. It could be that the recovery time and canopy closure was much faster with 15-inch than with 30-inch rows after the hail.
  5. With soybeans at $10.00 per bushel and row spacing with no aditional cost, the breakeven yield response is 0.0 bu/acre. The probability to exceed the breakeven is 82% and the average expected profit exceeding cost is $6.75 per acre.

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What was done

Foliar fungicide use on soybean has increased in Iowa during the last 10 years. The objective of this study was to use field-scale on-farm trials across Iowa to study foliar pyraclostrobin (Headline) applications on soybean and identify when these applications produced profitable yield responses. Most of the applications were done by farmers using ground sprayers but in about 6.7% trials the foliar fungicide was aerially applied.

Trial Locations

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Information

The map of Iowa shows county lines (black) and landform regions (gray) to clarify trial locations and general topographical attributes. The bulk of Iowa’s landmass falls primarily into 4 regions:Northwest Plains, Des Moines Lobe, and Iowan Surface, from west to east across the northern half of the state, and Southern Iowa Drift Plain across the southern half of the state.

Conclusions

  1. Of the 206 Headline foliar fungicide trials conducted on soybean between 2006 and 2015, 139 had significant yield response to foliar pyraclostrobin fungicide ranging from 1.3 to 7.7 bu/acre for individual trials.
  2. Across all years, foliar application of pyraclostrobin fungicide increased yield on average by 2.5 bu/acre, with a 90% confidence interval from 2.2 to 2.7 bu/acre.
  3. With soybeans at $10.00 per bushel and foliar fungicide application at $20.00 per acre, the breakeven yield response is 2.0 bu/acre. The probability to exceed the breakeven is 100% and the average expected profit exceeding cost is $4.64 per acre.

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What was done

The objective of this study was to use field-scale on-farm trials across Iowa to compare untreated strips to strips treated with foliar propiconazole 11.4% - trifloxystrobin 11.4% (Stratego) applications on soybean and identify when these applications produced profitable yield responses. Applications were done by farmers using ground sprayers.

Trial Locations

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Information

The map of Iowa shows county lines (black) and landform regions (gray) to clarify trial locations and general topographical attributes. The bulk of Iowa’s landmass falls primarily into 4 regions:Northwest Plains, Des Moines Lobe, and Iowan Surface, from west to east across the northern half of the state, and Southern Iowa Drift Plain across the southern half of the state.

Conclusions

  1. Of the 29 Stratego foliar fungicide trials conducted on soybean between 2007, 2008, 2011, 2014 and 2015, 22 had significant yield response to foliar propiconazole - trifloxystrobin (Stratego) fungicide ranging from 1.5 to 3.3 bu/acre for individual trials.
  2. Across all years, foliar application of propiconazole - trifloxystrobin (Stratego) fungicide increased yield on average by 2.0 bu/acre, with a 90% confidence interval from 1.4 to 2.5 bu/acre.
  3. With soybeans at $10.00 per bushel and fungicide application at $15.00 per acre, the breakeven yield response is 1.5 bu/acre. The probability to exceed the breakeven is 93% and the average expected profit exceeding cost is $4.75 per acre.

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What was done

Foliar fungicide use on soybean has increased in Iowa during the last 10 years. The objective of this study was to use field-scale on-farm trials across Iowa to study foliar prothioconazole 10.8% - Trifloxystrobin 32.3% (Stratego YLD) applications on soybean and identify when these applications produced profitable yield responses. Applications were done by farmers using ground sprayers.

Trial Locations

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Information

The map of Iowa shows county lines (black) and landform regions (gray) to clarify trial locations and general topographical attributes. The bulk of Iowa’s landmass falls primarily into 4 regions:Northwest Plains, Des Moines Lobe, and Iowan Surface, from west to east across the northern half of the state, and Southern Iowa Drift Plain across the southern half of the state.

Conclusions

  1. Of the 37 foliar fungicide trials conducted on soybean in 2011, 2014 and 2015, All 37 had significant yield response to foliar prothioconazole - trifloxystrobin (Stratego YLD) ranging from 1.3 to 1.6 bu/acre for individual trials.
  2. Across all years, foliar application of prothioconazole - trifloxystrobin (Stratego YLD) fungicide increased yield on average by 1.5 bu/acre, with a 90% confidence interval from 1.1 to 1.9 bu/acre.
  3. With soybeans at $10.00 per bushel and fungicide application at $20.00 per acre, the breakeven yield response is 2.0 bu/acre. The probability to exceed the breakeven is 2% and the average expected profit exceeding cost is $-5.18 per acre.

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What was done

Foliar fungicide use on soybean has increased in Iowa during the last 10 years. The objective of this study was to use field-scale on-farm trials across Iowa to study foliar Azoxystrobin (Quadris) applications on soybean and identify when these applications produced profitable yield responses. Applications were done by farmers using ground sprayers.

Trial Locations

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Information

The map of Iowa shows county lines (black) and landform regions (gray) to clarify trial locations and general topographical attributes. The bulk of Iowa’s landmass falls primarily into 4 regions:Northwest Plains, Des Moines Lobe, and Iowan Surface, from west to east across the northern half of the state, and Southern Iowa Drift Plain across the southern half of the state.

Conclusions

  1. Of the 18 Quadris foliar fungicide trials conducted on soybean in 2007, 15 had significant yield response to foliar Azoxystrobin (Quadris) fungicide ranging from 0.8 to 4.2 bu/acre for individual trials.
  2. Across all years, foliar application of Azoxystrobin (Quadris) fungicide increased yield on average by 2.1 bu/acre, with a 90% confidence interval from 1.5 to 2.7 bu/acre.
  3. With soybeans at $10.00 per bushel and fungicide application at $12.50 per acre, the breakeven yield response is 1.2 bu/acre. The probability to exceed the breakeven is 100% and the average expected profit exceeding cost is $19.91 per acre.

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What was done

Foliar fungicide use on soybean has increased in Iowa during the last 10 years. The objective of this study was to use field-scale on-farm trials across Iowa to study foliar fluxapyroxad - pyraclostrobin (Priaxor) applications on soybean and identify when these applications produced profitable yield responses. Most of the applications were done by farmers using ground sprayers.

Trial Locations

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Information

The map of Iowa shows county lines (black) and landform regions (gray) to clarify trial locations and general topographical attributes. The bulk of Iowa’s landmass falls primarily into 4 regions:Northwest Plains, Des Moines Lobe, and Iowan Surface, from west to east across the northern half of the state, and Southern Iowa Drift Plain across the southern half of the state.

Conclusions

  1. Of the 43 Priaxor foliar fungicide trials conducted on soybean between 2013 and 2018, 24 had significant yield response to foliar fluxapyroxad - pyraclostrobin (Priaxor) fungicide ranging from 1.8 to 4.2 bu/acre for individual trials.
  2. Across all years, foliar application of fluxapyroxad - pyraclostrobin (Priaxor) fungicide increased yield on average by 2.1 bu/acre, with a 90% confidence interval from 1.5 to 2.7 bu/acre.
  3. With soybeans at $10.00 per bushel and fungicide application at $25.00 per acre, the breakeven yield response is 2.5 bu/acre. The probability to exceed the breakeven is 11% and the average expected profit exceeding cost is $-4.20 per acre.

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What was done

Foliar fungicide use with insecticide on soybean has increased in Iowa during the last 10 years. The objective of this study was to use field-scale on-farm trials across Iowa to study foliar fluxapyroxad - pyraclostrobin (Priaxor) combined with alpha-cypermethrin (Fastac) applications on soybean and identify when these applications produced profitable yield responses. Most of the applications were done by farmers using ground sprayers.

Trial Locations

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Information

The map of Iowa shows county lines (black) and landform regions (gray) to clarify trial locations and general topographical attributes. The bulk of Iowa’s landmass falls primarily into 4 regions:Northwest Plains, Des Moines Lobe, and Iowan Surface, from west to east across the northern half of the state, and Southern Iowa Drift Plain across the southern half of the state.

Conclusions

  1. Of the 22 Priaxor foliar fungicide & Fastac Insecticide trials conducted on soybean between 2014 and 2018, 11 had significant yield response ranging from 3.7 to 11.2 bu/acre for individual trials
  2. Across all years, foliar application of fluxapyroxad - pyraclostrobin (Priaxor) fungicide with alpha-cypermethrin (Fastac) increased yield on average by 3.0 bu/acre, with a 90% confidence interval from 1.6 to 4.4 bu/acre.
  3. With soybeans at $10.00 per bushel and fungicide & insecticide application at $27.00 per acre, the breakeven yield response is 2.7 bu/acre. The probability to exceed the breakeven is 64% and the average expected profit exceeding cost is $3.11 per acre.

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What was done

Mid-season aphid infestations can substantially reduce soybean yields. Insecticides are used to control soybean aphids. These on-farm trials evaluated Hero pyrethroid (bifenthrin 11.25% and zeta-cypermethrin 3.75 %) insecticide in seven trials. Each trial had Hero applied in at least three replications compared with untreated control strips.

Trial Locations

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Information

The map of Iowa shows county lines (black) and landform regions (gray) to clarify trial locations and general topographical attributes. The bulk of Iowa’s landmass falls primarily into 4 regions:Northwest Plains, Des Moines Lobe, and Iowan Surface, from west to east across the northern half of the state, and Southern Iowa Drift Plain across the southern half of the state.

Conclusions

  1. Of the 7 aphid insecticide trials conducted in 2010, at 10% significane level, 2 trials in soybean had a positive yield response to Hero insecticide of 1.2, and 1.3 bu/acre.
  2. In 2010, application of Hero insecticide increased yield on average by 1.1 bu/acre, with a 90% confidence interval from 0.0 to 2.3 bu/acre.
  3. Aphid pressure was not documented.
  4. With soybeans at $10.00 per bushel and insecticide application at $12.00 per acre, the breakeven yield response is 1.2 bu/acre. The probability to exceed the breakeven is 45% and the average expected profit exceeding cost is $-0.82 per acre.

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What was done

Soybean plants require large amount of nitrogen. Increasing soybean biological fixation may lead to higher yields. The objective of this on-farm study was to determine the yield benefits of TerraMax (Bradyrhizobium-based inoculant) on soybean. Fifteen two-treatment on-farm replicated strip trials were conducted in 2017. TerraMax treatments were applied in furrow during planting and compared to untreated control in each trial.

Trial Locations

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Information

The map of Iowa shows county lines (black) and landform regions (gray) to clarify trial locations and general topographical attributes. The bulk of Iowa’s landmass falls primarily into 4 regions: Northwest Plains, Des Moines Lobe, and Iowan Surface, from west to east across the northern half of the state, and Southern Iowa Drift Plain across the southern half of the state.

Conclusions

  1. Of the 15 biological innoculant trials on soybean in 2017, TerraMax Bradyrhizobium-based inoculant had no significant effect on soybean yield.
  2. The average yield response to TerraMax was 0.0 bu/acre, with a 90% confidence interval from -0.7 to 0.7 bu/acre.
  3. With soybeans at $10.00 per bushel and Terramax application at $2.50 per acre, the breakeven yield response is 0.2 bu/acre. The probability to exceed the breakeven is 31% and the average expected profit exceeding cost is $-2.66 per acre.

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What was done

A new generation of biological products are designed to increase leaf chlorophyll concentration, root biological activity and stress tolerance. The objective of this on-farm study was to evaluate Vitazyme, a biostimulant (brassinosteroids, 1-triacontanol, and B vitamins) on soybean in Iowa. Ten two-treatment on-farm replicated strip trials were conducted between 2014 and 2015. Vitazyme treatments were foliar applied and compared to untreated strips.

Trial Locations

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Information

The map of Iowa shows county lines (black) and landform regions (gray) to clarify trial locations and general topographical attributes. The bulk of Iowa landmass falls primarily into 4 regions: Northwest Plains, Des Moines Lobe, and Iowan Surface, from west to east across the northern half of the state, and Southern Iowa Drift Plain across the southern half of the state.

Conclusions

  1. Of the 10 trials on soybean in 2014 and 2015, Vitazyme brassinosteroids, 1-triacontanol, and B vitamins biostimulant had no significant effect on soybean yield.
  2. The average yield response to Vitazyme biostimulant was -0.1 bu/acre, with a 90% confidence interval from -0.8 to 0.8 bu/acre.
  3. With soybeans at $10.00 per bushel and Vitazyme application at $10.00 per acre, the breakeven yield response is 1.0 bu/acre. The probability to exceed the breakeven is 2% and the average expected profit exceeding cost is $-10.64 per acre.

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What was done

The objective of this on-farm study was to evaluate Tryptophan, a biological co-product, on soybean in Iowa. Sixteen two-treatment on-farm replicated strip trials were conducted between 2017 and 2018. Tryptophan treatments were foliar applied and compared to untreated strips.

Trial Locations

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Information

The map of Iowa shows county lines (black) and landform regions (gray) to clarify trial locations and general topographical attributes. The bulk of Iowa landmass falls primarily into 4 regions: Northwest Plains, Des Moines Lobe, and Iowan Surface, from west to east across the northern half of the state, and Southern Iowa Drift Plain across the southern half of the state.

Conclusions

  1. Of the 16 trials on soybean in 2017 and 2018, Tryptophan biological had no significant effect on soybean yield.
  2. The average yield response to Tryptophan bio was 1.4 bu/acre, with a 90% confidence interval from -0.2 to 3.1 bu/acre.
  3. With soybeans at $10.00 per bushel and Tryptophan application at $7.00 per acre, the breakeven yield response is 0.7 bu/acre. The probability to exceed the breakeven is 77% and the average expected profit exceeding cost is $7.46 per acre.

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What was done

Nemastrike(TM) is a soybean seed treatment with activity on soybean cyst nematode. The objective of this on-farm study was to evaluate Nemastrike seed treatment on soybean in Iowa. Acceleron Seed Applied Solutions standard package was the control base fungicide/insecticide used in both treatments. Six two-treatment on-farm replicated strip trials were conducted in 2018.

Trial Locations

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Information

The map of Iowa shows county lines (black) and landform regions (gray) to clarify trial locations and general topographical attributes. The bulk of Iowa landmass falls primarily into 4 regions: Northwest Plains, Des Moines Lobe, and Iowan Surface, from west to east across the northern half of the state, and Southern Iowa Drift Plain across the southern half of the state.

Conclusions

  1. Of the 6 trials on soybean in 2018, Nemastrike seed treatment had no significant effect on soybean yield.
  2. The average yield response to Nemastrike bio was 1.6 bu/acre, with a 90% confidence interval from -0.4 to 3.7 bu/acre.
  3. With soybeans at $10.00 per bushel and Nemastrike application at $10.00 per acre, the breakeven yield response is 1.0 bu/acre. The probability to exceed the breakeven is 70% and the average expected profit exceeding cost is $6.39 per acre.

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What was done

Sulfur deficiencies have been reported recently in Iowa. The objective of this on-farm study was to determine whether Sulfur applications on soybean can increase yields. Fifteen two-treatment replicated strip trials were conducted by farmers in 2011. Sulfur in the form of SuperCal SO4 was broadcast at a rate of 50 lb S/acre and incorporated in the soil before soybean planting. The Sulfur treatments were compared to the untreated control.

Trial Locations

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The map of Iowa shows county lines (black) and landform regions (gray) to clarify trial locations and general topographical attributes. The bulk of Iowa landmass falls primarily into 4 regions: Northwest Plains, Des Moines Lobe, and Iowan Surface, from west to east across the northern half of the state, and Southern Iowa Drift Plain across the southern half of the state.

Conclusions

  1. Of the 15 sulfur trials on soybean in 2011, SuperCal SO4 pelletized gypsum had no significant effect on soybean yield.
  2. The average yield response to SuperCal SO4 pelletized gypsum was -0.9 bu/acre, with a 90% confidence interval from -1.7 to -0.1 bu/acre.
  3. With soybeans at $10.00 per bushel and Sulfur application at $7.00 per acre, the breakeven yield response is 0.7 bu/acre. The probability to exceed the breakeven is 77% and the average expected profit exceeding cost is $7.46 per acre.

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What was done

Gypsum sulfur applications may have residual effects on soil and crop yield beyond the first year. The objective of this on-farm study was to measure soybean yield effects from SuperCal SO4 applications to the previous corn crop. The yield data were collected in 2012 from strips that received SuperCal SO4 in 2011.

Trial Locations

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The map of Iowa shows county lines (black) and landform regions (gray) to clarify trial locations and general topographical attributes. The bulk of Iowa landmass falls primarily into 4 regions: Northwest Plains, Des Moines Lobe, and Iowan Surface, from west to east across the northern half of the state, and Southern Iowa Drift Plain across the southern half of the state.

Conclusions

  1. Of the 6 residual sulfur trials treated with SuperCal SO4 pelletized gypsum in 2011, no trials had significant yield responses to Residual Sulfur in 2012.
  2. In 2012, Residual Sulfur nutrient increased yield on average by 0.1 bu/acre, with a 90% confidence interval from -1.3 to 1.3 bu/acre.
  3. With soybeans at $10.00 per bushel and Residual Sulfur with no added cost per acre, the breakeven yield response is 0.0 bu/acre. The probability to exceed the breakeven is 54% and the average expected profit exceeding cost is $0.75 per acre.

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What was done

Maintaining optimum soil pH is important for plant growth. The objective of this on-farm study was to evaluate agronomic and economic benefits of SuperCal 98G, pelletized lime, on soybean yield. Ten two-treatment replicated strip trials were conducted in 2014 and 2015. The pelletized Lime was ground applied at 600 lb/acre and incorporated into the soil before planting.

Trial Locations

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The map of Iowa shows county lines (black) and landform regions (gray) to clarify trial locations and general topographical attributes. The bulk of Iowa landmass falls primarily into 4 regions: Northwest Plains, Des Moines Lobe, and Iowan Surface, from west to east across the northern half of the state, and Southern Iowa Drift Plain across the southern half of the state.