Can T-banding gypsum at planting prevent soil crusting and improve emergence in no-till corn and soybean?

Progress report for FNC21-1308

Project Type: Farmer/Rancher
Funds awarded in 2021: $8,982.00
Projected End Date: 01/31/2023
Grant Recipient: Stute Farms
Region: North Central
State: Wisconsin
Project Coordinator:
Dr. James Stute
Stute Farms
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Project Information

Description of operation:

Jim Stute operates Stute Farms in Walworth County, located on the edge of the Kettle Moraine in Southeast Wisconsin. The farm is roughly 160 acres and the operation consists of owned and leased land, all treated identically. Soils are primarily Fox silt loams, common to the region, which are lighter textured, rolling, have limited moisture holding capacity and are erosion prone. The farm is in the Mukwonago River Watershed, classified as an exceptional water resource by the Wisconsin Department of Natural Resources. The farm is in an area of high ground water recharge-defined and delineated by WDNR and included in the 2010 Walworth County Land and Water Resource Management Plan (Walworth County LURM, 2010). This area is critical for prevention of soluble nutrient leaching (including nitrate and sulphate) to protect baseflow of the Mukwonago River.

Current crop production includes corn, soybean and occasionally wheat, all no-till. Additional conservation practices include cover crops, use of certified nutrient management planning, in-season diagnostic tests, integrated pest management and subsurface application of nutrients. An example of diagnostic testing is the planned 2021 use of the preplant soil nitrate test to account for residual nitrate-nitrogen resulting from an extremely dry 2020 growing season. The farm has been in continuous no-till since 2003 and cover cropped since 1998.

Summary:

No-till improves sustainability by protecting the resource base. Many of the fragile soils in Southeast Wisconsin which could benefit most from no-till are also prone to surface crusting which can result in delayed or uneven emergence and reduced stands which reduce yield and farmer income. Users of conventional tillage cite this as a reason not to no-till, increasing erosion and surface water quality declines. Application of gypsum has been suggested as a solution which can also supply sulfur as a nutrient but commercial application rates far exceed rates needed for soil structural and nutrient benefits and supplies of flue gas desulfurization gypsum are dwindling as coal-fired power plants are closed, increasing price. Can low rates band-applied at planting address this problem?

 

A 2-year replicated field study will be conducted to evaluate the effect of gypsum applied at planting on stand establishment, sulfur nutrition and yield of corn and soybean. Gypsum will be applied through standard planter insecticide application attachments at maximum and one-half maximum rates and compared to a no gypsum and unlimited sulfur controls. Results and experiences will be shared through a dedicated field day, interactions with regional farmer-led watershed protection groups and in print materials.

Project Objectives:
  1. Determine if in-row band application of gypsum at planting can improve emergence and stand uniformity in corn and soybean;
  2. Determine the effect of gypsum application on crop yield;
  3. Evaluate the impact on sulfur fertility to modify current practices if necessary; and
  4. Share results with the agricultural community, focusing on farmer-led watershed protection groups.

 

Research

Materials and methods:

Two two-year field studies to investigate the impact of row-applied gypsum on crop emergence and yield were initiated near East Troy in 2021 in both corn (GYPC) and soybean (GYPSb). These trials represent both phases of the farms base annual rotation and it was intended to follow the rotation (i.e., opposite previous crop) in both studies but a rainout during planting of GYPC forced trial relocation and necessitated corn following corn, a practice not used on the farm. Trials will be conducted in rotation in 2022.

The soil is a Fox silt loam, 0-2% slope, and has been in continuous no-till since 2001, a corn-soybean rotation since 2011 and has not had a cover crop since 2010. Beyond the treatments applied, the trials followed the farms routine practices for crop culture, pest management and soil fertility except for starter fertilizer, whose rate of was reduced to 33% of routine to minimize interactions with treatments yet provide a “starter” effect. A summary of site conditions, field activities and inputs are reported in  Table 1.

Trial treatments include:

1). Control, no gypsum

2). Gypsum, half rate

3). Gypsum, full rate

4). No Gypsum, sulfur unlimited

Gypsum was applied in a T-band at planting using standard insecticide boxes on the planter [Kinze row units, 70 lb. capacity hopper, 10 paddle gate meter (Figure 1), 7” diffuser width]. Before planting, we compared different gypsum forms (pelletized, coarse and powder) to determine consistency of material flow and delivery rate and chose a commercial pelletized product (NutraSoft OP, The Andersons Inc., Maumee, OH 43537). Individual row units were calibrated for a uniform maximum rate, then a one-half maximum rate, based on planter transmission speeds for target crop seeding rates. 2021 application rates are listed in Table 1. It should be noted that soybean seeding rate was increased to result in an acceptable range of gypsum application rates.

The 4th treatment is included to provide a sulfur control in the event yield differences to treatment occur to help separate the material effect on soil physical properties from nutrient effects. Pelletized sulfur bentonite (0-0-0-90, Tiger 90CR, Tiger-Sul Products LLC, Shelton, CT 06484) was band applied between crop rows immediately after planting at a sulfur rate equivalent of 50 lb./acre, 2x the maximum recommended by UW-Extension (Laboski and Peters, 2012). Soil S was determined before planting (Table 1) and tissue sampled and analyzed for nutrient content following UW- Extension Recommendations.

Other than treatment differences, plots will be treated identically, following the cultural practices of the farm. Emergence data and observations were collected daily through the emergence period with special emphasis on uniformity and population. An assessment of final stand and delayed emergence as indicated by the presence of “peepers”, late emerging corn plants which are developmentally delayed and have minimal potential to contribute to yield was made thirty days after first emergence (30DAE). The degree of surface crusting was concurrently characterized using air-dry rupture measured using a Torvane shear vane penetrometer to measure the force required to break the crust. Final population was determined at mechanical harvest. Planned infiltration rate measurement was not performed because of the failure to install the apparatus immediately after planting (subsequent installation could potentially affect soil crust and influence results).

The experimental design is a randomized complete block with 4 replicates. Final plot size is 10 (4 row) by 50 feet. All data was collected from the center two rows to minimize border effects. Data were subject to analysis of variance procedures using RStudio (ver. 2021.09.1) and means separated with a protected LSD (p=0.10) where significant treatment effects were detected. The Cor procedure was used to characterize the relationship between tissue S and grain yield.

Previous SARE Farmer Rancher Grants and References_STUTE

Research results and discussion:

Gypsum had no effect on emergence or stand but influenced S fertility and increase grain yield in corn (Table 2) Gypsum had no effect on emergence or stand but influenced S fertility and increase grain yield in corn (Table 2) while having no effect on measured variables in soybean (data not shown). Overall growing season conditions influenced trial results, but early season conditions were not conducive to soil crust formation, leading to even emergence and uniform stands across all treatments. In general, the season was hot and dry, accumulating nearly 120% of normal growing degree days with just 46.2% of normal precipitation (Table 1). However, the 9-day period between planting and emergence (May 11-20) had 3 rainfall events totaling 0.47” and  the individual events tended to be gentle as opposed to the forceful rains experienced regionally in recent years and in 2021 (see below). Amounts were sufficient to keep the surface moist for initial emergence and subsequent events kept it moist for mostly complete emergence, measured at 3 and 6 days after initial emergence. Visual evidence of uniform emergence can be seen in Figure 2.

Stand and peeper prevalence measurements at 30DAE confirm the lack of treatment effect in stand establishment. However, concurrent measurement of shear resistance (as force applied) at the soil surface indicate a tendency of applied gypsum to influence crusting (p=0.234) which can be readily seen in Figure 3 (photo) and Figure 4 (data). The previous 30-day period experienced several cycles of soil wetting-drying (Table 1) under hot, sunny conditions conducive to crust formation. These trials will provide more data in the future to further evaluate this apparent effect.

The initial attempt at 2021 GYPC trial establishment on May 3 was rained out midway through planting (only control treatments got planted before rain) necessitating trial relocation. This is unfortunate because the 0.83” event was rapid and intense, resulting in crusting and a potentially different trial outcome.

Full rate gypsum significantly increased tissue S concentration measured at silking which likely accounts for the significant yield response since impact on stand establishment was a nonfactor (Table 2). The initial soil test level of 2.5 ppm is low and suggests a response to added S is likely under UW-Extension recommendations. Yield response was positively correlated with tissue S concentration (r=0.67, p=0.02) and tissue S was greatest with full-rate gypsum even though the amount of applied S was 22% of the unlimited S control. It is assumed that hot, dry soil conditions limited oxidation of the S controls elemental S reducing plant availability. The additional Ca supplied by the gypsum treatment is not responsible for the yield response due to the nonsignificant treatment effect on tissue Ca concentration (Table 2).

In addition to repeating trials in 2022, this project will examine the economic efficiency of using band-applied gypsum as a S source if the yield response is again apparent. This represents a potential sustainability gain if a waste product could replace manufactured, synthetic ammonium sulfate which is commonly used to supply S for row crop production in our region.

while having no effect on measured variables in soybean (data not shown). Overall growing season conditions influenced trial results, but early season conditions were not conducive to soil crust formation, leading to even emergence and uniform stands across all treatments. In general, the season was hot and dry, accumulating nearly 120% of normal growing degree days with just 46.2% of normal precipitation (Table 1). However, the 9-day period between planting and emergence (May 11-20) had 3 rainfall events totaling 0.47” and  the individual events tended to be gentle as opposed to the forceful rains experienced regionally in recent years and in 2021 (see below). Amounts were sufficient to keep the surface moist for initial emergence and subsequent events kept it moist for mostly complete emergence, measured at 3 and 6 days after initial emergence. Visual evidence of uniform emergence can be seen in Figure 2.

Stand and peeper prevalence measurements at 30DAE confirm the lack of treatment effect in stand establishment. However, concurrent measurement of shear resistance (as force applied) at the soil surface indicate a tendency of applied gypsum to influence crusting (p=0.234) which can be readily seen in Figure 3 (photo) and Figure 4 (data). The previous 30-day period experienced several cycles of soil wetting-drying (Table 1) under hot, sunny conditions conducive to crust formation. These trials will provide more data in the future to further evaluate this apparent effect.

The initial attempt at 2021 GYPC trial establishment on May 3 was rained out midway through planting (only control treatments got planted before rain) necessitating trial relocation. This is unfortunate because the 0.83” event was rapid and intense, resulting in crusting and a potentially different trial outcome.

Full rate gypsum significantly increased tissue S concentration measured at silking which likely accounts for the significant yield response since impact on stand establishment was a nonfactor (Table 2). The initial soil test level of 2.5 ppm is low and suggests a response to added S is likely under UW-Extension recommendations. Yield response was positively correlated with tissue S concentration (r=0.67, p=0.02) and tissue S was greatest with full-rate gypsum even though the amount of applied S was 22% of the unlimited S control. It is assumed that hot, dry soil conditions limited oxidation of the S controls elemental S reducing plant availability. The additional Ca supplied by the gypsum treatment is not responsible for the yield response due to the nonsignificant treatment effect on tissue Ca concentration (Table 2).

In addition to repeating trials in 2022, this project will examine the economic efficiency of using band-applied gypsum as a S source if the yield response is again apparent. This represents a potential sustainability gain if a waste product could replace manufactured, synthetic ammonium sulfate which is commonly used to supply S for row crop production in our region.

 

 

 

Participation Summary
1 Farmers participating in research

Educational & Outreach Activities

Participation Summary:

Education/outreach description:

No outreach activities in 2021.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.