11/23/2021

Corn Response to High pH Soil Environments

(Northwestern Kansas, Southwestern Nebraska, and Northeastern Colorado)

Written by Mike Kriegshauser, Aaron Vammer, Dalton Kampsen, Chris Weber, and Cody Sullivan

Key Findings

  • High soil pH can limit the uptake of several nutrients which can be detrimental to corn yield.
  • Three years of Pioneer field trials showed that corn hybrids can vary in their response to high soil pH under different soil organic matter levels.
  • Some products showed visual symptoms (yellowing) associated with high soil pH but still maintained yield.

High Soil pH Can Limit Corn Yields

  • Alkaline or high pH (>7) soils are naturally occurring in parts of the western Corn Belt, including northwestern Colorado, southwestern Nebraska, and northwestern Kansas.
  • High soil pH can limit the uptake of several nutrients, such as phosphorous, zinc, iron, manganese, boron, and copper (Figure 1).
  • Corn hybrids can respond differently to high soil pH as indicated by the presence of iron chlorosis.
  • Corn response to high soil pH may differ based on soil organic matter levels.

Photo - Severe iron chlorosis in a corn hybrid in low organic matter soil.

Figure 1. Severe iron chlorosis in a corn hybrid in low organic matter soil.

Corn Hybrid Evaluation in High pH Soils

  • Pioneer conducts field trials to evaluate corn hybrid performance in calcareous soil environments with various organic matter levels.
  • Information gained from these trials helps drive better product placement recommendations for high soil pH fields.

Field Research Methods

  • Trials were placed on soils with a historic high pH (>7.9) where iron chlorosis symptoms are likely to be observed (Figure 3).
  • Soil samples were taken across high pH locations to determine actual pH as well as organic matter levels.
  • Field observations were collected at 16 locations across northeast Colorado, southwest Nebraska, northwest Kansas over a four-year period.
  • Observations were collected early in the season (V7-V8) as well as late in the season (R3-R4). Yields were collected in most of these locations.
  • Pioneer® brand corn products were evaluated based on color (chlorosis) and yield.
  • A three-category rating system was used to rate response to high soil pH: S = Strength, A = Acceptable, and C = Consideration.
  • Observations were combined, and a final rating was assigned to each corn product for calcareous high pH soils.

Photo - Visual differences in early season chlorosis among Pioneer brand corn products in high pH soil.

Figure 2. Visual differences in early season chlorosis among Pioneer® brand corn products in high pH soil.

Results

  • Pioneer® brand corn products responded differently to high pH calcareous soils with varying levels of organic matter.
  • Some products showed visual symptoms (yellowing) associated with high pH soil but still maintained yield across the field.

Arial Photo -  Hybrid plot within a high pH area of the field.

Figure 3. Hybrid plot within a high pH area of the field.

 

Table 1. Corn product suitability to calcareous high pH soil.

Table - Corn product suitability to calcareous high pH soil.

Table - Corn product suitability to calcareous high pH soil.

Table - Corn product suitability to calcareous high pH soil.

Legend: S=Strength, A=Acceptable, C=Consideration

Conclusions and Management Considerations

  • Management practices for high pH soils include:
  • Performance ratings of Pioneer® brand products in calcareous high pH soils based on results of this study are shown in Table 1.
    • S = Strength – tolerates the condition better than other Pioneer brand products observed in the same environment.
    • A = Acceptable – has an average tolerance to the condition relative to other Pioneer brand products observed in the same environment.
    • C = Consideration – the hybrid is less tolerant of the environment relative to other Pioneer brand products observed. Consider another product choice. 

Factors in Selecting a Corn Product

  • Select corn products that show optimum yield performance.
  • Select corn products that can maintain acceptable plant and ear height.
  • Select corn products that can tolerate elevated soil pH levels.
  • Visit with your local Pioneer sales representative or dealer for information on Pioneer brand corn product options.

Reference

Lutt, N., D. Berning, and S. Endicott. 2016. Corn Management in High pH Soils. Pioneer Field Facts Vol. 16 No. 14.


Managing Corn in High pH Soils

How to Use Starter Fertilizers in Corn Production

Aggressive use of starter fertilizer can protect corn yields in high pH soil. Follow this overview on how to use them.

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Find the Right Seed Corn for Every Acre

Use our corn seed guide to explore Pioneer® brand corn products that will maximize yield potential on every acre.

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Optimum AcreMax XTremeOptimum AcreMaxOptimum AcreMax LeptraQrome

Agrisure Viptera Agrisure RWRoundup Ready Corn 2LibertyLinkHerculex IHerculex Xtra

Qrome® products are approved for cultivation in the U.S. and Canada. They have also received approval in a number of importing countries, most recently China. For additional information about the status of regulatory authorizations, visit www.biotradestatus.com. AMXT (Optimum® AcreMax® XTreme) - Contains a single-bag integrated refuge solution for above- and below-ground insects. The major component contains the Agrisure® RW trait, a Bt trait, and the Herculex® XTRA genes. In EPA-designated cotton growing counties, a 20% separate corn borer refuge must be planted with Optimum AcreMax XTreme products. AM - Optimum® AcreMax® Insect Protection system with YGCB, HX1, LL, RR2. Contains a single-bag integrated refuge solution for above-ground insects. In EPA-designated cotton growing counties, a 20% separate corn borer refuge must be planted with Optimum AcreMax products. AML - Optimum® AcreMax® Leptra® products with AVBL, YGCB, HX1, LL, RR2. Contains a single-bag integrated refuge solution for above-ground insects. In EPA-designated cotton growing countries, a 20% separate corn borer refuge must be planted with Optimum AcreMax Leptra products.

Roundup Ready® is a registered trademark used under license from Monsanto Company. Liberty®, Liberty Link® and the Water Droplet Design are trademarks of BASF. Agrisure® and Agrisure Viptera® are registered trademarks of, and used under license from, a Syngenta Group Company. Agrisure® technology incorporated into these seeds is commercialized under a license from Syngenta Crop Protection AG.

ALWAYS READ AND FOLLOW PESTICIDE LABEL DIRECTIONS. Roundup Ready® crops contain genes that confer tolerance to glyphosate, the active ingredient in Roundup® brand agricultural herbicides. Roundup® brand agricultural herbicides will kill crops that are not tolerant to glyphosate.

¹All Pioneer products are hybrids unless designated with AM1, AM, AML, AMX, AMXT, and Q in which case they are brands.

The foregoing is provided for informational use only. Please contact your Pioneer sales professional for information and suggestions specific to your operation. 2018-2021 data are based on 16 Pioneer Field Agronomist observation plots in northeast Colorado, northwest Kansas, and southwest Nebraska. Multi-year and multi-location is a better predictor of future performance. Do not use these or any other data from a limited number of trials as a significant factor in product selection. Product responses are variable and subject to a variety of environmental, disease, and pest pressures. Individual results may vary. Pioneer® brand products are provided subject to the terms and conditions of purchase which are part of the labeling and purchase documents.