Channel® Corn Seed Recommendations for High pH Soils

Trial Objective

A high soil pH is generally classified as 7.6 or higher and key nutrients, including iron, are less available to plants in these more alkaline soils. Corn products vary in their tolerance to pH and can be considered low tolerant, semi-tolerant, or tolerant to the effects of high soil pH. Products with a low tolerance to high pH soils can express iron deficiency chlorosis (IDC) symptoms including yellow leaves, interveinal chlorosis, and stunted growth. A better understanding of product performance under varying soil pH conditions is important for positioning products to help maximize yield potential.

In Western Kansas and Eastern Colorado, high soil pH is caused by excess lime from high calcium carbonate concentrations in the soil parent material, which often comes from eroded sidehills and cut areas in fields.

The objective of this ongoing trial is to determine the visual and potential yield response of 20 Channel^® brand corn products to high pH (7.6 to 8.5) soils.

Research Site Details

• For this trial, 41 corn products with varying relative maturities (RMs) and a 104 RM check product were planted in a high pH block at Goodland, KS and Vernon, CO.
• 21 of the 41 products were DEKALB^® RIB Complete^® brand blend corn products. For this report, only the DEKALB^® brand product results are shown.
• A visual color rating of the foliage was taken at the V8 (8 leaves) and VT (tassel) growth stages (Figure 1):
  • very dark green foliage = 2
  • pale-yellow color foliage = 8
• Each plot was 4 rows wide x 27.5 feet long. Each product was replicated 4 times.
• Soil pH was determined by grid sampling each trial area at a 1/10 acre density.

Understanding the Results

High pH color rating results for the 20 Channel^® brand corn products are shown in Table 1. Fourteen products were above average and highly recommended, five were above average and recommended in most situations, and one Channel^® brand product was below average and not recommended for high pH soils.

It is important to note that the visual rating scores are just the average taken across the replications in this trial, while the product placement recommendations are from the expertise of local Channel^® brand Technical Agronomists and based on multiple years of experience and observations across several fields. Though visual ratings are a good indicator of potential performance, previous results are included in the recommendations. Channel^® brand representatives can help with product placement questions.

Table 1. High pH Soil Recommendations for 20 Channel^® Brand Blend Corn Products.

Key Learnings

• High pH soils are typically found in areas with eroded topsoil and topography changes. In those situations, it can be difficult to compare yield potential between neutral and high pH areas of the field. Producers should keep this in mind while making yield comparisons on their own farm.
• The importance of selecting a product able to tolerate high pH soils varies based on the proportion of high pH soil acres in each field and the pH range within each field.
• The pH tolerance of any corn product is indicated by a visual color rating. However, color expression can also be influenced by other abiotic factors such as soil temperature, nutrient availability, and nutrient uptake. Producers should assess all potential problems when evaluating product performance under high pH soils and when selecting specific products for their fields.

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