DEKALB® Corn Products for High pH Soils

Click on a tab below to see data collected each year for this study

 

DEKALB® Corn Products for High pH Soils - 2020

 

TRIAL OBJECTIVE

  • A high soil pH is generally classified as having a soil pH of 7.6 or higher and could have the characteristics of excess lime, high soluble salt concentration, and high nitrate-nitrogen concentration. 

  • In Western Kansas and Eastern Colorado, excess lime from high calcium carbonate concentrations in the soil parent material is the source of the high pH, which is found on eroded sidehills and cut areas in fields. 

  • Corn products can respond differently to high pH soils, from tolerant to non-tolerant. Products that are non-tolerant usually express iron deficiency chlorosis (IDC) with symptoms including yellow leaves, interveinal chlorosis, and stunted growth. 

  • Key nutrients, including iron, are tied up in high pH soils and not available to the plant.      

  • Better product characterization allows for better product placement to help maximize yield potential.

  • The objective of this study was to determine the visual response of corn products to soil pH and yield potential in moderate pH (6.6 to 7.5) and high pH (7.6+) soils.  

 

RESEARCH SITE DETAILS

Location Oakley, KS     
Soil Type  Silt loam   

Previous
Crop
Corn     
Tillage
Type
 

Strip Tillage 


 
Planting Date 05/12/20    
Harvest Date 10/22/20  

Potential Yield
 (bu/acre)
235    
Seeding Rate
(seeds/acre)
30K

 

  • For this trial, 68 commercial and experimental corn products of varying relative maturities (RMs) were planted in two separate blocks in the same field. One block had a soil type with a high pH (7.6-8.1) and the other block was planted in a soil with a neutral pH (6.6-7.5). 
    • 35 products had RMs ranging from 103- to 107-day and were grouped as 105 RM.  
    • 33 products had RMs ranging from 108- to 113-day and were grouped as 110 RM. 
  • Nine of these products were DEKALB® brand blend corn products; only the results of the DEKALB products are shown in this report.  
  • A visual color rating of the foliage was taken at the V8 and VT growth stage: 
    • very dark green = 2 
    • pale-yellow color = 8 
  • For each pH block, the average yield of each product was compared to the average yield of all products within the RM group.  
  • Each trial was replicated in a high pH zone and a moderate pH zone in the same field at each block location. 
  • Soil pH was determined by grid sampling each trial area at a 1/10th acre density.
  • Trial was planted on a site that was previously planted in corn and a soil-applied insecticide was included across the trial to help control western corn rootworm. 

image Figure 1. Visual example of an 8 and 2 rating at the V8 growth stage.

UNDERSTANDING THE RESULTS

image Table 1. Average yield of corn product compared to average yield of relative maturity group.
  • There was no visual difference among products when planted in neutral pH soils (data not shown).

  • Average yields in this trial were less than expected this year and may have been a result of excessive heat and drought conditions.

  • Across the nine DEKALB® products tested, the average yield of the 105RM group was 5.8 bu/acre less than the average yield of the 110RM group in the high pH block.

  • Products in 110 RM group yielded on average 3.1 bu/acre more than the products in in the 105 RM group when planted in the neutral pH block. In optimal growing conditions, longer RM products generally have greater yield potential.    

  • DKC56-15RIB Brand Blend had green, healthy plant color at the V8 and VT growth stages and yielded greater than similar RM products on high pH soils and is highly recommended for high pH soils.

  • DKC60-87RIB Brand Blend and DKC61-40RIB Brand Blend had lower than average visual appearance but yielded greater than similar RM products on high and neutral pH soils. These products are recommended for most situations for high pH soils.

  • DKC53-27RIB Brand Blend and DKC54-64RIB Brand Blend had above average visual ratings but slightly below average yields to comparable RM corn products. These products are recommended to use with caution on high pH soils.

  • DKC55-54RIB Brand Blend had lower than average visual appearance but yielded greater than similar RM products on high and neutral soils.  Based on previous years data DKC55-54RIB Brand Blend is not recommended for high pH soils. 

  • DKC59-81RIB Brand Blend, DKC60-67RIB Brand Blend, and DKC62-98RIB Brand Blend had average to below average visual appearance and below average yields. It is recommended to use these products with caution on high pH soils.

KEY LEARNINGS

  • High pH soils are typically found in areas with eroded top soil and topography changes, which make it difficult to compare yields between neutral and high pH areas of the field. Producers need to 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 soil pH level and the proportion of high pH soil acres in each field.  

  • Corn product pH tolerance was indicated by a visual color rating, but 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 assessing product performance under high pH soils.

 

 

1019_R2

 

 

January 29, 2020

Selecting Dekalb® Corn Products for High pH Soils - 2019

 

TRIAL OBJECTIVE

  • Corn products often respond differently to high pH soils with some being susceptible, some semi-tolerant, and others tolerant in how they respond both in terms of yield and visual appearance. Hybrids that are susceptible usually express iron deficiency chlorosis (IDC) with symptoms including yellow leaves, interveinal chlorosis, and stunted growth. 

  • Key nutrients, including iron, phosphorus, copper, and zinc are tied up in high pH soils.1 A high soil pH for corn is generally classified as having a soil pH of 7.6 or higher and can be caused from either excess calcium carbonate, excess lime, high soluble salt concentration, and/or high nitrate-nitrogen concentration.2 In Western Kansas and Eastern Colorado, excess lime from high calcium carbonate concentrations in the soil parent material is the source of the high pH, which can be found on eroded sidehills and cut areas in fields.     

  • Better product characterization of response to soil pH allows for better product placement to maximize yield potential.

  • The objective of this study was to determine the visual and yield response of corn products to moderate (6.7 to 7.5) and high (7.6+) pH soils.  

 

RESEARCH SITE DETAILS

Location Burlington, CO     
Soil Type  Silt Loam  

Previous
Crop
Corn    
Tillage
Type
Strip tillage


 
Soil pH Range 6.7 to 8.1    
Harvest Date 10/21/19  

Potential Yield
 (bu/acre)
230    
Seeding Rate
(seeds/acre)
30K

 

UNDERSTANDING THE RESULTS

  • For this trial, a total of 75 different commercial and experimental corn products of varying relative maturities (RMs) were each planted in two separate pH blocks in the same field (See Table 3 for list of additional products). One block has a soil type with a high pH and the other block has a moderate pH: 
    • 42 products had RMs ranging from 103- to 107-day and were grouped as 105 RM  
    • 33 products had RMs ranging from 108- to 113-day and were grouped as 110 RM
  • Ten of these products were DEKALB® brand blend corn products; only the results of the DEKALB products are shown in this report. 

  • A visual color rating of the foliage was taken at the V8 and VT growth stage: 
    • very dark green = 2 
    • pale-yellow color = 8 
  • For each pH block, the average yield of each individual product was compared to the average yield of all the products within the RM group. This allowed us to better identify those products which performed above average on the high pH soil. 

  • Trial was replicated: 4 replications in the high pH zone and 4 replications in the moderate pH zone at each location. 

  • Soil pH was determined by grid sampling each trial area at a 1/10th acre density.

 
  • In this trial year, the lower than expected yields are attributed to cold, wet soils early in the growing season followed by extensive wind and heat during grain fill.  

  • Across all products tested, the average yield of the 105 RM group was 0.5 bu/acre greater compared to the average yield of the 110 RM group in the high pH block. 

  • On the moderate pH block, the average yield of the 110 RM group was 8.8 bu/acre greater compared to the average yield of the 105 RM group. In optimal growing conditions, longer RM products generally have greater yield potential.   

  • Visual estimations during vegetative stages closely correlated to the yield results (see Tables 1 and 2).

 

WHAT DOES THIS MEAN FOR YOUR FARM?

 

  • The importance of selecting a product able to tolerate high pH soils varies based on soil pH level and the proportion of high pH soil acres in each field.  

  • High pH soils are typically found in areas with eroded top soil and topography changes, which make it difficult to compare yields between neutral and high pH areas of the field. Producers need to keep this in mind while making yield comparisons on their own farm.

  • DEKALB® offers corn products for high pH soils, talk with your local seed representative for more information on product placement with your operation.  

 
Sources: 

1 National Soil Survey Center. 1998. Soil quality indicators : pH. United States Department of Agriculture Natural Resources Conservation Service. 

2 Ferguson, R.B. 2006. Nutrient management for agronomic crops in Nebraska. EC06-155.


1019_R2

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