Grain Corn Agronomy

 Farming Smarter Project

Project contact: Ken Coles


1. Determine optimum previous crop residue and seeding systems (conventional vs zero-till) for grain corn production under rain fed conditions in southern Alberta.
2. Determine optimum row spacing and plant populations for grain corn production under rain fed conditions in southern Alberta.
3. Determine optimum nitrogen response for grain corn production under rain fed conditions in southern Alberta.
4. Evaluate available low heat unit corn varieties under rain fed conditions in southern Alberta.

Timeline: 2015 – 2017; final report March 2018 
Collaborators: Brian Beres AAFC, Manjula Bandara AAFC
Locations: Lethbridge, Medicine Hat, Vauxhall, Bow Island


The overall project objectives were to perform  an unbiased assessment of state-of-the-art corn production technology for adaptation and development of management practices for successful, efficient and profitable grain corn production in the province. To take advantage of a huge production and profit opportunity for Alberta farmers, Farming Smarter looked for the best ways to grow grain corn in Alberta’s climate and soils. Major seed companies’ development investment in short season, early maturing grain corn varieties for Alberta and Saskatchewan offer Alberta crop farmers a huge opportunity.

Corn seedling

This 3-year study at four locations (Lethbridge, Bow Island, Medicine Hat, Brooks) conducted three trials under two field moisture conditions (dryland: DL, irrigated: I) at these locations. Each trial examined a different aspect of grain corn production agronomics including optimum plant population, different fertilizer types and rates and crop rotations. We used new grain corn short season maturity hybrids with Corn Heat Units (CHU) ranging 2000 -2150. These hybrids were selected from a number of seed brands (Pride Seeds, Dupont Pioneer, Monsanto and Pickseed) currently participating in the hybrid corn performance varietal trials conducted by the Alberta Corn Committee.


Farming Smarter staff harvest corn in the corn agronomy trial plots in fall 2016.

Field trials conducted at Lethbridge, Bow Island, Vauxhall and Medicine Hat collected data in all trials that included corn stand density, plant height, days to tasseling, silking, & maturity, lodging ratings, corn yield, and corn test weight.

Study 1: Plant Population and Row Spacing

The population and spacing study showed that narrow rows (20”) and high seeding rates (35,000 seeds/ac) produced maximum corn yields.  Corn yields were 9% higher when seeded on 20” spacing vs 30” spacing.  Generally, yield increases linearly with increasing plant population (Appendix 3, Table 1). Days to tassel, silk and maturity were one day longer from highest to lowest seeding rates (35,000 seeds/ac vs 15,000 seeds/ac), but did not noticeably effect maturity.

Study 2: Nitrogen Fertility Requirements

Nitrogen fertilizer had little effect on corn yield. Comparing total available nitrogen (soil available + fertilizer) versus corn yield showed very little response between 50lbs/ac and 200 lbs/ac. Below 50 lbs/ac and above 200 lbs/ac, there was a small yield decrease. Higher nitrogen rates also increased days to tassel, silk and maturity by approximately one day (Appendix 3, Table 2). 

Study 3. Tillage system and crop rotation impacts to corn production

This study did not show a significant yield difference between pre-plant tillage and direct seeding.  However, corn emergence in the conventional system was 99% and only 84% in the no-till plots. This is caused by hair-pinning and issues with residue from the previous crop. Better residue management at harvest; properly adjusted residue managers during planting and following a low residue crop could address these issues. For instance, grain corn yielded highest following pulse crops (as well as corn), when direct seeded. Further research may facilitate adapting planters to zero-tillage and prove the value of rain-fed corn production in southern Alberta.  

Study 4: Variety maturity rating performance

Studies 1-3 used the variety with lowest available heat unit rating. This study sought to roughly evaluate varieties from various companies with various maturity ratings. There was a 250 kg/ha increase in average yield by going from a 2000 CHU variety to a 2500 CHU variety (appendix 3, figure 13).  However, yields of different varieties at each CHU could vary as much as 1000 kg/ha (appendix 3, tables 5-9), making comparisons at various heat units difficult. Days to tassel, silk and maturity were all lengthened with increased CHU rating (figure 14), but not enough to cause problems for harvest.  The date of the first frost (-2°C) ranged from September 17 to October 24 (table 10) usually leaving adequate time for maturity.  Industry experts warn that most seed companies use differing methods in assigning CHU ratings; which this data set makes apparent.   The intent of this study was not to aid in variety selection, but to determine if there is opportunity for higher yields.

Read the complete project report

Final Grain Corn Report web


Farming Smarter grew plots of different crops in 2016 to plant the corn trail in for 2016 sequence trials.

Articles on the project

Grain Corn Offers Opportunity, Sarah Redekop
Farming Smarter Magazine, Fall 2017

Dry Soil Hampers Corn
Farming Smarter Magazine, Fall 2017, page 24

Learning in the field at Farming Smarter
Farming Smarter Magazine, Spring 2017, page 11

Corn plots at Lethbridge

Dryland grain corn can fit prairie rotations
Farming Smarter Magazine, Spring 2017, page 24 

Grain corn project surprises researchers
Farming Smarter Magazine, Spring 2016, page 26

Alberta Crop Industry Development Fund (ACIDF), 
Farming Smarter Magazine, Fall 2015, pg 12

Corn on Deck for Rotations
Farming Smarter Magazine, Spring 2015, pg 8- 9

Farming Smarter
Cypress County impress in Medicine Hat – July 14

Higher Seeding Rate Helps Grain Corn
The Western Producer—2017

Farming Smarter brings Innovation Together
Medicine Hat News—July 7, 2017

Project Videos

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