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Department of Agronomy

Kansas State University

1712 Claflin Rd.

2004 Throckmorton PSC

Manhatan, KS 66506



Extension Agronomy

Summary of 2018 Kansas Corn Yield Contest

Kansas Corn, in conjunction with K-State Research and Extension, conducted a Kansas Corn Yield Contest for the 2018 growing season. This contest was free to enter and was open to all corn producers in Kansas that were active members of the Kansas Corn Growers Association. The objectives of the contest were:

  • Recognize high-yielding Kansas corn farmers.
  • Improve crop management practices and increase efficiency for greater sustainability and profitability.
  • Share data collected among Kansas farmers and provide tips for improving management practices.

Field locations

A large concentration of the fields was located in Sheridan, Atchison, and Doniphan counties (Figure 1). Other fields were located in west, south, north central, and southeast Kansas.

Figure 1. Field locations for high-yield corn contest entries. Dryland (25 entries), Irrigated (9 entries).

Summary of Results

  • Yield
    • Average yield of the harvested plots was 234.2 bushels per acre (bu/a), ranging from 145.5 to 307.4 bu/a.
    • Average yield of the entire fields was 207.4 bu/a, ranging from 108.4 to 272.0 bu/a. This average value was 60% greater than the Kansas average (130 bu/a) for corn yield in 2018.
  • Crop management
    • Corn hybrids represented four different seed companies.
    • Planting date varied between April 10 and May 25. There was a 2.1 bu/a yield reduction for each day of delayed planting from April 10 (Figure 2A).
    • Average seeding rate was 28,000 seeds/a, varying between 16,000 to 36,000 seeds/a. There was a positive linear relationship between grain yield and seeding rate (Figure 2B) indicated by a 6 bu/a increase in yield per 1,000 seeds/a.
    • 88% of the fields implemented 30-inch row spacing.
    • Soybean was the most frequent previous crop (54%), followed by corn (25%), and wheat (21%).
    • For residue management, 84% of the farms conserved the previous crop residue, 10% grazed the residue, and 6% harvested it.
    • For tillage management, 22% of the farms utilized no-tillage, 44% used strip-tillage, and 34% used other tillage practices (e.g., disk, vertical, chisel).
    • A majority of the corn received (78%) received both pre- and post-emergence herbicide, while 22% only received pre-emergence treatment.
    • For pest management, 53% of the corn received fungicide application, while 9% received only insecticide treatment.

Figure 2. Relationship between grain yield and A) planting date, (B) seeding rate, and (C) amount of fertilizer N applied.

  • Nutrient management
    • 44% of the corn received starter fertilizer, 90% P fertilizer (averaging 62 lb P2O5/a), 55% K (averaging 65 lb K2O/a), and all the fields received N fertilization (averaging 117 lb N/a).
    • Grain yield and N fertilization were positively related (Figure 2C), with yields increasing 0.6 bu/a per unit of N applied (lb/a).
    • None of the farmers reported iron deficiency.
    • Lime was applied by 6% of the farmers, with the same for manure application (6%).

Yield Environments Summary

  • Yield
    • Average grain yield increased 37% from low- (<214 bu/a) to medium-yielding environments (214-257 bu/a) and 13% from medium- to high-yielding (>257 bu/a) environments.
  • Crop management
    • Planting date could be one of the main factors affecting grain yield. Averaging 12 days delayed on planting date for the low versus both the medium- and high-yielding environments (Figure 2A).
    •  Average seeding rate increased 65% from low to high yielding fields. As was shown in Figure 2B, a positive relationship was observed between yield and seeding rate.
    • A 41% irrigation adoption was observed in medium- and high-yielding fields versus no irrigation adopted for the low-yielding environment.
    • Most of the medium- and high-yielding fields (~85%) used both pre- and post-emergence herbicides, while a lower proportion (67%) of the low-yielding fields used both herbicides.
    • A greater proportion of the fungicide was reported to be applied in both medium- and high-yielding fields compared to low yielding environments (81% vs. 17%, respectively).
  • Fertilization
    • A lower amount of P and K fertilizers were applied in low-yielding fields (33 and 35 lb/a of P2O5 and K2O, respectively) compared to medium- and high-yielding fields (70 and 62 lb/a of P2O5 and K2O, respectively).
    • Average rate for fertilizer N application increased by 60% from low- to medium-yielding group and by 23% from medium- to high-yielding corn contest-winner entries. As was shown in Figure 3C, a positive relationship was observed between both variables.

Table 1. Summary of grain yield, crop management, and fertilizer strategies for different yield categories (low, medium, and high yield).


In summary, different management practices affect corn grain yield. Results from the 2018 Kansas Corn Yield Contest indicated that the use of irrigation, a balanced fertilization program (N, P, and K), mid-to-late April planting date (April 24), seeding rate above 30,000 seeds/a, use of fungicides, and pre- and post-emergence herbicides were all management practices implemented to maximize corn grain yields in Kansas.



Ignacio Ciampitti, Crop Production and Cropping Systems Specialist

Dale Fjell, Director of Research and Stewardship, Kansas Corn

Walter Carciochi, Visiting scholar, KSUCROPS lab

Luciana Nieto, Graduate student, KSUCROPS lab

Rafael Casaroto, Visiting scholar, KSUCROPS lab