Corn Product Yield Response to Irrigation Rate and Seeding Rate – Mingo, Kansas

Trial Objective:

  • With the increase in limited irrigation due to reductions in pumping capacity or restrictions on the amount of water producers are able to pump over a certain period of time, it is imperative that we test products under varying irrigation rates to develop better corn product recommendations by irrigation level.
  • The objective of this study was to evaluate the effect of different seeding rates under full irrigation versus limited irrigation.

Research Site Details

  • Seven DEKALB® brand blend corn products were planted in two adjacent blocks. One block received 100% full irrigation and one block received 50% irrigation. The yield goal for the 50% irrigation treatment was 190 bu/acre and for the 100% irrigation treatment was 250 bu/acre.
  • Each seed product was planted at 24,000, 30,000, 36,000, and 42,000 seeds/acre in each irrigation level block. Each treatment was replicated three times.
  • A total of 13.5 inches of rainfall was received during the growing season. The 100% full irrigation treatment received an additional 9 inches of water while the 50% irrigation treatment received an additional 5 inches of water.
  • Irrigation was provided with a center pivot system with nozzles placed within the crop canopy.
  • The trial site received a damaging hail storm at V6 (six visible leaf collars) growth stage that resulted in 80% defoliation and a plant population loss of 5 to 8%.

Understanding The Results

  • Across all seed products and seeding rates, the additional 4 inches of irrigation water applied to the full irrigation treatment yielded an additional 13.5 bu/acre.
  • 10 relative maturity (RM) and higher seed products yielded on average an additional 6.9 bu/acre at the 50% irrigation treatment and an additional 7.6 bu/acre at the 100% irrigation treatment compared to lower RM seed products across all seeding rates.

What Does This Mean for Your Farm?

  • Seed products may have different yield responses to seeding rates and amounts of available water.
  • Farmers should carefully consider corn product selection and seeding rate based on the irrigation capabilities in each field in order to maximize their economic return. Factors to consider are irrigation pumping costs versus expected yield potential.
  • Generally, in a fully irrigated environment, a longer-season product with a higher seeding rate should have high yield potential.
  • Farmers should work closely with their local sales team in selecting seed products and determining seeding rates for their field environments.