Corn Product Yield Response to Irrigation Rate and Seeding Rate - DEKALB®
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 Bayer tests 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 on corn yield under full irrigation versus limited irrigation.
Research Site Details
Seven DEKALB® brand blend corn products were planted on the curve in two adjacent blocks. One block received 100% full irrigation and one block received 50% irrigation. The yield goal for the 50% irrigation treatments were 190 bu/acre and for the 100% irrigation treatments were 265 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 16 inches of rainfall was received during the growing season. The 100% full irrigation treatments received an additional 16 inches of water while the 50% irrigation treatments received an additional 9 inches of water.
Irrigation was provided with a center pivot system with nozzles placed within the crop canopy.
The corn trial site was free from any disease, insect, or hail damage during the 2018 growing season. There was standing water periodically from rain and irrigation that was applied during the growing season.
Understanding the Results
When looking at the average yield across all seeding rates and corn products, the 50% irrigation treatment yielded 249.2 bu/acre and the 100% irrigation treatment yielded 250.8 bu/acre. This small difference in yield between the two irrigation treatments is not typical for the area and soil type. The environment at Hugoton, Kansas in 2018 was very wet and restricting irrigation did not greatly reduce yield.
The soil profile in the 100% irrigation treatment was in a highly saturated state for most of the growing season. This excess water could have actually hurt yield. It is also possible that nitrogen was lost through de-nitrification and reduced final yields in the 100% irrigation treatment.
What Does This Mean for Your Farm?
Corn products may have different yield responses to seeding rates and amounts of available water. Higher seeding rates do not always mean that a corn product will yield more bushels per acre. Enhanced competition at higher seeding rates in some corn products may reduce the number of kernels per row and the number of rows per ear.
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 higher seeding rate and a longer-season product may have a higher yield potential.
Farmers should work closely with their local sales team in selecting corn products and determining seeding rates for their field environments.