Nitrogen fertilization rate and method influences water and nitrogen productivity of forage winter wheat
Spring‐seeded annual forages are well adapted to the Great Plains; however, the influence of application rate and method of N fertilization on winter wheat (WW) (Triticum aestivum L.) forage productivity is unknown. A field study was conducted in a factorial design for 3 yr to determine the influence of N application rate and method on water and N productivity of awnletted WW ‘Willow Creek’. Urea was either broadcast or banded at planting using N fertilization rates of 0, 28, 56, and 84 kg N ha−1. The N application rate × method interaction was significant only for WW height. Weed herbage was low at WW forage harvest, 19 kg ha−1. As N fertilization rate increased from 0 to 84 kg N ha−1, wheat stem density and height increased by 70 and 78%, respectively, and herbage increased by 58%. Increased N rate increased WW water use quadratically, but water productivity (kg biomass ha−1 mm−1) was 68% greater at 84 kg N ha−1. However, N application method did not influence water use or productivity. Banded N application increased N accumulation in WW herbage by 11% compared to broadcast N. Increasing N rate reduced N productivity by 24% compared to 0 kg N ha−1. Willow Creek WW produced greater herbage yield as N fertilization rate increased with banded application. Willow Creek is a highly productive fall‐planted forage in this predominantly spring‐planted small grain–grain legume region.
This article is published as Lenssen, Andrew W., Upendra M. Sainju, Clain Jones, Kent McVay, and Terry Angvick. "Nitrogen fertilization rate and method influences water and nitrogen productivity of forage winter wheat." Agronomy Journal (2020). doi: 10.1002/agj2.20495.