Seeding rate effects on forage mass and vegetation dynamics of cool-season grass sod interseeded with sorghum-sudangrass

John A. Guretzky, Daren D. Redfearn

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


Interseeding annual warm-season grasses into perennial cool-season grasses has the potential to increase summer forage mass and nutritive value. Knowledge of how seeding rate affects annual warm-season grass establishment, forage mass, and vegetation dynamics remains limited. From 2016–2017, we conducted a field experiment evaluating the effects of seeding rates on sorghum-sudangrass (Sorghum bicolor × S. bicolor var. sudanense) density and forage mass and on the frequency of occurrence of plant species in cool-season grass sod in Lincoln, NE. The experiment had a completely randomized design consisting of six replicates of four seeding rates [0, 14, 28, and 35 kg pure live seed (PLS) ha−1 ] in sod mowed at a 2.5-cm height and one unseeded, non-mowed control treatment. Sorghum-sudangrass establishment increased with seeding rate from an average of 20 to 45 plants m−2 as the seeding rate increased from 14 to 35 kg PLS ha−1 . Forage mass depended on a seeding rate × harvest interaction, showing positive linear and cubic responses to seeding rate in consecutive harvests at 45 and 90 d after interseeding. To increase forage mass in perennial cool-season grass sod, producers should interseed sorghum-sudangrass with at least 28 kg PLS ha−1 . One-time seedings into cool-season, perennial grass sod have no residual effects on subsequent forage mass and vegetation dynamics.

Original languageEnglish (US)
Article number2449
Issue number12
StatePublished - Dec 2021


  • Annual warm-season grasses
  • Cool-season grass pasture
  • Forage management
  • Improved pasture
  • Pastureland
  • Perennial cool-season grasses
  • Permanent pasture
  • Smooth bromegrass
  • Tall fescue
  • Temperate pastures

ASJC Scopus subject areas

  • Agronomy and Crop Science


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