About Us | Help Videos | Contact Us | Subscriptions
 

Members of ASA, CSSA, and SSSA: Due to system upgrades, your subscriptions in the digital library will be unavailable from May 15th to May 22nd. We apologize for any inconvenience this may cause, and thank you for your patience. If you have any questions, please call our membership department at 608-273-8080.

 

Institutional Subscribers: Institutional subscription access will not be interrupted for existing subscribers who have access via IP authentication, though new subscriptions or changes will not be available during the upgrade period. For questions, please email us at: queries@dl.sciencesocieties.org or call Danielle Lynch: 608-268-4976.

Abstract

 

This article in AJ

  1. Vol. 99 No. 1, p. 195-202
     
    Received: Feb 13, 2006


    * Corresponding author(s): jholman@ksu.edu
 View
 Download
 Alerts
 Permissions
Request Permissions
 Share

doi:10.2134/agronj2006.0047

Structural Composition, Growth Stage, and Cultivar Affects on Kentucky Bluegrass Forage Yield and Nutrient Composition

  1. Johnathon D. Holman *a,
  2. Carl Huntb and
  3. Donn Thillc
  1. a Southwest Research and Extension Center, Kansas State Univ., Garden City, KS 67846
    b Dep. of Animal and Veterinary Science, Agricultural Science Building, Univ. of Idaho, Moscow, ID 83844
    c Dep. of Plant, Soil and Entomological Sciences, Agricultural Science Building, Univ. of Idaho, Moscow, ID 83844

Abstract

Kentucky bluegrass (Poa pratensis L.) is an important turf and forage grass, yet there is little information on its forage yield and nutrient composition. This study evaluated the effect of Kentucky bluegrass cultivar (Ascot, Kenblue, Limousine, and Touchdown), growth stage (boot, anthesis, and seed ripening), and structural composition (percentage head, leaf, and stem) on forage yield and nutrient composition. Nutrient composition measurements included dry matter, crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), lignin, and 48-h in vitro true digestibility (IVTD). Tall cultivars had the greatest yield, and yield tended to be greatest at seed ripening. Structural composition varied among cultivars due to differences in cultivar height and yield. Nutrient composition was not different among cultivars despite differences in structural composition among cultivars and nutrient composition differences among structural components. Leaves were greatest in IVTD (636 g kg−1), stems were greatest in NDF (740 g kg−1) and ADF (430 g kg−1), and lowest in CP (30 g kg−1) and IVTD (455 g kg−1), and heads were lowest in ADF (269 g kg−1) and greatest in lignin (83 g kg−1). Nutrient level was greatest at boot and averaged 435 g kg−1 NDF, 197 g kg−1 ADF, 17 g kg−1 lignin, 165 g kg−1 CP, and 766 g kg−1 IVTD. On average between boot and anthesis, CP decreased 0.57% d−1 in 2003 and 0.21% d−1 in 2004, and IVTD declined 0.47% d−1 in 2003 and 0.49% d−1 in 2004. Nutrient level decreased as the stand aged due to an increase in structural carbohydrates and a decrease in IVTD.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © 2007. American Society of AgronomyAmerican Society of Agronomy