Journal of Animal Science and Technology
Korean Society of Animal Science and Technology
Article

Effects of Alfalfa and Alfalfa-Grass Mixtures with Nitrogen Fertilization on Dry Matter Yield and Forage Nutritive Value

Iryna McDonald1, Rudra Baral1,*, Doohong Min1
1Kansas State University, Manhattan 66502, United States.
*Corresponding Author: Rudra Baral, Kansas State University, Manhattan 66502, United States. Phone: +1 785-532-2292. E-mail: rudrabaral@ksu.edu.

© Copyright 2021 Korean Society of Animal Science and Technology. This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Received: Oct 07, 2020; Revised: Dec 12, 2020; Accepted: Dec 21, 2020

Published Online: Jan 04, 2021

Abstract

Alfalfa <italic>(Medicago sativa </italic>L<italic>.) </italic>is an important forage legume grown in Kansas, USA and its productivity with cool-season grasses however is unknown. The objective of this study was to determine the dry matter yield (DMY) and forage nutritive value of alfalfa-grass mixtures compared to those of alfalfa and grasses grown in monoculture with and without nitrogen fertilization. Three different alfalfa varieties were planted (reduced-lignin alfalfa, Roundup Ready, and conventional alfalfa) and two kinds of cool-season grasses (smooth brome, <italic>Bromus inermis</italic> Leyss, and tall fescue, <italic>Festuca arundinacea</italic> Schreb) were planted as a monoculture or in alfalfa-grass mixtures. Nitrogen fertilizer (urea) was applied at a rate of 56 kg ha<sup>-1</sup> and 56 kg ha<sup>-1</sup> in 2016 and 2017, respectively and control treatments received no nitrogen. DMY was significantly higher in monoculture alfalfa and alfalfa-grass mixtures than in grass monocultures. Between alfalfa monoculture and alfalfa-grass mixtures, no significant differences in DMY were found. For all treatments, nitrogen application significantly increased DMY compared to the control.  In 2016 and 2017, the low-lignin alfalfa monoculture had the lowest acid detergent fiber (ADF) and the grass monocultures had the highest ADF. In 2016 and 2017, neutral detergent fiber (NDF) in smooth bromegrass and tall fescue was higher than in other species treatments. A low-lignin alfalfa monoculture had significantly lower NDF concentration compared to alfalfa-grass mixtures. When averaged over 2016 and 2017, relative feed value (RFV) was highest in low-lignin alfalfa and lowest in the grass monocultures. In both years, nitrogen fertilizer application did not affect nutritive values.

Keywords: Dry matter yield; Forage nutritive value; Alfalfa; Tall fescue; Smooth bromegrass; Nitrogen application