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The effects of simulated summer‐to‐winter grazing management on herbage production in a grass–clover sward
Author(s) -
Phelan P.,
Casey I. A.,
Humphreys J.
Publication year - 2014
Publication title -
grass and forage science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.716
H-Index - 56
eISSN - 1365-2494
pISSN - 0142-5242
DOI - 10.1111/gfs.12041
Subject(s) - grazing , agronomy , stolon , biology , yield (engineering) , metallurgy , materials science
The effects of summer‐to‐winter simulated grazing management factors, namely defoliation interval ( INT : 21, 42, 56 or 84 d), defoliation height ( DH : 2·7, 3·6, 5·3 or 6·0 cm) and final defoliation date ( FIN : 23 S eptember, 4 N ovember or 16 D ecember) on herbage production in a grass–clover sward were studied. Treatments were imposed between J uly and D ecember 2008, with all plots under common management in the following M arch to J une 2009. The 42‐d INT achieved the highest ( P < 0·001) total herbage yield at 11·00 t DM ha −1 . Shorter (21 d) and longer (56–84 d) intervals reduced annual clover herbage yield and biological nitrogen fixation estimates. Lowering DH from 6·0 to 2·7 cm in the summer‐to‐winter period increased sward clover content and clover herbage yield through to the following J une, 6 months after treatments ended. Delaying FIN from 23 S eptember to 16 D ecember had no significant effect on annual clover, grass or total herbage yield. Spring–summer clover herbage yield was positively correlated with spring–summer clover stolon mass ( R 2 = 0·54, P < 0·001) and, to a lesser extent, light penetration through the sward in the previous winter ( R 2 = 0·16, P < 0·05). A 42‐d INT with low DH (2·7–3·5 cm) is therefore recommended for grass–clover swards.