scholarly journals The Impact of Herbage Mass on Perennial Ryegrass Swards in Autumn on Autumn and over Winter Production and Characteristics

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1140
Author(s):  
Caitlin Looney ◽  
Astrid Wingler ◽  
Michael Egan

Accumulating herbage mass to facilitate the extension of the grazing season in autumn is commonly practised. The objective of the current study was to investigate the effect of accumulating varying target herbage masses (THM) in autumn and imposing different defoliation dates (DD), on herbage mass, sward quality and water-soluble carbohydrates in autumn and the subsequent spring. A 4 × 3 factorial split plot design was assigned with four THM (Low ≈ 500 kg·DM·ha−1, Medium ≈ 1500 kg·DM·ha−1, High ≈ 2000 kg·DM·ha−1 and Very high ≈ 3000 kg·DM·ha−1) and three DD (DD1—15 October, DD2—7 November and DD3—21 November), across two years. Measurements were carried out at each DD and in spring. Differences in sward quality were found between each THM on different DD. Sward quality reduced from DD2 to DD3 in the high THM (−13 g·kg−1 DM CP, p < 0.001). The very high THM had the lowest sward quality from DD1 (206 g·kg−1 DM CP, p < 0.001 and 787 g·kg−1 DM DMD, p < 0.05). This study has identified the defoliation date of THM in autumn as key to improving autumn management strategies for increased utilisation and sward quality.

2016 ◽  
Vol 43 (10) ◽  
pp. 931 ◽  
Author(s):  
Barbara Jurczyk ◽  
Ewa Pociecha ◽  
Janusz Košcielniak ◽  
Marcin Rapacz

Increased precipitation and snowmelt during warmer winters may lead to low-temperature waterlogging of plants. Perennial ryegrass (Lolium perenne L.) is one of the most important cool-season grasses in agriculture. It is well adapted to cold climates, and may be considered as a model system for studying the mechanisms involved in cold acclimation. The aim of this study was to evaluate the effects of waterlogging on photosynthetic acclimation to cold in perennial ryegrass. Two L. perenne genotypes that differ in their responses to waterlogging in terms of freezing tolerance were compared. We evaluated the effects of waterlogging during cold acclimation on the water-soluble carbohydrate concentration, ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity, photochemical efficiency of PSII, and transcript levels of the Rubisco activase (RcaA) and sucrose-sucrose fructosyltransferase (1-SST) genes. The genotype that did not accumulate water-soluble carbohydrates in the leaf under waterlogging showed a lower degree of feedback inhibition of photosynthesis under low temperature, and activated a photochemical mechanism of photosynthetic acclimation to cold. The other genotype accumulated water-soluble carbohydrates in the leaf during waterlogging, and activated a non-photochemical mechanism under cold conditions. Different photosynthetic acclimation systems to cold under waterlogging may be activated in these two contrasting L. perenne genotypes.


2017 ◽  
Vol 57 (7) ◽  
pp. 1507 ◽  
Author(s):  
A. Chen ◽  
R. H. Bryant ◽  
G. R. Edwards

The objective of the study was to evaluate the effect of perennial ryegrass cultivar and timing of herbage allocation on herbage nutritive value and milk production of mid-lactation dairy cows. An autumn grazing trial using 48 Friesian × Jersey spring-calving cows was conducted over 10 days. Twelve groups of four cows were allocated to three replicates of four treatments, namely, two perennial ryegrass cultivars (AberMagic or Prospect) offered either after milking in the morning (0830 hours) or afternoon (1630 hours). Cows were offered a daily herbage allowance of 30 kg DM/cow above ground level. There were no significant differences in sward structure and morphological characteristics between cultivars, except for Prospect having a lower average tiller mass (43.1 mg) than AberMagic (48.4 mg). The concentration of water-soluble carbohydrates (WSC) and organic matter digestibility in DM (DOMD) was greater in AberMagic (180 g/kg, 74.2%) than in Prospect (153 g/kg, 71.4%). Herbage DM percentage, WSC concentration and DOMD were lower in the morning than in the afternoon (18.8% vs 22.3% DM; 154 vs 179 g/kg WSC; 72.1% vs 73.5% DOMD). Herbage DM intake (12.0 kg/cow.day), milk yield (17.2 kg/cow.day) and milksolids yield (1.60 kg/cow.day) did not differ significantly among treatments. Cultivar choice and timing of allocation influenced herbage WSC concentration and digestibility, but did not alter milksolids production.


Agronomy ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 383 ◽  
Author(s):  
Cristian J. Moscoso ◽  
Sarah A. Morgan ◽  
M. Jordana Rivero

The objective of this study was to assess the joint effect of perennial ryegrass cultivars and drying methods on concentrations of water-soluble carbohydrates (WSC) and crude protein (CP) and WSC/CP ratio. AberMagic AR1 and Expo AR1 forage were collected in December 2016, March, June, September and November 2017 and either oven-dried at 60 °C for 48 h (OD_60), at 80 °C for 16 h (OD_80), frozen at −80 °C for 48 h then freeze-dried (−80_FD), or flash-frozen with liquid N then freeze-dried (LN_FD). Data were analyzed by ANOVA in a factorial design with cultivar and drying method as factors. AberMagic AR1 had between 9.0 to 31.5% higher WSC concentration than Expo AR1 in the four samplings. Freeze-drying preserved more WSC than oven-drying treatments (+22.7%), particularly in June. The CP concentration of Expo AR1 was higher only in December (+6.8%), and was 22.9 and 10.9% higher in OD_60 samples compared to LN_FD samples in December and November, respectively. The WSC/CP ratio varied in June, being greater in AberMagic AR1 (+36.1%). Drying method affected WSC/CP ratio in December, June and November where freeze-drying produced greater ratios. Drying techniques generated differences in WSC, CP and WSC/CP ratio, which may affect the accuracy of the estimated impacts of forages on productivity and N use efficiency.


1971 ◽  
Vol 19 (3) ◽  
pp. 184-188
Author(s):  
B. Deinum

Between 18 May and 29 June 1966, a 2-year-old sward of perennial ryegrass was grown at normal (390), low (88) or high (711 cal/cm2 day) light intensity and given 20-160, 40-320 and 80-360 kg N/ha at the 3 light intensities, respectively. At low rates of N, high light intensity exhausted the nitrate reserves of perennial ryegrass, diminished the CP content, but greatly increased the percentage of water-soluble carbohydrates. With high N, high light intensity decreased nitrate content but increased both CP and water-soluble-carbohhdrate content. (Abstract retrieved from CAB Abstracts by CABI’s permission)


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