scholarly journals Nitrate leaching and N2-fixation in grasslands of different composition, age and management

2004 ◽  
Vol 142 (2) ◽  
pp. 141-151 ◽  
Author(s):  
J. ERIKSEN ◽  
F. P. VINTHER ◽  
K. SØEGAARD
Keyword(s):  
Perennial Ryegrass ◽  
Nitrate Leaching ◽  
Dry Matter ◽  
Grazing Intensity ◽  
Dry Matter Production ◽  
Leaching Losses ◽  
N Removal ◽  
Matter Production ◽  
Over Time

Grass-legume associations may offer a way of improving the N efficiency of dairy farming, but may also have an adverse impact on the environment by increasing leaching losses. Nitrate leaching from four cropping sequences with different grassland frequency and management (long-term grazed, long-term cut, cereals followed by 1 and 2-year grazed leys) were investigated on a loamy sand in central Jutland for both unfertilized grass-clover (perennial ryegrass (Lolium perenne L.)/white clover (Trifolium repens L.)) and fertilized perennial ryegrass (300 kg N/ha) swards during 1997–2002. Furthermore, 1 year (2001) of N2 fixation in 1-, 2- and 8-year-old grass-clover pastures was determined. Nitrate leaching from grazed unfertilized grass-clover was always considerably lower than from grazed fertilized ryegrass. The effect of grassland age on nitrate leaching was insignificant in grass-clover but clear in grazed ryegrass, where levels increased dramatically with sward age. In production years 6–8, leaching from grass-clover was only 9–13% of the comparable losses from ryegrass. Under the cutting regime grass-clover showed a significant reduction in both yield and N-removal with increasing sward age, whereas for ryegrass these figures did not show any decreasing trend. N2 fixation was lower in 8-year-old swards compared with fully established 2-year-old swards as a consequence of lower dry matter production, lower clover content and a lower proportion of clover-N derived from the atmosphere. The results from the present study indicate that the higher leaching losses observed in fertilized grass compared with unfertilized grass-clover systems were caused by (1) a reduction in N2-fixation in grass-clover over time and (2) a reduction in dry matter production in grass-clover over time, lowering the grazing intensity and the recycling of grassland N via animal excreta.

scholarly journals Dry matter production of perennial ryegrass swards following varying levels of poaching damage on a free-draining earth soil

2010 ◽  
Vol 1 (1) ◽  
pp. 83-83 ◽  
Author(s):  
G Tuñon ◽  
E Kennedy ◽  
D Hennessy ◽  
P Kemp ◽  
N Lopez Villalobos ◽  
...  
Keyword(s):  
Perennial Ryegrass ◽  
Dry Matter ◽  
Dry Matter Production ◽  
Matter Production

Low rates of phosphorus fertiliser applied strategically throughout the growing season under rain-fed conditions did not affect dry matter production of perennial ryegrass (Lolium perenne L.)

2010 ◽  
Vol 61 (5) ◽  
pp. 353 ◽  
Author(s):  
L. L. Burkitt ◽  
D. J. Donaghy ◽  
P. J. Smethurst
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Dry Matter ◽  
Growing Season ◽  
Dry Matter Production ◽  
Pasture Production ◽  
Lolium Perenne L ◽  
Matter Production ◽  
Extractable P ◽  
Intensively Managed

Pasture is the cheapest source of feed for dairy cows, therefore, dairy pastures in Australia are intensively managed to maximise milk production and profits. Although soil testing commonly suggests that soils used for dairy pasture production have adequate supplies of phosphorus (P), many Australian dairy farmers still apply fertiliser P, often by applying smaller rates more frequently throughout the year. This study was designed to test the hypotheses that more frequent, but lower rates of P fertiliser applied strategically throughout the growing season have no effect on dry matter production and P concentration in perennial ryegrass (Lolium perenne L.), when soil extractable P concentrations are above the critical value reported in the literature. Three field sites were established on rain-fed dairy pasture soils ranging in P sorption capacity and with adequate soil P concentrations for maximising pasture production. Results showed that applied P fertiliser had no effect on pasture production across the 3 sites (P > 0.05), regardless of rate or the season in which the P was applied, confirming that no P fertiliser is required when soil extractable P concentrations are adequate. This finding challenges the viability of the current industry practice. In addition, applying P fertiliser as a single annual application in summer did not compromise pasture production at any of the 3 sites (P > 0.05), which supports the current environmental recommendations of applying P during drier conditions, when the risk of surface P runoff is generally lower. The current results also demonstrate that the short-term cessation of P fertiliser application may be a viable management option, as a minimal reduction in pasture production was measured over the experimental period.

Estimation in the Field of Individual Perennial Ryegrass Plant Position and Dry Matter Production Using a Custom-Made High-Throughput Image Analysis Tool

Crop Science ◽  
2015 ◽  
Vol 55 (6) ◽  
pp. 2910-2917 ◽  
Author(s):  
Chris L. Hunt ◽  
Chris S. Jones ◽  
Michael J. Hickey ◽  
John P. Koolaard ◽  
John West ◽  
...  
Keyword(s):  
Image Analysis ◽  
High Throughput ◽  
Perennial Ryegrass ◽  
Dry Matter ◽  
Dry Matter Production ◽  
Analysis Tool ◽  
Matter Production ◽  
Custom Made

The effect of grazing versus cutting on dry matter production of multispecies and perennial ryegrass‐only swards

2019 ◽  
Author(s):  
Cornelia Grace ◽  
Tommy M. Boland ◽  
Helen Sheridan ◽  
Eugene Brennan ◽  
Rochelle Fritch ◽  
...  
Keyword(s):  
Perennial Ryegrass ◽  
Dry Matter ◽  
Dry Matter Production ◽  
Matter Production

Effects of irrigation frequency and transient waterlogging on the production of a perennial ryegrass - white clover pasture

1997 ◽  
Vol 37 (2) ◽  
pp. 165 ◽  
Author(s):  
J. S. Dunbabin ◽  
I. H. Hume ◽  
M. E. Ireson
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
Dry Matter ◽  
Soil Surface ◽  
Dry Matter Production ◽  
Irrigation Frequency ◽  
Pasture Production ◽  
Absolute Increase ◽  
Irrigation Interval ◽  
Matter Production

Summary. Perennial ryegrass–white clover swards were irrigated for 3 years every 50, 80 and 120 mm of crop evapotranspiration minus rainfall (ETc–R) and water ponded on the soil surface for either 4, 12 or 24 h at each irrigation. Pasture production and clover content were highly seasonal, peaking in spring and autumn. Frequent irrigation increased dry matter production by an average of 56%. When irrigating at 50 mm ETc–R, dry matter production was decreased by ponding water on plots, 17% for 12 h ponding and 14% if ponded for 24 h. However, when irrigating at an interval of 80 mm ETc–R ponding increased dry matter production by 7% for 12 h ponding and by 25% for 24 h ponding. Ponding also increased production at an irrigation interval of 120 mm ETc–R by 25% for 12 h ponding but only by 2.4% for 24 h ponding. While these increases in dry matter production are large in relative terms the absolute increase in production is small. More water infiltrated per irrigation at longer irrigation intervals, and at longer ponding times. Frequently irrigated, rapidly drained swards used irrigation water most efficiently. The small gain in dry matter production achieved by prolonging ponding at longer irrigation intervals is an inefficient use of water and likely to recharge regional groundwater systems. Oxygen diffusion rate measurements suggested that ponding for as short as 4 h was likely to cause waterlogging stresses and that these stresses were higher when irrigating frequently. The relative increase in waterlogging stress by extending the period of ponding from 4 to 24 h was small.

Changes in growth rate and morphology of perennial ryegrass swards at high and low nitrogen levels

1971 ◽  
Vol 77 (1) ◽  
pp. 123-134 ◽  
Author(s):  
Alison Davies
Keyword(s):  
Growth Rate ◽  
Perennial Ryegrass ◽  
Dry Matter ◽  
Crop Growth ◽  
Dry Matter Production ◽  
Appreciable Effect ◽  
Crop Growth Rate ◽  
Nitrogen Levels ◽  
Matter Production ◽  
Time Of Year

SummaryThe nitrogen requirements for maximum production of perennial ryegrass swards in August/September were shown to be of the order of 4 kg N/ha/day. Further increases above this level had no appreciable effect on dry-matter production, leaf area or light intercepted, but maximum tiller numbers were considerably enhanced. Shortage of nitrogenous fertilizer had comparatively little effect on crop growth rate in the early stages of regrowth, but thereafter caused the rate to fall increasingly short of potential. At high fertilizer levels crop growth rate based on total above-ground parts was linearly related to percentage light intercepted in the first month after defoliation, but values subsequently became erratic and at times negative. This change in crop growth rate and the resulting halt in effective net dry-matter production could be associated with the overall pattern of leaf and tiller formation and death, maximum net yield being achieved at the point in time when three new leaves had been produced on each tiller since cutting. It is concluded that in August and September worth-while increases in harvestable net dry matter are unlikely to occur after this stage has been reached, and that managements based on the maintenance of a complete crop cover are not likely to be successful at this time of year.

Evaluation of the use of a small leaved clover as an alternative to fertiliser-N on tetraploid and diploid perennial ryegrass swards grazed to controlled sward heights by ewes and lambs

1990 ◽  
Vol 1990 ◽  
pp. 33-33
Author(s):  
J.E. Vipond ◽  
G. Swift ◽  
J. FitzSimons ◽  
T.H. McClelland ◽  
J.A. Milne ◽  
...  
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
Dry Matter ◽  
Dry Matter Production ◽  
Sheep Grazing ◽  
Nitrogen Fertiliser ◽  
Sward Height ◽  
Matter Production ◽  
Upland Pasture

Lamb performance at grass falls in July/August on upland farms. Allowing sward height to rise has been recognised as having an ameliorating effect [Keeling, 1987). The objective of this trial was to determine the influence of both sward quantity (sward height) and sward quality [sward type) on ewe and lamb performance from mid April to September. A further objective was the evaluation of clover as an alternative to nitrogen fertiliser.Three contrasting perennial ryegrass based swards were established in May 1987 for use in 1988 and 1989: a late heading diploid variety (D). CONTENDER and a late heading tetraploid variety [T) CONDESA sown alone or with S184 small leaved white clover [TO]. [D] swards represent the control being the normal upland pasture type. [T] companion ryegrass varieties have higher palatability and intake characteristics and, producing fewer tillers, are a compatible companion grass to white clover. Small leaved white clover was used owing to its higher persistency and dry matter production under continuous sheep grazing.

scholarly journals The effect of sward perennial ryegrass content and defoliation method on seasonal and total dry matter production

2010 ◽  
Vol 1 (1) ◽  
pp. 149-149 ◽  
Author(s):  
P Creighton ◽  
E Kennedy ◽  
T.J Gilliland ◽  
T Boland ◽  
M O'Donovan
Keyword(s):  
Perennial Ryegrass ◽  
Dry Matter ◽  
Dry Matter Production ◽  
Matter Production

Effects of spring grazing on dryland perennial ryegrass/white clover dairy pastures. 1. Pasture accumulation rates, dry matter consumed yield, and nutritive characteristics

2006 ◽  
Vol 57 (5) ◽  
pp. 543 ◽  
Author(s):  
F. R. McKenzie ◽  
J. L. Jacobs ◽  
G. Kearney
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
Dry Matter ◽  
Grazing Intensity ◽  
Water Soluble ◽  
Accumulation Rates ◽  
Leaf Stage ◽  
Rate Of Increase ◽  
The Impact ◽  
Over Time

A 3-year experiment (September 1999–August 2002) was conducted in south-western Victoria to determine the impact of spring grazing on pasture accumulation rates, dry matter (DM) consumed yield (estimate of DM yield), and pasture nutritive characteristics [metabolisable energy (ME), crude protein (CP), neutral detergent fibre (NDF), and water-soluble carbohydrates (WSC)] of a perennial ryegrass (Lolium perenne L.)–white clover (Trifolium repens L.) pasture. Spring grazing treatments, applied annually from September to November, were based on ryegrass leaf development stage with high (HF), medium (MF), and low (LF) grazing frequency being 2-, 3-, and 4-leaf stage, respectively, and post-grazing height as the grazing intensity with high (HI), medium (MI), and low (LI) grazing intensity being 3, 5, and 8 cm, respectively. Five combinations were used: HFHI, LFHI, MFMI, HFLI, and LFLI. A sixth treatment, rapid grazing (RG), maintained pasture between 1500 and 1800 kg DM/ha by grazing weekly during spring, and a seventh and eighth treatment, simulating forage conservation for early-cut silage (lock-up for 6–7 weeks; SIL) and late-cut hay (lock-up for 11–12 weeks; HAY), were also included. For the remainder of the year, all plots were grazed at the perennial ryegrass 3-leaf stage of growth, or when pasture mass had reached 2800 kg DM/ha, and grazed to a residual height of 5 cm. On average, pasture accumulation rates ranged from <5 (February–March) to 100–110 kg DM/ha.day (September–October). Overall, SIL resulted in a lower accumulation rate than all other treatments. High spring grazing frequency (including RG) treatments led to more grazing events than medium and low spring grazing frequency treatments. In Years 1, 2, and 3, DM consumed ranged from 9.7 (HAY) to 16.3 (RG), 4.2 (HAY) to 10.1 (HFHI), and 7.3 (SIL) to 10.9 t DM/ha.year (HAY), respectively. HAY resulted in a lower pasture ME content than SIL, HFHI, and LFHI spring grazing, and LFLI spring grazing resulted in a lower pasture ME content than all other treatments except HAY. HFHI grazing resulted in an increase in ME content over time, whereas the rate of increase in ME content over time was higher for LFLI spring grazing than for HAY, RG, and HFLI spring grazing. For all treatments, average pasture ME content ranged from 9.4 (January–February) to 11.4 MJ/kg DM (September). HAY resulted in a lower CP content than all treatments except LFLI grazing. RG resulted in no change in CP content over time. For all treatments, average pasture CP content ranged from a low of 11–14 (January–February) to a high of 24–28% DM (August–September). LFLI grazing resulted in a higher NDF content than HFHI, LFHI, MFMI, and HFLI grazing, while RG resulted in a lower NDF content than LFHI, MFMI, and HFLI. For all treatments, average pasture NDF content ranged from a low of 48–55 (August–September) to a high of 58–62% DM (January–February). All treatments resulted in an increase in pasture WSC content over time. The results demonstrate that frequent and intense grazing management (e.g. HFHI and RG) during spring is important in maintaining high pasture DM yields. Results also indicate positive pasture nutritive characteristic (ME, CP, and NDF) gains with more frequent spring grazing than with infrequent spring grazing. No treatment effect was observed for WSC content.

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