The effects of frequency of defoliation on the yield response of a perennial ryegrass sward to a wide range of nitrogen application rates

1978 ◽  
Vol 90 (3) ◽  
pp. 447-457 ◽  
Author(s):  
D. Reid
Keyword(s):  
Perennial Ryegrass ◽  
Dry Matter ◽  
Total Yield ◽  
Response Surfaces ◽  
Yield Response ◽  
Dry Matter Yield ◽  
Nitrogen Application ◽  
Nitrogen Rate ◽  
Wide Range ◽  
Cutting Frequency

SummaryIn a 3-year experiment on a sward of S. 23 perennial ryegrass 21 rates of nitrogen fertilizer ranging from 0 to 897 kg/ha were applied annually on plots cut three, five or ten times per year. The cutting dates within each frequency were decided on the basis of herbage growth stage. Four-parameter exponential curves fitted to the herbage yield data show that the pattern of response to nitrogen application in the five cuts per year treatment was markedly similar to that reported for a previous experiment (Reid, 1970). Alterations in the cutting frequency affected the pattern of dry-matter yield response to nitrogen, but not that of crude-protein yield response. The combined effects of cutting frequency and nitrogen rate are illustrated by response surfaces fitted to the dry-matter yield results using an extension of the equation for the curves fitted to the individual frequency results. These surfaces show that as the number of cuts per year was increased the total yield and the response to nitrogen decreased, but the response was maintained to an increasingly high nitrogen rate. The practical implications of the results are discussed in relation to intensive grazing managements for dairy cows.

A comparison of the yield responses of four grasses to a wide range of nitrogen application rates

1985 ◽  
Vol 105 (2) ◽  
pp. 381-387 ◽  
Author(s):  
D. Reid
Keyword(s):  
Dry Matter ◽  
Growth Curves ◽  
Yield Response ◽  
Dry Matter Yield ◽  
Meadow Fescue ◽  
Nitrogen Rate ◽  
Yield Data ◽  
Wide Range ◽  
Yield Responses ◽  
Nitrogen Rates

SUMMARYThe yield results are reported for an experiment in which 21 rates of nitrogen fertilizer were applied on pure-sown swards of four grasses, S. 24 and Barvestra perennial ryegrass, S. 37 cocksfoot and S. 53 meadow fescue. Growth curves fitted to the herbage yield data for each grass in each year are presented. On average the total dry-matter yield curves for the two ryegrasses were similar to one another, but showed a slightly smaller response to nitrogen rates below 300 kg/ha than did S. 23 ryegrass in an earlier experiment, and a more rapid decrease in response at higher rates. S. 37 cocksfoot had a similar dry-matter yield response to the ryegrasses at the low nitrogen rates, but the response decreased more rapidly at nitrogen rates over 250 kg/ha. The dry-matter yield response of S. 53 fescue decreased even more rapidly with nitrogen rates over 200 kg/ha. The mean estimates of the optimal nitrogen rate for each of the four grasses, i.e. the nitrogen rate at which the dry-matter response had decreased to 10 kg/kg N, was 380, 372, 357 and 327 kg N/ha for S. 24, Barvestra, S. 37 and S. 53 respectively, compared with 409 kg/ha for S. 23 ryegrass in the earlier experiment.

A comparison of silages made from red clover/grass, white clover/grass and high nitrogen grass swards for beef production

1985 ◽  
Vol 40 (2) ◽  
pp. 267-277 ◽  
Author(s):  
T. A. Stewart ◽  
I. I. McCullough
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
Dry Matter ◽  
Total Yield ◽  
Live Weight ◽  
Red Clover ◽  
Dry Matter Yield ◽  
Grass Silage ◽  
Matter Production ◽  
Grass Sward

ABSTRACTSilage cut twice annually (June and August) from a tetraploid red clover/grass sward and three times annually (May, July and September) from a low nitrogen (N) and high N perennial ryegrass/white clover sward was fed in proportion to dry-matter yield from each cut, over a 10-week period, each winter for 3 years to castrated male cattle of initial live weight 401 kg in year 1 and 425 kg in years 2 and 3. The silages were supplemented with 0, 1, 2 and 3 kg concentrate per head daily.Total dry-matter yield from the red clover/grass sward was similar to that from the perennial ryegrass/white clover sward (high N grass) receiving 360 kg N per ha but the digestibility, particularly of first cut material was much lower. Dry-matter production of the low N grass/white clover sward was 0·73 of high N grass sward and produced silages of similar digestibility and fermentation.Dry-matter intakes by the cattle were higher on the legume-based silages in years when clover made a worthwhile contribution to total yield, but this did not significantly improve utilization or animal performance compared with high N grass silage. Mean daily carcass gain per head on red clover/grass silage was 0·41 kg which was significantly less than the 0·61 kg on white clover/grass silage and 0·59 on high N grass (P < 0·001). Carcass output from red clover/grass silage was 618 kg/ha and 629 kg/ha from white clover/grass, both of which were significantly less than the 863 kg/ha from the high N grass silage (P < 0·001). Dressing proportion was also significantly poorer in animals fed red clover/grass silage compared with the other silage types.

The effects of a wide range of nitrogen application rates on the yields from a perennial ryegrass sward with and without white clover

1970 ◽  
Vol 74 (2) ◽  
pp. 227-240 ◽  
Author(s):  
D. Reid
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
Nitrogen Fertilizer ◽  
Crude Protein ◽  
Dry Matter ◽  
Growth Curves ◽  
Nitrogen Rate ◽  
Wide Range ◽  
Grass Sward ◽  
Nitrogen Rates

SUMMARYA series of twenty-one nitrogen fertilizer rates ranging from 0 to 800 lb nitrogen/acre (897 kg/ha)/annum was applied on a pure S. 23 perennial ryegrass sward and on an S. 23 ryegrass sward containing S. 100 white clover. Total yields of herbage dry matter and crude protein from both swards at all the nitrogen rates were determined each year by cutting the herbage five times at approximately the same stage of growth on each occasion. Four-parameter growth curves relating herbage yield to nitrogen rate were fitted to the data, and are presented for the first 3 years of the experiment. On the pure-grass sward the response of dry-matter yield to nitrogen rate was almost linear between the 0 and 300 lb nitrogen/acre (336 kg/ha) rates, then it decreased steadily, becoming non-significant about the 500 lb/acre (560 kg/ha) rate. In contrast the response of crude-protein yield was virtually linear from the 0 to the 600–700 lb nitrogen/acre (673–785 kg/ha) rates. The inclusion of white clover in the sward increased the yields of dry matter and crude protein at the low nitrogen rates, but decreased the responses, with the result that the yields and responses of the grass + clover sward were not significantly different from those of the pure-grass sward at nitrogen rates above about 300 lb/ acre (336 kg/ha). In terms of profitability at present fertilizer prices the optimum nitrogen rate for dry-matter production on both swards was estimated to be 400–450 lb/ acre (448–504 kg/ha), whereas that for crude-protein production was greater than 600 lb/acre (673 kg/ha). The value of clover in a sward receiving nitrogen fertilizer is discussed.

Yield and persistence of irrigated lucernes cut at different frequencies, at Tamworth, New South Wales.

1986 ◽  
Vol 26 (2) ◽  
pp. 165 ◽  
Author(s):  
GM Lodge
Keyword(s):  
Dry Matter ◽  
New South ◽  
Total Yield ◽  
Dry Matter Yield ◽  
South Wales ◽  
Cutting Frequency ◽  
Plant Persistence ◽  
Cutting Interval ◽  
The Mean ◽  
The Individual

Three irrigated lucerne cultivars, Pioneer Brand 545 (winter dormant), Condura 73 Brand (semiwinter dormant), and CUF 101 (highly winter active), were harvested at fixed cutting intervals of either 25, 28 ,35, 42 or 48 days from September to April in each of four years. This paper reports the effects of these cutting frequencies on the dry matter yield, leaf to stem ratio and persistence of these cultivars. The effect of cutting frequency on mean total yield (the sum of the mean yields for each harvest) was significant (P<0.05) in each year of the experiment, except year 3. Yields were highest in the 35-day cutting frequency in years 1 and 2. In the fourth year of the experiment the mean total yield of Pioneer Brand 545 and Condura 73 Brand was 29% higher (P<0.05) than CUF 101. By the fourth year substantial amounts of grass were present in the 25- and 28-day cutting interval plots. The contrasts between dormant and active cultivars for the dry matter yield of each of the individual harvests were not consistent in the first two years. In the third and fourth years the active initially outyielded the dormant cultivars at all cutting intervals, but yields of both were generally similar at the end of the season. Increasing the interval between successive harvests generally decreased the mean leaf to stem ratio. The ratio of leaf to stem for CUF 101 was significantly lower (P<0.05) than that for Pioneer Brand 545, with Condura 73 Brand tending to be intermediate. Within cutting intervals, mean declines in plant persistence were similar for cultivars from the different dormancy groups. Largest changes in plant frequency occurred in the fourth year when the mean frequency for the 25- and 28-day plots decreased from 69 to 12% compared with a mean decline from 74 to 65% for the 42- and 48-day cutting intervals. Productive stand life in this experiment was 3 years, even though disease was negligible. Under these conditions grass invasion was mainly related to harvest interval and much less to cultivar dormancy.

Effect of cutting frequency on species richness and dry matter yield of permanent grassland after grazing cessation

2016 ◽  
pp. 1-12
Author(s):  
Marie Stybnarova ◽  
Josef Hakl ◽  
Hana Bilosova ◽  
Pavlína Micova ◽  
Oldrich Latal ◽  
...  
Keyword(s):  
Species Richness ◽  
Dry Matter ◽  
Dry Matter Yield ◽  
Permanent Grassland ◽  
Cutting Frequency

Variation in plasticity within the S. 23 cultivar of Lolium perenne L.

1975 ◽  
Vol 85 (1) ◽  
pp. 111-121 ◽  
Author(s):  
J. Valentine ◽  
A. H. Charles
Keyword(s):  
Phenotypic Plasticity ◽  
Lolium Perenne ◽  
Dry Matter ◽  
Controlled Growth ◽  
Nitrogen Application ◽  
Lolium Perenne L ◽  
N Level ◽  
Wide Range ◽  
Growth Room ◽  
Regression Techniques

SUMMARYThe S. 23 cultivar of Lolium perenne L. has the ability to perform well in a wide range of environments and an experiment was designed to examine the phenotypic plasticity of S. 23 genotypes with particular reference to the level of nitrogen application.Genotypes of S. 23 grown in a controlled growth room at close spacing (5 cm) showed a wide range of dry-matter yields with the highest yielding 144 times that of the lowest at the last of six cuts taken at 4-week intervals. Genotypes maintained much the same order of yield from one nitrogen level to another, but there were exceptions. Regression techniques were used to further quantify genotype-environment behaviour and to measure response to the environment in which the plants were grown. Considerable variation in this character occurred and the correlation of mean yield and response was incomplete. Some of the genotypes combined the desirable characters of high mean yield and good response to improved environments, while others had high mean yields, but were not as well adapted to the highest N level.In the experiment no significant effects could be traced to differences in age of seed, but plants which had been maintained vegetatively for 7 years showed reduced vigour.

The seasonal distribution of nitrogen fertilizer dressings on pure perennial ryegrass swards

1984 ◽  
Vol 103 (3) ◽  
pp. 659-669 ◽  
Author(s):  
D. Reid
Keyword(s):  
Perennial Ryegrass ◽  
Nitrogen Fertilizer ◽  
Crude Protein ◽  
Dry Matter ◽  
Distribution Patterns ◽  
Seasonal Distribution ◽  
Experimental Designs ◽  
Residual Effects ◽  
Nitrogen Application ◽  
Yield Distribution

SummaryIn studies of the seasonal distribution of nitrogen fertilizer dressings on grassland using conventional experimental designs it is usually not possible to separate the true effects of an individual fertilizer dressing on the yield at a particular cut from the residual effects of previous dressings. An experiment is described which was designed to allow separation of the direct and residual effects, with certain restrictions, for a system involving five cuts and five possible fertilizer dressings per season on perennial ryegrass swards. From the results obtained over two harvest years on swards on two adjacent sites equations were derived relating the dry-matter and crude-protein yields of herbage to the rate of nitrogen application at five dressings in the season. Predictions of yield distribution patterns from the equations are compared with observed yields from various sequences of nitrogen dressings included in previous experiments at this Institute. Examples are also given of the prediction of sequences of nitrogen dressings required to obtain certain patterns of yield distribution.

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