Responses of nine tropical grasses to nitrogen fertilizer under rain-grown conditions in south-eastern Queensland. 1. Seasonal dry matter productivity

1984 ◽  
Vol 24 (126) ◽  
pp. 410 ◽  
Author(s):  
BG Cook ◽  
JC Mulder

Nine tropical grasses were fertilized with 25, 50 and 100 kg N/ha on ten occasions at two-month intervals. No nitrogen was applied when conditions were too cold and/or dry for pasture growth. Samples (> 10 cm height) were taken at four-week intervals to estimate dry matter yield. Growth patterns of all grasses were similar, with a warm season peak and cool season trough. Nitrogen treatments did not greatly alter the growth pattern, although all species showed a yield response to increasing levels of nitrogen. Cumulative dry matter yields of Chloris gayana cvv. Callide and Katambora, Setaria sphacelata var. sericea cv. Narok, Digitaria decumbens and Panicum maximum cv. Makueni did not differ at N25 (P < 0.05), each producing about 10 t/ha. This significantly exceeded 5 t/ha from Pennisetum clandestinum cv. Whittet and Panicum maximum cv. Gatton. The same high-yielding group produced 15-16 t/ha at N50, while Gatton yielded 11.4 t/ha and Whittet 8.4 t/ha. At N 100, Callide, Katambora and Makueni were the highest yielding grasses (24-26 t/ha), and Whittet the lowest (15 t/ha). Brachiaria decumbens cv. Basilisk and Paspalum plicatulum cv. Bryan died out before the final harvests. Species responsiveness is discussed in terms of increment in dry matter yield per unit of applied nitrogen.

Author(s):  
N. N. Ngerebara ◽  
L. O. Amadi ◽  
G. C. Vincent

Increase in yield of tropical grasses viz. digit grass (Digitaria decumbens), guinea grass (Panicum maximum) and pearl millet (Penisetum americanum) inoculated with tropical nitrogen-fixing bacterium, Spirillum lipoferum was investigated. The study was carried out for three consecutive years (2016-2018). Dry matter yields and protein content of the three tropical grasses were used for the assessment. In 2017, pearl millet (Penisetum americanum) and guinea grass (Panicum maximum) produced significantly higher protein content and dry matter yields. Projected yields using regression analysis of both pearl millet and guinea grass indicated that about 40kgN ha-1 yr-1 were replaced by inoculation. Although, protein production of guinea grass was lower during 2018, dry matter yield responses were similar to those of 2017. This research has shown that inoculation with Spirillum lipoferum, a tropical nitrogen-fixing bacterium reduced acetylene and increased yields or reduced nitrogen fertilizer requirement of the tropical grasses as well as replacement of up to 40KgN ha-1. This amount is agro-economically important and suggests the viability and potential for grass-bacteria systems.


1973 ◽  
Vol 24 (6) ◽  
pp. 875 ◽  
Author(s):  
MA Laredo ◽  
DJ Minson

Chloris gayana, Digitaria decumbens, Panicum maximum, Pennisetum clandestinum, and Setaria splendida were each cut at three stages of growth, dried, chaffed, and separated into "leaf" and "stem" fractions using a gravity separator. The mean purity of the leaf and stem fractions were 78 and 93%. Each fraction was fed to eight sheep to determine voluntary intake and dry matter digestibility. Mean voluntary intake of leaf was 46% higher than that of stem (57.7 v. 39.6 g/kg0.75), despite a slightly lower dry matter digestibility of the leaf fraction (52.6 v. 55.8%). The higher intake of the leaf fraction was associated (r =0.74, P< 0.01) with a shorter retention time of dry matter in the reticulo-rumen (mean 23.8 v. 31.8 hr), which appeared to be caused by the large surface of the leaf fraction initially available to bacterial degradation (mean 128 v. 41 sq cm/g). Ground leaf and stem samples showed no difference in rate of digestion in vitro since structural differences had been destroyed. The energy required to grind 1 g sample in a laboratory mill was less for leaf than stem (mean 234 v. 411 J/g) with a significant correlation between voluntary intake and grinding energy (r = –0.81). In the past a high voluntary intake has been attributed to a high bulk density, but in this study bulk density of the stem fraction was three times that of the leaf fraction and negatively correlated with voluntary intake (r = –0.70, P< 0,001). It was concluded that different plant fractions may be eaten in different quantities, despite similar dry matter digestibilities, and that in any study of the voluntary intake of roughages it is necessary to determine physical properties of the feed in addition to chemical composition.


1969 ◽  
Vol 58 (4) ◽  
pp. 448-455
Author(s):  
A. Sotomayor-Ríos ◽  
F. J. Juliá ◽  
J. A. Arroyo-Aguilú

The effect of three harvest intervals (30, 45 and 60 days) on the yield, crude protein (CP), digestible protein (DP), and mineral (calcium, Ca; phosphorus, P; potassium, K; and magnesium, Mg) composition of 10 forage grasses was determined during a 1-year period at the Isabela Substation. The species studied included three Brachiarias, five Digitarias and two Cynodons. As the 30-day harvest interval, the dry matter yield (DMY) ranged from 25,859 to 19,041 pounds per acre per year. The highest DMY was obtained by Transvala digitgrass (Digitaria decumbens, PRPI. 6439) Stargrass (Cynodon nlemfuensis PRPI. 2341) had the highest CP and DP contents. The highest DMY at the 45-day interval was obtained by Transvala digitgrass, being significantly different (P < .05) from other grasses. The DMY ranged from 29,532 to 20,962 pounds per acre per year. Digitaria eriantha had the highest CP and DP contents. Stargrass had the highest DMY and CP at the 60-day harvest interval. The DMY ranged from 37,504 to 30,269 pounds per acre per year. Mean Ca and Mg contents in the grasses increased at the 45-day interval, with no Ca increase but a Mg decrease at 60 days. Mean P and K contents decreased as the harvest intervals increased. The yielding ability of the grasses was encouraging, especially in the Transvala digitgrass and Stargrass species. The CP and DP contents tended to vary as plants matured, suggesting that studies of mineral absorption and/or utilization of forage grasses by niminants should be undertaken.


1973 ◽  
Vol 13 (61) ◽  
pp. 153 ◽  
Author(s):  
DJ Minson

On five occasions during the growing season Chloris gayana, Digitaria decumbens and Pennisetum clandestinum were fertilized with urea at 125 or 500 kg ha-1 and cut after one month's regrowth. The minimum nitrogen level in herbage was 0.96 per cent and hence voluntary intake of these feeds was not limited by a nitrogen deficiency per se. Fertilizing at the high level increased dry matter yield (P < 0.01) and depressed the leaf percentage significantly in C. gayana. Each cut was fed to ten wethers to determine digestibility and voluntary intake. The higher rate of nitrogen fertilizer increased the overall mean dry matter digestibility 2.2 per cent, organic matter digestibility 1.3 per cent and voluntary intake of dry matter 2.3 gWkg0.75 (P > 0.05). Within the harvests significant increases and decreases in digestibility and voluntary intake were found. The direction and magnitude of these changes in feeding value were not correlated with differences in yield, leaf percentage or nitrogen content.


1978 ◽  
Vol 90 (3) ◽  
pp. 447-457 ◽  
Author(s):  
D. Reid

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.


1985 ◽  
Vol 105 (2) ◽  
pp. 381-387 ◽  
Author(s):  
D. Reid

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.


1969 ◽  
Vol 72 (4) ◽  
pp. 531-543
Author(s):  
Angel V. Méndez-Cruz ◽  
Norma Corchado-Juarbe ◽  
Víctor Siberio-Torres

An evaluation of the hay obtained from tropical grasses coastcross I (Cynodon dactylon), stargrass (Cynodon nlemfuensis), callie (Cynodon plectostachyus), slenderstem (Digitaria pentzii), and guinea (Panicum maximum) was made at three harvest intervals (35-, 45-, and 55-day) and four storage periods (γ than 4, 4 to 8, 8 to 12, and < than 12 months). In vivo dry matter digestibility and voluntary intake trials were performed with Holstein steers, weighing from 340 to 390 kg. Mean digestibility was 60.8%, 56.8% and 55.0%, respectively, for 35-, 45- and 55-day harvest intervals. The mean reduction caused by storage was from 60.8 to 50.6%, from 56.8 to 48.8%, and from 55.0 to 47.2% for the 35-, 45-, and 55-day intervals, respectively. The lower digestibility values were measured in callie. Voluntary intake declined 12, 18, and 17% and the digested dry matter voluntary intake declined from 1.47 to 1.1%, from 1.31 to 0.9%, and from 1.15 to 0.82%. Crude protein content decreased by 17.0, 15.4, and 15.6% for the respective intervals. The major detrimental effect in hay quality was observed after a 12-month storage. Plant maturity influenced the mean increase of neutral detergent fiber (NDF) from 69.7 to 72.6 and 76.6%, acid detergent fiber (ADF) from 37.9 to 43.4 and 47.7%; and lignin content, from 5.2 to 9.3% for the three growth intervals. This increase was 9, 16, and 42% for each parameter. However, as storage effect, NDF, ADF, and lignin content were raised by 4.3%, 12.3%, and 5.0%, respectively.


1970 ◽  
Vol 10 (42) ◽  
pp. 32
Author(s):  
MJ Playne

A survey was made of the sodium concentration in eight grass and legume pasture species in the Townsville region. The grass species could be characterized according to sodium concentration. Panicum maximum, Chloris gayana, and Cenchrus setigerus were 'high-sodium' species (>0.40 per cent Na), whereas Urochloa mosambicensis had a medium sodium concentration, and Cenchrus ciliaris, Heteropogon contortus, and the legumes Stylosanthes humilis and Phaseolus atropurpureus were `low-medium� species (<0.10 per cent Na). The sodium concentration in five species grown at five sites located within 257 kilometres of Townsville, Queensland, was also examined at one stage of growth. Since several common pasture species contained low levels of sodium (<0.05 per cent of dry matter) deficiency symptoms could occur in grazing stock under certain circumstances.


2017 ◽  
Vol 39 (2) ◽  
pp. 149 ◽  
Author(s):  
Francisco Duarte Fernandes ◽  
Gustavo José Braga ◽  
Allan Kardec Braga Ramos ◽  
Liana Jank ◽  
Marcelo Ayres Carvalho ◽  
...  

2014 ◽  
Vol 94 (4) ◽  
pp. 705-715 ◽  
Author(s):  
J. I. Arroquy ◽  
M. V. Cornacchione ◽  
D. Colombatto ◽  
C. Kunst

Arroquy, J. I., Cornacchione, M. V., Colombatto, D. and Kunst, Jr., C. 2014. Chemical composition and in vitro ruminal degradation of hay and silage from tropical grasses. Can. J. Anim. Sci. 94: 705–715. This study was conducted to evaluate the effects of preservation type on chemical composition and in vitro ruminal degradation of warm-season grasses (WSG). Treatments consisted of two factors (6×2): the first factor was tropical grasses: Cenchrus ciliaris (cv. Biloela, and cv. Molopo), Chloris gayana (cv. Callide and cv. Finecut), Panicum maximum, and Brachiaria bryzanta; and the second factor was preservation type (hay vs. silage). Cell wall, hemicellulose, cellulose, and water-soluble carbohydrate (P<0.05) concentrations were different among WSG. In general, hay or silage altered fiber content compared with fresh. For instance, hemicellulose and cellulose contents were lower in silage than in hay and fresh grass (P<0.05). Gas production rates were higher in silage from 0 to 24 h of fermentation, except at 4 h of incubation. After 24 h, gas production (GP) rate was similar for both preservation types, whilst potential GP was similar between preservation types. However, silage had decreased lag time compared with hay (P<0.01). Silage had greater dry matter disappearance than hay (P<0.05), and gas production yield was similar for grass species and preservation type. Our results indicate that WSG conserved as silage showed beneficial changes in chemical composition and dry matter degradation compared with hay.


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