Differences among orchardgrass cultivars in response to hay and rotational grazing management

1995 ◽  
Vol 75 (1) ◽  
pp. 147-157 ◽  
Author(s):  
Y. A. Papadopoulos ◽  
M. A. Price ◽  
L. F. Laflamme ◽  
N. R. Fulton ◽  
G. M. Hunter ◽  
...  

This study was conducted to compare orchardgrass (Dactylis glomerata L.) cultivar performance under contrasting management systems (hay vs. rotational grazing) during the first two production years. The trial consisted of eight orchardgrass cultivars broadcast seeded in a randomized complete-block design, with three replications. The perimeter of each replication was fenced, and the area was divided into two sections. The first section was managed as a simulated hay production system. The second section was managed by simulating a rotational grazing system using crossbred ewes. Dry matter (DM) yield was determined before harvesting or grazing. Tiller density (TD) and leaf area index (LAI) were measured on four cultivars prior to harvesting and grazing. Excellent DM yield and persistence were obtained from all cultivars in both years under hay management but varied considerably under grazing management. Cultivar ranking according to DM yield under hay management was different from ranking based on performance under pasture management. One group of four cultivars had a decrease in yield of 19.9% in the second year of grazing, over the first year, but yield of the remaining group increased by 5.7% (SED = 9.83). Production of hay was similar for both groups. Early-maturing cultivars yielded 7% more DM and had higher crop growth rates (CGR), LAI and TD than late-maturing cultivars. Growth characteristics of orchardgrass cultivars as measured by DM yield, CGR, LAI and TD were modified by management practice. As a result, evaluating orchardgrass varieties under a hay management system was not effective in determining their performance under grazing. Key words:Dactylis glomerata, cultivar evaluation, cultivar development, grazing, yield, yield components

2021 ◽  
Vol 42 (4) ◽  
pp. 2503-2522
Author(s):  
Maria Catiane Silva Veloso Araújo ◽  
◽  
Eleuza Clarete Junqueira de Sales ◽  
Flávio Pinto Monção ◽  
Vicente Ribeiro Rocha Júnior ◽  
...  

The objective of this study was to evaluate the effects of two grazing management strategies on structural, productive and nutritional parameters of Marandu grass (Urochloa brizantha cv. Marandu). A completely randomized block design with two pasture management strategies and eight replications (blocks) was used. The grazing management strategies were: (1) low intensity rotational grazing (LI), with a pre-grazing sward height of 40 cm and a post-grazing sward height of 24 cm, i.e., a defoliation intensity of 50%; (2) High intensity rotational grazing (HI), with a pre-grazing sward height of 40 cm and a post-grazing sward height of 10 cm (±70% defoliation intensity). Pastures were sampled before and after grazing for estimation of forage mass, forage accumulation rate, structural characteristics, nutritional value and dry matter intake.The LI strategy resulted in higher dry matter production than HI before (18.33%) and after grazing (49.06%), increasing pre-grazing forage density by 13.21% (P < 0.05). The production of potentially digestible dry matter was highest (P < 0.05) in LI strategy (21.3% before and 39.6% after grazing, respectively). Higher post-grazing green forage mass (45%) increased the residual crude protein in LI. The LI management strategy increased forage mass production and can be used in Marandu grass pastures.


2020 ◽  
Vol 56 (4) ◽  
pp. 495-505
Author(s):  
Lucas da Rocha Carvalho ◽  
Lilian Elgalise Techio Pereira ◽  
Sila Carneiro Da Silva

AbstractThe perennial forage peanut is a stoloniferous, perennial tropical legume with potential for use in pastures. Based on the hypothesis that under intermittent stocking herbage accumulation would follow a similar pattern to that described for tropical forage grasses, the objective of this study was to evaluate canopy characteristics and herbage accumulation of forage peanut subjected to strategies of rotational grazing management. Treatments corresponded to all possible combinations of two grazing frequencies (regrowth interrupted at 95% and maximum canopy light interception – LI95% and LIMax) and two grazing severities (post-grazing canopy heights (CHs) equivalent to 40 and 60% of the pre-grazing heights). Treatments were imposed to experimental units during an adaptation period (from November 2014 to January 2015) and the subsequent experimental period lasted from February 2015 to April 2016, comprising two consecutive pasture growing seasons with no interruption between them (summer I to summer II). The pre-grazing targets of LI95% and LIMax corresponded to CHs of 13 and 18 cm, respectively. Forage peanut showed high grazing tolerance as pre-grazing leaf area index (except during summer I and autumn/winter), total herbage, and leaflet dry matter accumulation varied only with seasons. Higher rates of herbage production were recorded during summer I and summer II, followed by those during late and early spring and autumn/winter. Since there was no difference in the pattern of herbage accumulation between LI95% and LIMax and stolons predominated at the bottom of the canopies, forage peanut may be rotationally grazed with greater flexibility than most tropical forage grasses. Recommended pre-grazing CHs are within 13 and 18 cm, and post-grazing heights between 40 and 60% of the pre-grazing height.


2017 ◽  
Vol 68 (12) ◽  
pp. 1131 ◽  
Author(s):  
W. Badgery ◽  
G. Millar ◽  
K. Broadfoot ◽  
J. Martin ◽  
D. Pottie ◽  
...  

Grazing management has been identified as a means of increasing livestock production and improving the composition of perennial pastures. The benefits of intensive rotational grazing have been the subject of much debate, but few studies have evaluated contrasting management of intensive rotational systems. A grazing management experiment was established on a pasture with cocksfoot (Dactylis glomerata L., varieties Porto and Kara) as the dominant species, to investigate different stocking rates, paddock numbers and rotation speeds, and a flexible treatment that adjusted grazing time, rest periods and stock numbers for optimal pasture utilisation. Data were collected on pasture composition and diet quality assessed by using faecal analysis, animal weight changes and pasture characteristics. Animal production per hectare was greatest for fast rotations (56 days’ rest) at high stocking rates (HStR, 13.6 dry sheep equivalents (DSE) ha–1), but continuous grazing (CG) was equally productive. Although flexible grazing based on the 3–4-leaf stage was proposed as the best balance between pasture production and quality, this treatment had lower stocking rates (9.2 DSE ha–1) and was not as productive. No treatment negatively affected pasture composition over the 4-year period. Area of bare ground was highest for the HStR CG treatment; however, the 30-paddock rotations were able to limit bare ground at the same stocking rate. The results indicated that intensive rotational grazing could be effectively managed by using green herbage allowance. In spring, green herbage allowance needed to be 1–1.5 kg green dry matter (DM) DSE–1 day–1, which increased to 5 kg green DM DSE–1 day–1 as the quality of green DM decreased, to allow selective grazing to enhance diet quality.


Author(s):  
J.P.J. Eerens ◽  
J.R. Crush ◽  
S.L. Woodward ◽  
K.A. Macdonald ◽  
W.A. Carter

A whole-farm systems comparison of combinations of perennial ryegrass and white clover cultivars rotationally grazed by dairy cows over two complete seasons evaluated improvements in perennial ryegrass and white clover cultivars resulting from plant breeding efforts. There were four treatments comprised of two ryegrass mixtures and two clover mixtures in a 2 x 2 factorial design, each replicated three times in a randomised block design giving 12, self-contained 4-ha farmlets each stocked at three multiparous Friesian cows/ ha. All pastures were sown in April 1998, using seed obtained through commercial sources, with a high endophyte (>70% endophyte infection) specification for the ryegrass cultivars. A grow out test, carried out after sowing, showed that two of the ryegrass cultivars used in the mix of older cultivars (80R) had less than 70% endophyte infection (Ellett 50%, Nui 62%, Yatsyn 94%) resulting in an average endophyte infection of 69% for that mix. The mix of newer ryegrass (98R) cultivars had an average endophyte infection of 92% (Aries HD 91%, Bronsyn 98%, Samson 87%). While seedling densities (ryegrass and clover) were similar for all mixtures at the start, from late summer of the first year onward, tiller densities were around 30% lower (due to predation of endophyte-free plants and tillers by the Argentine stem weevil) in the 80R treatment. The lower tiller density opened up the sward at an opportune time for clover expansion, which the newer clover cultivars (98C) Sustain and Challenge converted into a higher clover production than from the older clover cultivars (60C) Huia and Pitau. The 80R treatment had a greater spring surplus requiring more conservation than the 98R treatment, which had a more even growth distribution over the year. Differences in endophyte infection levels had a major impact on pasture composition, especially clover content; reducing the endophyte level of seed sown from 90% to 70% may create an opportunity to increase the clover content and quality of young pastures in the Waikato. Keywords: cultivars, dairying, endophyte, perennial ryegrass, tiller density, white clover


2020 ◽  
Vol 16 (8) ◽  
Author(s):  
Pryanka Thuyra Nascimento Fontes ◽  
Douglas Baracho Oliveira Santos ◽  
Jailson Lara Fagundes ◽  
Alfredo Acosta Backes ◽  
Bráulio Maia de Lana Sousa ◽  
...  

The digit grass is a highly cultivated species in Northeast Brazil, especially in Sergipe and Alagoas. However, research related to the management of fertilization of this specie is incipient. This experiment was carried out to examine the productive potential of digit grass and its morphological changes in response to nitrogen fertilization. The experimental period was from August 2014 to July 2015. Treatments consisted of five levels of nitrogen fertilization (0, 50, 100, 300 and 600 kg ha-1) arranged in a randomized-block design with four replicates. Urea was used as a source of nitrogen. Height, light interception (LI), leaf area index (LAI), total tiller density (TTD), basal tiller density (BTD) and total (TDM), leaf (LDM) and stem dry matter (SDM) accumulations were influenced (P0.05) by the nitrogen doses, fitting a positive quadratic equation. Nitrogen fertilization did not influence (P0.05) dead material accumulation rate or aerial tiller density. Overall, the increasing nitrogen doses culminated in increased canopy height, LI and LAI as a result of the increase in TTD and BTD, which in turn elevated TDM, LDM and SDM. The herbage yield potential of digit grass can be increased with the application of 478 kg N ha-1, enabling its use as an alternative in intensive animal production systems.


1993 ◽  
Vol 120 (3) ◽  
pp. 301-310 ◽  
Author(s):  
J. L. Brock ◽  
R. H. Fletcher

SUMMARYThe morphology of independent plants of perennial ryegrass (Lolium perenne L.) in mixed swards under intensive sheep grazing was studied at Palmerston North, New Zealand in 1988/89. Intact plants of two cultivars, ‘Grasslands Nui’ and ‘Grasslands Ariki’, were sampled from pastures under rotational grazing, set stocking, and a combination of both systems, every 2 months for 16 months, by taking turves (250 × 250 mm) and washing out the plants. Characters measured for each plant were: number of flower heads, leaves and tillers; basal stem and internode stolon length; flower head, leaf blade, leaf sheath and stolon dry weight (DW). Additional pasture data on tiller density and dispersion and herbage DW to ground level were also collected.Perennial rye grass exhibited a strong clonal growth pattern similar to that of white clover (Trifolium repens L.) but with a better balance between growth at the apex and death of old basal stem. Release of branch stolons to form new plants was regular, which maintained population stability. Formation of internode (I) stolon appeared to be a response of heavily shaded tillers for survival by elevation of the growing point to a more favourable position. The total DW of ryegrass stolon in pastures was greater than that of the companion white clover.There was little seasonal variation in number of tillers or basal (B) stem length per plant. During the reproductive period (late spring/early summer) plants were heavier and had more leaves and internode stolon than at other times of the year. Grazing management had little effect on plant structure, but plants under rotational grazing had 75% greater DW, less basal stem and reduced probability of internode stolon formation than plants under set stocking. Nui plants had heavier but fewer tillers than Ariki did, resulting in little difference in plant DW. Ariki had fewer single-tiller plants and a higher proportion of multiple-tiller (> 7) plants than Nui had. The structure of the populations was not affected by season, management or cultivar and remained stable throughout the year, with a log-normal distribution of plant size. Because of the uniformity of plant structure, plant density in pastures paralleled tiller density, averaging 1900, 3360 and 2330 plants/m2 for rotationally grazed, set stocked and combined grazing treatments respectively.In view of the strong influence that grazing management can have on ryegrass performance and persistence in pastures, the lack of response at the level of plant and population structure to grazing management suggests that some other level of organization within the ecology of the pasture is of greater importance.


2009 ◽  
Vol 66 (1) ◽  
pp. 8-19 ◽  
Author(s):  
Sila Carneiro da Silva ◽  
Adriana Amaral de Oliveira Bueno ◽  
Roberta Aparecida Carnevalli ◽  
Marina Castro Uebele ◽  
Fernando Oliveira Bueno ◽  
...  

Grazing strategies promote changes in sward structure that can affect patterns of herbage accumulation and sward flexibility to management. This experiment evaluated sward structural characteristics and herbage accumulation of Mombaça guinea grass (Panicum maximum Jacq. cv. Mombaça) subjected to rotational stocking managements. Treatments involved grazing when swards reached either 95 or 100% interception of the incident light (LI), to post-grazing heights of 30 and 50 cm, and were allocated to 2,000 m² paddocks according to a randomised complete block design in a 2 × 2 factorial arrangement with four replications, from January 2001 to February 2002. Sward canopy changed from a vertical to a more horizontal orientation as the light interception area index and height increased from post to pre-grazing. Leaf canopy height pre-grazing was stable throughout the year and around 90 and 115 cm for the 95% and 100% LI treatments respectively, indicating a potential for development and use of target-based grazing management practices. Herbage mass pre and post-grazing was lower for the 95% than the 100% LI treatments, but with higher proportion of leaf and lower proportions of stem and dead material. Treatment effects on herbage accumulation were cumulative and became more evident as the experiment progressed, with up to 6 t ha-1 DM advantage to the 95/30 treatment. Although based on a single year experiment, grazing management should aim for low herbage mass during the transition period from winter to spring in order to allow fast recovery of swards and favour herbage accumulation during the following growing season.


1969 ◽  
Vol 42 (4) ◽  
pp. 239-247 ◽  
Author(s):  
L. Rivera-Brenes ◽  
E. N. Colón-Torres ◽  
F. Gelpí ◽  
J. Torres-Más

The Lajas Valley is a semiarid region located in the southwestern corner of the Island. Annual rainfall fluctuates from 40 to 60 inches with rather prolonged dry spells. Guinea grass is the prevailing and most important pasture forage. Very little or no fertilizer at all is used and, generally speaking, the grazing management is poor. In 1952, an experiment was started with Guinea grass submitted to different fertilizer treatments, under rotational grazing. A randomized-block design already described in another paper (3) was used and each treatment of 0, 40, and 80 pounds of nitrogen per acre was applied as ammonium sulfate every 4 months was replicated three times. Results obtained indicate that fertilization pays even in this relatively dry section of the Island.


2020 ◽  
pp. 82-91

The study was conducted to evaluate the effect of Nypa fruticans pruning regimes on the regeneration of mangrove (Rhizophora racemosa) at Okorombokho in Eastern Obolo, Akwa Ibom State, Nigeria. The Nypa was pruned at a uniform height of 10 cm and the area protected with used fishing nets against infiltration by Nypa seeds in tidal floods. Mangrove plants of similar height were interplanted among pre-existing stands, out of which ten plants were tagged in each sub-plot for the measurement of plant height, leaf area index, and stem girth. Three pruning regimes (0, 4, and 6 weekly pruning (WPR) were adopted and soil samples were collected from 0-15 and 15-30 cm depths. The study was a 3x2 factorial in randomized complete block design with three replications. Soil properties showed consistent differences with depth than with pruning regimes. Bulk density (BD) was statistically similar, averaging 1.04 and 1.06 Mgm-3 in 0-15 and 15-30 cm, respectively, while saturated hydraulic conductivity (Ksat), respectively averaged 0.64 and 0.27 cm h-1 . Electrical conductivity (EC), available phosphorous (Av.P) and base saturation (BS) were significantly (p≤0.05) greater in 4WPR (5.77 dS m-1 ; 30.07 mg g-1 ; 85.4%) than 6WPR (4.54 dS m-1 ; 25.82 mg g1 ; 76.2%) and 0WPR (3.57 dS m-1 ; 23.02 mg g-1 ; 74.3%). Plant height (PH) of mangrove averaged throughout the study was significantly (p≤0.05) greater in 4WPR (80.3 cm) than 0WPR (62.5 cm) but similar to 6WPR (73.4 cm). Stem girth (SG) of mangrove was similar but in the order 4WPR (1.06 cm)>6WPR (0.98 cm)>0WPR(0.86 cm). The pattern of variation in other mangrove growth parameters was similar to plant height and stem girth. The study also showed that PH and SG were negatively correlated with sand, Av.P, and EA but positively correlated with silt and clay, EC, and BS. Results indicated that mangrove species (Rhizophora racemosa) growth was optimum 4WPR than 0WPR and 6WPR and could, therefore, be recommended as a management practice for controlling the growth of Nypa fruticans and regenerating mangrove (Rhizophora racemosa) in the study area.


1996 ◽  
Vol 76 (2) ◽  
pp. 269-276 ◽  
Author(s):  
M. Duru ◽  
I. Calviere

Leaf growth of two forage grasses (Dactylis glomerata L. and Festuca arundinacea Schreb.) was studied as a function of the sward state after a cut. Two heights of cut (3 and 6 cm) and a variable number of previous cuts were used to reach different residual leaf area index (IFr), and non-structural carbohydrate (CNS) concentration and quantity. For both species, four treatments were studied in 2 consecutive years. In mid-May for each of the species, the IFr ranged from 0 to 1, and the quantity of CNS varied from 12 to 25 g 100 g−1 DM according to the treatments. Over the 3 wk of regrowth, the IF reached values ranging from 1 to 7 and its increase depended on the IFr and the quantity of CNS. Among the three components of the quantity of CNS (weight of sheath per tiller, tiller density and CNS concentration), only the first two had a significant effect on the IF increase. Tiller mortality occurred when the quantity of CNS or the IFr were the lowest and it contributed little to the growth of lower leaves. No significant differences were found between the two species. Key words: carbohydrates, leaf area index, tiller, cut


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