Evaluating the performance of alfalfa cultivars in rotationally grazed pastures

2005 ◽  
Vol 85 (1) ◽  
pp. 147-150
Author(s):  
Y. A. Papadopoulos ◽  
D. B. McKenzie ◽  
K. B. McRae ◽  
E. A. Clark ◽  
E. Charmley

Although alfalfa (Medicago sativa L.) is an important and reliable hay crop in eastern Canada, it is generally not considered suitable for pastures. However, local studies have shown that alfalfa is capable of superior yield in mixtures under rotational grazing. This study evaluates the performance of commercially available, locally adapted, hay-type alfalfa cultivars and new experimental, grazing-type alfalfa synthetics under hay and two rotationally grazed regimes. Ten alfalfa cultivars, including five hay-type and five grazing-type cultivars, were seeded with the timothy (Phleum pratense L.) cultivar, Richmond, in mixtures. The two pasture regimes consisted of grazing to low and high residual heights. Over two dry growing seasons, the pasture management with high residual grazing height was more productive than the low; on average lenient rotational grazing pressure (high residual heights) produced 20% higher yield than low residual heights. Alfalfa cultivars selected specifically for continuous grazing were not, on average, superior to those hay-type cultivars selected for general adaptability to soil and environmental conditions in Atlantic Canada. Differences among cultivars within alfalfa type were significant. Over 2 production years, mixtures containing the hay-type cultivar, Apica, and the grazing type, Alfagraze, produced more dry matter on average than three others in the study, regardless of management regime. Key words: Grazing height, cattle grazing

1985 ◽  
Vol 65 (3) ◽  
pp. 787-791
Author(s):  
H. A. BURITY ◽  
B. E. COULMAN ◽  
M. A. FARIS

A greenhouse experiment has shown that total nitrogenase activity of alfalfa (Medicago sativa L.) is not significantly affected when grown in association with timothy (Phleum pratense L.), smooth bromegrass (Bromus inermis Leyss) or orchardgrass (Dactylis glomerata L.) except after initial harvest when decreased alfalfa activity was associated with smooth bromegrass or orchardgrass. It was concluded that mixed cultures of alfalfa with timothy, smooth bromegrass or orchardgrass have no effect on alfalfa N2 fixation. The results also suggest the occurrence of N transference from alfalfa to associated grasses. It is speculated that this transfer is not primarily due to the death of roots and nodule tissue (after harvest), but involves some degree of N excretion during the period before initial harvest.Key words: Alfalfa-grass mixtures, N2-fixation, nodule activity, N-transference


Plants ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 46
Author(s):  
Noriyuki Ida ◽  
Arihiro Iwasaki ◽  
Toshiaki Teruya ◽  
Kiyotake Suenaga ◽  
Hisashi Kato-Noguchi

Cyatheaceae (tree ferns) appeared during the Jurassic period and some of the species still remain. Those species may have some morphological and/or physiological characteristics for survival. A tree fern was observed to suppress the growth of other ligneous plants in a tropical forest. It was assumed that the fern may release toxic substances into the forest floor, but those toxic substances have not yet been identified. Therefore, we investigated the phytotoxicity and phytotoxic substances of Cyathea lepifera (J. Sm. ex Hook.) Copel. An aqueous methanol extract of C. lepifera fronds inhibited the growth of roots and shoots of dicotyledonous garden cress (Lepidum sativum L.), lettuce (Lactuca sativa L.), and alfalfa (Medicago sativa L.), and monocotyledonous ryegrass (Lolium multiflorum Lam.), timothy (Phleum pratense L.), and barnyardgrass (Echinochloa crus-galli (L.) P. Beauv.). The results suggest that C. lepifera fronds may have phytotoxicity and contain some phytotoxic substances. The extract was purified through several chromatographic steps during which inhibitory activity was monitored, and p-coumaric acid and (-)-3-hydroxy-β-ionone were isolated. Those compounds showed phytotoxic activity and may contribute to the phytotoxic effects caused by the C. lepifera fronds. The fronds fall and accumulate on the forest floor through defoliation, and the compounds may be released into the forest soils through the decomposition process of the fronds. The phytotoxic activities of the compounds may be partly responsible for the fern’s survival.


1974 ◽  
Vol 54 (1) ◽  
pp. 89-104 ◽  
Author(s):  
R. W. SHEARD

Nitrogen, supplied as NH4NO3 to timothy (Phleum pratense L.) and bromegrass (Bromus inermis L.) or as N derived from alfalfa (Medicago sativa L.) growing in association with timothy, enhanced the utilization of surface applications of pelleted, 32P-labelled calcium phosphate. The proportion of the P in timothy derived from a single application of 60 kg P/ha increased from a range of 16% to 21% without N to a range of 38% to 43% with an application of 60 kg N/ha before spring growth and repeated after the first and second harvests. At the first two harvests, growing timothy in association with alfalfa further increased the proportion. The increase was greater at the second harvest and at the lower rates of N, amounting to an increase of one-third at applications of 15 and 30 kg N/ha. The proportion of P in the first harvest of bromegrass which was derived from a surface application was increased 17% to 26% as the rate of P was increased from 40 to 120 kg P/ha; however, N fertilizer as NH4NO3 increased fertilizer P utilization from 17% to 32% as the rate of N was increased from zero to 120 kg N/ha at the 40 kg P/ha rate, and from 26% to 57% with increasing N at the 120 kg P/ha rate. Similar data were obtained when the rates of N application were repeated for the second and third harvests. A relationship, developed between the N concentration in the grass species and the percent utilization of fertilizer P, would suggest that enhancement in utilization of P was, in part, the result of an increase in the assimilated N in the plant. The experiments illustrate that it is imperative to provide adequate N for efficient utilization of surface-applied P by perennial forage grasses.


1982 ◽  
Vol 62 (1) ◽  
pp. 125-130 ◽  
Author(s):  
UMESH C. GUPTA ◽  
C. B. WILLIS

A greenhouse study was conducted to determine the effects of liming and fumigation of soil with methyl bromide on the nutrient concentration of alfalfa (Medicago sativa L.) and timothy (Phleum pratense L.). The four lime levels used gave soil pH values of 5.1, 5.6, 6.3 and 6.7. Liming had a significant effect on yield and on concentration of all nutrients measured, except Cu. Soil fumigation increased the yield of timothy significantly, but not of alfalfa, and the plant tissue concentrations of P, S, Mo, Mn and Zn in both crops were increased significantly when compared to non-fumigation. A significant interaction was noted among crops, lime levels, and fumigation treatments, in which the alfalfa tissue P and Mn increases with fumigation were much higher at lower soil pH levels than at higher soil pH levels. Tissue K, Fe and B concentrations in timothy and N in timothy and alfalfa decreased significantly with fumigation.


1979 ◽  
Vol 57 (23) ◽  
pp. 2711-2716 ◽  
Author(s):  
Roy Turkington

Ramets of Medicago sativa L., M. Iupulina L., and Trifolium repens L. were sampled from 10-year-old fields of Bromus inermis Leyss., Phleum pratense L., and Dactylis glomerata L. The ramets were multiplied and transplanted into artificial swards in all combinations of legumes and site of origin. Differences in "performance" (in terms of dry weights and number of survivors) were shown. The most striking effect was that the number of survivors of T. repens and M. sativa (and dry weight of T. repens) was greatest when the species was transplanted back into swards of the grass species from which they had been sampled. This trend is not applicable to dry weights of M. sativa, but an alternative trend is clearly demonstrated.In a second experiment, ramets of M. sativa were sampled from 1-, 3-, and 10-year-old fields of B. inermis, P. pratense, and D. glomerata and treated as above. The most striking effect is that the performance monitored in experiment 1 may be seen developing through the 1- and 3-year-old stages, demonstrating that the microcoevolutionary processes operating within a community are rapid events.


1984 ◽  
Vol 64 (3) ◽  
pp. 403-409 ◽  
Author(s):  
UMESH C. GUPTA ◽  
J. A. MacLEOD

Field experiments were conducted at three locations in Prince Edward Island to determine the effects of various sources of S (Agri-Sul, gypsum, and Urea-Sul) on S concentration of tissue and yields of forages and cereals. Gypsum was effective in increasing the S concentration in plant tissues. Agri-Sul at 10–80 kg S∙ha−1 was generally ineffective in increasing the S concentration of forages and cereals. In the absence of added S (check treatments), the plant tissue S concentrations in alfalfa (Medicago sativa L.) and timothy (Phleum pratense L.) ranged from 0.18 to 0.39 and from 0.14 to 0.27%, respectively. In wheat (Triticum aestivum L.) and barley (Hordeum distichon L.), the S concentrations varied from 0.12 to 0.26 and from 0.13 to 0.20% in the boot stage tissue and grain, respectively, in the check treatments. In general, the S concentration was higher in the boot stage tissue than in the grain. Pea (Pisum sativum L.) seeds and vegetative material from the check treatments contained 0.19–0.24% and 0.17–0.36% S, respectively. Gypsum or Urea-Sul did not increase the yields of forages or cereals. In one instance Agri-Sul slightly increased the alfalfa yield (5–8.5%), but this was not associated with tissue S increases. Plant tissue S levels as low as 0.12–0.18% appeared to be adequate for barley, wheat, timothy, peas, and alfalfa. Key words: Sources of sulfur, tissue S, yields, cereals, forages


2004 ◽  
Vol 84 (1) ◽  
pp. 217-221 ◽  
Author(s):  
D. Spaner and A. G. Todd

Oats (Avena sativa L.) or barley (Hordeum vulgare L.) sown at increasing seeding rates of 23, 45 and 68 kg ha-1 with a timothy (Phleum pratense L.)-alfalfa (Medicago sativa L.) mixture (harvested at cereal soft dough) resulted in increasing forage yields containing decreasing alfalfa, crude protein, P and Ca percentage in the planting year. Barley out-yielded oats by 11% in the planting year. Oats or barley sown at seeding rates up to 68 kg ha-1 do not impede underseeded forage establishment or forage production in the subsequent year in central Newfoundland. The implications of farmer-directed on-farm experimentation are discussed. Key words: Hordeum vulgare L., Avena sativa L., Phleum pratense L, Medicago sativa L., underseeding


1967 ◽  
Vol 15 (3) ◽  
pp. 221-228
Author(s):  
G.C. Ennik

Mole activity, measured by numbers of molehills and nests, was progressively less under the following types of grassland management: cutting, continuous grazing, rotational grazing with low N-application, rotational grazing with high N-application. No relation between density of worms and the mole population was evident as worms were so irregularly distributed. Mole activity was little affected by a high soil-moisture level. (Abstract retrieved from CAB Abstracts by CABI’s permission)


1974 ◽  
Vol 82 (3) ◽  
pp. 497-506 ◽  
Author(s):  
G. N. Harrington ◽  
D. Pratchett

SUMMARYA series of stocking rate trials running for differing periods between 1961 and 1972 are summarized. Weight gains of steers grazed at 2·4, 1·2, 0·8 and 0·6 ha/300 kg animal on Cymbopogon/Hyparrhenia/Themeda pasture are detailed. Subtreatments included continuous and rotational grazing and the removal of the unpalatable Cymbopogon afronardus.Weight gains at 0·6 ha/animal were higher than a linear relationship between stocking rate expressed as animals/ha and weight gain would predict. This was ascribed to the dominance of the high quality grass Brachiaria decumbens at this grazing pressure.Rotational grazing was less productive than continuous grazing, because C. afronardus increased more rapidly under this management, but there was less soil erosion. Removal of C. afronardus increased cattle growth rates and gains/ha by over 40% at 0·6 ha/animal. The cost of clearing this weed should be recovered in 2 years from a commercial cattle ranch. A grazing pressure of ca. 0·8 ha/animal is expected to maximize long-term profits on C. afronardus-free Ankole rangeland and in 3 years in this trial average gains of 0·29 kg/day/animal were achieved. This was an annual production level of 131 kg/ha/annum, which compared with 53 kg/ha at 2·4 ha/animal and 143 kg/ha at 0·6 ha/animal.


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