EFFECTS OF INITIAL HARVEST DATE ON PRODUCTIVITY AND PERSISTENCE OF ALFALFA AND BROMEGRASS

1972 ◽  
Vol 52 (5) ◽  
pp. 801-804 ◽  
Author(s):  
J. D. McELGUNN ◽  
D. H. HEINRICHS ◽  
R. ASHFORD

Alfalfa (Medicago sativa L.), bromegrass (Bromus inermis Leyss.), and a mixture of the two were grown on irrigated land and subjected to six defoliation schedules in which the initial cutting date varied in time. Delaying the initial defoliation until mid-June resulted in greatest seasonal yield even though the last cutting in this schedule was made in the 1st week of September, usually considered somewhat late for cutting in Saskatchewan. Nitrogen at the rate of 112 kg/ha doubled the yield of bromegrass but did not increase the yield of the alfalfa–bromegrass mixture, indicating that nitrogen fixation was adequate for the crop. Alfalfa and the alfalfa–bromegrass mixtures yielded about 50% more forage than the N-fertilized bromegrass and three times as much as unfertilized bromegrass. At the end of the experiment, dandelions (Taraxacum officinale Weber) had invaded pure stands of alfalfa but not mixed stands of alfalfa and bromegrass.

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


1976 ◽  
Vol 54 (17) ◽  
pp. 1997-1999 ◽  
Author(s):  
W. T. McDonough

Seeds of smooth brome grass (Bromus inermis Leyss.) and alfalfa (Medicago sativa L. cultivar Ladak) were allowed to imbibe in water or solutions of polyethylene glycol (Carbowax 1540), mannitol, or sodium chloride. Seed water potentials were determined over a 72-h period after transfer of seeds to thermocouple psychrometer chambers. Seed water potentials were lower than osmotic potentials of the media, but these two potentials were not clearly related to each other. Possible reasons for the lack of gradation in response are discussed.


1965 ◽  
Vol 45 (2) ◽  
pp. 162-168 ◽  
Author(s):  
D. A. Cooke ◽  
S. E. Beacom ◽  
W. K. Dawley

Two grass–alfalfa mixtures were compared for seven consecutive years when continuously and when rotationally grazed by yearling Hereford steers. The productivity of rotationally grazed pastures as affected by annual application of fertilizers was also determined. Intermediate wheatgrass (Agropyron intermedium L.) and alfalfa (Medicago sativa L.) compared favorably with the standard mixture of bromegrass (Bromus inermis L.) and alfalfa for pasture purposes. Production of dry matter ranged from approximately 2.5 to 0.5 tons per acre in the first and seventh year respectively. Precipitation in these two years was 20.7 and 7.7 in. respectively. Rotational grazing did not increase beef production. Fertilization of bromegrass–alfalfa with 20 lb of N per acre and with 20 lb of N + 40 lb of P2O5 per acre resulted in average yearly increase of 18 and 32 lb of beef per acre respectively. Fertilization of intermediate wheatgrass– alfalfa resulted in comparable increase of 1 and 26 lb of beef per acre respectively.


1984 ◽  
Vol 64 (3) ◽  
pp. 677-682 ◽  
Author(s):  
J. WADDINGTON ◽  
S. BITTMAN

Forages were seeded with and without a Polish rapeseed (Brassica campestris L.) companion crop at two dates in each of 3 yr. In each test, forage seedlings grew much better where seeded alone; growth under the companion crop varied from poor to fairly good, depending on the year and the forage species. Russian wild ryegrass (Elymus junceus Fisch.) established poorly under rapeseed. Bromegrass (Bromus inermis Leyss.) establishment was satisfactory in all tests, although production in the year following was usually much less than where it was seeded alone. Alfalfa (Medicago sativa L.) and sainfoin (Onobrychis viciaefolia Scop.) establishment was poor to fair under rapeseed. A mid-May seeding date with the companion crop resulted in better forage growth by fall than a later seeding date. A feature of all tests was the severe infestation of volunteer rapeseed the year following seeding in all forages except bromegrass. Because of growth suppression during the establishment year, and difficulties with volunteer rapeseed in legumes in the year following establishment, it is suggested that Polish rapeseed is not a good companion crop when establishing legumes and Russian wild ryegrass.Key words: Bromegrass, alfalfa, Russian wild ryegrass, sainfoin, rapeseed, companion crops, forage establishment


1991 ◽  
Vol 71 (4) ◽  
pp. 1029-1037 ◽  
Author(s):  
S. Bittman ◽  
J. Waddington ◽  
D. H. McCartney

This study was conducted to evaluate the yield and persistence of seven contrasting alfalfa (Medicago sativa L. sensu lato) strains growing in binary mixture with smooth bromegrass (Bromus inermis Leyss.) under different fertilizer and cutting managements. The alfalfa strains were seeded in mixtures with smooth bromegrass in 1980 in northeast Saskatchewan and harvested each year, 1982 through 1987. Two fertilizer treatments (0 and 18 kg ha−1 P) and two cutting managements (2 and 3-4 cuts) were imposed annually. The application of P fertilizer increased the total yield (6-yr average) from 1.47 t ha−1 in control plots to 2.52 t ha−1 in the fertilized plots. Frequent cutting reduced average total yield from 2.59 t ha−1 (2-cut system) to 1.4 t ha−1. Fertility and cutting management did not affect the proportion of alfalfa or weeds in the harvested herbage. The alfalfa strain significantly affected total yield and the proportion of alfalfa and weeds throughout the years of this study. The strain ScMf3713, a M. sativa subsp. falcata (L.) Arcang. type, outyielded all entries during the last 3 yr of this study. The study suggests that alfalfa strains of the falcata subspecies germplasm showed superior long-term performance when the alfalfa was grown in a binary mixture with bromegrass. Key words: Medicago sativa L., falcata, Bromus inermis Leyss., phosphorus, simulated grazing


2002 ◽  
Vol 82 (2) ◽  
pp. 337-347 ◽  
Author(s):  
F. Katepa-Mupondwa ◽  
A. Singh ◽  
S. R. Smith Jr. ◽  
W. P. McCaughey

The continuing development of adapted alfalfa (Medicago sativa L.) cultivars that combine high yield, disease resistance, winterhardiness, and grazing tolerance is of great value to the beef cattle industry in western Canada. This study evaluated alternative management strategies and plant measurements for assessing the grazing tolerance of alfalfa cultivars over 3 yr. Seven hay-type, four pasture-type, and one dual-purpose (hay or graze) cultivars were established in pure stands and in mixture with meadow bromegrass (Bromus riparius Rehm. syn.B. biebersteinii Roem & Schult). Stands were defoliated under continuous or rotational stocking with beef cattle (Bos taurus). Plants we reassessed for winterhardiness, percent alfalfa within row, percent alfalfa cover, basal area and species composition. Continuous stocking resulted in consistent and significant differences between cultivars, whether persistence was measured as percent alfalfa within row, percent cover and basal area, in both pure and mixed stands (P < 0.05). High correlations between measurement techniques (r = 0.74 to 0.99; P < 0.05) confirmed the value of alfalfa within row and alfalfa cover as time and labour efficient methods to evaluate grazing persistence. Competition between alfalfa and meadow bromegrass resulted in a significant confounding effect under rotational stocking (P < 0.05). Winter injury was identified as an important criteria to evaluate for grazing persistence. The most grazing-tolerant genotypes were selected for subsequent breeding efforts to combine winterhardiness, grazing tolerance, and high productivity. This research showed that grazing method, grass competition, and severe winter conditions strongly influence differential survival of alfalfa cultivars under grazing in western Canada. Key words: Alfalfa, grazing tolerance, grazing systems, Medicago sativa L., Medicago falcata L. Arcang, persistence


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