Effect of sowing time on the establishment and early production of tropical and temperate pasture mixtures under irrigation in south-eastern Queensland

1981 ◽  
Vol 21 (111) ◽  
pp. 410
Author(s):  
KF Lowe ◽  
TM Bowdler ◽  
JC Mulder

The most effective time to sow irrigated perennial pastures containing tropical and temperate species was investigated over three years at Gatton, south-eastern Queensland. Three mixtures were sown each month between September and June and in split sowings where the tropical species were sown in September or March, and the temperate species in May. Autumn sowings produced the most seedlings of sown species 40 d after sowing. Of the autumn months, May was the most suitable, with an establishment of 181 plants/m2 and a weed population of only 19 plants/m2. Tropical grass establishment was less than 8 plants/m2 from all sowing times. A considerable proportion of tropical grass sown in autumn appeared in spring. Split sowings were not as effective as autumn sowings and favoured the tropical species, which were sown first. Dry matter yield of sown species in the establishment year varied from 0.9 t/ha for February sowings to 12.0 t/ha for April sowings; weed yields varied from 5.8 t/ha for September sowings to 0.8 t/ha for May sowings. Tropical grass contribution was greatest from the split sowing in which the tropical species were sown in September. Temperate species yields were highest from May sowings. In the second year yields of temperate species declined substantially, mainly because of poor persistence of ryegrass. Although tropical grass yields increased in all treatments, this increase was not sufficient in the autumn sowings to compensate for the low ryegrass yields.

1983 ◽  
Vol 34 (4) ◽  
pp. 367 ◽  
Author(s):  
I Vallis

Unground legume materials labelled with 15N were applied to the soil surface under a Rhodes grass pasture in south-eastern Queensland and the recovery of the applied 15N was followed over periods of 1-3 years. Comparisons were made between two legumes, Macroptiliurn atropurpureurn cv. Siratro and Desrnodiurn intorturn cv. Greenleaf, between leaf and stem materials of different nitrogen (N) concentrations (0.5-3.8% N), and between fresh and dried materials. After 1 year, 15N in the applied materials had decreased by 25-91%, and 7-25% was recovered in the Rhodes grass. Except for leaf material of Greenleaf, these changes showed a positive, non-linear relationship to the percentage of N (%N) in the applied materials. The changes for leaves of Greenleaf were less than would be predicted from their %N. Drying Siratro leaves and stems before applying them to the soil surface did not significantly affect the above changes. For N-poor materials (0.5-1.8% N) applied at 380-1360 g dry matter m-2, uptake of 15N by Rhodes grass was greater in the second year than in the first year, whereas for N-rich materials (3.8%N) applied at 140 g dry matter m-2 uptake of 15N in the second and third years was only 23 and 12% respectively of that in the first year.


1968 ◽  
Vol 8 (31) ◽  
pp. 177 ◽  
Author(s):  
RJ Jones ◽  
Davies J Griffiths ◽  
RB Waite ◽  
IF Fergus

Five irrigated pasture mixtures (four containing tropical and temperate species and one containing only temperate species (winter mixture) ) were compared under grazing at three nitrogen levels -nil, 100, and 300 lb N an acre a year as urea-over a four-year period 1960-1963. Pastures were grazed for approximately one week every six weeks with a twelve-week rest period in the winter of 1962 and 1963. Under this management mean annual yields of dry matter increased from 15,700 lb to 25,000 lb an acre over the four-year period. Pasture growth rates varied from over 90 lb DM an acre a day in early summer to 10-40 lb DM an acre a day in winter due to variations in radiation and temperature. Urea increased pasture dry matter yields and also the yields of nitrogen measured in 1961 and 1962. Mean response was 19 lb and 14.5 lb DM/lb N applied at the N100 and N300 rates respectively. Yield of nitrogen was increased by a mean of 79 lb an acre a year by application of urea, but there was no significant difference between rates. Dry matter responses to urea were small in winter and spring and large in summer and autumn. The N300 rate reduced the yield of white clover in the first two years of the pasture, but there was no reduction in the yield of white clover at the N100 rate compared with the N0 treatment. There were no significant differences in yield between the pasture mixtures in the establishment year. In subsequent years mixtures containing summer and winter species outyielded (P<0.001) the winter mixture, particularly in summer and autumn. The pattern of production was similar for all mixtures and there was no significant difference between mixtures in yield of nitrogen. Chloris gayana Kunth CV. Samford and Setaria sphacelata (Schum) Stapf and C. E. Hubbard CV. Nandi. were the most successful summer grasses and Bromus unioloides (Willd.) H.B.K. cv. Priebes, the best winter grass. Three Paspalum species failed to compete with the Setaria and three winter grasses were low yielding after the first year. Trifolium repens L. CV. Ladino was the only successful legume of three winter and three summer legumes sown. It enabled yields of 400 lb N an acre a year to be achieved, increased total soil nitrogen, and made an estimated contribution of 760-810 lb N an acre over the four-year period. It is considered to be the key species for irrigated pastures in south-eastern Queensland.


1997 ◽  
Vol 37 (5) ◽  
pp. 537 ◽  
Author(s):  
D. J. Donaghy ◽  
J. M. Scott ◽  
W. J. Fulkerson

Summary. The present study investigated, in a subtropical environment, the timing of defoliation treatments in spring and summer irrigation management on the survival of perennial (Lolium perenne cv. Yatsyn) and biennial (L. multiflorum cv. Noble) ryegrass in a mixed ryegrass–white clover (Trifolium repens) pasture over the first summer, and seedling recruitment the following autumn. Defoliation options were related to various ryegrass plant development stages such as the number of leaves per tiller attained during regrowth, stem elongation and seed set. The criterion for timing of frequent defoliation was 1 leaf/tiller regrowth and infrequent defoliation 3 leaves/tiller. Both pasture types were defoliated either frequently or infrequently at specific times from sowing to mid summer. Half the plots were irrigated from 30 November to 6 April while the remaining plots were not irrigated over this period. There was no survival of biennial ryegrass plants into autumn of the second year and pasture production was entirely from seedling recruitment of seed set in the previous spring. The maximum seedling recruitment (plant population 89% of spring in establishment year) was achieved by infrequent defoliation in mid spring and then cessation of defoliation until mid summer to allow plants to set seed. However, this resulted in a production loss of 3094 kg dry matter/ha of ryegrass and clover. In contrast, production of perennial ryegrass in the second year was reliant almost exclusively on individual ryegrass plants surviving the summer, as there was little seed set and virtually no seedling recruitment. There would appear to be 2 contrasting defoliation requirements to optimise perennial ryegrass persistence. Infrequent defoliation from sowing to early spring (22 March–2 September) and frequent defoliation in early summer (19 November–3 February) resulted in maximum plant survival and minimum tropical grass incursion. Frequent, compared with infrequent, defoliation up to 2 September decreased root dry matter in February by 45% to 1.66 g dry matter/plant. However in early summer, frequent defoliation maximised survival, presumably by reducing shading by tropical grasses, and preventing a closed canopy which encourages ‘rust’ infestation of the ryegrass. Irrigation of ryegrass over summer, in situations likely to become waterlogged, will only be of benefit in dry years and if scheduling is frequent enough to benefit ryegrass rather than tropical grass. These results highlight the importance of maintaining an infrequent defoliation interval to maximise persistence of perennial ryegrass in the subtropics. More frequent defoliation may be necessary in late spring/early summer to reduce the impact of leaf rust.


2017 ◽  
Vol 14 (2) ◽  
pp. 155-160
Author(s):  
MAR Sharif ◽  
MZ Haque ◽  
MHK Howlader ◽  
MJ Hossain

The experiment was conducted at the field laboratory of the Patuakhali Science and Technology University, Patuakhali, Bangladesh during the period from November, 2011 to March 2012 under the tidal Floodplain region to find out optimum sowing time for the selected three cultivars (BARI Sharisha-15, BINA Sharisha-5 and BARI Sharisha-9). There were four sowing dates viz. 30 November, 15 December, 30 December and 15 January. Significant variations due to different sowing dates were observed in plant height, total dry matter, leaf area index, number of siliqua plant-1, seeds silique-1, 1000-grain weight, grain yield and HI. Results showed that the highest grain yield (1.73 t ha-1) was obtained from the first sowing (30 November) with BINA Sharisha-5 and it was significantly different from the yields of all other combination.J. Bangladesh Agril. Univ. 14(2): 155-160, December 2016


Author(s):  
Svetlana Vasil'evna Ivanova ◽  
Olga Vasil'evna Kurdakova ◽  
Aminat Msostovna Konova ◽  
Anna Yurievna Gavrilova

In the course of the experiment, the effect of increasing doses of nitrogen fertilizers on the yield of clover of the meadow variety Nadezhny, entered in the State Register of Breeding Achievements in 2012, was analyzed. A comparison is also made of this influence with the timothy of the meadow variety Leningradskaya 204. It was established that the pre-sowing introduction of mineral nitrogen for clover and timothy has influenced the productivity of these crops, but the nature of this effect varies depending on the type of grass. The introduction of N20 against the background of P30K90, which provided an increase in control of 51.2% for green mass and 33.6% for air-dry matter, was optimal for meadow clover of the first year of life. For grassland clover second year of life, the best option was N0P30K90, which gave an increase of 56.6% to the control on green mass and 50.6% on air-dry matter. A further increase in the dose of nitrogen on the options caused a decrease in yield increase. Timothy meadow for two years of life was traced responsiveness to the provision of nitrogen. The most productive in all respects was the option N120P30K90.    


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
J. J. H. Nati ◽  
M. B. S. Svendsen ◽  
S. Marras ◽  
S. S. Killen ◽  
J. F. Steffensen ◽  
...  

AbstractHow ectothermic animals will cope with global warming is a critical determinant of the ecological impacts of climate change. There has been extensive study of upper thermal tolerance limits among fish species but how intraspecific variation in tolerance may be affected by habitat characteristics and evolutionary history has not been considered. Intraspecific variation is a primary determinant of species vulnerability to climate change, with implications for global patterns of impacts of ongoing warming. Using published critical thermal maximum (CTmax) data on 203 fish species, we found that intraspecific variation in upper thermal tolerance varies according to a species’ latitude and evolutionary history. Overall, tropical species show a lower intraspecific variation in thermal tolerance than temperate species. Notably, freshwater tropical species have a lower variation in tolerance than freshwater temperate species, which implies increased vulnerability to impacts of thermal stress. The extent of variation in CTmax among fish species has a strong phylogenetic signal, which may indicate a constraint on evolvability to rising temperatures in tropical fishes. That is, in addition to living closer to their upper thermal limits, tropical species may have higher sensitivity and lower adaptability to global warming compared to temperate counterparts. This is evidence that freshwater tropical fish communities, worldwide, are especially vulnerable to ongoing climate change.


Author(s):  
V. A. Petruk

The results of field studies for 2017 - 2019 are presented. yields of perennial grasses sown at different times of the growing season. Spring, summer, and winter sowing periods were compared. Alfalfa, clover, rump, and also their mixtures were sown in 2017 under the cover of barley. The value of the cover crop yield of spring and summer sowing periods did not differ significantly and amounted to 4-5 t / ha of absolutely dry matter. Winter barley crops have not formed. On average, over 2 years of use, the highest yields were observed in alfalfa-crust grass mixtures - 3.4 t / ha of absolutely dry matter. The lowest yield was obtained in the single-species seeding of the rump. Correspondingly, in the spring, summer and winter periods of sowing, the yield of rump was 1.6; 1.1 and 1.3 t / ha. With a late sowing period, the yield of perennial grasses is significantly lower compared to spring and summer. With winter sowing periods, the yield was the highest for grass stands of alfalfa and alfalfacrust grass mixture - 2.3 and 2.4 t / ha. It should be noted that in the second year of use, the yield by the sowing dates in single-species crops and grass mixtures is leveled. The winter crops of perennial grasses in the first year of use formed a low yield. Only in the second year (third year of life) the productivity of perennial grasses of winter sowing began to increase. Consequently, in the area under perennial grasses of the winter sowing period, during one growing season (the next year after sowing), the crop was not actually formed. Based on the data obtained, production can be recommended for spring and summer planting of perennial grasses under the cover of barley. The winter sowing period provides economically valuable crop yields only by the third year of life.


2012 ◽  
Vol 36 (2) ◽  
pp. 227-231
Author(s):  
Nargis Jahan ◽  
M M Golam Adam

A field experiment was carried out at University of Dhaka from March to July, 2011 to study the effect of time of sowing on the growth and yield of BARI mung-5. The treatments consisted of three dates of sowing viz. March 15, April 15 and May 15. The crop responded significantly to sowing time and 15 April sowing seeds produced plants having maximum plant height (68.4 cm), leaves/plant (29.33), total dry matter/plant (17.99), branches/plant (8.17), pods/plant (11.33), pod length (8.78 cm), seeds/pod (11.17), 1000 seed weight (46.52 g), seed yield/plant (5.33 g), yield/ha (1.77 t) and harvest index (29.58 %) at harvest. The seed yield decreased by 36.8 and 49.9% when seed sown early (15 March) or late (15 May) due to production of lower yield components.   DOI: http://dx.doi.org/10.3329/jbas.v36i2.12966   Journal of Bangladesh Academy of Sciences, Vol. 36, No. 2, 227-231, 2012    


1982 ◽  
Vol 22 (115) ◽  
pp. 76 ◽  
Author(s):  
KA Boundy ◽  
TG Reeves ◽  
HD Brooke

The effect of serial planting on dry matter production, leaf area, grain yield and yield components cf Lupinus angustifoiius (cvv. Uniwhite, Uniharvest and Unicrop) and L. albus (cv. Ultra) was investigated in field plots at Rutherglen in 1973 and 1974. Delayed planting reduced dry matter production of all cultivars, and leaf area for Ultra. Differences in dry matter partitioning were observed between the late flowering Uniharvest, and the early flowering Unicrop and Ultra. In Uniharvest, delayed plantings resulted in a greater proportion of total dry matter being produced during the flowering phase, whereas the reverse was true for Unicrop and Ultra. The later flowering cultivars showed marked grain yield and yield component reduction with later sowing. Yields were reduced by 160.6 kg/ha and 222.5 kg/ha for each week's delay in sowing Uniharvest and Uniwhite, respectively. This effect was offset in the early flowering cultivars by greater development of lateral branches. In addition, when Unicrop and Ultra were planted in April, pod and flower abortion on the main stem resulted from low temperatures at flowering time. Optimum sowing time was early April for Uniwhite and Uniharvest, and early May for Unicrop and Ultra. Excellent vegetative growth under ideal moisture conditions highlighted the poor harvest indices of lupins and the scope for genetic improvement in the genus.


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