Effects of limestone on pasture yields and the pH of two krasnozems in north-western Tasmania

1982 ◽  
Vol 22 (115) ◽  
pp. 100
Author(s):  
BA Rowe

Ground limestone and molybdenum were applied to well fertilized, clover based, perennial pastures established on krasnozems with a pH of 5.5 at Elliott and Central Castra in north-western Tasmania. The experiments began in 1971 and continued until June 1976 at Central Castra and April 1979 at Elliott. Limestone was applied in increments of 2.5 t/ha over several years to achieve a maximum cumulative application of 12.5 t/ha at Central Castra and 15.0 t/ha at Elliott. These broadcast applications of limestone increased the pH of the surface 75 mm of the soils by 0.1 units for each tonne of limestone applied per hectare. Large increases in soil pH were recorded in the surface 150 mm of the soils when measured 18 months after the last limestone application but the increases were small (less than 0.2 pH units) below this depth. Limestone applications totalling 7.5-15.0 t/ha significantly increased pasture dry matter yields in more than half the harvests taken in summer, autumn and early spring but not in late spring. These increases, which ranged from 200-1200 kg/ha, are of potential agricultural importance since they occurred when feed supplies often restrict production from dairy herds grazing dryland pasture in northwestern Tasmania. The factor or factors limiting production on the unlimed plots have not been identified but, contrary to previous reports, the yield increases from the limestone applications were not due to an increase in the availability of molybdenum associated with the increase in soil pH.

1982 ◽  
Vol 22 (115) ◽  
pp. 100
Author(s):  
BA Rowe

Ground limestone and molybdenum were applied to well fertilized, clover based, perennial pastures established on krasnozems with a pH of 5.5 at Elliott and Central Castra in north-western Tasmania. The experiments began in 1971 and continued until June 1976 at Central Castra and April 1979 at Elliott. Limestone was applied in increments of 2.5 t/ha over several years to achieve a maximum cumulative application of 12.5 t/ha at Central Castra and 15.0 t/ha at Elliott. These broadcast applications of limestone increased the pH of the surface 75 mm of the soils by 0.1 units for each tonne of limestone applied per hectare. Large increases in soil pH were recorded in the surface 150 mm of the soils when measured 18 months after the last limestone application but the increases were small (less than 0.2 pH units) below this depth. Limestone applications totalling 7.5-15.0 t/ha significantly increased pasture dry matter yields in more than half the harvests taken in summer, autumn and early spring but not in late spring. These increases, which ranged from 200-1 200 kg/ha, are of potential agricultural importance since they occurred when feed supplies often restrict production from dairy herds grazing dryland pasture in northwestern Tasmania. The factor or factors limiting production on the unlimed plots have not been identified but, contrary to previous reports, the yield increases from the limestone applications were not due to an increase in the availability of molybdenum associated with the increase in soil pH.


1965 ◽  
Vol 5 (19) ◽  
pp. 417 ◽  
Author(s):  
FC Crofts

Nitrogen fertilizer applied as sulphate of ammonia at 23 to 92 pounds of nitrogen an acre in early spring made forage available for grazing six weeks earlier and returned 19 to 22 pounds of additional dry matter (with 14 to 19 per cent crude protein) for each pound of fertilizer nitrogen applied. However, the responses to nitrogen fertilizer became progressively less over the late spring and summer period and the responses in the autumn, when additional forage is urgently needed for winter reserves, were relatively small.


2021 ◽  
pp. 1-17
Author(s):  
Leo Roth ◽  
José Luiz C. S. Dias ◽  
Christopher Evans ◽  
Kevin Rohling ◽  
Mark Renz

Garlic mustard [Alliaria petiolata (M. Bieb.) Cavara & Grande] is a biennial invasive plant commonly found in the northeastern and midwestern United States. Although it is not recommended to apply herbicides after flowering, land managers frequently desire to conduct management during this timing. We applied glyphosate and triclopyr (3% v/v and 1% v/v using 31.8% and 39.8% acid equivalent formulations, respectively) postemergence to established, second-year A. petiolata populations at three locations when petals were dehiscing, and evaluated control, seed production and seed viability. Postemergence glyphosate applications at this timing provided 100% control of A. petiolata by 4 weeks after treatment at all locations whereas triclopyr efficacy was variable, providing 38-62% control. Seed production was only reduced at one location, with similar results regardless of treatment. Percent seed viability was also reduced, and when combined with reductions in seed production, we found a 71-99% reduction in number of viable seed produced plant-1 regardless of treatment. While applications did not eliminate viable seed production, our findings indicate that glyphosate and triclopyr applied while petals were dehiscing is a viable alternative to cutting or hand-pulling at this timing as it substantially decreased viable A. petiolata seed production. Management Implications Postemergence glyphosate and triclopyr applications in the early spring to rosettes are standard treatments used to manage A. petiolata. However, weather and other priorities limit the window for management, forcing field practitioners to utilize more labor-intensive methods such as hand-pulling. It is not known how late in the development of A. petiolata these herbicides can be applied to prevent viable seed production. Since prevention of soil seedbank replenishment is a key management factor for effective long-term control of biennial invasive species, we hypothesized late spring foliar herbicide applications to second year A. petiolata plants when flower petals were dehiscing could be an effective management tool if seed production or viability is eliminated. Our study indicated that glyphosate applications at this timing provided 100% control of A. petiolata plants by 4 weeks after treatment at all locations, whereas triclopyr efficacy was inconsistent. Although both glyphosate and triclopyr decreased viable seed production to nearly zero at one of our three study locations, the same treatments produced significant amounts of viable seed at the other two locations. Our findings suggest late spring glyphosate and triclopyr applications should not be recommended over early spring applications to rosettes for A. petiolata management, as our late spring application timing did not prevent viable seed production, and may require multiple years of implementation to eradicate populations. Nonetheless, this application timing holds value in areas devoid of desirable understory vegetation compared to no management practices or mechanical management options including hand-pulling when fruit are present, as overall viable seed production was reduced to similar levels as these treatments.


1963 ◽  
Vol 14 (6) ◽  
pp. 778 ◽  
Author(s):  
DE Harrison

During the late winter and early spring of 1960, and again to a lesser extent in 1961 and 1962, many lettuce crops in the Murray Valley area of north-western Victoria were seriously affected by a disease characterized by blackening, dry rotting, and collapse of the affected leaves. The incidence of disease varied from about 10% up to practically complete destruction of some plantings. A yellow bacterium was consistently isolated from affected plants and proved to be pathogenic to lettuce. Laboratory studies have shown that the organism agrees closely with the recorded description of Xanthomonas vitians (Brown) Dowson, which has not, apparently, been previously studied in Australia.


2010 ◽  
Vol 24 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Vince M. Davis ◽  
Greg R. Kruger ◽  
Bryan G. Young ◽  
William G. Johnson

Horseweed (Conyza canadensis) is a common weed in no-till crop production systems. It is problematic because of the frequent occurrence of biotypes resistant to glyphosate and acetolactate synthase (ALS)-inhibiting herbicides and its ability to complete its life cycle as a winter or summer annual weed. Tactics to control horseweed while controlling other winter annual weeds routinely fail; herbicide application timing and spring emergence patterns of horseweed may be responsible. The objectives of this experiment were to (1) determine the influence of fall and spring herbicides with and without soil residual horseweed activity on spring-emerging glyphosate-resistant (GR) horseweed density and (2) evaluate the efficacy and persistence of saflufenacil on GR horseweed. Field studies were conducted in southern Indiana and Illinois from fall 2006 to summer 2007 and repeated in 2007 to 2008. Six preplant herbicide treatments were applied at four application timings: early fall, late fall, early spring, and late spring. Horseweed plants were counted every 2 wk following the first spring application until the first week of July. Horseweed almost exclusively emerged in the spring at both locations. Spring horseweed emergence was higher when 2,4-D + glyphosate was fall-applied and controlled other winter annual weeds. With fall-applied 2,4-D + glyphosate, over 90% of the peak horseweed density was observed before April 25. In contrast, only 25% of the peak horseweed density was observed in the untreated check by April 25. Starting from the initiation of horseweed emergence in late March, chlorimuron + tribenuron applied early fall or early spring, and spring-applied saflufenacil at 100 g ai/ha provided greater than 90% horseweed control for 12 wk. Early spring–applied saflufenacil at 50 g ai/ha provided 8 wk of greater than 90% residual control, and early spring–applied simazine provided 6 wk of greater than 90% control. When applied in late spring, saflufenacil was the only herbicide treatment that reduced horseweed densities by greater than 90% compared to 2,4-D + glyphosate. We concluded from this research that fall applications of nonresidual herbicides can increase the rate and density of spring emerging horseweed. In addition, spring-applied saflufenacil provides no-till producers with a new preplant herbicide for foliar and residual control of glyphosate- and ALS-resistant horseweed.


Author(s):  
G.W. Sheath ◽  
R.W. Webby ◽  
W.J. Pengelly

Comparisons of controlling late spring to early summer pasture growth on either easy or steep contoured land with either a fast rotation or continuous grazing policy were made in self-contained farmlets for two years. Pasture control was maintained over more land by controlling steep land first and with continuous grazing. Animal performances (ewes, steers) were generally similar for the mid-November to early January treatment period, and subsequently until May shearing. In the first year better animal performances occurred in "steep control" farmlets during winter and early spring, but this was less evident in the second year. Priority control of steep land during late spring-early summer is recommended because of likely longer-term benefits in pasture composition,density and production. Quick rotation grazing through the period provides a better ability to recognise and manage pasture quantities and should be adopted if summer droughts are anticipated. For well fenced properties in summer-wet areas and with integrated stock grazing, continuous grazing during late spring-early summer may be equally suitable. Keywords: hill country, grazing management, pasture control


2007 ◽  
Vol 13 ◽  
pp. 259-262
Author(s):  
K.N. Tozer ◽  
S. Ates ◽  
N.R. Mapp ◽  
M.C. Smith ◽  
R.J. Lucas ◽  
...  

Pasture growth, botanical composition and sheep grazing preference were measured over 20 months in tall fescue (cultivar Advance), without endophyte (Nil) or infected with AR542 (MaxPTM) endophyte, and clover pastures sown into a dryland soil, Canterbury, New Zealand. Pastures were rotationally grazed with sheep, with grazing preference for the two endophyte treatments measured in late autumn and early spring. Annual dry matter production from April 2004 to April 2005 was not significantly different between AR542 (6293 kg DM/ha) and Nil (5864 kg DM/ha) tall fescue. The number of tall fescue plants/m2 and their basal diameter was greater for AR542 (35 plants/m2, 7.5 cm diameter) than Nil endophyte tall fescue (28 plants/m2, 6.8 cm diameter). AR542 endophyte tall fescue pastures had fewer weeds, mainly annual grasses, than Nil endophyte pastures throughout the trial. Grazing preference, measured by the number of sheep grazing each plot, and decline in pasture height did not differ between Nil and AR542 tall fescue. Keywords: tall fescue, novel endophyte, AR542, botanical composition, weed, grazing preference


1970 ◽  
Vol 74 (1) ◽  
pp. 139-145
Author(s):  
A. P. Draycott ◽  
R. Holliday

SUMMARYSix field experiments (1963–8) in eastern England compared solid fertilizer with liquid fertilizer or anhydrous ammonia for sugar beet. Two glasshouse experiments investigated the interaction between depth of placement of fertilizer and soil moisture.Yields of sugar were the same from broadcast solid and sprayed liquid in all the experiments, but nitrogen uptake by the crop was less from liquid than from solid. Three experiments tested placement of liquid 4 in to the side and either 2 or 6 in below the seed. Plants with deep-placed fertilizer consistently out-yielded those with shallowplaced fertilizer, but yields were never significantly different from broadcast solid fertilizer. Dry-matter yields of sugar beet grown in containers indoors showed that the crop responded to deep placement when the surface soil was watered infrequently.With anhydrous ammonia injected during seed-bed preparation, sugar yield and nitrogen uptake were the same as with solid fertilizer in the seed bed, and were greater than with anhydrous ammonia injected in the ploughed land during early spring. A side-band injection of anhydrous ammonia before singling gave a crop containing as much nitrogen at harvest as, but less sugar than, nitrogen applied in the seed bed.


2018 ◽  
Vol 58 (6) ◽  
pp. 1043 ◽  
Author(s):  
A. Jonker ◽  
G. Molano ◽  
E. Sandoval ◽  
P. S. Taylor ◽  
C. Antwi ◽  
...  

Elevated water-soluble carbohydrate (WSC) concentration in the diet may affect rumen fermentation and consequently reduce methane (CH4) emissions. The objective of the present study was to determine CH4 emissions from male sheep (8 per treatment) in respiration chambers for 48 h and fed either a conventional diploid (CRG), a high-sugar diploid (HSG) or a tetraploid (TRG) perennial ryegrass cultivar, each offered at 0.7 or 1.0 kg dry matter (DM)/day during periods in early spring 2013 (P1), early autumn 2014 (P2) and late spring 2014 (P3). There was a significant (P < 0.001) interaction between cultivar and period for CH4 yield (g/kg DM intake). In P1 yield was 9% lower (P = 0.007) for sheep fed HSG than for sheep fed CRG or TRG, in P2 yield was 16% lower (P < 0.001) for sheep fed TRG than that for sheep fed CRG or HSG, and in P3 yield was 15% lower (P < 0.001) for sheep fed TRG than that for sheep fed CRG, with HSG-fed sheep being intermediate and not significantly different from either CRG or TRG. Despite there being a cultivar × period interaction, overall, CH4 yield was lower for sheep fed HSG or TRG than for sheep fed CRG (P < 0.001). There were no cultivar × level of feed offer interactions and, overall, yield of CH4 was 9% higher (P = 0.003) for sheep offered 0.7 than for sheep offered 1.0 kg DM/day. In each period, one or other of the high-WSC diploid (HSG) or tetraploid cultivars (TRG) gave lower CH4 yields than did the control diploid (CRG), suggesting that CH4 yield is reduced by characteristics of these cultivars. However, the effect was not consistently associated with either cultivar and could not be attributed to higher forage water-soluble carbohydrate concentrations.


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