Changes in bicarbonate-extractable phosphorus of a basalt-derived duplex soil associated with applications of superphosphate to pasture grazed by sheep

1999 ◽  
Vol 50 (4) ◽  
pp. 547 ◽  
Author(s):  
J. W. D. Cayley ◽  
G. A. Kearney
Keyword(s):  
Perennial Ryegrass ◽  
Empirical Model ◽  
Soil Phosphorus ◽  
Subterranean Clover ◽  
Single Superphosphate ◽  
Olsen P ◽  
Current Value ◽  
Stocking Rates ◽  
Similar Soil ◽  
Extractable Soil

The effect of 3 successive yearly applications of single superphosphate (SSP) to pastures on bicarbonate- extractable soil phosphorus (Olsen P) was measured. The soil was a duplex derived from basalt and the pastures, based on perennial ryegrass and subterranean clover, were continuously stocked with sheep. Six levels of SSP were compared at 3 stocking rates. The amount of P applied annually varied from 0 to 100 kg/ha. These data were used to create an empirical model which used the current value for Olsen P (Olsen Pn), the amount of P applied as fertiliser that year (fert Pn), and a lower limit for Olsen P for basalt-derived duplex soils (Olsen Plow) to predict the Olsen P for the following year (Olsen Pn+1). The model had the form: Olsen Pn+1 = Olsen P low + afert Pn + b(Olsen Pn – Olsen Plow). Olsen P low was fixed at 3 mg P/kg soil, and the coefficients a and b were 0.0995 and 0.8020. The model accounted for 96.6% of the variance in Olsen Pn+1. This model was tested at the same site at 2 other periods: when fertiliser was withheld for 3 years and again after applications of SSP were resumed. The model was also tested against data from another experiment conducted on a similar soil. The model can estimate the amount of fertiliser required to maintain the P status of the soil and predicts that to increase Olsen P by 1 unit in the following year it is necessary to apply 10 kg P/ha in excess of soil maintenance requirement.

Comparison of single superphosphate and superphosphate coated with bauxite residue for subterranean clover production on phosphorus-leaching soils

Soil Research ◽  
2000 ◽  
Vol 38 (3) ◽  
pp. 735 ◽  
Author(s):  
Robert Summers ◽  
Martin Clarke ◽  
Tim Pope ◽  
Tim O'Dea
Keyword(s):  
Field Experiment ◽  
Soil Phosphorus ◽  
Bauxite Residue ◽  
Phosphorus Uptake ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Single Superphosphate ◽  
Glasshouse Experiment ◽  
The Impact ◽  
Coated Granules

Bauxite residue from alumina refining was used to coat granules of single superphosphate to reduce the leaching of phosphorus in coarse, sandy soils for pastures in high rainfall areas of south-western Australia (>800 mm annual average). The impact of coating the superphosphate on the leaching of phosphorus was measured in a glasshouse experiment and the effectiveness of the fertiliser using dry herbage yield of subterranean clover (Trifolium subterraneum) was measured in a field experiment. The glasshouse experiment measured the effect of coating the superphosphate with bauxite residue at 0, 5, 10, 15, 20, 25, 30, 35, and 40% by weight. A coating of 25% (by weight) was chosen for the field experiment. In the glasshouse experiment, the coated granules were applied to columns of soil, where subterranean clover was grown under leaching conditions. A coating of 30%, by weight, reduced leaching of single superphosphate by about half. Increasing the coating of bauxite residue also increased the phosphorus uptake and increased the plant growth. In the field trial, the effectiveness of single superphosphate with a bauxite residue coating of 25% by weight was increased on average by 100% in Year 1, 303% in Year 2, and 158% in Year 3, relative to freshly applied single superphosphate. The bauxite residue coating also increased the phosphorus content of the herbage in a similar manner to the increases in yield. Limited soil phosphorus tests showed only minor increases in the residues of phosphorus where the superphosphate had been coated with bauxite residue.

Tactical versus continuous stocking in perennial ryegrass-subterranean clover pastures grazed by sheep in south-western Victoria. 1. Stocking rates and herbage production

2001 ◽  
Vol 41 (8) ◽  
pp. 1099 ◽  
Author(s):  
R. A. Waller ◽  
P. W. G. Sale ◽  
G. R. Saul ◽  
G. A. Kearney
Keyword(s):  
Perennial Ryegrass ◽  
Dry Matter ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Stocking Rate ◽  
Soil Fertility Status ◽  
Western Victoria ◽  
Terminal Sire ◽  
Autumn And Winter ◽  
Stocking Rates

A 4-year field experiment was carried out in south-western Victoria to determine whether tactical stocking might improve perennial ryegrass (Lolium perenne L.) persistence and prime lamb production, compared with the more common practice of year-around continuous stocking. Tactical stocking consisted of variable length summer, autumn and winter rotations and continuous stocking in spring. The 2 grazing strategies were compared on 2 contrasting pastures: an upgraded pasture, sown with newer cultivars of perennial ryegrass and subterranean clover (Trifolium subterraneum L.) with 26 kg phosphorus/ha.year, and a more typical naturalised perennial ryegrass pasture receiving 6 kg phosphorus/ha.year. Paddocks were grazed by Border Leicester x Merino ewes, which were mated to a terminal sire to lamb in September. The effects of the grazing systems and pasture treatments on herbage production and stocking rate are presented in this paper. Herbage production was similar between the treatments, but tactical stocking significantly increased herbage mass during the growing season (P<0.05) compared with continuous stocking. In spring each year, the herbage mass generally exceeded 3000 kg dry matter/ha in tactically stocked paddocks and averaged 500–900 kg dry matter/ha higher than the mass on continuously stocked paddocks. This enabled the year-round stocking rate to be increased by an average of 9% over the 4 years of the experiment. We considered that the stocking rates could not be further increased, despite the higher herbage mass in spring, as stock reduced the dry herbage to a low residual mass by the opening rains in autumn. In contrast, stocking rates averaged 51% higher on the upgraded pasture compared with the typical pasture over the 4 years of the experiment. This indicates that pasture improvement and soil fertility status have a much greater impact on productivity than changes to grazing method. However, tactical stocking was able to increase the sustainability of prime lamb production on upgraded pastures in a dry summer climate, by maintaining herbage cover on the paddocks over the summer–autumn period.

scholarly journals Microsite effects on abundance of sown species on uncultivable slopes

2016 ◽  
Vol 16 ◽  
pp. 269-273
Author(s):  
G.B. Douglas ◽  
R.A. Moss ◽  
T.L. Knight ◽  
C.M. Lloyd-West ◽  
R. Gray ◽  
...  
Keyword(s):  
Perennial Ryegrass ◽  
Dry Matter ◽  
Subterranean Clover ◽  
Major Influence ◽  
Individual Species ◽  
Vast Array ◽  
Hill Country ◽  
Olsen P ◽  
Steep Slopes ◽  
Grazed Swards

Hill country has a vast array of microsites that may influence the success and uniformity of establishment of oversown pasture species and their persistence. In spring 2014, studies were conducted at Woodville (southern Hawke's Bay; summer-wet) and Cheviot (North Canterbury; summer-dry) to determine the effect of gentle (14-21o) and steep (32-40o) slopes on the presence and contribution to sward dry matter (DM) of oversown species in rotationally grazed swards aged 30 or 36 months. Gentle slopes had greater soil water content (29 versus 25%) and Olsen P (34 versus 26 μg/ ml) than nearby steep slopes. Perennial ryegrass (94 versus 80%) and phalaris (6 versus 2%) were present in a greater proportion of plots on gentle than on steep slopes, respectively, whereas subterranean clover had a greater presence on steep than on gentle slopes (6 versus 1%). Perennial ryegrass comprised a higher percentage of DM in swards on gentle than on steep slopes (27 versus 11%). The percentage of DM contributed by other individual species did not differ significantly between slope classes. The persistence of most sown species was unaffected by slope; microsite variation was not a major influence on species persistence. Keywords: hill country, microsites, pasture species, plant-microsite matches

Effects of superphosphate fertiliser and stocking rate on the nutritive value of perennial ryegrass and subterranean clover herbage

1999 ◽  
Vol 50 (4) ◽  
pp. 537 ◽  
Author(s):  
G. R. Saul ◽  
G. A. Kearney ◽  
P. C. Flinn ◽  
C. L. Lescun
Keyword(s):  
Perennial Ryegrass ◽  
Crude Protein ◽  
Dry Matter ◽  
Nutritive Value ◽  
Subterranean Clover ◽  
Stocking Rate ◽  
Western Victoria ◽  
Stocking Rates ◽  
Infertile Soils

The effect of superphosphate fertiliser on digestible dry matter (DDM) and crude protein (CP) percentages of perennial ryegrass and subterranean clover was assessed on a long-term, grazed experiment in western Victoria. CP of both species increased significantly (3–6 units) where long-term average phosphorus (P) applications were 33 kg/ha.year compared with 1 kg/ha.year. CP of herbage was also greater on paddocks grazed at higher (9–23 ewes/ha) than lower (5–13 ewes/ha) stocking rates (1–3 units). DDM of subterranean clover significantly increased (8–10 units) with higher superphosphate applications but there was little effect on the DDM of perennial ryegrass. Long-term applications of superphosphate were associated with larger increases in both DDM and CP than if the same rate was applied in autumn of the year of measurement. For subterranean clover, 30 kg/ha of P applied to infertile soils (Olsen P 5 mg/kg) in autumn increased the DDM of herbage collected in September by only 4–6 units. The nutritive value of most volunteer pasture species also increased with higher superphosphate applications but the DDM of these species was usually inferior to perennial ryegrass. The results highlight the importance of monitoring nutritive value, pasture composition, and herbage production to quantify fully the likely effect of fertiliser applications on animal production.

Accumulation of plant nutrients and changes in soil properties of sandy soils under fertilized pasture in southeastern South-Australia .I. Phosphorus

Soil Research ◽  
1987 ◽  
Vol 25 (2) ◽  
pp. 193 ◽  
Author(s):  
DC Lewis ◽  
AL Clarke ◽  
WB Hall
Keyword(s):  
Organic Phosphorus ◽  
Soil Phosphorus ◽  
Balance Sheet ◽  
South Australia ◽  
Single Superphosphate ◽  
Phosphorus Accumulation ◽  
Total Soil Phosphorus ◽  
Clay Layers ◽  
Stocking Rates ◽  
Phosphorus Levels

The accumulation of phosphorus applied as superphosphate over a 25-year period to pastures growing on sand over clay soils was measured in three areas of different rainfall in the south-east of South Australia. Total soil phosphorus levels increased in the 0-10 cm, 10-30 cm and 30 cm-clay layers for all areas, but no accumulation occurred in the clay layer. For every 100 kg ha-1 of single superphosphate (9.6% phosphorus) applied, 2.0, 3.2 and 3.5 kg ha-1 of phosphorus accumulated in the 0-10 cm layer for the Hundreds of Coles, Willalooka and Senior respectively. The recoveries of applied phosphorus in the sand layer for the three areas were 42, 57 and 75% for Coles, Willalooka and Senior respectively. The annual accumulation rates of organic phosphorus in the top 30 cm of soil ranged from 2.4 to 3.5 kg ha-1. By using a 'balance sheet' approach, the annual maintenance phosphate requirements for the three areas were calculated. These ranged from 60 to 165 kg ha-1 of superphosphate, and were associated with differences in leaching losses, stocking rates and organic phosphorus accumulation.

Effects of phosphorus fertiliser and rate of stocking on the seasonal pasture production of perennial ryegrass-subterranean clover pasture

1998 ◽  
Vol 49 (2) ◽  
pp. 233 ◽  
Author(s):  
J. W. D. Cayley ◽  
M. C. Hannah ◽  
G. A. Kearney ◽  
S. G. Clark
Keyword(s):  
Growth Rate ◽  
Maximum Yield ◽  
Subterranean Clover ◽  
Grazing Pressure ◽  
Yield Response ◽  
Potential Yield ◽  
Constant Growth Rate ◽  
Single Superphosphate ◽  
Pasture Production ◽  
Stocking Rates

The response of pastures based on Lolium perenne L. and Trifolium subterraneum L. to single superphosphate was assessed at Hamilton, Victoria, by measuring the growth of pastures during winter, spring, and summer over 7 years from 1979 to 1987. The seasons were defined by the pattern of pasture production, rather than by calendar months. Winter was the period of constant growth rate following the autumn rain; spring was the period of accelerating growth rate until growth rate changed abruptly following the onset of dry summer weather. Pastures were grazed with sheep at a low, medium, or high grazing pressure, corresponding generally to stocking rates of 10, 14, or 18 sheep/ha. At each level of grazing pressure, single superphosphate was applied at 5 rates from 1979 to 1982; the highest rate, expressed as elemental phosphorus (P), was reduced from 100 to 40 kg/ha during this time. In addition there was an unfertilised treatment. In 1984, fertiliser was applied at 6 rates from 4 to 40 kg P/ha. No fertiliser was applied in the remaining years, including 1983. Pasture production was measured from 1979 to 1982 and from 1985 to 1987. Total pasture dry matter (DM) accumulation per year at the highest stocking rate was less than the other treatments in 4 of the years. Averaged over all years and fertiliser treatments, the annual net production was 10·1, 10·1, and 9·0 t DM/ha (P < 0·05) for plots grazed at low, medium, and high stocking rates, respectively. The amount of fertiliser required to reach a given proportion of maximum yield response did not vary between winter and spring in any year, but the greater potential yield in spring (P < 0 ·001) meant that as more fertiliser was applied, the disparity between pasture grown in winter and pasture grown in spring increased. Differences in this disparity between extreme levels of P ranged from 1·4 t DM/ha in a drought to about 7 t DM/ha in a good season. The implications for managing farms when pastures are fertilised at higher rates than currently practised by district farmers are that systems of animal production with a requirement for plentiful good quality pasture in spring, such as ewes lambing in spring, should be used. The benefit of spring lambing over autumn lambing was supported when the 2 systems were compared over 26 years using the GrassGro decision support system. Well fertilised pasture systems will also allow more scope for conserving pasture as hay or silage, and increase opportunities for diversification in the farming enterprise, such as spring-growing crops.

Available phosphorus, sulfur, potassium, and other cations in a long-term grazing experiment in south-western Victoria

2002 ◽  
Vol 53 (12) ◽  
pp. 1349 ◽  
Author(s):  
J. W. D. Cayley ◽  
M. R. McCaskill ◽  
G. A. Kearney
Keyword(s):  
Nutrient Status ◽  
Grazing Pressure ◽  
Available Phosphorus ◽  
Plant Responses ◽  
Single Superphosphate ◽  
Soil P ◽  
Olsen P ◽  
Western Victoria ◽  
Stocking Rates

Relationships between amounts of superphosphate applied to pasture and stocking rate on available nutrient status were assessed from 1979 to 2000 on a chromosol derived from basalt at Hamilton, Victoria. The pastures were stocked with sheep at low, medium, or high grazing pressures in factorial combination with 6 levels of superphosphate. Overall annual amounts of single superphosphate (8.8% P, 11% S, 19% Ca) applied ranged from 0.4 to 36 kg P/ha. Potassium chloride (KCl) was applied to all plots periodically. Average stocking rates ranged from 7 to 19 dry sheep equivalents (DSE)/ha. The nutrient status of plots was monitored by sampling the soil to a depth of 10 cm, avoiding the areas used by the sheep for camping. In 1994, samples of topsoil (0–5 cm and 5–10 cm) were taken from the camp areas and non-camp areas in each plot in order to assess 'plant-available' P, S, and extractable cations. Changes in P and S with depth to 80 cm in high and low grazing pressure treatments were also assessed. The influence of cumulative P applied on Olsen P varied with time and grazing pressure. During the first 12–15 years, the Olsen P of high grazing pressure plots was greater than that of low grazing pressure plots, but subsequently the reverse has been the case. Plant-available S also increased where more superphosphate had been applied. Levels were greater than 7 mg S/kg soil except at the lowest level of superphosphate, indicating that forms of P fertiliser with less S could be used here. After initial applications of KCl, this fertiliser was not applied for 8 years. During this time the K status fell from 270 to 120 mg K/kg soil, just above where plant responses to K are likely, emphasising the need to monitor the K status of productive pastures on these soils. Levels of exchangeable Mg2+ fell as more superphosphate was used, whereas levels of Ca2+ rose. The Olsen P of soil deeper than 10 cm was always less than 5 mg P/kg soil. P supply to deep-rooted pasture plants may thus be limiting when the topsoil is dry. These results, together with published assessments of animal production at this site, show that for pastures fertilised annually, the Olsen P associated with the most profit varied from 7 mg P/kg soil at 7 ewes/ha (10.5 DSE/ha), to 14 mg P/kg soil at 18 ewes/ha.

Corrigendum to: Effects of phosphorus fertiliser and rate of stocking on the seasonal pasture production of perennial ryegrass-subterranean clover pasture

2002 ◽  
Vol 53 (12) ◽  
pp. 1383
Author(s):  
J. W. D. Cayley ◽  
M. C. Hannah ◽  
G. A. Kearney ◽  
S. G. Clark
Keyword(s):  
Growth Rate ◽  
Maximum Yield ◽  
Subterranean Clover ◽  
Grazing Pressure ◽  
Yield Response ◽  
Potential Yield ◽  
Constant Growth Rate ◽  
Single Superphosphate ◽  
Pasture Production ◽  
Stocking Rates

The response of pastures based on Lolium perenne L. and Trifolium subterraneum L. to single superphosphate was assessed at Hamilton, Victoria, by measuring the growth of pastures during winter, spring, and summer over 7 years from 1979 to 1987. The seasons were defined by the pattern of pasture production, rather than by calendar months. Winter was the period of constant growth rate following the autumn rain; spring was the period of accelerating growth rate until growth rate changed abruptly following the onset of dry summer weather. Pastures were grazed with sheep at a low, medium, or high grazing pressure, corresponding generally to stocking rates of 10, 14, or 18 sheep/ha. At each level of grazing pressure, single superphosphate was applied at 5 rates from 1979 to 1982; the highest rate, expressed as elemental phosphorus (P), was reduced from 100 to 40 kg/ha during this time. In addition there was an unfertilised treatment. In 1984, fertiliser was applied at 6 rates from 4 to 40 kg P/ha. No fertiliser was applied in the remaining years, including 1983. Pasture production was measured from 1979 to 1982 and from 1985 to 1987. Total pasture dry matter (DM) accumulation per year at the highest stocking rate was less than the other treatments in 4 of the years. Averaged over all years and fertiliser treatments, the annual net production was 10·1, 10·1, and 9·0 t DM/ha (P < 0·05) for plots grazed at low, medium, and high stocking rates, respectively. The amount of fertiliser required to reach a given proportion of maximum yield response did not vary between winter and spring in any year, but the greater potential yield in spring (P < 0 ·001) meant that as more fertiliser was applied, the disparity between pasture grown in winter and pasture grown in spring increased. Differences in this disparity between extreme levels of P ranged from 1·4 t DM/ha in a drought to about 7 t DM/ha in a good season. The implications for managing farms when pastures are fertilised at higher rates than currently practised by district farmers are that systems of animal production with a requirement for plentiful good quality pasture in spring, such as ewes lambing in spring, should be used. The benefit of spring lambing over autumn lambing was supported when the 2 systems were compared over 26 years using the GrassGro decision support system. Well fertilised pasture systems will also allow more scope for conserving pasture as hay or silage, and increase opportunities for diversification in the farming enterprise, such as spring-growing crops.

Arrowleaf clover improves lamb growth rates in late spring and early summer compared with subterranean clover pastures in south-west Victoria

2010 ◽  
Vol 50 (8) ◽  
pp. 807 ◽  
Author(s):  
A. N. Thompson ◽  
A. J. Kennedy ◽  
J. Holmes ◽  
G. Kearney
Keyword(s):  
Perennial Ryegrass ◽  
Growth Rates ◽  
Nutritive Value ◽  
Subterranean Clover ◽  
Growing Season ◽  
Early Summer ◽  
Late Spring ◽  
South West ◽  
Stocking Rates ◽  
Lamb Growth

The profitable production of lamb from pasture-based systems is dependent on high levels of pasture production being efficiently utilised by sheep of superior genetic merit. Pastures that can extend the pasture-growing season and provide high quality feed in late spring and summer have the potential to increase production efficiency and the proportion of lambs that meet market specifications. In this paper we tested the hypothesis that arrowleaf clover (cv. Arrotas), a cultivar selected for late maturity, would supply feed of higher nutritive value than conventional annual legumes and perennial ryegrass mixtures during December and January and this would improve lamb growth rates over this period. Two experiments were conducted to compare the nutritive value of pasture and growth rates of lambs grazing arrowleaf clover, subterranean clover (cv. Leura) or subterranean clover/perennial ryegrass mixtures at different stocking rates during late spring and early summer in south-west Victoria. In the second experiment an arrowleaf clover/perennial ryegrass treatment was also included. Lambs were removed from the plots when they could no longer maintain liveweight. Arrowleaf clover extended the growing season by 4–6 weeks and provided feed of significantly higher digestibility than subterranean clover during December and January. The digestibility of arrowleaf and perennial ryegrass was comparable, but arrowleaf had significantly higher crude protein content during this period. Lambs grazing arrowleaf clover at stocking rates up to 24 lambs/ha grew at or above 100 g/day until the end of January, whereas lambs grazing subterranean clover and perennial ryegrass mixed pastures could not maintain weight by mid-to-late December in both years and were removed from the pastures. At the highest stocking rates total lamb production from arrowleaf clover monoculture pastures in late spring and early summer was ~400 kg liveweight/ha, and was more than double that achieved from the subterranean clover and perennial ryegrass/subterranean clover mixed pastures. The perennial ryegrass/arrowleaf clover mixed pastures in the second experiment produced a similar quantity of lamb per hectare as the arrowleaf clover monoculture pastures at the same stocking rate. In this paper we demonstrated that late-maturing arrowleaf clover can be a profitable, special purpose lamb-finishing pasture. Arrowleaf clover was most suited to more elevated parts of the landscape where estimated carrying capacity was 20 to 40% greater than that from lower lying parts of the landscape that were more subject to water logging and weed infestation. The risks of including arrowleaf clover pastures into the farming system could be reduced by direct drilling arrowleaf clover, which has relatively poor winter production, into existing perennial ryegrass pastures.

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