Effects of previous superphosphate applications on the pasture environment and the response by pasture to a current dressing

1962 ◽  
Vol 13 (5) ◽  
pp. 836 ◽  
Author(s):  
KD McLachlan ◽  
BW Norman

A study was made of the effect of previous superphosphate applications on the response by pasture to the calcium, phosphorus, and sulphur in a current dressing. The trial was located on the Southern Tableland of New South Wales on soils of granitic, sedimentary, and basaltic origin. In each case the legume component of the pasture was subterranean clover (Trifolium subterraneurn L.). The evidence shows that there is scope for altering the phosphorus and sulphur content of superphosphate to produce more efficient fertilizers for particular stages in pasture development and for particular soils. The residual value of the phosphorus was greater than the residual value of the sulphur in superphosphate. Even on the basaltic soils, phosphate "fixation" was of no practical significance. Nevertheless, any change in the relative phosphorus sulphur requirement of pastures with increasing amounts of superphosphate previously applied, resulted from a decline in the requirement for phosphorus, not from a change in the sulphur requirement. The number of years since the last application of superphosphate was shown to be the best predictor of responses to both phosphorus and sulphur, which indicated that the residual value of both these elements is limited in time. Implications of the lapse rate – the decline in effectiveness of the fertilizer with time – are discussed. The results show that pasture production was limited by phosphorus deficiency on soils where previous evidence suggested that the build-up of organic matter may be limited by sulphur deficiency.

2003 ◽  
Vol 43 (10) ◽  
pp. 1221 ◽  
Author(s):  
M. D. A. Bolland ◽  
J. S. Yeates ◽  
M. F. Clarke

The dry herbage yield increase (response) of subterranean clover (Trifolium subterraneum L.)-based pasture (>85% clover) to applications of different sources of sulfur (S) was compared in 7 field experiments on very sandy soils in the > 650 mm annual average rainfall areas of south-western Australia where S deficiency of clover is common when pastures grow rapidly during spring (August–November). The sources compared were single superphosphate, finely grained and coarsely grained gypsum from deposits in south-western Australia, and elemental S. All sources were broadcast (topdressed) once only onto each plot, 3 weeks after pasture emerged at the start of the first growing season. In each subsequent year, fresh fertiliser-S as single superphosphate was applied 3 weeks after pasture emerged to nil-S plots previously not treated with S since the start of the experiment. This was to determine the residual value of sources applied at the start of the experiment in each subsequent year relative to superphosphate freshly-applied in each subsequent year. In addition, superphosphate was also applied 6, 12 and 16 weeks after emergence of pasture in each year, using nil-S plots not previously treated with S since the start of the experiment. Pasture responses to applied S are usually larger after mid-August, so applying S later may match plant demand increasing the effectiveness of S for pasture production and may also reduce leaching losses of the applied S.At the same site, yield increases to applied S varied greatly, from 0 to 300%, at different harvests in the same or different years. These variations in yield responses to applied S are attributed to the net effect of mineralisation of different amounts of S from soil organic matter, dissolution of S from fertilisers, and different amounts of leaching losses of S from soil by rainfall. Within each year at each site, yield increases were mostly larger in spring (September–November) than in autumn (June–August). In the year of application, single superphosphate was equally or more effective than the other sources. In years when large responses to S occurred, applying single superphosphate later in the year was more effective than applying single superphosphate 3 weeks after pasture emerged (standard practice), so within each year the most recently applied single superphosphate treatment was the most effective S source. All sources generally had negligible residual value, so S needed to be applied each year to ensure S deficiency did not reduce pasture production.


1985 ◽  
Vol 25 (4) ◽  
pp. 758 ◽  
Author(s):  
DG Hall ◽  
EC Wolfe ◽  
BR Cullis

Pasture production, ewe and lamb growth, ewe wool production and diet quality were studied on lucerne-subterranean clover pastures at Wagga Wagga, New South Wales. Lucerne was sown at rates of 0.75 to 3.0 kg/ha, and the pastures were rotationally grazed with Border Leicester x Merino ewes at 9.6 or 12.7 sheep/ha, the ewes lambing in August- September. Lucerne density declined by 45% over the 3 years on all treatments. The clover cultivar sown, Woogenellup, had low persistence, particularly at 12.7 sheep/ha. The density of lucerne had little effect on annual wool and lamb production, although the ewes grew faster on the denser lucerne in summer and the sparser lucerne in winter. At 12- 7 sheep/ha, there was an extra 19% total lamb weight by the end of November and an extra 22% of finer wool (1 �m) annually, but the fleeces had a higher proportion of wool tenderness. The major limitations of the lucerne-subterranean clover pastures to sheep production were the low quality of the diet in early summer, and low pasture production in late winter. In early summer the lucerne was rapidly consumed, leaving only moderate quality clover and grass residues, which limited lamb growth, while in winter pregnancy toxaemia occurred, fleeces were tender and wool growth was low, particularly during a drought in 1976.


Soil Research ◽  
1994 ◽  
Vol 32 (5) ◽  
pp. 995 ◽  
Author(s):  
CJ Smith ◽  
MB Peoples ◽  
G Keerthisinghe ◽  
TR James ◽  
DL Garden ◽  
...  

Changes in the chemistry of an acidic grey massive earth soil in response to various ameliorant treatments (gypsum and phosphogypsum in the presence or absence of lime) were investigated in a subterranean clover-based pasture in the southern highlands of New South Wales. Lime, gypsum, and phosphogypsum, or lime in combination with gypsum and phosphogypsum were broadcast at 2500 kg ha-1 on the surface of the soil in May 1990. Pasture production was determined and the soil was sampled to 25 cm depth, 6 and 18 months after treatment application. Surface soil pH was increased to 6-1 by the application of lime, gypsum plus lime and phosphogypsum plus lime treatments in the 0-5 cm depth interval, but remained unchanged when gypsum or phosphogypsum was used alone. Calcium chloride extractable aluminium increased down the soil profile under all treatments to 10-15 cm, but was highest in the gypsum treatment at depth. The application of phosphogypsum increased the 0.01 m CaCl2 extractable fluoride in the surface 5 cm from 26 to 43 �M. In contrast, fluoride concentrations were decreased to between 5.3 and 7.3 �M in the lime, gypsum plus lime and phosphogypsum plus lime treatments. Gypsum and phosphogypsum decreased the concentration of Al3+ in solution and on the exchange sites in the 0-5 cm depth interval. However, the effectiveness of the amendments to reduce toxic Al3+ concentrations were confined to the surface 5 cm. The concentration of aluminium and the activity of Al3+ in the 0-5 cm soil layer at both soil samplings were decreased by the amendments. Lime, and gypsum or phosphogypsum in combination with lime, were the most effective treatments for reducing the activity of Al3+. The activity of Al3+ increased with depth in all treatments. The pH and activity of Al3+ measured in the 0.01 m CaCl2 extracts plot near the gibbsite solubility line and suggest that Al solubility was controlled by this mineral. Exchangeable Ca in the 0-5 cm soil layer was significantly increased by the application of lime whereas exchangeable aluminium was decreased by lime, gypsum and phosphogypsum. There was no significant change in exchangeable cations other than Al below the surface 5 cm which suggests limited leaching of lime, gypsum and phosphogypsum in the profile within the 18 month study period. Pasture yield was significantly increased by the addition of lime and was related to the decrease in the activity of Al3+ in the surface soil.


2010 ◽  
Vol 61 (6) ◽  
pp. 435 ◽  
Author(s):  
B. S. Dear ◽  
M. B. Peoples ◽  
R. C. Hayes ◽  
A. D. Swan ◽  
K. Y. Chan ◽  
...  

Changes in pasture yield and botanical composition due to gypsum application were examined on Vertosols at two locations of differing soil sodicity, Grogan and Morangarell, in southern New South Wales. Two pasture treatments were examined. One was an annual pasture comprised of 3 annual legumes (2 subterranean clover Trifolium subterraneum L. cultivars, Clare and Riverina, and balansa clover T. michelianum Savi cv. Paradana), while the second treatment consisted of lucerne (Medicago sativa L.) cv. Aquarius sown in a mixture with the same annual legumes. Gypsum had no effect on the establishment or persistence of lucerne at either site. Gypsum increased the number of subterranean clover seedlings present in autumn in annual swards at the more sodic Grogan site in each of the 4 years, but provided no difference when the clover was in a mixture with lucerne. Annual legume seed yields in annual-only swards increased with gypsum by up to 58% at Grogan and 38% at Morangarell. Seed yields of both cultivars of subterranean clover declined as a proportion of the total annual legume seed bank when lucerne was included in the mixture, in contrast to balansa clover (at Grogan) and the naturalised annual legumes, burr medic (M. polymorpha L.) and woolly clover (T. tomentosum L.), which all increased in relative seed yield in the presence of lucerne. Total pasture production at the Grogan site increased with gypsum by up to 15% per annum in annual swards and 36% in lucerne swards depending on the season. Yield responses to gypsum by the lucerne component were observed in 10 of the 13 seasonal yield measurements taken at Grogan. However, total pasture yield and seasonal yields were unaffected by both gypsum and pasture type at the less sodic Morangarell site. It was concluded that sowing a diverse mixture of annual legumes or polycultures was conducive to maintaining productive pastures on these spatially variable soils. Lucerne dried the soil profile (0.15–1.15 m) more than annual pastures at both sites. The combination of gypsum and lucerne enhanced water extraction at depth (0.6–1.15 m) at the Grogan site increasing the size of the dry soil buffer whereas gypsum increased soil water at depth (>0.6 m) under annual swards.


1969 ◽  
Vol 9 (38) ◽  
pp. 320 ◽  
Author(s):  
K Spencer ◽  
D Bouma ◽  
DV Moye

Values obtained by a number of established soil test procedures for phosphorus and sulphur were correlated with yield responses to addition of the relevant nutrient, by subterranean clover-based pastures at 21 sites in south-eastern New South Wales. Colwell's bicarbonate-soluble P and Bray's P, phosphorus values showed sufficiently close associations with response to added phosphorus to be useful for predictive purposes ; Bray's P, values generally gave smaller coefficients. In general, the pasture on soils testing less than 25 p.p.m. bicarbonate-extractable P in the surface three inches responded appreciably to applied phosphorus (relative yields were <85 per cent). The corresponding value for the Bray P, procedure was 10 p.p.m. P. Soil samples from 0-1, 0-3, and 3-6 inch depths gave similar correlations with response. The time of soil sampling did not affect the relationships but winter pasture production was not as closely related to soil test values as was spring production. By contrast, soil tests for sulphur were not reliable but some discrimination between soils could be made with a 500 p.p.m. phosphate extraction. Values from soil samples collected in the winter were less closely related to response than were values from samples collected in the autumn.


1969 ◽  
Vol 9 (38) ◽  
pp. 310 ◽  
Author(s):  
K Spencer ◽  
D Bouma ◽  
DV Moye ◽  
EJ Dowling

A series of 21 standardized field experiments was set out on established subterranean clover (Trifolium subterranem) pastures in south-eastern New South Wales in the autumn of 1963. Pasture growth at eleven of the 21 sites responded to phosphorus addition ; eight responded to sulphur addition. A dual deficiency existed at five sites. Seasonal pasture production was increased by up to 3,200 lb of dry matter an acre by phosphorus addition, and by up to 5,500 lb by sulphur addition. Clover was the component responsive to phosphorus and/or sulphur at most sites. To determine whether site characteristics can provide a basis for predicting the phosphorus or sulphur status of a pasture, several climatic and soil components of the environment were correlated with responses. Phosphorus status was not related to the rainfall, temperature or elevation at the site, nor to the kind of soil or soil pH. The more deficient pastures were younger, and, on the granitic soils only, present phosphorus status reflected the amount of superphosphate used in the past. Sulphur status was significantly related to rainfall for the podzolic soils only (r = 0.72) ; the driest sites tended to be the most sulphur deficient ones. Sulphur status showed a poor overall relationship with temperature, the trend being for the occurrence of more deficient soils at lower temperatures or higher elevations. Within the podzolic soils, the relationship with temperature was more definite (r = 0.69). There was no association with kind of soil or past superphosphate use, but there was a moderate to strong relationship (r = -0.78) with soil pH (the less acid, the more S deficient).


1986 ◽  
Vol 26 (6) ◽  
pp. 681 ◽  
Author(s):  
A Pinkerton ◽  
JR Simpson

Previous studies on soils from old pastures in southern New South Wales have demonstrated that nutrients have accumulated at the soil surface, but that the 40-100-mm depth layer in many profiles has become strongly acidic (e.g. pH 4.7), and high in extractable aluminium. Poor growth of subterranean clover has occurred on such soils during dry periods and may be associated with poor root growth in the acidic, nutrient-poor subsurface layers. Possible nutritional causes of these observations were investigated using reconstituted soil profiles. The root and shoot growth of subterranean clover, wheat, oats and lucerne were compared in unamended profiles and in profiles amended by applying nutrients or calcium carbonate (lime) to correct the more obvious deficiencies of the subsurface layers. Subterranean clover grew well as long as the surface soil remained moist, so that plants could utilise the nutrients potentially available within it. When the surface (0-40 mm) was allowed to dry but the subsurface layers remained moist, growth was poor unless phosphate was applied to the moist layer. Subsurface application of lime alone was ineffective. Nitrogen application increased clover growth in the presence of added phosphate or surface moisture, but nitrogen alone did little to alleviate the effects of surface drought. Wheat, and to a lesser extent oats, responded to subsurface lime when the surface was moist, and both responded to subsurface phosphate when the surface was dry. Lucerne responded to subsurface phosphate similarly to subterranean clover but the response was more than doubled in the presence of additional borate and lime. Lime without borate was not effective. When the surface was maintained moist, liming both the surface (0-40 mm) and subsurface layers improved the response over liming the subsurface layer only. The results suggest that declining fertility and productivity in old pastures developed on acid soils may not be rectified by liming alone, but that cultivation, ripping or drilling of phosphate, and in some cases addition of borate, may be required to improve the penetration of nutrients, particularly phosphorus, to greater depth.


2002 ◽  
Vol 42 (2) ◽  
pp. 149 ◽  
Author(s):  
M. D. A. Bolland ◽  
W. J. Cox ◽  
B. J. Codling

Dairy and beef pastures in the high (>800 mm annual average) rainfall areas of south-western Australia, based on subterranean clover (Trifolium subterraneum) and annual ryegrass (Lolium rigidum), grow on acidic to neutral deep (>40 cm) sands, up to 40 cm sand over loam or clay, or where loam or clay occur at the surface. Potassium deficiency is common, particularly for the sandy soils, requiring regular applications of fertiliser potassium for profitable pasture production. A large study was undertaken to assess 6 soil-test procedures, and tissue testing of dried herbage, as predictors of when fertiliser potassium was required for these pastures. The 100 field experiments, each conducted for 1 year, measured dried-herbage production separately for clover and ryegrass in response to applied fertiliser potassium (potassium chloride). Significant (P<0.05) increases in yield to applied potassium (yield response) were obtained in 42 experiments for clover and 6 experiments for ryegrass, indicating that grass roots were more able to access potassium from the soil than clover roots. When percentage of the maximum (relative) yield was related to soil-test potassium values for the top 10 cm of soil, the best relationships were obtained for the exchangeable (1 mol/L NH4Cl) and Colwell (0.5 mol/L NaHCO3-extracted) soil-test procedures for potassium. Both procedures accounted for about 42% of the variation for clover, 15% for ryegrass, and 32% for clover + grass. The Colwell procedure for the top 10 cm of soil is now the standard soil-test method for potassium used in Western Australia. No increases in clover yields to applied potassium were obtained for Colwell potassium at >100 mg/kg soil. There was always a clover-yield increase to applied potassium for Colwell potassium at <30 mg/kg soil. Corresponding potassium concentrations for ryegrass were >50 and <30 mg/kg soil. At potassium concentrations 30–100 mg/kg soil for clover and 30–50 mg/kg soil for ryegrass, the Colwell procedure did not reliably predict yield response, because from nil to large yield responses to applied potassium occurred. The Colwell procedure appears to extract the most labile potassium in the soil, including soluble potassium in soil solution and potassium balancing negative charge sites on soil constituents. In some soils, Colwell potassium was low indicating deficiency, yet plant roots may have accessed potassum deeper in the soil profile. Where the Colwell procedure does not reliably predict soil potassium status, tissue testing may help. The relationship between relative yield and tissue-test potassium varied markedly for different harvests in each year of the experiments, and for different experiments. For clover, the concentration of potassium in dried herbage that was related to 90% of the maximum, potassium non-limiting yield (critical potassium) was at the concentration of about 15 g/kg dried herbage for plants up to 8 weeks old, and at <10 g/kg dried herbage for plants older than 10–12 weeks. For ryegrass, there were insufficient data to provide reliable estimates of critical potassium.


Author(s):  
C. During ◽  
A.J. Mcneur

THE PHOSPHATE CYCLE under grazing and the practical significance of phosphate fixaltion are briefly discussed, as are maintenance requirements of fertilizers, effects on pasture production when fertilizers are not used for one or two years, and finally, liming.


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