Uptake of selenite fertilizer by subterranean clover pasture in Western Australia

1989 ◽  
Vol 29 (4) ◽  
pp. 517 ◽  
Author(s):  
BR Whelan

. Subterranean clover (Trifolium subterraneum) based pastures were fertilised with sodium selenite at 9 rates from 0 to 800 g Se/ha on 2 sites in 1983. In order to measure the residual value in 1984 and 1985, further applications of sodium selenite were superimposed on the original 9 treatments. Green pasture was sampled annually, dry pasture was sampled once, only in 1984 and the concentration of selenium in the pasture was measured. The sampled pasture was sorted into 2 components: subterranean clover, and non-subterranean clover. Except for the third site that had a quadratic response for the non-subterranean clover component of the pasture, the concentration of selenium in plants increased linearly with application rate. The selenium concentration in subterranean clover was lower than that in the other species in the pasture. Differences between years were large: in 1985, the concentration in plant material was twice that in 1983 and 1984. The dry summer feed had higher concentrations of selenium than the green pasture. The residual value of selenite was 25% in the first year and 15% in the second year. Adequate dietary levels of selenium for sheep would require an annual application of about 200 g sodium selenite/ha to these soils.

1955 ◽  
Vol 6 (4) ◽  
pp. 553 ◽  
Author(s):  
RC Rossiter ◽  
PG Ozanne

A 2-year field experiment is described, in which an annual-type pasture was grown on a soil of lateritic origin with various initial rates of rock phosphate and superphosphate. The soil was acutely deficient in plant-available phosphorus at the outset. Application of superphosphate led to the expected increases in total pasture production, but rock phosphate also gave substantial yield increases, even during the first season. Differential species effects were noted; subterranean clover (Trifolium subterraneum L.) and cape-weed (Cryptostemma calendula Druce) responded about equally to superphosphate, but the clover responded to rock phosphate to a greater extent than did cape-weed. Both relative efficiency for total plant growth and percentage utilization of applied phosphorus were much higher with the soluble phosphatic fertilizer than with rock phosphate, especially in the first year. However, phosphorus recovery from rock phosphate was as high in the second year as in the first, whereas there was a marked decrease in the second year from superphosphate.


1955 ◽  
Vol 6 (4) ◽  
pp. 398 ◽  
Author(s):  
AG Tyson

Seddon gravelly sandy loam from Kangaroo Island has proved to be grossly deficient in both total and available native phosphorus. Growth of subterranean clover (Trifolium subterraneum L.) in this soil is virtually nil unless phosphatic fertilizers are applied to it. Experiments with eight different phosphatic fertilizers showed that thermal phosphates of the Rhenania type were slightly superior to monocalcic phosphate as a source of plant phosphorus on Seddon soil. Both types of phosphate were equally efficient in the contrasting Urrbrae loam. Rock phosphate proved to be an extremely poor source of plant phosphorus. In the first year the availability of monocalcic phosphate applied to the Seddon soil was 20 per cent. or half that of material applied to the Urrbrae loam. The comparative residual value in the second year of applied phosphate was greater, however, in the Seddon soil than in the Urrbrae loam. Yields and phosphate availability were influenced by seasonal variation, but the phosphorus content of the plant material was nearly constant in different years for any particular yield from the same soil. The requirement for phosphorus at yields below the maximum was greater, however, in plants growing on Urrbrae loam than on Seddon soil. At maximum yields the ratio N/P205 was constant for plants from the two soils, but this did not hold where phosphorus was in minimum supply. The availability of residual phosphate from Seddon soil to which small annual additions of fertilizer had been made over 12 years was markedly lower than that from virgin soil to which phosphate had been added 12 months previously. The lower availability from the partially developed soil has been tentatively ascribed to the concurrent accumulation of organic matter. Results support the practice of making small annual applications of superphosphate to Urrbrae loam but it would appear that greater overall production could be obtained from Seddon soil by heavier initial applications. Amounts of P205 as low as 0.17-0.20 per cent. were found in the dry matter of subterranean clover growing on Seddon soil. Values below 0.3 per cent. are considered to be indicative of phosphate deficiency.


1973 ◽  
Vol 13 (60) ◽  
pp. 75 ◽  
Author(s):  
KD McLachlan ◽  
Marco DG De

Calcium sulphate was applied initially at rates equivalent to 0, 8.4, 16.8, 33.6 or 50.4 kg sulphur ha-1 to an existing subterranean clover (Trifolium subterraneum) -phalaris (Phalaris tuberosa) sward. At two of these rates, 8.4 and 33.6 kg sulphur ha-1, four maintenance levels (0, 8.4, 16.8 and 33.6 kg) were applied in each of the succeeding three years. In the production of dry matter, most efficient use of the fertilizer was made when the requirement of the pasture (33.6 kg S ha-1) was fully met in the first year, and subsequent annual dressings were made at the rate of 8.4 kg S ha-1 a year. Plant response was related to the level of sulphur available, and the success of particular programmes depended on the rapidity with which the potential yield of the pasture was realized under them. There was evidence, with the change from clover to grass dominance, that grass made more efficient use of residual sulphur in producing dry matter than did clover. Low maintenance rates were effective because they enhanced the residual value of the initial application.


1982 ◽  
Vol 22 (119) ◽  
pp. 420 ◽  
Author(s):  
K Spencer

To assess the feasibility of adding selenium to pastures likely to be associated with White Muscle Disease and related disorders in stock, plants of subterranean clover (Trifolium subterraneum L.) were raised in pots and supplied with rates of selenium (as selenate) and sulfur (as sulfate) in factorial combinations. On the soil used, increasing rates of selenium progressively depressed growth of clover and increased its selenium concentration; sulfur stimulated growth up to an addition of about 16 yg S/g and depressed the selenium concentration only when selenium was added. More sulfur was required to depress the selenium concentration to a threshold level, which was characteristic of a particular selenium application rate, at high initial selenium levels than at low. Clover growth was reduced when the sulfur to selenium ratio in the tops was less than 50: 1. Application rates greater than 0.025 �g Se/g soil (= 40 g/ha) produced young clover plants with excessive levels of selenium for consumption by stock. The safe rate for application to a mixed pasture is likely to be considerably less than that value. Field experiments confirmed that appreciable diminution of the selenium concentration in pasture as a result of sulfur addition occurred only when selenium was in plentiful supply. Grasses were much more affected than clovers. It is concluded that the negative interaction demonstrated between selenium and sulfur is of no practical significance when each is added at rates appropriate to the treatment of low sulfur-low selenium pastures.


1979 ◽  
Vol 19 (101) ◽  
pp. 689 ◽  
Author(s):  
SK Walker ◽  
GP Hall ◽  
DH Smith ◽  
RW Ponzoni ◽  
GJ Judson

The responses in liveweight, wool weight and survival, to selenium supplementation, were studied in young sheep from weaning to yearling age. The experiment was conducted over three years. In the first year, one sodium selenite supplementation rate was used (total dose 46.5 mg). During the following two years two supplementation rates were administered (total doses 46.5 mg and 93 mg). Mean concentrations of selenium in whole blood in unsupplemented sheep varied from 0.19-0.56 pmol l-l and from 0.20-0.44 pmol l-1 in the two years in which concentrations were measured. Supplementation, which commenced at lamb marking, increased the selenium concentration in sheep at weaning and thereafter. Selenium supplementation improved the break-of-season weight (P < 0.01) and yearling weight (P < 0.01 ) but not weaning weight (0.05 < P < 0.1 ). Hogget fleece weight was improved (P < 0.01 ) and mortality reduced (P < 0.01) by selenium supplementation. There was a treatment x year interaction in mortality rates (P < 0.01 ). There were no significant differences between the two supplementation rates


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.


1963 ◽  
Vol 3 (10) ◽  
pp. 180 ◽  
Author(s):  
K Spencer

Yield responses d a native pasture on a basaltic soil near Willow Tree, New South Wales, were measured in the second, fourth, and seventh years after the application of several rates of calcium sulphate in the first year. The value of the residues declined sharply at first and then more slowly. Fifty per cent of the potential response by the legumes (the responsive component of the pasture) was achieved by an application of 7lb of sulphur an acre in the first year ; residues from an application of 20 lb of sulphur an acre were required in the second year, and from 48 lb S of sulphur an acre in the fourth year, to obtain the equivalent responses. By the seventh year, effects were too small to allow the derivation of a comparable figure.


1998 ◽  
Vol 49 (2) ◽  
pp. 225 ◽  
Author(s):  
C. J. Thomson ◽  
C. K. Revell ◽  
N. C. Turner ◽  
M. A. Ewing ◽  
I. F. Le Coultre

A long-term rotation experiment located in south-western Australia was used to measure the effect of rotation and time of germinating rains on the productivity and botanical composition of grazed annual pastures in 2 contrasting seasons in an environment with an average annual rainfall of 325 mm. The density of self-regenerating seedlings of subterranean clover (Trifolium subterraneum), capeweed (Arctotheca calendula), and grasses (Lolium rigidum, Hordeum leporinum, Bromus diandrus) was greatly increased (approx. 3 times the density) when there was a second year of pasture after crop compared with the first year after crop. The lower plant density resulted in first-year pastures having only about 33% of the autumn biomass accumulation of second-year pastures. This difference in early pasture growth had no effect on total pasture production in 1992, but in 1993 total pasture production was 30% greater in second-year pastures compared with first-year pastures. Botanical composition varied between and within seasons with the percentage of subterranean clover increasing throughout the season and the percentage of capeweed decreasing throughout the season. Grasses comprised <20% of the biomass in all seasons and treatments. Production of subterranean clover seed in 1993 was higher in a 1 : 2 crop-pasture rotation than in a 1 : 1 crop-pasture rotation and direct drilling in the cropping phase increased seed set compared with conventional tillage in both 1 : 1 and 1 : 2 crop-pasture rotations. Capeweed seedlings emerged in large numbers after rainfall between February and May and subsequently showed a relative growth rate twice that of subterranean clover and the grasses, but exclusion of rainfall until June resulted in a significant reduction in the emergence of capeweed seedlings. Additionally, capeweed had a lower rate of seedling survival compared with other pasture species, and this is contrary to observations by other researchers that capeweed is highly resistant to moisture stress during early growth.


1961 ◽  
Vol 1 (2) ◽  
pp. 81
Author(s):  
KD McLachlan

Superphosphate was applied in summer (December) or in autumn (March) to an existing mixed pasture of subterranean clover (Trifolium subterraneum L.) and phalaris (Phalaris tuberosa L.), growing on apodsolic soil of p H 5.8. Time of application effects were recorded at the lowest level of applied phosphate. The main effect was on the botanical composition of the pasture. The summer application favoured clover, the autumn one grass. This effect is explained as a change in the relative ability of the species to compete for superphosphate. These results suggest how time and rate of application of superphosphate may be used to manage pasture composition. In the first year, when clover growth was encouraged, the earlier application also increased the total yield of pasture. In the second and third years, changes in the yield of grass were offset by changes ill the yield of clover and the effect of time of application on total pasture yield was not significant.


1994 ◽  
Vol 74 (3) ◽  
pp. 285-290 ◽  
Author(s):  
Umesh C. Gupta ◽  
J. A. MacLeod

This study was conducted in Prince Edward Island (PEI) Canada to determine the effect of various sources of selenium (Se) (i) sodium selenate (ii) selcote (iii) selcote 2 year and (iv) lime coated Se-granules on the Se concentration in cereals, forages and soybeans. All sources were applied to the soil at 10 g Se ha−1. For soybeans, sodium selenate was also applied as a foliar spray. All sources, in the year of application, proved effective in raising the feed crop Se to more than 100 μg Se kg−1, the minimum level required to prevent Se deficiency diseases in livestock. Lime coated Se granules resulted in much lower Se in all crops than other Se sources. Selenium concentration in soybean grain was higher than in cereals and forages treated with Se. Selenium concentration in soybean grain was higher following foliar applications of sodium selenate (3005 μg kg−1) than following soil application (1930 μg kg−1). Experiments conducted at a second location produced similar results. In most cases, soybean grain contained higher Se than either the whole plant or leaves. Selcote resulted in significantly higher Se, during the first year in soybean and forages, than selcote 2 year. This relationship was not consistent on cereals. Selenium concentrations in the second year crop of soybeans were below the minimum required level of 100 μg kg−1 needed to prevent Se deficiency in livestock for all Se sources except for the selcote 2 year source. Only the latter Se source resulted in a Se concentration of > 100 μg kg−1 for 2 yr. Soybeans fertilized with Se should prove to be an excellent feed crop for enriching grain with Se. Key words: Podzol soils, selcote, sodium selenate, barley, oat, forages, soybeans, crop Se


Sign in / Sign up

Export Citation Format

Share Document