Responses of serradella and subterranean clover to phosphorus from superphosphate and Duchess rock phosphate

1985 ◽  
Vol 25 (4) ◽  
pp. 902 ◽  
Author(s):  
MDA Bolland

The responses of yellow serradella, slender serradella and subterranean clover to phosphorus from superphosphate and an apatite rock phosphate from Duchess, north-eastern Australia, were measured in a field experiment near Esperance, W.A. Over the 16 months of the experiment, dry herbage yields depended upon the phosphorus content of dried herbage. For each sampling time, the relationship between dry herbage yield and the phosphorus content of dried herbage was similar for both fertilizers and for all three species. At each rate of fertilizer application, the amount of phosphorus absorbed by the plants from the rock phosphate was less than that from superphosphate, and this limited yield. When fertilized with superphosphate, subterranean clover absorbed less phosphorus than the serradellas for each rate of fertilizer application, and this also reduced yield. Thus less phosphorus from superphosphate was required to produce serradella than was required to produce the same weight of subterranean clover. When fertilized with rock phosphate, 1982 herbage production was in the order: yellow serradella> subterranean clover>slender serradella. 1982 seed yields were: subterranean clover>yellow serradella> slender serradella. 1 983 herbage yields were: slender serradella>yellow serradella> subterranean clover. For herbage yields, for each rate of fertilizer application, this order was also dictated by the amount of phosphorus absorbed by each of the three species.


1991 ◽  
Vol 31 (6) ◽  
pp. 777
Author(s):  
MDA Bolland

The effect of superphosphate applications (0, 25, 50, 75, 100 and 125 kg P/ha to the soil surface) on the dry matter (DM) herbage production of dense swards of subterranean clover (Trifolium subterraneum cv. Junee) and yellow serradella (Ornithopus compressus cv. Tauro) was measured in a field experiment on deep, sandy soil in south-western Australia. The swards were defoliated with a reel mower at weekly intervals from 88 to 158 days after sowing, to a height of 2 cm for the first 9 cuts, 4 cm for the tenth cut and 5 cm for the eleventh cut. Yellow serradella was more productive than subterranean clover. Consequently, for the relationship between yield and the level of phosphorus (P) applied, yellow serradella supported larger maximum yields and required less P than subterranean clover, to produce the same DM herbage yield. Maximum yields of yellow serradella were 12-40% larger. To produce 70% of the maximum yield for yellow serradella at each harvest, yellow serradella required about 50% less P than subterranean clover. However, when yields were expressed as a percentage of the maximum yield measured for each species at each harvest, the relationship between yield and the level of P applied was similar for both species, and they had similar P requirements.



1959 ◽  
Vol 10 (3) ◽  
pp. 305 ◽  
Author(s):  
RC Rossiter

A large number of strains of subterranean clover was grown as single plants and in swards in a series of 1-year experiments. The relationship between the interval from seeding to flowering ("maturity grading") and the production pattern varied according to plant density. In the case of single plants, both total yields and seed yields increased linearly with increasing maturity grading. With swards, on the other hand, total yields showed scarcely any relation to increasing maturity grading – there was a slight decline, in fact – while seed production fell rapidly. Hence the early strain Dwalganup gave the lowest seed yields as single plants, but the highest seed yields in swards, whereas the reverse situation held for the late strains Wenigup and Tallarook. The main factor responsible for the differences in these production patterns was considered to be available soil moisture supply. It was shown that in the few cases where soil moisture was severely limiting in spring for single plants, yields levelled off (and seed yields even declined) at higher maturity gradings. Three points are discussed at some length: the influence of environment on the seed yield of strains grown as single plants, the effect of plant density on the ratio seed weight/total weight, and production in relation to maturity grading in swards.



1994 ◽  
Vol 45 (7) ◽  
pp. 1557 ◽  
Author(s):  
I Kuhnel

This study examines the relationship between the Southern Oscillation Index and the sugarcane yield anomalies at 27 mills in north-eastern Australia (Queensland) for the period 1950-1989. The major results of this work indicate that the SO1 alone seems to have only a limited value as predictor of total sugarcane yields over large areas (i.e. the whole of Queensland). However, on a smaller scale, the SO1 appears to be a useful indicator of yields for the northern sugarcane districts. In these northern areas, the highest correlations with the SO1 are reached during the southern hemisphere spring and summer months 6 to 11 months prior to the harvest. They are negative and explain about 40% of the total variance. They also suggest that a positive SO1 during the spring and summer months tends to be followed by lower-than-normal yields at the following harvest and vice versa. This signal is rather robust and withstands rigorous significance testing. Moreover, it appears that the relationship between the SO1 and the sugarcane yields has been relatively strong and stable for the past 40 years, but weakened substantially during the 1930-1940 period.



1985 ◽  
Vol 25 (3) ◽  
pp. 595 ◽  
Author(s):  
MDA Bolland

In three experiments located near Esperance, Western Australia, the effect of superphosphate phosphorus on seed yields of subterranean clover, serradella and annual medics was measured on newly-cleared soils, using low seeding rates. In two experiments, the relationship between seed yield and the amount of phosphorus applied was linear for subterranean clover and serradella; seed yields increasing by 7-24 kg/ha for each kg/ha of phosphorus applied, depending on species, strain or cultivar, and location. In the third experiment, seed yields of annual medic species also increased markedly with increasing amounts of applied superphosphate phosphorus, this response also depended on species and strain or cultivar, but the responses become less marked with increasing amounts of phosphorus. For the annual medic species, the phosphorus treatments had no effect on average weight of one burr, number of seeds per burr, weight of one seed, or the rate of softening of hard seeds as measured both in a 15/60� alternating temperature oven (one cycle/day) or for samples of burrs collected periodically during summer from the field. For all legumes, the appearance of first flowers was not affected by phosphorus treatment.



Author(s):  
Surya Gentha Akmal ◽  
Agus Santoso ◽  
Yonvitner ◽  
Ernik Yuliana ◽  
Jiří Patoka

Cherax quadricarinatus is a parastacid crayfish native to parts of north-eastern Australia and southern New Guinea. It is a relatively large and highly fecund species in comparison with other crayfish of this genus. Since C. quadricarinatus was previously assessed as an invasive species in Indonesia, further monitoring of this species in this region was recommended. Detailed understanding of its spatial behaviour can be the basis for further research aimed at improved management. Field sampling was performed outside its native range in Java, Indonesia from 2019–2020, resulting in data useful for modelling the species' spatial distribution. The occurrence of the species was confirmed in 66 of 70 surveyed localities with 51 new records for Indonesia. Future investigations focused on the relationship between the spatial distribution and dispersal pattern of C. quadricarinatus and its interactions with native biota and entire ecosystems were recommended.



1994 ◽  
Vol 45 (7) ◽  
pp. 1427 ◽  
Author(s):  
RAC Jones

During 1989-92, subterranean clover ( Trifolium subterraneum L.) was grown in field experiments in which swards of six cultivars were infected with bean yellow mosaic potyvirus (BYMV) by transplanting small BYMV-infected subterranean clover plants into them. The swards were then grazed by sheep or mown to simulate grazing. The infected transplants were the primary virus source for subsequent spread by aphids. Spread initially centred on infected transplants resulting in circular expanding infected patches. Later, secondary patches, isolated affected plants and more generalized infection sometimes developed. The extent of spread within swards from the transplants varied with cultivar, BYMV isolate, site and year. Final BYMV incidence ranged from 12% of plants symptom-affected by isolate MI in cv. Junee in 1991 to 100% by isolate SMB in cv. Leura in 1992. BYMV spread mostly occurred in spring and was increased around the edges of areas of bare ground in swards. In two experiments at one site in which 'mini swards' of cvv. Green Range, Karridale and Leura were mown repeatedly, BYMV-infection decreased herbage yields (dry weights) by 12-16% while seed yields were decreased significantly (by 37-40010) in one experiment. In a grazing experiment at a second site with swards of cvv. Esperance and Karridale, BYMV-infection decreased overall yields of herbage by 18-39% and seed by 11-12%; herbage yield losses within symptom-affected patches were 28-49%. In a further grazing experiment at this site with swards of cvv. Junee and Karridale, BYMV-induced losses determined from symptom-affected patches were 21-29% for herbage and 15-25% for seed. In a grazing experiment with swards of cvv. Denmark and ~ e u r a ' at a third site, BYMV-induced overall herbage yield decreases of 8-12% were still recorded despite extensive BYMV spread to control swards; yield losses within symptom-affected patches were 18-25% for herbage and 35-47% for seed. Seed yield losses were due to decreased seed size (mean seed weight), fewer seeds being produced, or both. Estimates of the effects of different levels of BYMV infection on herbage yields in partially infected grazed swards were obtained for cvv. Denmark, Karridale and Leura by plotting individual quadrat data for herbage dry weights against % symptom-affected plants. Losses increased in proportion to the level of infection, but their magnitude also varied with cultivar and experiment. It is concluded that BYMV infection of subterranean clover pastures is cause for concern, not only as regards herbage yield losses but also as regards depletion of the seed bank, which, when compounded year by year, results in pasture deterioration. Early and prolonged aphid activity, reseeding the pasture with susceptible cultivars, heavy grazing and extended growing seasons are all likely to magnify BYMV-induced losses.



1992 ◽  
Vol 32 (8) ◽  
pp. 1095 ◽  
Author(s):  
BS Dear ◽  
DJ Conlan ◽  
MF Richards ◽  
NE Coombes

The tolerance of 6 cultivars of Trifolium subterraneum (subterranean clover) to simazine applied at 0.63 and 1.25 kg a.i./ha was determined under weedfree conditions in the field by measuring herbage and seed yields. Large herbage yield losses occurred as a result of the simazine in spring in the 2 years of the experiments. In 1989, spring herbage yield losses of the cultivars at the 0.63 and 1.25 kg/ha simazine rates averaged 56 and 82%, respectively. In 1990 the spring herbage yield losses were 27 and 51%. Significant variation in tolerance was observed between cultivars in both years, with Trikkala being the most tolerant and Karridale the most susceptible cultivar. Rate of herbicide had the greatest effect on herbage yield, with cultivar having a smaller effect. In 1989, with relatively favourable spring conditions, clover seed yields were depressed by simazine, but in 1990 when drier conditions prevailed during flowering and seed set, seed yields were unaffected or slightly increased by simazine in all cultivars except the early-flowering cultivar Dalkeith. Seed yields of simazine-treated swards were 196-1480 kg/ha in 1989 and 359-686 kg/ha in 1990. The seed yield response in 1990 suggests that herbicides which retard growth in winter help to conserve soil water and, therefore, may benefit seed filling later in the season. The presence of Lolium rigidum at spraying did not reduce the effect of the herbicide on clover herbage yield and had no effect on seed set. Although simazine may reduce herbage yields and, in some cases, seed yields, its use may be justified for the control of annual grasses when other factors such as disease control, pasture quality, and level of weed competition are considered.



1987 ◽  
Vol 27 (1) ◽  
pp. 87 ◽  
Author(s):  
MDA Bolland

In 2 experiments on sandy soil near Esperance, W. A., superphosphate and Duchess (Queensland) apatite rock phosphate were either left on the soil surface after application (topdressed) or incorporated into the top 10 cm of the soil with a rotary hoe (incorporated). One experiment was on Fleming gravelly sand which had a greater capacity to adsorb phosphorus than did the deep yellow sand (Gibson sand) used in the other experiment. Dry matter or seed yield of subterranean clover and phosphorus content of dry herbage or seed were used as indicators of the effectiveness of the phosphorus treatments. Compared with topdressed superphosphate, incorporation of superphosphate did not greatly influence its effectiveness on the Gibson soil, but reduced its effectiveness by about 20% on the Fleming soil. Relative to topdressed rock phosphate, incorporation of rock phosphate almost doubled its effectiveness on the Fleming soil, and improved its effectiveness by about 1.5 times on the Gibson soil. Superphosphate was the more effective fertiliser. Relative to topdressed superphosphate, the effectiveness of topdressed and incorporated Duchess rock phosphate, respectively, was about 15 and 30% on the Fleming soil, and about 25 and 40% on the Gibson soil. There was no evidence of any leaching of phosphorus from Duchess rock phosphate from the 0-10 cm layer of either soil, nor of superphosphate on the Fleming soil. However, on the Gibson soil, there was some leaching of superphosphate to below 10cm, but not below 20 cm.



1999 ◽  
Vol 50 (2) ◽  
pp. 191 ◽  
Author(s):  
R. L. Aitken ◽  
T. Dickson ◽  
K. J. Hailes ◽  
P. W. Moody

Split-plot field experiments, with main plots consisting of various rates of calcitic lime and single rates of dolomite, gypsum, and calcium silicate, were conducted at each of 4 sites to determine the effect of band-applied magnesium (Mg) on maize yield. The sites were acidic with pH values of 4.5, 4.9, 5.0, and 6.1 and exchangeable Mg levels of 0.16, 0.10, 6.0, and 2.0 cmol(+)/kg, respectively. Magnesium significantly (P < 0.05) increased grain yield at the 2 low-Mg sites, both of which were strongly acidic and responsive to lime application, but the nature of the Mg × lime interaction was different at each of the 2 responsive sites. The absence of a response to Mg at lime rates ≥1 t/ha at one responsive site was attributed to the presence of small amounts of Mg in the calcitic lime and/or an improved root environment enabling better exploitation of the soil Mg. Supplying a readily soluble source of Mg in the fertiliser band also resulted in increased grain yield in the gypsum, dolomite, and calcium silicate treatments at the 2 Mg-responsive sites. When the initial soil pH was strongly acidic, exchangeable Mg levels increased with increasing lime rate, suggesting that the small quantities of Mg that occur in the majority of liming materials may be of importance with respect to Mg nutrition. In contrast, gypsum application exacerbated the Mg deficiency at one site. The relationship between grain yield response and soil Mg level across all sites indicated that above an exchangeable Mg level of 0.27 cmol(+)/kg there would be little likelihood of a response to applied Mg.



1991 ◽  
Vol 31 (6) ◽  
pp. 745 ◽  
Author(s):  
JF Taylor ◽  
PW Ladds ◽  
ME Goddard

Effects on carcass weights of region of origin, season and year of slaughter, breed, sex, age and pregnancy status were examined for 4229 cattle slaughtered in selected Australian abattoirs in 1973 and 5708 cattle in 1977-78. For non-pregnant cows slaughtered in 1973, the relationship between carcass weight and presence of cyclic activity of the ovaries was examined at slaughter. Data from abattoirs in Rockhampton, Mackay and Townsville are also presented on carcass weights of about 641 000 cattle killed from January 1977 to November 1979. In 1977-78, at abattoirs in northern, central and eastern Australia, carcass weights of slaughtered bulls averaged 269 kg, steers 263 kg and cows 188 kg, compared with mean carcass weights of 263, 276 and 186 kg for all bulls, steers and cows killed in 3 northern Queensland abattoirs during 1977-79. Cows slaughtered in north-eastern Australian abattoirs in 1973 averaged 160 kg. After adjusting for breed, sex and age differences, carcass weights of cattle slaughtered in 1977-78 differed by region of origin, with greater weights from subtropical than from northern tropical and coastal regions; and by season of slaughter, with lowest weights being recorded in spring. Carcass weights of cows from tropical regions and slaughtered in 1973 increased by 10 kg (British breed), 32 kg (Brahman) and 69 kg (British x Brahman), as age increased from 2 to 5 years. With increased age beyond 5 years, carcass weights of these cows decreased. Conversely, carcass weights of British breed cows reared in subtropical regions and slaughtered in 1977 increased by 37 kg throughout the 2-12 year age range. After adjusting for breed, age, season and regional differences, mean carcass weights of non-pregnant, cycling cows and cows grouped according to trimester of pregnancy were not different. Carcass weights of cows which were non-pregnant and non-cycling were 12 kg less than cows which were non-pregnant but cycling. Cycling prevalence in Brahman cows exceeded those of British breed or British x Brahman cows from northeastern Australia, when compared at the same age and carcass weight. Age had no effect on cycling prevalence when cows were compared at the same carcass weight.



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