Nitrogen fixation by subterranean clover (Trifolium subterraneum L.) in an acid soil in response to moisture deficits

1989 ◽  
Vol 21 (1) ◽  
pp. 9-14 ◽  
Author(s):  
A.G. Davey ◽  
R.J. Simpson
1980 ◽  
Vol 20 (106) ◽  
pp. 568 ◽  
Author(s):  
KD McLachlan

A study was made of the role of superphosphate and lime on subterranean clover (Trifolium subterraneum) production on an infertile acid soil in pot culture. Both fertilizers increased the exchangeable calcium in this deficient soil. Lime and superphosphate were involved in nodulation of the clover plants. There was no evidence of the direct involvement of either of them in the nitrogen fixation process, but they did increase nitrogen uptake by the plants. Once the legume functioned adequately, full expression of the yield response to phosphorus on this deficient soil followed. Most efficient phosphorus use occurred at the lime 1255, superphosphate 2000 kg ha-1 level (lime 1/2, P 16). Heavy lime dressing reduced exchangeable magnesium and the phosphorus available to the plant. Aluminium and pH were involved in the effects observed. Lime reduced CaCl2-extractable aluminium and the titratable acidity in the soil. Phosphate increased the CaCl2-extractable aluminium and apparently reduced the titratable aluminium. The combined treatments reduced these three attributes and promoted increased plant growth. Increased plant growth was associated with increased aluminium uptake by the plants, which suggests that the real effect of aluminium may have been on the calcium and phosphorus uptake by the plants, rather than on the toxic nature of the element itself.


1954 ◽  
Vol 5 (2) ◽  
pp. 247 ◽  
Author(s):  
JR Harris

A study was made of a number of effective and ineffective strains of Rhizobium trifolii in association with subterranean clover (Trifolium subterraneum L.), variety Bacchus Marsh. Where these were inoculated singly into sterilized soils in pot experiments conducted in the greenhouse, typical effective, ineffective, or intermediate plant reactions were obtained. Where more than one strain was inoculated, competition between strains took place and was reflected in nodule pattern and plant reaction. Some strains consistently failed to produce appreciable nodules in the presence of other rhizobia, some showed modification to varying degrees, and some were unaffected. Such behaviour was found to be closely linked with the ability of the strain to proliferate in the rhizosphere of the host plant, and placement of inoculum was shown to influence plant reaction. The concept of "incursion" as a property of a rhizobial strain is suggested. An incursive strain is one able to migrate from the initial site of inoculation and establish an adequate population in the root zone of the susceptible host despite the presence of active elements of the indigenous microflora and microfauna, including antagonistic and predatory forms. The property of incursion is independent of considerations of efficiency of nitrogen fixation or virulence for the host plant. Strains of rhizobia which are poorly incursive may fail to infect the host upon which they have been inoculated if subject to competition from indigenous rhizobia already established in the soil. The necessity of assessing properties of virulence and incursion as well as efficiency of nitrogen fixation in selecting rhizobia for purposes of commercial inoculation is stressed, and the methods of making such tests are discussed.


1954 ◽  
Vol 5 (4) ◽  
pp. 608 ◽  
Author(s):  
AG Tyson

Manganese deficiency of subterranean clover (Trifolium subterraneum L.) appeared in pots of a Kangaroo Island soil, the pH of which had been changed by the addition of small amounts of lime from 6.2 (the natural pH) to 6.3-6.5. As a result of this deficiency, yields were severely depressed. The symptoms of manganese deficiency in subterranean clover are described. Chemical analyses of healthy plants showed manganese contents, expressed on a dry matter basis, varying from 30 p.p.m. on a slightly acid soil to over 300 p.p.m. on a strongly acid soil. Plants in various stages of manganese deficiency showed only 4-25 p.p.m. It is suggested that, at the flowering stage, 25 parts of manganese per million parts of dry matter represents the minimum amount of manganese for healthy growth of subterranean clover. Applications of manganese sulphate to the soil at a rate of 56 lb/acre prevented the appearance of manganese deficiency symptoms, increased the manganese content of the clover to 35 p.p.m., and led to nearly a 20-fold increase in growth. Manganese deficiency in subterranean clover has also been seen in the field on Kangaroo Island and one sample examined showed only 9.4 p.p.m. of manganese on a dry matter basis.


1952 ◽  
Vol 3 (2) ◽  
pp. 95 ◽  
Author(s):  
AJ Anderson ◽  
DV Moye

In a study of the factors concerned in the effect of lime on subterranean clover (Trifolium subterraneum L.) on an acid soil where nodulation is defective, it has been found that responses equal to those obtained with heavy dressings of lime can be obtained by the application of molybdenum together with only 2 cwt. of lime per acre at seeding. Marked response to molybdenum was obtained only where low levels of lime were used. Where heavier dressings of lime were applied the clover grew normally and did not then require treatment with molybdenum. Where no lime was used nodulation was defective and, during the first two )ears, response to molybdenum did not occur or was very small. Nodulation subsequently improved on the unlimed soil and response to molybdenum progressively increased over the five-year period of the experiments. In the year of sowing best results were obtained where the inoculated seed was drilled with the lime. The evidence suggests that defective nodulation of subterranean clover may be expected on new land where the soil reactions are less than pH 5.0, and that soils of higher pH but with minimum values less than pH 5.5 are also suspect. The importance of treatment with adequate superphosphate in addition to lime and molybdenum in the development of subterranean clover on this acid soil is stressed. The interpretation and significance of the positive and negative lime-molybdenum interactions obtained are discussed.


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.


2008 ◽  
Vol 59 (9) ◽  
pp. 824 ◽  
Author(s):  
R. C. Hayes ◽  
B. S. Dear ◽  
B. A. Orchard ◽  
M. B. Peoples ◽  
P. L. Eberbach

This study compared the relative tolerances of subterranean clover (Trifolium subterraneum L.), balansa clover (T. michelianum Savi.), and gland clover (T. glanduliferum Boiss.) to acid soil conditions. Seed yield, seedling density, herbage production, N2 fixation, and herbage mineral composition of the 3 legumes were assessed when grown on an acid soil (pHCa of 4.3 and 15% exchangeable Al [0–0.10 m]) with and without the addition of lime (CaCO3). Annual legume species were sown in a mixed sward together with burr medic (Medicago polymorpha L.), and in mixtures with either lucerne (Medicago sativa L.), chicory (Cichorium intybus L.), or phalaris (Phalaris aquatica L.). Due to drier than average seasonal conditions, none of the perennial species persisted beyond the first summer. Lime increased the herbage production of annual legumes by 18–22% and total pasture production by 14% in both 2002 and 2003. Subterranean clover was the most tolerant of the annual legumes to acid soil conditions, showing no visible toxicity symptoms and no response to lime in terms of seed yield. In contrast, both balansa and gland clovers exhibited visual symptoms of manganese toxicity in the absence of lime, with Mn concentrations in the shoots of 817 mg/kg and 626 mg/kg, respectively. Both species responded positively to lime with seed yields increasing by 45% and 124%, respectively. Lime increased the proportion of herbage N derived from N2 fixation by subterranean clover from 29 to 40% and by gland clover from 30 to 43%. Lime had no effect on the proportion of N2 fixed by balansa clover (29–31%), suggesting a suboptimal symbiosis of rhizobia with that species. Adding chicory or phalaris to the pasture mix increased sward herbage production in the establishment year by 39% and 21%, respectively. Based on leaf symptoms and herbage yield responses to lime, Mn toxicity was present in lucerne with tissue levels of up to 916 mg/kg, but no symptoms were observed in chicory (1129 mg/kg) or phalaris (403 mg/kg). Chicory and phalaris were more tolerant of acidity and high levels of Mn than lucerne, gland clover, and balansa clover. The study highlighted the value of the small-seeded annual legumes, balansa clover and gland clover, to the production of mixed pasture swards even in drier than average seasonal conditions. Although more sensitive to acid soils than subterranean clover, they set a greater number of seeds and, in the case of balansa clover, a greater weight of seed under moisture stress in the establishment year than the larger seeded subterranean clover.


1959 ◽  
Vol 12 (1) ◽  
pp. 26 ◽  
Author(s):  
JF Loneragan

It has been shown that calcium has a specific effect upon nitrogen fixation by subterranean clover (Trifolium subterraneum. L.).


1953 ◽  
Vol 4 (2) ◽  
pp. 151 ◽  
Author(s):  
KD McLachlan

The results of a field experiment on two acid podzolized soils in the Heytesbury area, Victoria, are presented. Nutrient elements were tested on a phalaris (Phalaris tuberosa L.) - subterranean clover (Trifolium subterraneum L.) pasture on an area cleared from heath and on an adjoining area cleared from timber with an understorey of heath. Responses of clover to lime and copper, and interactions between these treatments were obtained. There was no response to potash, zinc, manganese, molybdenum, iron, magnesium, or boron on either soil. Lime increased the yield of clover at both sites, the greater effect occurring on the area cleared from timber. The effect of lime was not due to the release of soil molybdenum. Lime corrected defective nodulation, increased the survival of the plants, and to some extent also increased the yield of individual plants. The relative significance of these effects of lime in determining the final yield of clover per acre is discussed. The effect of copper was very different on the two soils. On the area cleared from heath, copper deficiency was severe. Here, copper increased the yield in the absence as well as in the presence of lime. The effect was considerably greater in the presence of lime, and this positive interaction was highly significant. Copper increased the number of plants per unit area and the yield of individual clover plants. On the area cleared from timber, copper decreased the yield in the absence of lime. Where lime had been applied, the effect of copper on the yield, though not significant, was positive. The evidence presented indicates that copper is also required on this soil. A copper deficiency symptom of subterranean clover is described. It is suggested that the copper status of the soils may influence the distribution of trees in the area.


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