Comparative growth responses of N2-fixing and N-fertilized subterranean clover on acid soils

1987 ◽  
Vol 97 (1) ◽  
pp. 151-154 ◽  
Author(s):  
S. F. Wright ◽  
R. J. Wright ◽  
O. L. Bennett

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.



1959 ◽  
Vol 12 (4) ◽  
pp. 205 ◽  
Author(s):  
William A. Williams ◽  
Burgess L. Kay


1969 ◽  
Vol 20 (3) ◽  
pp. 435 ◽  
Author(s):  
D Bouma

Subterranean clover plants were grown in river sand or in culture solutions with and without phosphorus. Some phosphorus-deficient plants were sprayed once every 2–3 days with solutions (pH 2.5) of several phosphorus compounds at various concentrations, with and without wetting agents. Dry weights of tops and roots were significantly increased by most spray treatments compared with control plants grown without phosphorus. Foliar applications of 50 mM phosphoric acid solutions, containing little or no wetting agent, generally gave the greatest response. In the first experiment the plant dry weight in the best spray treatment was twice as high and in the second experiment 3.5 times as high as in the controls without applied phosphorus. In these spray treatments plant dry weight was no more than 40% of that in the control treatment receiving root phosphorus. Two days after application of 32P (solution pH 5.5, 0.01 mM phosphate) to the centre leaflet of either the first or the fourth trifoliate leaf, 70% of the tracer could be removed by washing with 20 ml water. Seven days after application of the tracer the treated leaflet of the first or the fourth trifoliate leaf still contained 77 or 70% respectively of the amount absorbed by the plant. In another experiment, in which 32P was applied in a 30 mM H3PO4solution at pH 2.5 or 5.0, washing of the treated leaflet 2 days after application removed 42 and 60% of the tracer respectively. Seven days after application the treated leaflet contained 28 and 34% respectively of the residue after washing. Relatively slow rates of uptake of phosphorus applied to the leaves were considered to be at least partly responsible for the poor growth responses compared with phosphorus applied to the roots. It was concluded that foliar applications of phosphorus offered little scope as a practical means of hastening the recovery from phosphorus deficiency.



1964 ◽  
Vol 15 (4) ◽  
pp. 609 ◽  
Author(s):  
KD Nicolls ◽  
JL Honeysett

In glass-house experiments, cobalt was added at rates corresponding to 18, 32, or 36 oz CoSO4.7H2O per acre to 27 soils, mostly krasnozems. This treatment raised the cobalt content of subterranean clover tops significantly on only 13 soils, and on only five of the 13 by more than 0.05 p.p.m. Cobalt in control plants ranged from 0.05 to 0.32 p.p.m. The largest recovery of applied cobalt, by two successive crops of subterranean clover, was 4% of that applied. Mechanical contamination of plant material was avoided by adding the cobalt before sowing the first crop. Perennial ryegrass and white clover gave similar results, over four or five harvests. The implications for the practice of top-dressing pastures with cobalt salts are discussed. Cobalt application at the 36 oz rate increased cobalt in subterranean clover more than the 18 oz on three of the four soils tested at the two rates. There was some evidence for a greater recovery of applied cobalt from the more acid soils, over a pH range of 4.9 to 6.2.



1985 ◽  
Vol 25 (1) ◽  
pp. 149 ◽  
Author(s):  
LJ Horsnell

The response of improved pastures to the application of superphosphate is low on the acid sedimentary soils, of the Southern Tablelands of New South Wales, which contain high levels of exchangeable aluminium. An investigation was made into the effect of surface-applied fertilizers on soil pH and on the establishment and growth of lucerne and phalaris on these soils. At 6 weeks after the application of gypsum, superphosphate, or superphosphate plus potassium sulfate, soil pH (H2O) had decreased markedly. This effect extended to a depth of 20 cm, but decreased with time. Initially, lime application increased the pH of the surface soil only. When superphosphate was applied with lime the pH of the soil under the lime layer decreased to the same level as that found in the soil treated with superphosphate alone. Lime, however, had penetrated into the subsoil 102 weeks after application and substantially more so after 13 years. Soil pH (0.01 M CaCl2) was not depressed by the application of fertilizers. Growth and persistence of both species in the first summer were poor, but growth responses to phosphorus, lime and nitrogen increased after the first year. Lucerne showed large growth responses to lime, greater than those found on plots receiving nitrogen fertilizer. Lime reduced aluminium levels both in lucerne plants and in soil. It is suggested that the slow penetration of lime into the soil, the relatively quick effect of superphosphate in increasing subsoil acidity, and high soil aluminium levels are together responsible for the poor persistence and slow growth of both lucerne and phalaris in the early stages. The subsequent large dry matter responses of lucerne to lime are possibly related to increased nitrogen fixation and a lowering of plant and soil aluminium levels. It is suggested that the lime responses of phalaris are also related to lower aluminium levels.



1983 ◽  
Vol 23 (121) ◽  
pp. 192 ◽  
Author(s):  
SM Bromfield ◽  
RW Cumming ◽  
DJ David ◽  
CH Williams

Three methods of estimating available manganese and aluminium status in acid soils were compared on three groups of soils from the Pejar district near Goulburn, New South Wales in which differences in pH had been brought about by different periods under subterranean clover pasture. Managanese extracted by 0.01 M calcium chloride gave the best correlation with the manganese concentration in rape and subterranean clover grown in pot culture, and provided the best index of available manganese. Soil solution manganese was inferior to CaCl2-extractable manganese and was more difficult to determine. Extraction with neutral ammonium acetate was unsatisfactory because this reagent overestimated available forms of manganese in soils containing high levels of reactive manganese. Aluminium extracted by 0.01 M CaCl2 was well correlated with exchangeable aluminium and with percentage aluminium saturation of the effective cation exchange capacity. None of the three measures of aluminium status alone was an effective index for predicting lime response by rape on these soils because both manganese and aluminium status were involved in this response. These three parameters were equally effective in multiple regressions for yield responses of rape to lime. Because of its relative ease of determination, CaCl2 extraction is preferred as a practical measure of aluminium status. Aluminium interacted with and increased the toxic effects of manganese in rape. Thus CaCl2-extractable manganese alone only provided a satisfactory index of a 'critical' value for manganese toxicity in rape for soils low in available aluminium. Subterranean clover was only slightly affected by aluminium and manganese levels in these soils, and manganese toxicity symptoms were only observed on soils containing 50 ppm or more CaCl2-extractable manganese. Nodulation failure in pots occurred in all soils with pH below 5.2 (water) or below 4.3 in CaCl2, whereas nodulation was normal when these soils were treated with CaCO3 to raise the pH to 5.8-6.0 (water). With one exception nodulation appeared adequate at field sites from which soils showing nodulation failure in the glasshouse had been collected.



1995 ◽  
Vol 27 (4-5) ◽  
pp. 663-671 ◽  
Author(s):  
M.B. Peoples ◽  
D.M. Lilley ◽  
V.F. Burnett ◽  
A.M. Ridley ◽  
D.L. Garden


1985 ◽  
Vol 36 (5) ◽  
pp. 695 ◽  
Author(s):  
RA Culvenor

Tolerance to excess manganese in 13 Mediterranean accessions and 3 Australian cultivars of phalaris was determined in solution culture with manganese concentrations from 0.5 to 210 ppm. The effect of aluminium (0, 2.5, 5-0 ppm) on the response of two accessions to excess manganese was studied in a second experiment. Phalaris was very tolerant to excess manganese. Shoot yield at 150 ppm manganese ranged from 25 to 50% of the maximum yield, which was achieved at 0.5 ppm in some lines and at 40 ppm in others. The cultivars Australian and Sirosa were among the most tolerant types. With one exception, Algerian accessions were the least tolerant. These accessions were of similar tolerance to Egret, the most tolerant wheat cultivar examined. All phalaris lines were much more tolerant than Isis wheat, Clipper barley, Woogenellup subterranean clover and Jumbuck rape. Variation in tolerance of high internal manganese levels was the principal determinant of relative tolerance within phalaris. Shoot manganese concentrations causing 10% yield reduction ranged from 730 to 2200 8g g-1 dry wt. The greater tolerance of phalaris compared with the other species was due to lower manganese uptake and higher internal tolerance. Presence of aluminium in the solution did not increase the susceptibility of phalaris to manganese toxicity. Aluminium strongly reduced manganese uptake in phalaris. It is concluded that selection for manganese tolerance need be only of low priority in developing a phalaris cultivar with improved tolerance of acid soils.



2003 ◽  
Vol 43 (1) ◽  
pp. 61 ◽  
Author(s):  
G. D. Li ◽  
K. R. Helyar ◽  
C. M. Evans ◽  
M. C. Wilson ◽  
L. J. C. Castleman ◽  
...  

Two permanent pastures (annual pasture v. perennial pasture) were established in 1992 as part of the long-term field experiment, MASTER — Managing Acid Soils Through Efficient Rotations. The primary objective of the experiment was to develop an agricultural system that is economically viable and environmentally sustainable on the highly acidic soils in south-eastern Australia. This paper reports on the effects of lime on the botanical composition changes of annual and perennial pastures over 9 years. In general, lime increased the proportion of the desirable species, such as phalaris (Phalaris aquatica) in perennial pasture and subterranean clover (Trifolium subterraneum) in annual pastures, and decreased the proportion of the undesirable species, such as Vulpia spp., in both annual and perennial pastures, ultimately improving the quality of feed-on-offer to animals. As a result, the limed pastures carried 24% more sheep than the unlimed pastures, while maintaining individual animal performance similar for both limed and unlimed pastures. The phalaris-based perennial pasture was more stable in terms of maintaining the sown species than the annual pasture. Lime improved the persistence of phalaris and the longevity of the phalaris-based pasture should be at least 10 years. Lime changed the direction of plant succession of annual pastures. Without lime, Vulpia spp. gradually became more dominant while ryegrass and subterranean clover became less dominant in annual pastures. With lime, barley grass (Hordeum leporinum) gradually invaded the sward at the expense of ryegrass, thus reducing the benefits of lime, but this effect was less for the perennial pastures than for annual pastures. Liming perennial pastures should be more beneficial than liming annual pastures because of the beneficial effects on pasture composition. In addition, previously published work reported that liming perennial pastures improved sustainability through better use of water and nitrogen.



1992 ◽  
Vol 32 (8) ◽  
pp. 1061 ◽  
Author(s):  
AM Ridley ◽  
DR Coventry

Yield responses of 3 mixed grass-clover pastures [Phalaris aquatica L. cv. Sirosa (phalaris), Dactylis glomerata cv. Porto (cocksfoot), and annual grass based Trifolium subterraneum L. cv. Trikkala (subterranean clover) pastures] were measured over 5 soil pH treatments at 2 sites in Victoria. One site (Beechworth) was strongly acidic [pH(CaCl2) < 4.21 to a depth of 40 cm and contained high concentrations of soil aluminium (Al). At the other site (Lake Rowan), yield responses to lime application had been measured previously, but only in Al-sensitive wheat cultivars. At Beechworth, pasture yield responses to lime were not consistent but. when observed. occurred in autumn and winter in all 3 pasture types. Phalaris pastures showed yield increases more often than cocksfoot and annual pastures. Low magnesium and calcium concentrations may have limited dry matter production, although yields were reasonable on all treatments. Where lime was applied, growth responses may have been due to alleviation of Al toxicity. At Beechworth, pasture yield was increased where lime increased pH from 4.2 to 4.6 and decreased soil Al (measured in 10 mmol CaCl2/L) from 11 to <3 �g/g soil. Herbage manganese concentrations were not high in phalaris and subterranean clover, and cocksfoot manganese standards were not available. At Lake Rowan (pH 4.7, Al <1 �g/g), no growth responses to lime were seen in any pasture treatment, and annual grass based pastures sometimes had higher yields than phalaris and cocksfoot pastures. On strongly acidic soils such as at Beechworth, incorporation of lime prior to pasture establishment should be considered. Perennial grasses may reduce further soil degradation through acidification. Soil A1 concentrations are commonly lower in ley-cropping areas, and the inclusion of perennial grasses in ley pastures requires further evaluation.



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