The influence of aluminium on phosphate sorption by whole plants and excised roots of some pasture legumes

1973 ◽  
Vol 24 (3) ◽  
pp. 341 ◽  
Author(s):  
CS Andrew ◽  
PJVanden Berg

The effects of aluminium (0, 0.5, 1.0, and 2.0 p.p.m.) on dry matter production and subsequent short-term uptake and translocation of phosphorus in whole plants, and on the uptake of phosphorus by excised roots, of six tropical pasture legumes were ascertained. Macroptilium lathyroides, Desrnodiurn uncinaturn, Lotononis bainesii, and Stylosanthes hurnilis were tolerant species in terms of effects on dry matter production. Glycine wightii was a sensitive species and Medicago sativa a very sensitive one. In the whole plant study, plants were grown in Solution culture with a phosphorus concentration of 2 p.p.m., under the above aluminium treatments. Aluminium increased the subsequent uptake of phosphorus (tops+roots) in all species (phosphorus substrate concentration 1 x 10-5M labelled with 32P, 1 and 3 hr uptake periods). Phosphorus uptake in the tops of the four tolerant species was increased by aluminium treatment, and in the two sensitive species it uas reduced. In both the absence and presence of applied aluminium, L. bainesii was the most efficient species per unit weight of root tissue in sorbing total phosphorus, and in addition had the highest efficiency of translocation of phosphorus from roots to tops. S. humilis was also an efficient species. In the excised root study, addition of aluminium to the solution enhanced the sorption of phosphorus by all species. The enhancement was greater in a relatively strong phosphorus solution (2 x 10-4 M) than in a dilute solution (1 x 10-4). The sorption of phosphorus by excised roots of S. humilis from dilute and relatively strong phosphorus substrates was greater than that of other species, both in the absence and presence of added aluminium. L. bainesii was omitted from the excised root experiments.

1989 ◽  
Vol 40 (4) ◽  
pp. 833
Author(s):  
JD McFarlane

Seven rates of copper were applied to the soil prior to the sowing of strawberry clover (Trifolium fragiferumL. cv. Palestine) on an alkaline peat deficient in copper. Symptoms of copper deficiency were evident only on the untreated plots where the clover did not set seed nor persist into the second year.Over five years� production, 1.0 kg Cu/ha continued to provide adequate copper, with regular dressings of superphosphate, for maximum dry matter production and seed yield. It was found that seed yield was more sensitive than vegetative dry matter yield to sub-optimal copper supply. At the lowest rate of applied copper (0.125 kg/ha), the vegetative yield ranged from 53% to 80% of the maximum harvest yield, whereas the seed yield ranged from 15% to 50% of maximum yield.For tissue sampled in the spring, the proposed critical range for copper concentration in the youngest open leaf (YOL) for vegetative dry matter production is 3-35 mg Cu/kg whereas that for seed production is 4.5-5.5 mg Cu/kg. At other times of the year the critical concentrations were higher. It was not clear if this was due to environmental conditions or changing internal requirements for copper.The critical copper concentration range in whole top (WT) tissue of 3.0-4.0 mg/kg for vegetative dry matter production could be applied to all samplings. For seed yield the critical range for copper concentration in WT was 4.0-5.0 mg/kg for the spring harvests. The critical copper concentration in seed for seed production was 5.0-6.0 mg/kg. In the pasture situation a critical concentration of 5.0-6.0 mg Cu/kg in the WT should be adopted when the animal requirement is considered.


Author(s):  
R.E. Fitzgerald

Recent increases in the value of gold have led to renewed interest in gold mining - particularly by the dredging of the river flats bordering West Coast rivers. In any future licensing of such dredging, the rehabilitation of the "destroyed" land will be a major consideration. Nitrogen is the main nutrient limiting the growth of radiata pine on the gold dredge tailings; this paper outlines initial results of an exploratory legume-fertilizer trial on levelled tailings in the Taramakau River valley. Twelve legume species were grown with and without superphosphate (+ MO, Mg and K). Tree lucerne (Cytisus proliferus) , Russell lupin (Lupinus polyphyllus) and yellow tree lupin (L. arboreus) grew well without the application of fertilizer but the pasture legumes had substantially increased dry matter production where P was added - in white clover (Trifolium repens) dry matter production was increased from 5.4 to 8.9 t/ha; and total N was 180 and 310 kg N/ha. Tree nutrition and growth were greatly improved by association with a vigorous legume species, In addition, the presence of legumes improved the appearance of the tailings and with a pasture species grazing potential was created


2000 ◽  
Vol 40 (7) ◽  
pp. 939 ◽  
Author(s):  
R. A. Ballard ◽  
N. Charman

The ability of 11 species of annual medics (Medicago doliata, M. laciniata, M. littoralis, M. minima, M. orbicularis, M. polymorpha, M. praecox, M. rigidula, M. rigiduloides, M. tornata and M. truncatula) to nodulate and fix nitrogen with naturalised rhizobia from 28 South Australian soils was assessed. The number of rhizobia in the soils was estimated. Medic shoot dry matter production and nodulation were measured, after inoculation of medic seedlings with a soil suspension, in 2 glasshouse experiments. The number of medic rhizobia ranged from 0.4 10 2 to 1.5 10 6 per gram soil. Medicago laciniata was the only medic species tested which was not consistently nodulated by the soil rhizobia. While all the other species formed nodules, they varied widely in their ability to form an effective symbiosis. Symbiotic performance (which indicates how much growth the medic line achieved, when compared to an effective inoculation treatment) of the medic species ranged from 3% (M. rigiduloides) to 67% (M. praecox). Herald (M. littoralis) achieved a symbiotic performance of 49% and it was estimated that this would be insufficient to meet the nitrogen requirements of a Herald-based pasture during early growth. The symbiotic performance of Santiago (M. polymorpha) was low (17%) and erratic (from –6 to 72%). The ability of the rhizobia to form an effective symbiosis varied widely also between soil regions. For example, the rhizobia in Riverland soils resulted in only 31% of the shoot dry matter of those in Eyre Peninsula soils, in association with M. polymorpha. There are significant opportunities to improve the symbiotic performance of a number of the species of annual medics examined in this study. Options to improve the effectiveness of the symbiosis of medics with naturalised soil rhizobia are discussed.


1986 ◽  
Vol 26 (4) ◽  
pp. 445
Author(s):  
DK Muldoon

The elements nitrogen, phosphorus, potassium, sulfur and zinc were sequentially omitted from a 'complete' fertiliser applied to plots on an alkaline soil, and lucerne (Medicago sativa) was sown immediately afterwards. The dry matter production of lucerne was measured in repeated cuts over 2 years; its mineral composition was determined periodically. In a second experiment 4 rates of phosphorus were applied to a l -year-old stand of lucerne and dry matter production recorded for 1 year. Lucerne yields in the first year were reduced from 17-1 8 t/ha to less than 14 t/ha by omitting phosphorus. Yields universally decreased in the second year as the 50 kg/ha P applied at sowing was depleted through the removal of 40 kg/ha P in forage. Following this depletion a linear yield response up to 80 kg/ha P was found (experiment 2). Omitting phosphorus fertiliser reduced the plant phosphorus concentration from 0.23 to 0.21% when sampled 15 months after sowing. The plant phosphorus concentration decreased with time in all treatments. The available soil phosphorus level decreased from an initial 12 to 6-7 �g/g after 6 months and further to 2 �g/g after 30 months. Fertiliser phosphorus raised the soil phosphorus level but this also was depleted to 2-3 �g/g in 30 months. Omitting zinc reduced the plant zinc concentration. However, neither the omission of nitrogen, potassium, sulfur nor zinc from the fertiliser had any effect on lucerne yields.


Author(s):  
R.B. Allen ◽  
I.R. Mcdonald ◽  
N.A. Cullen

White clover (Trifolium repens), red clover (T. pratense), subtcrrnnean clover (T. subterraneum) and alsike clover (T. hybridum) were sown singly or in combinations at three sites in Otago. Ryegrass (Lolium perenne) was included in all clover treatments and was also sown alone. Lucerne (Medicago sativa) was sown alone at two sites. Herbage dry matter production was measured over a three-year period. At the high fertility lnvermay site, white and red clovers gave similar total and legume dry matter production and were markedly superior to alsike and subterranean clovers. White and nlsike clovers were most productive at the higher altitude, low fertility Berwick site, and at the dry, medium fertility Dunback site red clover produced the highest yields. Lucerne greatly outyielded all other species in the second and third years at Invermay and in the third year at Dunback.


1973 ◽  
Vol 13 (65) ◽  
pp. 705 ◽  
Author(s):  
BJ Scott

The dry matter production of a pasture of barrel medic (Medicago truncatula cv. Jemalong) under different rates and methods of application of superphosphate was examined, during 1971 and 1972, on a phosphorus deficient soil at Condobolin, New South Wales. The treatments were factorial combinations of four rates of superphosphate (0, 126, 376, and 753 kg ha-1) and four methods of application of superphosphate (surface spread i.e. topdressed, surface applied in bands, placed at 5 cm depth, and placed at 1 0 cm depth). The dry matter production and phosphorus uptake results demonstrated the effectiveness of subsurface placement of superphosphate, but relative ineffectiveness of surface application during the dry winters experienced. The results also showed that root development in the dry 0-2 cm zone was restricted compared with that in the deeper moist soil layers. Soil phosphorus tests showed that one year after topdressing phosphorus had not moved below the 2-4 cm depth layer, even at 753 kg ha-1 of superphosphate.


1976 ◽  
Vol 27 (5) ◽  
pp. 625 ◽  
Author(s):  
CS Andrew ◽  
AD Johnson

The chemical composition of tops and roots of nodulated and non-nodulated plants of some tropical and temperate pasture legumes grown in sand culture is reported and discussed in relation to nodulation efficiency and dry matter production, and nutrient interaction. In most species, increasing pH raised the nitrogen concentrations in the tops of nodulated plants; calcium treatment had little effect. Increasing the calcium concentration of the nutrient solution from 0.125 to 2.0 mM markedly increased the calcium~ concentration in the tops of all species, but in the roots to only a minor extent. Concentrations in tops differed between species. Concentrations in the tops of modulated plants were increased as a result of increasing pH, particularly at the low calcium treatment and for those species sensitive to low pH (Glycine wightii, Medicago species). Increasing the calcium concentration lowered the magnesium concentration, but the total cation content was not significantly affected. In the tropical species, phosphorus concentrations in the tops were increased by reducing pH at both calcium treatments; values were higher at the low calcium treatment than at the high calcium treatment. Roots accumulated inore phosphorus than the tops. Differences in the response of the species cannot be directly related to their mineral composition. With respect to nodulation and dry matter production, it is considered that the pH is the dominant factor and operates in the nodule initiation phase and in subsequent nitrogen production. _______________ *Part I, Aust. J. Agric. Res., 27: 611 (1976).


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