Nodulation and growth of pasture legumes with naturalised soil rhizobia. 1. Annual Medicago spp.

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.


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.



1969 ◽  
Vol 49 (3) ◽  
pp. 339-349 ◽  
Author(s):  
H. Gasser ◽  
L. Lachance ◽  
P. Gervais

In two experiments, one with alfalfa and the other with birdsfoot trefoil, we have been able to show that a late cut in October does not adversely affect dry matter yield (DAI) of the legumes. Three cuts during a harvesting season ending on September 5 were detrimental to alfalfa, since lower yields were obtained the following year of harvest. Birdsfoot trefoil varieties were affected differentially. Three cuts did not affect the yield of Viking the following year, but did so of Empire. Significant differences in dry matter yields were obtained between DuPuits and Vernal and between Viking and Empire. Protein in the forage followed inversely the same pattern as that of DM yields, that is, where the intervals were shortest, the protein content was highest, and conversely. The total available carbohydrate and the nitrogen content of the roots were lowest following the treatments which had the shortest intervals between them.



1972 ◽  
Vol 23 (6) ◽  
pp. 945 ◽  
Author(s):  
JF Angus ◽  
R Jones ◽  
JH Wilson

Under conditions of adequate moisture an erect-leaf barley cultivar, Lenta, responded to an increase in density (resulting from doubling of the sowing rate) with increases in dry matter production and in grain yield, whereas the cultivar Research, which has long lax leaves, responded with decreases in dry matter production and yield. In a study of canopy structure and its effects on light interception and utilization, it was found that in Research, with a leaf area index (LAI) of 6.1, the leaves were concentrated near the canopy surface and a relatively small proportion of the above-crop light penetrated through this layer. The net crop photosynthesis of this canopy (measured in a field assimilation chamber) was 3.8 g CO2/m2.hr when visible radiation was 313 W/m2. With Lenta (LAI 7.0) on the other hand, leaves were concentrated in the middle layers of the canopy and the light was more evenly distributed throughout the canopy. The net crop photosynthesis with the same radiation as for Research was 4.3 g CO2/m2.hr. The relative rates of photosynthesis at various levels in the canopies were determined by introducing 14CO2 into the assimilation chambers enclosing the cultivars and observing where the 14C was fixed. With Research most of it was localized near the canopy surface while with Lenta most of it was near the centre of the canopy. Of the 14CO2 taken up, 7 % was fixed in the leaf sheaths of Research and 12% in those of Lenta.



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.



2003 ◽  
Vol 1 (1) ◽  
pp. 35
Author(s):  
J.L. Martin Polo ◽  
C.J. Valle Gutierrez ◽  
A. Blanco de Pablos ◽  
M.E. Sánchez Rodríguez

In two «dehesa» grasslands with different soils, one over slate and the other over granite, studies were carried out toinvestigate the influence that phosphoric fertilization, surface tillage of pastures and oat sowing have on the primaryproduction and its nutritive value, on the index of utilization of raining water, and on the evolution of oat stubble withtime. Additionally, economic studies of the previous results have been carried out. Phosphoric fertilization and superficialtilling of pastures did not have a relevant influence on the primary production. Additionally, in the successive regrowthover oat stubble there was no response to phosphoric fertilization. The production increments with respect tocontrols are related to the preparatory tillage for sowing the oats, and the changes that the vegetation experimented.This effect decreased with time. The dry matter production in the oat treatments was higher than in the pastures, bothin slate and granite soils. In dehesa systems the use of raining water for the production of 1 kg dry matter ha-1 was verylow, and, on the average, 0.278 and 0.588 l m-2 were needed in pastures, but this amount decreased significantly in theoats: 0.059 and 0.110 l m-2 in slates and granites, respectively; with better use of the water in the more fertile soils. Theeconomic response to the oat sowing was about 252 and of 160 euros ha-1 year-1 in slates and granites, but there was noeconomic response to the fertilization and superficial tilling of pastures during the period of the experiment.



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



2010 ◽  
Vol 58 (1) ◽  
pp. 81-89 ◽  
Author(s):  
Z. Tóthné Zsubori ◽  
I. Pók ◽  
Z. Hegyi ◽  
C. Marton

Leafy hybrids represent a new direction in the breeding of silage maize. Not only does the increased number of leaves above the ear in these hybrids lead to an increase in dry matter production, but the large quantity of carbohydrates formed and stored in the leaves results in silage with better chemical quality. Many papers have been published abroad on this subject, but few data have been reported in Hungary.The present work aimed to examine the effect of genotype and year on six leafy and non-leafy silage maize hybrids over a period of four years (2002–2005), with special emphasis on the plant height, ear attachment height, leaf number, and fresh and dry matter yield.The results showed that the number of leaves above the ear was much higher for the two leafy hybrids (8.00 and 9.35) than the average of the other hybrids (5.56, averaged over the years). This trait was in close negative correlation (r 2 = −0.7346) with the ratio of ear attachment height to total plant height, a trait with strong genetic determination, little influenced by the year. In leafy hybrids the main ear was located far lower down, but the total plant height was similar to that of the other hybrids. The ratio of ear attachment height to plant height was 0.36 for the leafy hybrids, but ranged from 0.41 to 0.45 for the other hybrids (averaged over the years). In wetter years the hybrids were taller and had greater dry matter production per plant than in the dry year.



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.



1987 ◽  
Vol 38 (2) ◽  
pp. 231 ◽  
Author(s):  
AR Aston

Wheat was grown in temperature controlled water-baths in order to regulate the temperature of the roots, the growing apex and the zone of leaf extension. Twenty-two alternating day and night temperatures varying between 26 and 2�C were studied. All plants experienced the same aerial environment. Leaf extension rates were measured on 6 days throughout the early growth stages and dry matter production was determined after 39 days. Night leaf extension was found to be related not only to the temperature of the meristem and leaf extension zone during the night, but also to the temperature experienced during the preceding day. Leaf extension during the day was determined by daytime temperature, and also the temperature conditions of the previous night. These growth patterns were explained in terms of leaf sugar concentrations, which were measured at the end of the experiment. Dry matter production was found to be exponentially related to the time-corrected mean daily temperature of the apex, leaf extension zone and roots. These results confirm the suggestion that the improved early vigour of wheat sown by conventional cultivation practices with a minimum of surface residues compared to direct drilled wheat, could at least partially have been due to the different patterns in soil temperature.



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