Effects of environmental variables on the competition between inoculum strains and naturalized populations of Rhizobium trifolii for nodulation of Trifolium subterraneum L. and on rhizobia persistence in the soil

1982 ◽  
Vol 33 (5) ◽  
pp. 803 ◽  
Author(s):  
J Brockwell ◽  
RR Gault ◽  
M Zorin ◽  
MJ Roberts
Keyword(s):  
Plant Growth ◽  
Soil Ph ◽  
Environmental Variables ◽  
Trifolium Subterraneum ◽  
Climatic Conditions ◽  
Cumulative Effects ◽  
First Year ◽  
Rhizobium Trifolii ◽  
Eastern Australia ◽  
Second Year

Experiments were conducted at six field sites in south-eastern Australia with three cultivars of Trifolium subterraneum L, inoculated with diverse strains of Rhizobium trifolii. The various locations provided different edaphic and climatic conditions for plant growth, and naturalized populations of R. trifolii provided competition in forming nodules for the inoculum strains. Success of the inocula in forming nodules in the first year was used as an index of competitiveness, and success in the second year as an index of persistence. Inoculum strains formed a majority of nodules in the first year but fewer in the second. Inocula generally persisted better at those sites which had smaller populations of naturalized rhizobia. Competitiveness and persistence did not appear to be related characteristics, although some strains were superior to others especially in terms of persistence. Values for strain persistence tended to be similar at locations where the Mt Barker cultivar was grown, indicating an effect of host on the expression of this character. Significant effects of soil texture, soil pH, or growth temperature (individually) on the relative competitiveness and persistence of the inoculum strains could not be measured, although the cumulative effects of these (and other) environmental variables may have been substantial. The inoculum strains could be assembled into groups according to strong relationships of nodulating performance at each harvest. Within these distinct groups, the nodulation behaviour of the strains relative to each other remained approximately constant, irrespective of the absolute levels of competitiveness or persistence, the location of the experiment, or the year of the harvest.

scholarly journals The influence of meteorological conditions on major quantitative and qualitative traits of buckwheat (Fagopyrum esculentum Moench)

2003 ◽  
Vol 48 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Radojka Maletic ◽  
Radosav Jevdjovic
Keyword(s):  
Precipitation Amount ◽  
Seed Mass ◽  
Climatic Conditions ◽  
Meteorological Conditions ◽  
First Year ◽  
Lower Mass ◽  
Second Year ◽  
Average Plant ◽  
Fagopyrum Esculentum Moench ◽  
Year 2000

The results of two-year investigations of buckwheat raised in agroecological conditions of South Banat (Pancevo) and West Serbia (Gorobilje) are presented in the paper. Based on the obtained investigation data, we confirm the hypothesis that buckwheat is a plant suited to more humid regions, since we have determined higher yield of the plant on locations with higher precipitation amount. During 1999, the yield of buckwheat was higher at the location in Pancevo and the next year at the location in Gorobilje. Also, in the year 2000, values of average plant height, number of seeds per plant and seed mass per plant were higher at the location in Gorobilje, whereas in the year 1999 (first year of investigation), which from the aspect of climatic conditions could be considered as optimal, plant yield and all other investigated parameters were better in case of buckwheat originating from the location in Pancevo. In the year 2000, in regard to the seed proportionally medium fractions were more present, which is, among other things, the result of the influence of higher precipitation amount. In regard to the exploitation value of the seed, better germination was registered for seed produced in 2000 (at both locations), although it had lower mass compared to the seed produced in 1999. Blossoming (blooming) in the first study year at both locations started 5 to 7 days earlier compared to the second year of investigations and lasted 5 to 8 days longer. On the other hand, in the second year of investigations at both locations harvesting started 10 to 12 days earlier compared to the previous year.

The short-term effects of rock phosphate and super-phosphate on a subterranean clover pasture.

1955 ◽  
Vol 6 (4) ◽  
pp. 553 ◽  
Author(s):  
RC Rossiter ◽  
PG Ozanne
Keyword(s):  
Rock Phosphate ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Phosphorus Recovery ◽  
Available Phosphorus ◽  
First Year ◽  
Short Term ◽  
Pasture Production ◽  
Total Plant ◽  
Second Year

A 2-year field experiment is described, in which an annual-type pasture was grown on a soil of lateritic origin with various initial rates of rock phosphate and superphosphate. The soil was acutely deficient in plant-available phosphorus at the outset. Application of superphosphate led to the expected increases in total pasture production, but rock phosphate also gave substantial yield increases, even during the first season. Differential species effects were noted; subterranean clover (Trifolium subterraneum L.) and cape-weed (Cryptostemma calendula Druce) responded about equally to superphosphate, but the clover responded to rock phosphate to a greater extent than did cape-weed. Both relative efficiency for total plant growth and percentage utilization of applied phosphorus were much higher with the soluble phosphatic fertilizer than with rock phosphate, especially in the first year. However, phosphorus recovery from rock phosphate was as high in the second year as in the first, whereas there was a marked decrease in the second year from superphosphate.

Temporal variation in soil acidity

Soil Research ◽  
1997 ◽  
Vol 35 (5) ◽  
pp. 1115 ◽  
Author(s):  
M. K. Conyers ◽  
N. C. Uren ◽  
K. R. Helyar ◽  
G. J. Poile ◽  
B. R. Cullis
Keyword(s):  
Temporal Variation ◽  
Soil Ph ◽  
Soil Acidity ◽  
Soil Depth ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Variable Response ◽  
Related Factors ◽  
Exchangeable Al ◽  
Eastern Australia

Seasonal variation in the response of crops and pastures to limestone application has been observed on acidic soils in south-eastern Australia. Our hypothesis was that temporal variation in soil acidity related factors may contribute to this variable response. Soils from 4 annual pasture sites were sampled at least monthly for 3 years during 1988–1990 to monitor changes in pH(CaCl2) and in concentrations of exchangeable aluminium (Al) and manganese (Mn). The sites received no fertiliser or cultivation and therefore allowed for the estimation of natural temporal variation. Temporal variation in soil pH during a year ranged from 0 to 0·45 pH units depending on the site, soil depth, and the weather conditions. The larger changes in soil pH were associated with more extreme climatic conditions than normal, e.g. following the break of season after a hot, dry summer (autumn 1988) or during periods of above-average rainfall in autumn and early spring (1990). Temporal variation in pH was less than the spatial variability at the sites but greater than the long-term net acidification rate reported for the region. Temporal variation in the concentration of exchangeable Al ranged from 0 to 0·4 cmol(+)/kg during a year and varied primarily with the inverse of pH. Variations in the concentration of exchangeable Mn ranged from 0·05 to 0·35 cmol(+)/kg during a year. The concentration of exchangeable Mn increased over summer to an extent dependent on the drying of the soil. At the 2 sites with duplex profiles, maxima in the concentration of exchangeable Mn also occurred in spring, particularly in the warm wet spring of 1990. Soil tests for soil acidity therefore represent guides to probable risks of toxicity, as pH and the concentrations of exchangeable Al and Mn may change between soil sampling, sowing, and the period of crop or annual pasture growth. Such variations will alter the responsiveness of crops and pastures to lime.

Ecological segregation in a subterranean reptile assemblage in arid Australia

1989 ◽  
Vol 10 (3) ◽  
pp. 277-295 ◽  
Author(s):  
Klaus Henle
Keyword(s):  
National Park ◽  
Reproductive Effort ◽  
Arid Zone ◽  
Daily Maximum ◽  
First Year ◽  
Lizard Species ◽  
Eastern Australia ◽  
Food Size ◽  
Late Maturity ◽  
Second Year

AbstractThe organisation of the subterranean component of an arid zone reptile community was studies in Kinchega National Park (Eastern Australia) from September 1985 to May 1987. Three species of fossorial or semifossorial lizards and two species of snakes were found in Kinchega. All species were habitat generalists, but microhabitat, food size and food taxon clearly separated them. All species were primarily nocturnal although Lerista xanthura was occasionally active during the day. All three lizard species were active from September to May. Activity of Eremiascincus richardsonii and L. xanthura were significantly correlated with monthly mean daily maximum and minimum temperatures. The optimum temperature of L. punctatovittata was 28.8 °C in daytime retreats. Biomass ranged from 505-900 g/ha in E. richardsonii and from 968-1152 g/ha in L. punctatovittata. All three lizard species produced only one clutch per year. L. punctatovittata and E. richardsonii reached sexual maturity at the end of their second year, L. xanthura matured in its first year. The data show that subterranean lizard guilds have a different structure than diurnal and non-fossorial noctunal lizard assemblies. The data also indicate a correlation of late maturity and low reproductive effort in fossorial lizards.

scholarly journals Herbaceous Perennial Trials in Central Alabama, 1996-97

2000 ◽  
Vol 10 (1) ◽  
pp. 222-228
Author(s):  
J. Raymond Kessler ◽  
Jeff L. Sibley ◽  
Bridget K. Behe ◽  
Darby M. Quinn ◽  
James S. Bannon
Keyword(s):  
United States ◽  
Southeastern United States ◽  
Performance Comparison ◽  
Climatic Conditions ◽  
First Year ◽  
Performance Information ◽  
Herbaceous Perennials ◽  
Information Reliability ◽  
Second Year ◽  
Herbaceous Perennial

Fifty-seven herbaceous perennials were evaluated from July 1996 to October 1997 in USDA Hardiness Zone 8. Plants in this study generally performed better the first year after planting than the second year. Several selections did not reemerge the second year, though some natural reseeding occurred. Still other selections never fully recovered from the winter months or succumbed to stress in the summer. Plants that maintained an attractive foliage display while not in bloom and plants that had a high bloom rating during the bloom season are worth incorporating into a full sun perennial or mixed border in the southeastern United States. Performance of perennials in the landscape may vary from year to year as climatic conditions affect performance. Comparison of results from variety trials at other locations should help increase performance information reliability for perennial selection.

Seedbanks and seedling emergence of saffron thistle (Carthamus lanatus) in eastern Australian pastures

2002 ◽  
Vol 53 (12) ◽  
pp. 1327 ◽  
Author(s):  
B. S. Grace ◽  
A. W. Sheppard ◽  
R. D. B. Whalley ◽  
B. M. Sindel
Keyword(s):  
Weed Management ◽  
Seedling Survival ◽  
Seedling Emergence ◽  
First Year ◽  
Seed Loss ◽  
Eastern Australia ◽  
Mesh Bags ◽  
Second Year ◽  
Number Of Seeds ◽  
Over Time

Weed management has often proved difficult because of persistent seedbanks that allow recruitment to occur for many years after the weed has otherwise been controlled. The number of seeds in seedbanks of Carthamus lanatus, a widespread and troublesome weed, has not been investigated. Little is known about longevity of its seedbanks in pastures of eastern Australia.The numbers of seeds in the soil and the rate of seed loss were investigated at 3 sites in eastern Australia. Seedbanks were found to be patchy, and they had mean densities between 815 and 2290 seeds/m2 after the main germination flush. These seedbanks decreased over time and between 11 and 15% of seeds remained in the soil after 2 years without further input. More seeds were lost in the first year than in the second year, and pasture cover did not affect the rate of seed loss.Seeds buried in mesh bags and exhumed regularly showed that dormancy was lost, induced, then lost again within the 2-year experiment. Maximum seed germinability coincided with peak germination times. The likelihood of a seed producing a seedling was reduced when seeds were sown at high density. C. lanatus seeds appear to be well adapted for persistence in eastern Australian pastures by maintaining a bank of seeds that generally germinate when conditions favour seedling survival.

scholarly journals Hydrocyanic acid content and growth rate of sorghum x sudangrass hybrid during fall

2013 ◽  
Vol 37 (4) ◽  
pp. 299-305
Author(s):  
Flávia Fernanda Simili ◽  
Maria Lúcia Pereira Lima ◽  
Maria Izabel Merino de Medeiros ◽  
Claudia Cristina Paro de Paz ◽  
Ana Claudia Ruggieri ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Height ◽  
Dry Matter ◽  
Plant Age ◽  
Hydrocyanic Acid ◽  
First Year ◽  
Dry Matter Yield ◽  
Cyanide Poisoning ◽  
Central Brazil ◽  
Second Year

In central Brazil after soybean or other annual agricultural species is harvested, sorghum hybrids are planted in the fall in order to establish pastures for grazing animals. This study conducted for two consecutive years aimed at quantifying the contents of hydrocyanic acid in the leaves and determining plant height, forage dry matter yield and the leaf/stem ratio for sorghum hybrid 1P400 at different ages. Statistical analysis was performed by regression analysis based on plant age. Leaf HCN content decreased with plant growth, ranging from 205.0 and 230.3 mg HCN/100 g leaf DM at two weeks old to 5.9 and 6.1 mg HCN/100 g leaf DM at five weeks old in the first and second year, respectively. The average heights measured varied from 60 and 56 cm, in the 4th week, to 117 and 151 cm, in the 8th week, during the first and second experimental year, respectively. Forage mass increased linearly with age and displayed average of 1.411 and 1.637 kg DM/ha in the first year and, 2.905 and 3.640 kg DM/ha in the second year, during the 7th and 8th week, respectively. Leaf proportion decreased while stem increased linearly with plant age. The leaf/stem ratio decreased with plant growth, elongation and increasing stem weight. The sorghum hybrid should be grazed only after five weeks or when the plant height is above 80 cm, in order to avoid the risk of cyanide poisoning.

Survival and seasonal germination of seeds of Avena fatua and A. ludoviciana

1968 ◽  
Vol 19 (5) ◽  
pp. 721 ◽  
Author(s):  
PH Quail ◽  
OG Carter
Keyword(s):  
Soil Type ◽  
Dominant Species ◽  
First Year ◽  
Moisture Regime ◽  
Seed Type ◽  
Wild Oats ◽  
Eastern Australia ◽  
Buried Seed ◽  
Second Year ◽  
Better Than

The effects of soil type, temperature, and moisture on the survival and seasonal germination of seeds of A. fatua and A. ludoviciana, buried at five depths in the soil, were studied in a glasshouse experiment. Seeds of both species germinated only when mean weekly minimum temperatures were below 20°C and mean weekly maxima below 28°. A. fatua germinated better than A. ludoviciana in the 20–30° range and was therefore the dominant species in autumn germinations of wild oats. Both species germinated throughout winter. Only 30% of the seeds sown produced seedlings. Of these 90% emerged in the first year after seeding and the remainder in the second year. Only 2% of the seeds sown remained viable after 18 months. The depth at which the seeds were buried, seed type, soil type. and moisture regime all affected the survival of seeds and the percentage that produced seedlings. An explanation is offered for the dominance of A. ludoviciana in the northern wheat-belt of eastern Australia.

scholarly journals Results of researching different methods of creating fodder areas in arid region of Northern Caspian

2021 ◽  
Vol 209 (06) ◽  
pp. 2-11
Author(s):  
Galina Bulahtina ◽  
Yuriy Podoprigorov ◽  
Andrey Hyupinin
Keyword(s):  
Species Composition ◽  
Arid Region ◽  
Arid Zone ◽  
Single Species ◽  
Climatic Conditions ◽  
First Year ◽  
Extreme Conditions ◽  
Caspian Region ◽  
Natural Pasture ◽  
Second Year

Abstract. Purpose. The research is aimed at developing methods for creating highly productive and highly nutritious pasture agrophytocenoses, adapted to the extreme conditions of the arid zone of the Northern Caspian region. Methods. The paper provides an assessment of the productivity of perennial one-species (Agropyron) and poly-species (Agropyron, Eutoria, Kochia) agrophytocenoses for a five-year period of their vegetation, depending on the timing (autumn, spring) and sowing methods (ordinary, scattered). Results. These phytocenoses, created in the harsh climatic conditions of the semi-desert on light chestnut soils with a low level of fertility (humus – 0.68 %), starting from the first year, formed the yield 2–7 times higher than the natural pasture. According to the results of the study, it was revealed that a significant role in the creation of arid forage phytocenosis was played by the sowing method and species composition, including the scattered sowing method turned out to be more productive (in monospecific – by 57–70 %, in poly-species – by 63–82 %), the yield of the poly-species composition of the phytocenosis, starting from the second year, increased by 1–2 t/ha for all years of the study in comparison with the monospecific composition both on the row and on the spread method of sowing. Scientific novelty. All created agrophytocenoses for all variants had a fodder value 3–10 times higher than the natural pasture, including the presence of different plant species on the pasture increased the collection of fodder units in comparison with a single-species pasture by 1.5–2 times, and the spread method of sowing also increased the provision of pasture fodder with protein by 0.18–0.2 t/ha. Already by the second year of plant development, it was noted that the presence of shrubs and semi-shrubs on the forage lands creates better conditions than the aftermath of the corn crop for snow retention, and, accordingly, contributes to a greater accumulation of moisture in the soil.

Studies on the fertility of seddon soil (Kangaroo Island, South Australia). 1. The response of subterranean clover to various phosphatic fertilizers.

1955 ◽  
Vol 6 (4) ◽  
pp. 398 ◽  
Author(s):  
AG Tyson
Keyword(s):  
Phosphorus Content ◽  
Sandy Loam ◽  
South Australia ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Phosphate Deficiency ◽  
First Year ◽  
Phosphate Availability ◽  
Second Year ◽  
Phosphatic Fertilizers

Seddon gravelly sandy loam from Kangaroo Island has proved to be grossly deficient in both total and available native phosphorus. Growth of subterranean clover (Trifolium subterraneum L.) in this soil is virtually nil unless phosphatic fertilizers are applied to it. Experiments with eight different phosphatic fertilizers showed that thermal phosphates of the Rhenania type were slightly superior to monocalcic phosphate as a source of plant phosphorus on Seddon soil. Both types of phosphate were equally efficient in the contrasting Urrbrae loam. Rock phosphate proved to be an extremely poor source of plant phosphorus. In the first year the availability of monocalcic phosphate applied to the Seddon soil was 20 per cent. or half that of material applied to the Urrbrae loam. The comparative residual value in the second year of applied phosphate was greater, however, in the Seddon soil than in the Urrbrae loam. Yields and phosphate availability were influenced by seasonal variation, but the phosphorus content of the plant material was nearly constant in different years for any particular yield from the same soil. The requirement for phosphorus at yields below the maximum was greater, however, in plants growing on Urrbrae loam than on Seddon soil. At maximum yields the ratio N/P205 was constant for plants from the two soils, but this did not hold where phosphorus was in minimum supply. The availability of residual phosphate from Seddon soil to which small annual additions of fertilizer had been made over 12 years was markedly lower than that from virgin soil to which phosphate had been added 12 months previously. The lower availability from the partially developed soil has been tentatively ascribed to the concurrent accumulation of organic matter. Results support the practice of making small annual applications of superphosphate to Urrbrae loam but it would appear that greater overall production could be obtained from Seddon soil by heavier initial applications. Amounts of P205 as low as 0.17-0.20 per cent. were found in the dry matter of subterranean clover growing on Seddon soil. Values below 0.3 per cent. are considered to be indicative of phosphate deficiency.

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