Nutrient potential and capacity. II. Relationship between potassium potential and buffering capacity and the supply of potassium to plants

1966 ◽  
Vol 17 (6) ◽  
pp. 849 ◽  
Author(s):  
NJ Barrow
Keyword(s):  
Free Energy ◽  
Multiple Regression ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Buffering Capacity ◽  
Plant Roots ◽  
Exchangeable Potassium ◽  
Percentage Saturation ◽  
The Relationship ◽  
Free Energy Of Exchange

The potassium status of 22 soils with low reserves of non-exchangeable potassium was assessed by measuring: (a) the potassium potential (the free energy of exchange of potassium for calcium plus magnesium); (b) the soil's capacity to resist a change in potential ("buffering capacity"); (c) the amount of exchangeable potassium and its percentage saturation. The ability of these measures to predict the supply of potassium was tested by growing subterranean clover (Trifolium subterraneum L.) in pots and determining its potassium content at successive harvests. The soil's buffering capacity was found to affect the supply of potassium even when uptake was small. It is suggested that this was partly because buffering capacity affects the rate of supply by diffusion to plant roots. As the uptake of potassium became progressively larger, the potential became increasingly unsuitable as a single index of availability, but a multiple regression containing terms for potential and for buffering capacity continued to account for a large proportion (89%) of the variation. The relationship obtained can be used to indicate the amount of potassium required to bring a deficient soil to a desirable status.

Nutrient potential and capacity. III. Minimum value of potassium potential for availability to Trifolium subterraneum in soil and in solution culture

1967 ◽  
Vol 18 (1) ◽  
pp. 55 ◽  
Author(s):  
NJ Barrow ◽  
CJ Asher ◽  
PG Ozanne
Keyword(s):  
Fine Root ◽  
Plant Root ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Solution Culture ◽  
Buffering Capacity ◽  
Free Energy Of Exchange ◽  
Solution Cultures ◽  
Very High ◽  
Nutrient Solutions

Plants of subterranean clover (Trifolium subterraneum L.) were grown in a range of soils until the supplies of potassium were exhausted. The potassium potential of each soil was then measured by determining the free energy of exchange of potassium for calcium plus magnesium. In soils of very high buffering capacity the potassium potential of the exhausted soil was about –6000 cal/equiv. In soils of lower buffering capacity the potential of the exhausted soil was higher but this may have been an artefact due to release of potassium from fine root material left in the soil at harvest. Subterranean clover plants were also grown in large volumes of well-stirred nutrient solutions which were held at a range of potassium concentrations. Again it was found that the plants were unable to take up potassium when the potassium potential was about –6000 cal/equiv. It is suggested that the potentials were similar because diffusion gradients were negligible in the exhausted soil and also in the swiftly flowing solutions. At potentials above –6000 cal/equiv. availability of potassium appeared to be greater in the solution cultures than in soils. It is suggested that this occurred because, in soils, the uptake of potassium causes the potential at the plant root to be lower than in the bulk of the soil.

scholarly journals Host plant recognition by the root feeding clover weevil, Sitona lepidus (Coleoptera: Curculionidae)

2004 ◽  
Vol 94 (5) ◽  
pp. 433-439 ◽  
Author(s):  
S.N. Johnson ◽  
P.J. Gregory ◽  
P.J. Murray ◽  
X Zhang ◽  
I.M. Young
Keyword(s):  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Plant Roots ◽  
Grass Species ◽  
Movement Rates ◽  
Sitona Lepidus ◽  
Macro Scale ◽  
Significant Difference ◽  
Invasive Techniques ◽  
Root Feeding

AbstractThis study investigated the ability of neonatal larvae of the root-feeding weevil, Sitona lepidus Gyllenhal, to locate white clover Trifolium repens L. (Fabaceae) roots growing in soil and to distinguish them from the roots of other species of clover and a co-occurring grass species. Choice experiments used a combination of invasive techniques and the novel technique of high resolution X-ray microtomography to non-invasively track larval movement in the soil towards plant roots. Burrowing distances towards roots of different plant species were also examined. Newly hatched S. lepidus recognized T. repens roots and moved preferentially towards them when given a choice of roots of subterranean clover, Trifolium subterraneum L. (Fabaceae), strawberry clover Trifolium fragiferum L. (Fabaceae), or perennial ryegrass Lolium perenneL. (Poaceae). Larvae recognized T. repens roots, whether released in groups of five or singly, when released 25 mm (meso-scale recognition) or 60 mm (macro-scale recognition) away from plant roots. There was no statistically significant difference in movement rates of larvae.

Response of defoliated swards of subterranean clover and yellow serradella to superphosphate applications

1991 ◽  
Vol 31 (6) ◽  
pp. 777
Author(s):  
MDA Bolland
Keyword(s):  
Field Experiment ◽  
Sandy Soil ◽  
Dry Matter ◽  
Maximum Yield ◽  
Subterranean Clover ◽  
Soil Surface ◽  
Trifolium Subterraneum ◽  
Herbage Yield ◽  
Ornithopus Compressus ◽  
The Relationship

The effect of superphosphate applications (0, 25, 50, 75, 100 and 125 kg P/ha to the soil surface) on the dry matter (DM) herbage production of dense swards of subterranean clover (Trifolium subterraneum cv. Junee) and yellow serradella (Ornithopus compressus cv. Tauro) was measured in a field experiment on deep, sandy soil in south-western Australia. The swards were defoliated with a reel mower at weekly intervals from 88 to 158 days after sowing, to a height of 2 cm for the first 9 cuts, 4 cm for the tenth cut and 5 cm for the eleventh cut. Yellow serradella was more productive than subterranean clover. Consequently, for the relationship between yield and the level of phosphorus (P) applied, yellow serradella supported larger maximum yields and required less P than subterranean clover, to produce the same DM herbage yield. Maximum yields of yellow serradella were 12-40% larger. To produce 70% of the maximum yield for yellow serradella at each harvest, yellow serradella required about 50% less P than subterranean clover. However, when yields were expressed as a percentage of the maximum yield measured for each species at each harvest, the relationship between yield and the level of P applied was similar for both species, and they had similar P requirements.

Phosphate applied to soil increases the effectiveness of subsequent applications of phosphate for growing wheat shoots

1998 ◽  
Vol 38 (8) ◽  
pp. 865 ◽  
Author(s):  
M. D. A. Bolland ◽  
M. J. Baker
Keyword(s):  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Phosphorus Retention ◽  
Single Superphosphate ◽  
Mitscherlich Equation ◽  
Curvature Coefficient ◽  
Glasshouse Experiment ◽  
Phosphorus Application ◽  
The Relationship ◽  
Field Plots

Summary. Amounts of phosphorus ranging from 0 to 599 kg P/ha were applied as single (ordinary) superphosphate once only in 1976 to plots of a field experiment on a lateritic ironstone gravel sand. Subterranean clover (Trifolium subterraneum) and cereals (wheat, Triticum aestivum, and barley, Hordeum vulgare) were grown in rotation on the plots for 20 years after phosphorus application. In 1996, samples of the <2 mm fraction of the top 10 cm of soil were collected from the field plots to measure phosphorus retention by soil and for a glasshouse experiment. The phosphorus retention index, a measure of the capacity of the soil to sorb phosphorus, decreased from 35 to 2 mL/g as the amount of phosphorus applied 20 years previously increased from 0 to 599 kg/ha. In the glasshouse experiment, wheat was grown for 35 days in soil to which 9 amounts of freshly-applied powdered single superphosphate (0, 0.0125, 0.025, 0.05, 0.1, 0.2, 0.4, 0.8 and 1.6 g P/pot, for 1.8 kg soil/pot) were applied to the original phosphorus treatments. The value of the curvature coefficient of the Mitscherlich equation fitted to the relationship between yield of dried shoots and the amount of fresh-phosphorus applied increased with increasing amount of phosphorus applied 20 years previously. That is, the fresh-phosphorus treatments became more effective for producing dried wheat shoots as the amount of previously applied phosphorus increased.

Copper nutrition of subterranean clover (Trifolium subterraneum L. cv. Seaton Park). III. Effects of phosphorus supply on the relationship between copper concentrations in plant parts and yield

1981 ◽  
Vol 32 (2) ◽  
pp. 283 ◽  
Author(s):  
DJ Reuter ◽  
AD Robson ◽  
JF Loneragan ◽  
DJ Tranthim-Fryer
Keyword(s):  
Copper Deficiency ◽  
Phosphorus Deficiency ◽  
Potassium Phosphate ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Young Leaf ◽  
Plant Parts ◽  
High Concentrations ◽  
Four Levels ◽  
The Relationship

The effects of phosphorus supply on the relationship of copper supply with copper concentrations in various plant parts and yield of Seaton Park subterranean clover were examined. Plants were grown in a glasshouse for 40 and 74 days in pots with four levels of potassium phosphate (0, 13, 39, 65 mg phosphorus/pot) and six levels of copper sulfate (0, 50, 100, 200, 400, 800 pg copper/pot) added, in factorial combination, to a sand deficient in both phosphorus and copper. By increasing the phosphorus levels copper deficiency was induced partly by promoting growth and diluting copper concentrations in plants; and also by depressing copper absorption. Increasing phosphorus changed the distribution of copper in plant tops and the shape of curves relating copper concentration in whole plant tops to yield. At 39 mg phosphorus/pot, the relationship at Day 74 had a marked 'Piper-Steenbjerg' curvature, largely as a result of unusually high copper concentrations in the stems plus petioles of severely copper-deficient plants. At 65 mg phosphorus/pot, the relationship had no 'Piper-Steenbjerg' curvature for whole tops and only a relatively small curvature for stems plus petioles. The data suggests that 'Piper-Steenbjerg' curves in subterranean clover result primarily from high concentrations of copper in the stems plus petioles of severely deficient plants. At both harvests, young leaf blades had critical copper concentrations of around 3 �g copper/g at both 39 and 65 mg phosphorus/pot. However, copper-deficient plants with severe phosphorus deficiency did not respond to copper, and generally had copper concentrations below this critical level in all plant parts. The results confirm the value of copper analysis of young leaf blades for diagnosing copper deficiency in subterranean clover with moderately deficient to luxury supplies of phosphorus.

Zinc in subterranean clover (Trifolium subterraneum L. cv. Seaton Park). II. Effects of phosphorus supply on the relationship between zinc concentrations in plant parts and yield

1982 ◽  
Vol 33 (6) ◽  
pp. 1001 ◽  
Author(s):  
DJ Reuter ◽  
JF Loneragan ◽  
AD Robson ◽  
D Plaskett
Keyword(s):  
Zinc Deficiency ◽  
Subterranean Clover ◽  
Zinc Content ◽  
Trifolium Subterraneum ◽  
Plant Analysis ◽  
Plant Parts ◽  
Phosphorus Toxicity ◽  
Zinc Concentrations ◽  
High Concentrations ◽  
The Relationship

The effect of phosphorus on the relationship of zinc concentrations in various plant parts to yield of Seaton Park subterranean clover was examined. Plants were grown in a glasshouse at three levels of phosphorus (39, 65 and 130 mg phosphorus/pot; denoted P1, P2 and P3 respectively) and six levels of zinc added in factorial combination to a sand deficient in both phosphorus and zinc. At the lowest three levels of zinc supply, plants were severely to moderately deficient in zinc: in them, increasing levels of phosphorus depressed growth and induced high concentrations of phosphorus (> 1 % DM) in several plant parts and symptoms of phosphorus toxicity in leaves. At the highest three levels of zinc supply, plants at P1 were phosphorus deficient: application of P2 and P3 increased growth and induced zinc deficiency primarily by diluting the available zinc. In addition, P3 appeared to depress slightly the zinc content of plant tops by another mechanism. In severely zinc-deficient plants, phosphorus supply changed the relationships between zinc concentrations in various plant parts and yield of whole tops, probably as the result of phosphorus toxicity. In the youngest open leaf blades, an asymptotic relationship at P1 changed at P2 and P3 to sigmoidal and to 'Piper-Steenbjerg' relationships respectively. These changes would not have invalidated the use of plant analysis for diagnosing zinc deficiency. In moderately zinc-deficient plants, phosphorus supply had little or no effect on the relationships of zinc concentration in plant parts to yield of shoots. As a result, critical concentrations in plant parts generally remained constant over the whole range of phosphorus supply. The data refute suggestions that high levels of phosphorus in plant parts inactivate the zinc within them, thus removing a potential problem in the use of plant analysis for diagnosing zinc deficiency in subterranean clover. The results confirm the previous suggestion that a concentration range of 12-14 �g zinc/g in the youngest, open leaf blade is critical for diagnosis of zinc deficiency in subterranean clover.

Seed softening patterns from single seed crops of subterranean clover (Trifolium subterraneum L.) in a cool temperate environment

1995 ◽  
Vol 35 (8) ◽  
pp. 1117 ◽  
Author(s):  
PM Evans ◽  
EJ Hall
Keyword(s):  
Seed Set ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
First Year ◽  
Original Seed ◽  
Cool Temperate ◽  
Set Up ◽  
Negative Exponential ◽  
Seed Crops ◽  
The Relationship

An experiment was set up in northern Tasmania with 7 cultivars of subterranean clover widely ranging in maturity and levels of hardseededness. They were planted as pure swards and in a mixture with perennial ryegrass. After seed set in the first year, all seedling regenerations were counted and then killed, and seed populations were measured each summer for 6 years. No significant differences in seed losses existed between the pure swards and the mixtures or between cultivars. Negative exponential functions of the relationship between seed banks and time fitted the data well with r2 ranging from 0.87 (Nungarin) to 0.998 (Trikkala). By mid-summer of the sixth year the percentages of the original seed left in the ground were: Enfield 12%, Woogenellup 19%, Trikkala 20%, Nungarin 21%, Larisa 24%, and Karridale and Mt Barker 31%. Seeds at higher latitudes were lost at about half the rates experienced at lower latitudes with drier, hotter summers. The higher percentages of seed remaining in plots with later maturing cultivars suggest that environmental conditions favoured the production of hard seeds while the reverse was the case with very early, hardseeded cultivars like Nungarin.

The relationship between temperature fluctuations and the softening of hard seeds of some legume species

1966 ◽  
Vol 17 (5) ◽  
pp. 625 ◽  
Author(s):  
BJ Quinlivan
Keyword(s):  
Critical Factor ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Temperature Fluctuations ◽  
Maximum Temperature ◽  
Hard Seeds ◽  
Maximum Temperatures ◽  
The Relationship ◽  
Fluctuating Temperatures ◽  
Main Factor

Hard seeds of subterranean clover (Trifolium subterraneum L.) of the Geraldton and Bacchus Marsh strains, and of West Australian blue lupin (Lupinus varius L.), were subjected to various daily fluctuating temperatures within the normal summer environmental range (15–75°C). The main factor determining the rate of softening of the hard seeds was the maxinlum temperature of the fluctuation. Provided the temperature changed by some 15°C , the amplitude of the fluctuation did not appear to be a critical factor. The softening of hard seeds of any particular species did not commence until the amplitude of the temperature fluctuation, or the maximum temperature, reached a certain level, which in turn varied with the species. Beyond this level the rate of softening increased with increasing fluctuations to a point where the rate became very rapid, and thereafter wider fluctuations or higher maximum temperatures did not give significant increases.

The relationship between the phosphorus status of subterranean clover plants and the dry weight responses of detached leaves in solutions with and without phosphate

1976 ◽  
Vol 27 (1) ◽  
pp. 53 ◽  
Author(s):  
D Bouma ◽  
EJ Dowling
Keyword(s):  
Diagnostic Technique ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dry Weight ◽  
Distilled Water ◽  
Total Light ◽  
Detached Leaves ◽  
Preceding Period ◽  
Phosphate Treatment ◽  
The Relationship

In four experiments subterranean clover plants (Trifolium subterraneum L., cv. Mt. Barker) were grown at different levels of phosphorus applied to solution cultures, to Perlite and to pots containing phosphorus-deficient soil. Leaves detached from deficient plants, placed in 3mM fructose 1,6-diphosphate or in 6mM NaH2PO4.2H2O for periods of 8–12 hr and then in distilled water under fluorescent lights (31,000–33,000 lx) for total light periods of 75–115 hr (18 hr light per 24 hr), showed greater increases in dry weight than corresponding leaves placed in distilled water without an initial phosphate treatment. By contrast, there were no differences in dry weight increases between similarly treated leaves from non-deficient plants; thus a clear distinction could be made between deficient and non-deficient plants. Dry weight increases of deficient leaves during the light period were markedly dependent on the length of the preceding period in phosphate solutions. Maximum increases occurred after periods of 8–12 hr, depending on the degree of phosphorus stress of the leaves. For non-deficient leaves initial uptake periods of up to 12 hr gave dry weight increases under the lights close to or the same as those of leaves in distilled water only, while periods of 24 and 48 hr resulted in greatly reduced dry weight increases. The possible application of the results as the basis for a simple diagnostic technique is discussed.

Seed-Setting in subterranean clover (Trifolium Subterraneum L.). II. Strain-environment interactions in single plants

1958 ◽  
Vol 9 (6) ◽  
pp. 745 ◽  
Author(s):  
JJ Yates
Keyword(s):  
Negative Relationship ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Atmospheric Environment ◽  
Protective Mechanism ◽  
Seed Setting ◽  
Early Maturing ◽  
The Relationship ◽  
Mature Seeds ◽  
Number Of Seeds

The relationship between seed-setting (expressed as mature seeds per inflorescence), strain, and environment was investigated in subterranean clover, with special reference to burr burial. Single plants of a range of maturity types were grown in two environments, one cool and moist, the other hot and dry but with frequent watering of the plant roots. In the mild environment, early-maturing strains buried a high proportion of burrs, and late-maturing strains relatively few. Under the more severe conditions, late-maturing types buried the majority of their burrs. Seed-setting in buried burrs was generally good, and relatively constant in all the strains and the two environments tested. The capacity to set seed above the ground varied widely amongst strains, and within each strain was greater in the mild environment. The results indicate that seed-setting is influenced strongly by the microenvironment of inflorescences and developing burrs, and that strains differ in sensitivity to such microenvironment. Burr burial is apparently a protective mechanism against unfavourable factors (probably low relative humidity and high temperature) of the atmospheric environment. Under the more severe environmental conditions, there was a positive correlation between seed-setting above the ground and percentage leaf in the plant tops. It is presumed that this was due partly to amelioration of the microenvironrnent by the foliage. The negative relationship between efficiency of seed-setting above the ground and proportion of burrs buried is discussed in terms of natural selection. The microenvironmeilt, and the differential response of strains, affected not only the number of seeds per inflorescence, but also the weight and viability of the seeds produced. The concept of a threshold embryo weight for viability is discussed.

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