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The use of acid soil‐tolerant annual legume pasture species and liming to raise soil pH can have legacy effects that improve subsequent wheat crop growth in acid soils. We established a two‐year experiment in a semi‐arid environment with and without historical lime application to investigate how acid soils (±lime) influence the legacy effects of annual legume pastures. We measured legume and cereal growth and yield, soil‐borne disease incidence, rhizosheath organic acid type and amount, legume biological nitrogen fixation (BNF) and soil moisture in Year 1, and soil microbial biomass carbon (MBC) and wheat yield and quality in Year 2. Minor differences in soil moisture and soil‐borne diseases occurred between cereals and legumes, and the poor BNF contribution of all pasture legumes improved in lime treatments. Pasture legumes produced more organic acids than cereals, which increased in limed treatments. Soil MBC in Year 2 was greater following legumes than cereals. Year 2 wheat grain yield increased following pasture legumes, more so in limed treatments. The contribution of organic acid exudation by annual legume pastures to microbial community legacy effects warrants further scrutiny in semi‐arid environments, particularly when acid soils limit typical rotational benefits. [ABSTRACT FROM AUTHOR]

Serradella (Ornithopus) species are high‐quality pasture legumes that originate from the Mediterranean basin and have been increasingly used in southern Australian temperate grazing systems. They are generally regarded as tolerant of soils with low pH and, by inference, elemental toxicities such as aluminium (Al). No studies have examined the effect of high Al concentrations on the growth of French serradella (Ornithopus sativus Brot.) or newly developed cultivars of yellow serradella (O. compressus L.). Several cultivars/accessions of each species were grown in low ionic‐strength nutrient solutions at pHCa 4.5 containing a range of Al concentrations. Their susceptibility to root growth inhibition by Al was benchmarked against reference species ranging from Al‐sensitive to Al‐tolerant. Most serradella cultivars had moderate‐to‐high Al tolerance in solution culture but one yellow and two French serradella cultivars ranked alongside the Al‐sensitive reference species. A subset of cultivars and reference species were then grown in an Al‐toxic soil to test the validity of the solution culture results; these cultivars spanned the apparent range in Al sensitivity/tolerance indicated by the solution culture experiment. Variation in the relative root length achieved in Al‐toxic solution culture explained ~59% of the variation in the relative root length achieved in the acidic Al‐toxic soil. This result supports the conclusion that Al tolerance varies among serradella and that some cultivars may not thrive in soils with pHCa < 4.5 and elevated extractable Al concentrations. [ABSTRACT FROM AUTHOR]

Abstract: Sum‐accelerated pseudospectral methods herein are used to describe the kinetic energy matrix within density functional theory descriptions of few‐atom systems. The resulting energies are compared to the conventional finite difference results. It is demonstrated that the sum‐acceleration allows for significantly improved scaling with respect to the grid step size and matrix bandwidth while maintaining a computational speed equivalent with that of the finite difference description. In addition, analytical expressions for the pseudopotential matrix elements are introduced to alleviate the eggbox effect—the dependence of the energy on the relative position of the atoms and grid points. [ABSTRACT FROM AUTHOR]

Aims: Low-molecular-weight organic anions (carboxylates) influence rhizosphere processes and may enhance plant phosphorus acquisition. We examined the root exudate profile of a range of pasture and grain legumes and focused on the little-investigated carboxylate, citramalate.Methods: Twelve species of pasture legumes and herbs, including four Lotus spp. and two crop legumes, Cicer arietinum and Lupinus albus, were grown in a glasshouse for six weeks. The composition and amounts of carboxylates were measured in rhizosheath soil as well as in root exudates from roots washed free of their rhizosheath.Results: Citrate and malate were found in the rhizosheath of all species. However, citramalate was present in the rhizosheath of only Lotus species (10-82% of total exuded carboxylates). Cicer arietinum had the largest amount of carboxylates in its rhizosheath and fastest rate of carboxylate exudation into the trap solution.Conclusions: Citrate and malate were found in the rhizosheath of all species in this study, but citramalate was only found in the root exudates and rhizosheath of Lotus spp. Further investigation into the role of citramalate in Lotus spp. is merited. [ABSTRACT FROM AUTHOR]

Aims: The legumes most often used in temperate pastures such as Trifolium subterraneum have relatively high external P requirements for maximum growth. We investigated root traits associated with P acquisition in current and novel pasture legumes, as well as temperate grasses which have lower P requirements. Methods: Thirteen legume species, two pasture grasses, and three high carboxylate-exuding crop species ( Lupinus albus, L. angustifolius, Cicer arietinum) were grown in a glasshouse for six weeks. Rhizosphere carboxylates and root morphological traits were measured. Results: Ornithopus spp. had rhizosphere carboxylates in similar quantities to the Lupinus spp. (> 40 μmol g root dry mass) . Trifolium subterraneum lines had relatively large average root diameter, reduced specific root length and very short average root hair length resulting in specific root hair cylinder volumes (RHCVs) only 14-20 % of the grasses. However, O. sativus, O. compressus and Biserrula pelecinus had specific RHCVs more comparable to the grasses. Conclusions: Novel pasture legume species with root morphology more comparable to that of grasses than T. subterraneum were identified. Of these, Ornithopus spp. were notable as they also had high rhizosphere carboxylates relative to root dry mass. [ABSTRACT FROM AUTHOR]

Development of more phosphorus (P)-efficient pasture legumes could improve the P balance of pasture systems. Trifolium subterraneum (subterranean clover) is the most widely-grown annual pasture legume in southern Australia and is host to arbuscular mycorrhizal fungi (AMF). To examine the potential to alter colonisation level through breeding, 97 lines from the core collection of subterranean clover (core lines) and 42 cultivars (cultivar lines) were grown in a glasshouse in a low-P sandy acid field soil with indigenous AMF (Experiment 1). To examine the robustness of rankings, two cultivars (Riverina and Woogenellup) were also grown in 11 field soils (Experiment 2). To examine whether the presence of AMF changed other root traits important for P uptake, cultivars Riverina and Woogenellup were grown in two low-P field soils (sand, sandy loam), either pasteurised to remove indigenous AMF or unpasteurised, and with and without addition of inoculum of AMF (Experiment 3). The range of colonisation for core lines and cultivar lines was similar (∼12–68% of root length), however, the core lines had higher mean colonisation (37% vs 33%) and a greater proportion of lines with >40% of root length colonised (41% vs 24% of lines). Woogenellup was more heavily colonised than Riverina in eight soils and had a similar level of colonisation in three soils. In the sand, pasteurisation resulted in shoot DM increasing by up to 100% (possibly due to reduction in root diseases). Inoculation, in pasteurised and unpasteurised soil, resulted in an increase in shoot DM, shoot P concentration and shoot P content of ∼100%, increased average root diameter by up to 13%, decreased specific root length by up 30% and decreased root mass ratio; effects on average root hair length were variable. In the unpasteurised sandy loam, shoot P concentrations were higher than in the sand, and inoculation slightly increased shoot P concentration, but not shoot DM; the effects of inoculation on root traits were mostly small. We conclude that potential may exist to select subterranean clover for higher or lower colonisation by AMF using cultivar lines. Also, indigenous AMF may be less effective at enhancing plant P uptake and growth than inoculants. Finally, key root traits for enhancing plant P-uptake may change in the presence of AMF, but not sufficiently so to warrant deliberate inclusion or exclusion of AMF when screening germplasm for such traits. [ABSTRACT FROM AUTHOR]

Time-dependent density functional theory is utilized to simulate an asymmetrical jellium model, representing a nano-scale vacuum-tube diode comprised of bulk lithium. A sharp tip on one end of the jellium model allows for enhanced field emission upon interaction with an external laser field, leading to a preferential net current direction. This is verified by comparing the rate of electron transfer between the effective anode and cathode tips for both the diode jellium model and a symmetric cylinder jellium shape for various laser phase parameters. This rate of transfer is shown to significantly increase with smaller separation distances. With stronger laser intensities, this rate similarly increases but levels off as local near-field enhancements become negligible. [ABSTRACT FROM AUTHOR]

In the article, the author offers information on treatment of Hispanic American clergies and religious heads. The author mentions the importance of language as part of cultural sensitivity for providing proper treatment to a specialized population of task force run by heads consisting of reverend Eduardo Nevares, sister Miriam Perez and reverend Antonio Flore. It cites various cultures including the Latino cultures where interpersonal relationship is given the utmost importance.

The coupled Maxwell and time-dependent Kohn-Sham equations are solved using the Riemann-Silberstein vectors to represent the electromagnetic fields. Momentum-space time propagation of the Riemann-Silberstein vectors are proposed and test calculations are presented to show the accuracy of the approach. [ABSTRACT FROM AUTHOR]

An efficient and accurate basis comprised of Volkov states is implemented and tested for time-dependent simulations of interactions between strong laser pulses and crystalline solids. The Volkov states are eigenstates of the free electron Hamiltonian in an electromagnetic field and analytically represent the rapidly oscillating time-dependence of the orbitals, allowing significantly faster time propagation than conventional approaches. The Volkov approach can be readily implemented in plane-wave codes by multiplying the potential energy matrix elements with a simple time-dependent phase factor. [ABSTRACT FROM AUTHOR]

The integrating factor and exponential time differencing methods are implemented and tested for solving the time-dependent Kohn-Sham equations. Popular time propagation methods used in physics, as well as other robust numerical approaches, are compared to these exponential integrator methods in order to judge the relative merit of the computational schemes. We determine an improvement in accuracy of multiple orders of magnitude when describing dynamics driven primarily by a nonlinear potential. For cases of dynamics driven by a time-dependent external potential, the accuracy of the exponential integrator methods are less enhanced but still match or outperform the best of the conventional methods tested. [ABSTRACT FROM AUTHOR]

The stochastic variational method is applied to excitonic formations within semiconducting transition metal dichalcogenides using a correlated Gaussian basis. The energy and structure of two- to six-particle systems are investigated along with their dependence on the effective screening length of the two-dimensional Keldysh potential and the electron-hole effective mass ratio. Excited state biexcitons are shown to be bound, with binding energies of the L=0 state showing good agreement with experimental measurements of biexciton binding energies. Ground and newly discussed excited state exciton-trions are predicted to be bound and their structures are investigated. [ABSTRACT FROM AUTHOR]

Differences in root morphology and acclimation to low‐phosphorus (P) soil were examined among eight legume species from the Trifolium Section Tricocephalum to understand how these root attributes determine P acquisition. Ornithopus sativus was included as a highly P‐efficient benchmark species. Plants were grown as microswards in pots with five rates of P supplied in a topsoil layer to mimic uneven P distribution within a field soil profile. Topsoil and subsoil roots were harvested separately to enable measurement of the nutrient‐foraging responses. Critical P requirement (lowest P supply for maximum yield) varied over a threefold range, reflecting differences in root morphology and acclimation of nutrient‐foraging roots to P stress. Among the species, there was a 3.2‐fold range in root length density, a 1.7‐fold range in specific root length, and a 2.1‐fold range in root hair length. O. sativus had the lowest critical P requirement, displayed a high root length density, the highest specific root length, and the longest root hairs. Acquisition of P from P‐deficient soil was facilitated by development of a large root hair cylinder (i.e. a large root–soil interface). This, in turn, was determined by the intrinsic root morphology attributes of each genotype, and the plasticity of its root morphology response to internal P stress. Root acclimation in low‐P soil by all species was mostly associated with preferential allocation of mass to nutrient‐foraging roots. Only O. sativus and four of the Trifolium species adjusted specific root length beneficially, and only O. sativus increased its root hair length in low‐P soil. [ABSTRACT FROM AUTHOR]

Background: The BIOCHIP is an indirect immunofluorescence diagnostic investigation which identifies multiple autoantibodies with a mosaic panel of target antigen‐specific substrates in a single incubation field. The EUROIMMUN Dermatology Profile ELISA allows simultaneous investigation of the six most important autoantibodies in bullous autoimmune dermatoses. Evaluation of the BIOCHIP Mosaic 7, compared to that of the EUROIMMUN Dermatology Profile ELISA, when used as a diagnostic investigation in pemphigus and pemphigoid, was undertaken in an Australian cohort. Methods: The serum of 27 patients was analysed including patients with pemphigus vulgaris (n = 10), pemphigus foliaceous (n = 4), bullous pemphigoid (n = 8), mucous membrane pemphigoid (n = 3) and negative controls (n = 2). Results of the BIOCHIP were compared with the EUROIMMUN Dermatology Profile ELISA, as well as with histology, direct immunofluorescence and indirect immunofluorescence. Results: In pemphigus vulgaris, sensitivity & specificity for the BIOCHIP Mosaic 7 were 100% and 94.1%, comparable to that of the EUROIMMUN Dermatology Profile ELISA with 80% sensitivity and 100% specificity. In bullous pemphigoid, sensitivity of the BIOCHIP was 87.5% and sensitivity of the EUROIMMUN Dermatology ELISA profile was 75%, whilst specificities for both diagnostic methods were 100% in our limited cohort. There was substantial or almost perfect concordance between the BIOCHIP Mosaic 7 and EUROIMMUN Dermatology Profile ELISA for pemphigus vulgaris and bullous pemphigoid. Conclusion: The BIOCHIP Mosaic 7 is a rapid, reliable diagnostic investigation in pemphigus and bullous pemphigoid. Results indicate it is comparable to the EUROIMMUN Dermatology Profile ELISA, whilst also providing additional testing with salt split skin, on one field. [ABSTRACT FROM AUTHOR]

Proteins coimmunoprecipitating with protein kinase C (PKC) &epsiv; in fibroblasts were identified through matrix-assisted laser desorption/ionisation time of flight mass spectrometry (MALDI TOF m/s). This method identified myosin IIA in PKC &epsiv; immunoprecipitates, as well as known PKC &epsiv; binding proteins, actin, β''Cop and cytokeratin. Myosin is not a substrate for PKC &epsiv;. Immunofluorescence analysis showed that PKC &epsiv; is colocalised with actin and myosin in actomyosin stress fibers in fibroblasts. Inhibitors of PKC and myosin ATPase activity, as well as microfilament-disrupting drugs, all inhibited spreading of fibroblasts after passage, suggesting a role for a PKC &epsiv;–actin–myosin complex in cell spreading. [Copyright &y& Elsevier]

In recent decades several pasture legumes have been available in southern Australia as potential alternatives to the most widely used annual pasture legume Trifolium subterraneum. Little is known about their soil phosphorus (P) requirements, but controlled environment experiments indicate that at least some may differ in their P fertiliser requirements. In this study, pasture legume varieties, including T. subterraneum as the reference species, were grown at up to four sites in any one year over a 3-year period (in total, seven site × year experiments) to measure herbage growth responses in spring to increased soil P availability. A critical soil test P concentration (corresponding to 95% maximum yield) was estimated for 15 legumes and two pasture grasses. The critical soil P requirements of most of the legumes did not differ consistently from that of T. subterraneum , indicating their soil fertility management should follow the current soil test P guidelines for temperate Australian pastures. However, the critical P requirement of Medicago sativa was higher than that of T. subterraneum , but remains ill-defined because extractable soil P concentrations in these experiments were often not high enough to permit a critical P estimate. Three forage crop legumes (Trifolium incarnatum , Trifolium purpureum , Trifolium vesiculosum) and two pasture legumes (Ornithopus compressus , Ornithopus sativus) had lower critical soil test P concentrations. It may be feasible to manage pastures based on these species to a lower soil test P benchmark without compromising yield. Extractable phosphorus concentrations of soil corresponding to near-maximum pasture legume growth can be used as benchmarks for soil phosphorus management in temperate grass–legume pastures. In this study, the soil phosphorus requirements of alternative pasture legumes used in southern Australia were assessed and compared with that of the widely used legume Trifolium subterraneum. The results indicate that published soil test phosphorus benchmarks for T. subterraneum are appropriate for many alternative legumes, but also demonstrate that some can be fertilised to lower benchmark concentrations without compromising yield. [ABSTRACT FROM AUTHOR]

Annual pasture legumes with a superior ability to acquire soil phosphorus (P) and a low external critical P requirement could reduce the need for P fertiliser. Roots of pasture legumes grown in field soil will commonly be colonised by arbuscular mycorrhizal fungi (AMF). However, recent research suggests a second community of arbuscule-forming root-colonising fungi may be present: fine root endophytes (FRE). AMF are known to enhance P acquisition by plants under certain conditions, whereas very little is known about FRE and their impact on plant P status. We, therefore, grew plants at seven levels of P supply to determine and compare the external critical P requirements of two species of Ornithopus and two cultivars of Trifolium subterraneum when colonised predominantly by FRE (FRE-dominant treatment) or both FRE and AMF (mixed treatment). As expected from previous studies, the Ornithopus species had a lower critical P requirement than the T. subterraneum cultivars. However, for the Ornithopus species only, the FRE-dominant community had a significantly lower external critical P requirement (24–31 mg P kg −1 soil) than the mixed community (50–58 mg P kg −1 soil). Moreover, at low-P supply (≤15 mg applied P kg −1 soil), Ornithopus species in the FRE-dominant treatment had longer specific root length, smaller average root diameter, 45–128% greater total root length, and lower shoot and root P concentration than in the mixed treatment. We concluded that comparisons among experiments of root morphological traits and external critical P requirements can be affected by the presence of different communities of arbuscule-forming root-colonising fungi and that these effects may vary among plant species. [ABSTRACT FROM AUTHOR]

Background and aims: The growth and root morphology responses to soil phosphorus (P) fertility by five cultivars of Trifolium subterraneum (a temperate annual pasture legume) were examined to assess whether differences in root morphology and/or root acclimation to P stress influenced P-acquisition by the clover varieties, or their critical P requirements (i.e. the rate of P supply needed for maximum shoot yield).Methods: The clovers were grown as microswards in soil with P stratified in a topsoil layer to mimic growth conditions and soil P availability in a pasture. Yield and P content of shoots, and roots from the topsoil and subsoil layers was determined after 5 weeks growth in a controlled-environment cabinet. The lengths, diameters, and root hair lengths of nutrient foraging roots from the topsoil layer were quantified.Results: The shoot yield of the cultivars was similar when grown with high soil P fertility. However, the cultivars varied up to 1.5-fold in their ability to yield at low levels of soil P supply, and by 1.6-fold in their critical P requirements. All cultivars acclimated to low P soil by increasing root length density in the topsoil but those that yielded relatively well did so by maintaining a large root hair cylinder volume (i.e. they explored more soil) under low soil P conditions. This was associated with maintenance of dry matter allocations to topsoil roots and higher specific root lengths. Both factors assisted development of high root length density for nutrient foraging. Root acclimation responses to P were compared among the cultivars at equivalent relative shoot yields to assess the influence of plant P stress as a trigger for nutrient foraging. The least P-efficient cultivars slowed their allocation of dry matter to foraging roots at lower levels of P stress.Conclusions: The results suggest variation within T. subterraneum for root proliferation and specific root length could be targeted in breeding for improved P-acquisition efficiency. [ABSTRACT FROM AUTHOR]

The mainstream pasture legume species such as Trifolium subterraneum, T. repens and annual Medicago spp. used in the temperate pasture systems of southern Australia have high critical external requirements for phosphorus (P) (i.e. P required to achieve 90% of maximum yield). This work aimed to identify alternative pasture legume species that could be used in systems with lower P input. Shoot and root biomass of 12 species of pasture legume was measured in response to seven rates of P applied to the top 48 mm of soil in a pot experiment. Most species had maximum yields similar to T. subterraneum, but some required only one-third of the applied P to achieve this. The critical external P requirement of the species, ranked from lowest to highest, was as follows: Ornithopus compressus = O. sativus < Biserrula pelecinus < T. michelianum = T. vesiculosum = T. glanduliferum < T. hirtum = Medicago truncatula = T. purpureum = T. incarnatum < T. spumosum = T. subterraneum. An ability to maximise soil exploration through a combination of high root-length density, high specific root length and long root hairs (i.e. a large specific root-hair-cylinder volume) was associated with a low critical external P requirement. The results indicate that Ornithopus spp. could be used to achieve productive, low P-input pasture systems. [ABSTRACT FROM AUTHOR]

Root traits related to phosphorus (P) acquisition are used to make inferences about a species' P-foraging ability under glasshouse conditions. However, the effect on such root traits of constrained canopy spread, as occurs in dense pasture swards, is unknown. We grew micro-swards of Trifolium subterraneum L. and Ornithopus compressus L. at 15 and 60 mg kg-1 soil P in a glasshouse. Shoots either spread beyond the pot perimeter or were constrained by a cylindrical sleeve adjusted to canopy height. After 8 weeks, shoot and root dry mass (DM), shoot tissue P concentration, rhizosphere carboxylates, arbuscular mycorrhizal (AM) fungal colonisation, total and specific root length (TRL and SRL respectively), average root diameter (ARD) and average root hair length (ARHL) were measured. In all species and treatments, constrained canopy spread decreased root DM (39-59%), TRL (27-45%) and shoot DM (10-28%), and increased SRL (20-33%), but did not affect ARD, ARHL and AM fungal colonisation. However, shoot P concentration and content increased, and rhizosphere carboxylates increased 3.5 to 12-fold per unit RL and 2.0- to 6.5-fold per micro-sward. Greater amounts of rhizosphere carboxylates when canopy spread was constrained appeared to compensate for reduced root growth enabling shoot P content to be maintained. [ABSTRACT FROM AUTHOR]

Aims: Trifolium subterraneum L. is the predominant annual pasture legume in southern Australia. Cultivars with improved phosphorus (P) foraging ability would improve the P-use efficiency of agricultural systems. We therefore investigated variation in root traits related to P-uptake among six cultivars. Methods: Micro-swards were grown at six levels of P in field soil with indigenous arbuscular mycorrhizal (AM) fungi for six weeks. Dry matter yield, tissue P concentration, rhizosphere carboxylates, AM fungal colonisation and root morphological traits were measured. Results: The cultivars showed similar shoot and root yield responses to P supply. Average root diameter did not change, specific root length (SRL) increased and root tissue density (RTD) decreased with increased P supply. Amounts of total rhizosphere carboxylates were low (<1.2 nmol cm root). The percentage of root length colonised by AM fungi was greatest (29-43 %) at an intermediate level (8 mg kg dry soil) of P supply. Conclusions: Most differences among cultivars were reasonably consistent across P supply levels, indicating greater numbers of lines could be screened reliably at a single P level. Low colonisation by AM fungi at low P supply deserves consideration when selecting soils for cultivar comparisons. Increased SRL and decreased RTD at high P supply likely result from self-shading within the micro-swards and warrant further investigation. [ABSTRACT FROM AUTHOR]

Background and aims: This work aimed to quantify the critical external requirement for phosphorus (P) (i.e. extractable-P concentration required for 90 % of maximum yield) for a number of temperate legume species and understand differences in dry matter allocation, P distribution and P acquisition efficiency among these species. Methods: Shoot and root growth of five legume and one grass species was assessed in response to six rates of P mixed into the top 45 mm of soil in a pot experiment. Dactylis glomerata and Trifolium subterraneum were used as benchmark species; they are commonly grown together in mixed temperate pastures and have low and high critical external requirements for P, respectively. Growth was compared with four alternative legume species: Ornithopus compressus, Ornithopus sativus, Biserrula pelecinus and Trifolium hirtum, that have root morphologies better suited to soil exploration and nutrient acquisition than that of Trifolium subterraneum. Results: Dactylis glomerata, Ornithopus compressus and Ornithopus sativus had maximum yields equal to or greater than Trifolium subterraneum but achieved this at rates of P less than half that of Trifolium subterraneum. Biserrula pelecinus and Trifolium hirtum had critical P requirements between that of Trifolium subterraneum and the Ornithopus species, but also had lower yields. Root dry matter of Dactylis glomerata and the Ornithopus species in the fertilised soil layer was only marginally changed in response to low P supply. In contrast, Trifolium subterraneum, Trifolium hirtum and to a lesser extent Biserrula pelecinus markedly increased root dry matter allocation to this soil layer. Species with lower critical P requirements were able to take up more P per unit root dry mass than those with higher critical P requirements, particularly at lower levels of P addition. Conclusions: The high P acquisition efficiencies of the Ornithopus species and Dactylis glomerata were likely to have contributed to their low critical external P requirements. It was surmised that differences in root morphology traits underpin the differences in acclimation to low P stress and P acquisition efficiency among the species. [ABSTRACT FROM AUTHOR]

Annual pasture legume species can vary more than 3-fold in their critical external phosphorus (P) requirement (i.e. P required for 90% of maximum yield). In this work we investigated the link between root morphology, P acquisition and critical external P requirement among pasture species. The root morphology acclimation of five annual pasture legumes and one grass species to low soil P availability was assessed in a controlled-environment study. The critical external P requirement of the species was low (Dactylis glomerata L., Ornithopus compressus L., Ornithopus sativus Brot.), intermediate (Biserrula pelecinus L., Trifolium hirtum All.) or high (Trifolium subterraneum L.). Root hair cylinder volumes (a function of root length, root hair length and average root diameter) were estimated in order to assess soil exploration and its impact on P uptake. Most species increased soil exploration in response to rates of P supply near or below their critical external P requirement. The legumes differed in how they achieved their maximum root hair cylinder volume. The main variables were high root length density, long root hairs and/or high specific root length. However, total P uptake per unit surface area of the root hair cylinder was similar for all species at rates of P supply below critical P. Species that maximised soil exploration by root morphology acclimation were able to prolong access to P in moderately P-deficient soil. However, among the species studied, it was those with an intrinsic capacity for a high root-hair-cylinder surface area (i.e. long roots and long root hairs) that achieved the lowest critical P requirement. [ABSTRACT FROM AUTHOR]