Effects Of Phosphorus Availability Research Articles

Identifying limitations for invasion: the effect of phosphorus availability on the growth of the non-native tree, Tipuana tipu

Context Despite being a crucial factor in plant growth and fitness, the nutritional requirements of non-native invasive plants are poorly understood and rarely considered when assessing invasion risk; yet, they are particularly relevant in many parts of the world with nutrient-poor soils. Aims We investigated the growth response of a native South American tree species (Tipuana tipu), to soil concentrations of phosphorus (P). T. tipu is widely introduced in some regions of western Australia and South Africa, and we aimed to determine whether soil P availability constrains establishment, naturalisation or invasion of the species. Methods We grew T. tipu (Benth.) Kuntze (Fabaceae), a species that is invasive in some regions, from seed in a glasshouse. All treatments were supplied baseline nutrients, and P from 0 to 640 μg P g−1 dry substrate. Plant height and the number of mature leaves were recorded regularly. Plant biomass, P, and nitrogen (N) concentrations were analysed following destructive harvest. Key results Phosphorus availability had a significant effect on all measured aspects of plant growth. Seed P resources were sufficient to support growth for about 7 weeks, with plants at very low soil P availability (≤5 μg P g−1 dry soil) unable to sustain growth beyond that time. P-toxicity symptoms were observed when substrate P exceeded optimum concentrations (40–160 μg P g−1 dry soil). Conclusions Growth of young T. tipu seedlings was very slow at very low soil P concentrations. Under these conditions, seeds may germinate, and seedlings may survive for a short time, but self-sustaining populations are unlikely to be established. Our study adds to a growing body of research that shows that nutrient requirements of introduced plants and soil nutrient availability influence invasion risk and should be considered in risk assessments for managing species invasions at the landscape level.

EFFECTS OF PHOSPHORUS AVAILABILITY ON NODULATION AND NITROGEN UPTAKE BY THREE LEGUME CROPS IN TWO GHANAIAN SOILS

Purpose: A greenhouse study of Soybean, Cowpea and Pigeon Pea was made at University of Ghana, to determine the effects of phosphorus availability on nodulation and nitrogen uptake by the afore mentioned legumes in two Ghanaian soils, Adenta and Nzema series.
 Methodology: Three P rates of 0mg, 50mg and 100mg P of TSP and TPR were applied to a kilogram of soil per pot in two soil series. The pots were arranged using Randomized Complete Block Design. GenstatR was used to do the statistical analysis.
 Findings: The results from this study showed that with or without Triple Super Phosphate (TSP) or Togo Phosphate Rock (TPR), soybean did not form nodules in the Nzema soil but nodulated with TSP application in the Adenta soil. The absence of nodulation even with high P from TSP by soybean in Nzema soil is surprising but the observation in the Nzema soil may be attributed to the absence of soybean Rhizobium cells or insignificant numbers of these rhizobia. The results of the present data indicated that treatments with higher P application gave higher N uptake and showed the link among P application, high nodule dry weight, and N uptake. The improvement in the dry matter yield of pigeon pea and cowpea on Adenta soil and soybean on the Nzema soil at TPR50 and TPR100 show the importance of P application to dry matter yield of legumes. Significant difference that was shown by cowpea on Nzema soil could be attributed to the ability of the crop to desorp P from sparingly available P sources through exudation of high amounts of organic acid anions, mainly citrate.
 Unique contributions to theory, practice and policy: In the soil, Rhizobium species must recognize their specific host before nodulation may take place and the absence of the appropriate Rhizobium species with the introduction of a legume into a given soil may result in no or poor nodulation. Low P availability is a challenge for crop species to nodulate since the rhizobia responsible for nitrogen fixation have a high P requirement. The toxicity of Aluminum to rhizobia may be due to inhibition of DNA replication because of binding of Aluminum to DNA. One factor that could have accounted for the better nodulation in soil is the higher acidity. The optimum pH for effective rhizobia growth in soils is between pH 6 and 7.

EFFECTS OF PHOSPHORUS AVAILABILITY ON NODULATION AND NITROGEN UPTAKE BY THREE LEGUME CROPS IN TWO GHANAIAN SOILS

Purpose: A greenhouse study of Soybean, Cowpea and Pigeon Pea was made at University of Ghana, to determine the effects of phosphorus availability on nodulation and nitrogen uptake by the afore mentioned legumes in two Ghanaian soils, Adenta and Nzema series.
 Methodology: Three P rates of 0mg, 50mg and 100mg P of TSP and TPR were applied to a kilogram of soil per pot in two soil series. The pots were arranged using Randomized Complete Block Design. GenstatR was used to do the statistical analysis.
 Findings: The results from this study showed that with or without Triple Super Phosphate (TSP) or Togo Phosphate Rock (TPR), soybean did not form nodules in the Nzema soil but nodulated with TSP application in the Adenta soil. The absence of nodulation even with high P from TSP by soybean in Nzema soil is surprising but the observation in the Nzema soil may be attributed to the absence of soybean Rhizobium cells or insignificant numbers of these rhizobia. The improvement in the dry matter yield of pigeon pea and cowpea on Adenta soil and soybean on the Nzema soil at TPR50 and TPR100 show the importance of P application to dry matter yield of legumes. Significant difference that was shown by cowpea on Nzema soil could be attributed to the ability of the crop to desorp P from sparingly available P sources through exudation of high amounts of organic acid anions, mainly citrate.
 Unique contributions to theory, practice and policy: In the soil, Rhizobium species must recognize their specific host before nodulation may take place and the absence of the appropriate Rhizobium species with the introduction of a legume into a given soil may result in no or poor nodulation. Low P availability is a challenge for crop species to nodulate since the rhizobia responsible for nitrogen fixation have a high P requirement. The toxicity of Aluminum to rhizobia may be due to inhibition of DNA replication because of binding of Aluminum to DNA. One factor that could have accounted for the better nodulation in soil is the higher acidity. The optimum pH for effective rhizobia growth in soils is between pH 6 and 7.

Effects of phosphorus availability and phosphorus utilization behavior of Microcystis aeruginosa on its adaptation capability to ultraviolet radiation

Effects of phosphorus availability and phosphorus utilization behavior of Microcystis aeruginosa on its adaptation capability to ultraviolet radiation

Effects of phosphorus availability and phosphorus utilization behavior of Microcystis aeruginosa on its adaptation capability to ultraviolet radiation

Phosphorus (P) plays a critical role in eutrophication and algal growth; therefore, improving our understanding of the impact of P is essential to control harmful algal blooms. In this study, Microcystis aeruginosa was treated with 5-h ambient irradiation in the medium with different dissolved inorganic P (DIP) concentrations, DIP-free, moderate-DIP, and high-DIP, to explore its growth and other physiological responses. Compared to photosynthetically active radiation (PAR), UV-A (320–400 nm) and UV-B (280–320 nm) radiation had inhibitive effects on the photosynthesis and growth of M. aeruginosa, while high P availability could alleviate or eliminate the negative effects of UV radiation. The photosynthetic parameters had a minimum reduction and quickly recovered after re-inoculation under high-DIP conditions. Confirmed by SEM, photosynthetic pigments, the generation of reactive oxygen species (ROS), superoxide dismutase (SOD) activity and other methods, ambient UV radiation exerted oxidative stresses rather than direct lethal effects on M. aeruginosa. Photosynthetic parameters indicated that algal UV-adaptation processes could include decreasing photo-induced damages and increasing self-repair efficiency. The P acquired by M. aeruginosa cells can have two function, which included alleviating UV-induced negative effects and sustaining algal growth. Consequently, UV-adaptation processes of M. aeruginosa resulted in an elevated demand for DIP, which resulted to increased P uptake rates and cellular P quota under moderate and high-DIP conditions. Therefore, the production of carotenoid and phycocyanin, and SOD activity increased under UV stress, leading to a better adaptation capability of M. aeruginosa and decreased negative effects of UV radiation on its growth. Overall, our findings demonstrated the significant interactive effects of P enrichment and irradiation on typical cyanobacteria, and the strong adaptation capability of M. aeruginosa in the eutrophic UV-radiated waters.

Effects of phosphorus availability on later stages of primary succession in Gongga Mountain glacier retreat area

Intra- and interspecific competition and modifications in environmental characteristics are the main drivers of plant community dynamics, but few studies have investigated the combined effects of competition and phosphorus (P) availability on ecological succession. Seedlings of conifers Abies fabri and Picea brachytyla were collected from the late-stage Hailuogou glacier retreat area and grown under different P regimes (control and P fertilization) to investigate the impact of intra- and interspecific competition on photosynthetic capacity, resource (water, N and P) use efficiency and growth performance in two types of native soil. In the control treatment, there were no differences in the total biomass of A. fabri between the two competition patterns under either type of soil, whereas interspecific competition decreased the total biomass of P. brachytyla grown in the soil collected from A. fabri plots. However, under P fertilization, A. fabri individuals exposed to interspecific competition showed a stronger competitive ability, as their total biomass, absolute height growth rate, net photosynthetic rate, water use efficiency (δ13C) and leaf P content were significantly higher under interspecific competition compared to intraspecific competition. No differences in these traits were detected in P. brachytyla between the two competition patterns. The results indicated that P plays an important role in determining asymmetric competition patterns among Pinaceae species. The interactive effect of interspecific competition and P availability highlighted here could influence the community composition and dynamics of plants during late-stage primary succession in a glacier retreat area.

Drivers of tree species distribution across a tropical rainfall gradient

AbstractUnderstanding the factors shaping species distribution patterns along tropical rainfall gradients is necessary to predict the consequences of climate change for tropical tree communities. Direct effects of water availability exclude wet forest species from dry forests, but the exclusion of dry forest species from wet forests remains unexplained. We tested the hypothesis that high light and nutrient requirements exclude dry forest species from dark, infertile, wet forests. We transplanted seedlings of 26 woody species to six sites along a pronounced regional rainfall gradient across the Isthmus of Panama. We examined the effects of soil moisture, phosphorus and light availability, and species' drought resistance on seedling performance, and linked the results directly to known species distribution patterns. Surprisingly, seedlings of wet forest species did not exhibit a home advantage: All species survived better under moister conditions, and the effects of phosphorus availability and light on seedling performance did not differ among species from dry or wet forests. Instead, dry forest species had intrinsically slower growth rates than wet forest species, which may lead to their exclusion from wet forests at later life history stages. High phosphorus exacerbated susceptibility to drought, although the mechanism remains unknown. Overall, our results demonstrate that seedling performance across tropical rainfall gradients is determined primarily by variation in soil water availability across space and time, while variation in nutrient and light availability plays a lesser role. Future changes in rainfall patterns will therefore have direct and pervasive consequences for forest composition and ecosystem function.

Nutrient Uptake and Removal by Potato Cultivars as Affected by Phosphate Fertilization of Soils with Different Levels of Phosphorus Availability

ABSTRACT Studies in the past decades have focused on how tuber yield of potato grown on different types of soil is affected by phosphate fertilizer rates. However, little is known about the effects of phosphorus availability in the soil and of phosphate fertilization on nutrient uptake and removal by the main potato cultivars currently grown in Brazil. Thus, in this study we investigated the influence of P fertilization rates on dry matter (DM) yield and nutrient uptake and removal in [...]

Effects of Phosphorus Availability on Plant Growth and Soil Nutrient Status in the Rice/Soybean Rotation System on Newly Cultivated Acidic Soils

Acid soils are worldwide spread, where low phosphorus (P) availability is considered as the major limiting constraint for crop growth, particularly on the newly cultivated acidic soils. Traditionally, the rotation system of rice with leguminous crops has been often used on acid soils. However, little is known about how P availability affects this traditional rotation system on acid soils. In the present study, two years of soil pot experiments had been done using rice (Oryza sativa L.) as the first crop and soybean (Glycine Max L.) as the second crop. The results showed that rice growth were significantly affected by P fertilization on acid soils. Sufficient P application increased plant height, shoot biomass, tiller number, and panicle dry weight compared to that of no P fertilization in both two years’ studies. The growth of following crop soybean was also influenced by P supply, and the P efficient genotype HX1 exhibited more adaptive to low P than the P inefficiency genotype BD2, as reflected by better growth of HX1 than BD2. Rhizosphere pH and soil nutrient status was significantly influenced by the rotation system. An increased tendency of rhizosphere pH was observed after the growth of rice and soybean. Soil N concentration was significantly increased after planting HX1 but not BD2. Furthermore, rice rotated with HX1 resulted in higher P fertilizer use efficiency (PFUE). Taken together, we conclude that the rice-soybean rotation with optimal P supply is a suitable agricultural mode on acid soils, and rotating with the P efficient soybean genotype could benefit more in soil nutrient status, which might increase the agriculture sustainability on acid soils.

The relationship between an introduced predator–prey pair, largemouth bass and bluegill, and the chlorophyll concentration in farm ponds

An empirical study was conducted on the effects of an introduced predator–prey pair, largemouth bass and bluegill, on pelagic productivity in 22 ponds in central Japan. In the univariate analysis, the effect of fish invasion on chlorophyll concentration was not evident, primarily because this effect was screened by the positive and negative effects of phosphorus availability and the pond area, respectively. A positive effect on chlorophyll concentration was detected in the best statistical model using nutrient availability and pond area as independent factors. Fish invasion decreased the relative biomass of crustaceans to rotifers. This study showed that the invasion of these exotic fishes affected the pelagic community in the pond.

Effect of phosphorus availability on the selection of species with different ploidy levels and genome sizes in a long‐term grassland fertilization experiment

Polyploidy and increased genome size are hypothesized to increase organismal nutrient demands, namely of phosphorus (P), which is an essential and abundant component of nucleic acids. Therefore, polyploids and plants with larger genomes are expected to be selectively disadvantaged in P-limited environments. However, this hypothesis has yet to be experimentally tested. We measured the somatic DNA content and ploidy level in 74 vascular plant species in a long-term fertilization experiment. The differences between the fertilizer treatments regarding the DNA content and ploidy level of the established species were tested using phylogeny-based statistics. The percentage and biomass of polyploid species clearly increased with soil P in particular fertilizer treatments, and a similar but weaker trend was observed for the DNA content. These increases were associated with the dominance of competitive life strategy (particularly advantageous in the P-treated plots) in polyploids and the enhanced competitive ability of dominant polyploid grasses at high soil P concentrations, indicating their increased P limitation. Our results verify the hypothesized effect of P availability on the selection of polyploids and plants with increased genome sizes, although the relative contribution of increased P demands vs increased competitiveness as causes of the observed pattern requires further evaluation.

Mycorrhizal status of Cyperaceae from New Caledonian ultramafic soils: effects of phosphorus availability on arbuscular mycorrhizal colonization of Costularia comosa under field conditions

Plants from the Cyperaceae family (sedges), usually considered as non-mycorrhizal, constitute almost exclusively the herbaceous stratum of the ultramafic maquis in New Caledonia. These plants are pioneers and are important for the ecological restoration of mined areas. Costularia comosa, one of the most common sedges in this environment, was grown under field conditions on ultramafic soil, fertilized or not with phosphate and/or nitrogen. Results showed that the addition of phosphate to the soil induced a clear increase in mycorrhizal colonization of C. comosa and an increase in arbuscule abundance, reflecting the establishment of a functional mycorrhizal symbiosis. Significant positive correlations were found among mycorrhizal parameters and plant or soil phosphorus concentrations. Nitrogen fertilization did not affect mycorrhizal colonization of C. comosa. The improvement in mycorrhizal colonization by phosphate fertilization did not influence significantly nickel concentrations in the roots and shoots of plants. This study demonstrated that phosphate fertilization of ultramafic soil improved mycorrhizal colonization of C. comosa, with formation of a functional symbiosis under field conditions.

Effects of phosphorus availability and genetic variation of leaf terpene content and emission rate in Pinus pinaster seedlings susceptible and resistant to the pine weevil, Hylobius abietis

We studied the effects of phosphorus fertilisation on foliar terpene concentrations and foliar volatile terpene emission rates in six half-sib families of Pinus pinaster Ait. seedlings. Half of the seedlings were resistant to attack of the pine weevil Hylobius abietis L., a generalist phloem feeder, and the remaining seedlings were susceptible to this insect. We hypothesised that P stress could modify the terpene concentration in the needles and thus lead to altered terpene emission patterns relevant to plant-insect signalling. The total concentration and emission rate ranged between 5732 and 13,995 μg·g(-1) DW and between 2 and 22 μg·g(-1) DW·h(-1), respectively. Storage and emission were dominated by the isomers α- and β-pinene (77.2% and 84.2% of the total terpene amount amassed and released, respectively). In both resistant and susceptible families, P stress caused an increase of 31% in foliar terpene concentration with an associated 5-fold decrease in terpene emission rates. A higher terpene content in the leaves implies that the 'excess carbon', available under limiting growth conditions (P scarcity), is allocated to terpene production. Sensitive families showed a greater increase in terpene emission rates with increasing P concentrations, which could explain their susceptibility to H. abietis.

The Effect of Phosphorus Availability on Decomposition Dynamics in a Seasonal Lowland Amazonian Forest

Once the weathering of parent material ceases to supply significant inputs of phosphorus (P), vegetation depends largely on the decomposition of litter and soil organic matter and the associated mineralization of organic P forms to provide an adequate supply of this essential nutrient. At the same time, the decomposition of litter is often characterized by the immobilization of nutrients, suggesting that nutrient availability is a limiting factor for this process. Immobilization temporally decouples nutrient mineralization from decomposition and may play an important role in nutrient retention in low-nutrient ecosystems. In this study, we used a common substrate to study the effects of native soil P availability as well as artificially elevated P availability on litter decomposition rates in a lowland Amazonian rain forest on highly weathered soils. Although both available and total soil P pools varied almost three fold across treatments, there was no significant difference in decomposition rates among treatments. Decomposition was rapid in all treatments, with approximately 50% of the mass lost over the 11-month study period. Carbon (C) and nitrogen (N) remaining and C:N ratios were the most effective predictors of amount of mass remaining at each time point in all treatments. Fertilized treatments showed significant amounts of P immobilization (P < 0.001). By the final collection point, the remaining litter contained a quantity equivalent to two-thirds of the initial P and N, even though only half of the original mass remained. In these soils, immobilization of nutrients in the microbial biomass, late in the decomposition process, effectively prevents the loss of essential nutrients through leaching or occlusion in the mineral soil.

The effect of phosphorus availability on the carbon economy of contrasting common bean (Phaseolus vulgaris L.) genotypes

A common response to low phosphorus availability is increased relative biomass allocation to roots. The resulting increase in root:shoot ratio presumably enhances phosphorus acquisition, but may also reduce growth rates by diverting carbon to the production of heterotrophic rather than photosynthetic tissues. To assess the importance of increased carbon allocation to roots for the adaptation of plants to low P availability, carbon budgets were constructed for four common bean genotypes with contrasting adaptation to low phosphorus availability in the field ("phosphorus efficiency"). Solid-phase-buffered silica sand provided low (1 microM), medium (10 microM), and high (30 microM) phosphorus availability. Compared to the high phosphorus treatment, plant growth was reduced by 20% by medium phosphorus availability and by more than 90% by low phosphorus availability. Low phosphorus plants utilized a significantly larger fraction of their daytime net carbon assimilation on root respiration (c. 40%) compared to medium and high phosphorus plants (c. 20%). No significant difference was found among genotypes in this respect. Genotypes also had similar rates of P absorption per unit root weight and plant growth per unit of P absorbed. However, P-efficient genotypes allocated a larger fraction of their biomass to root growth, especially under low P conditions. Efficient genotypes had lower rates of root respiration than inefficient genotypes, which enabled them to maintain greater root biomass allocation than inefficient genotypes without increasing overall root carbon costs.

The effect of phosphorus availability on the carbon economy of contrasting common bean ( Phaseolus vulgaris L.) genotypes

A common response to low phosphorus availability is increased relative biomass allocation to roots. The resulting increase in root:shoot ratio presumably enhances phosphorus acquisition, but may also reduce growth rates by diverting carbon to the production of heterotrophic rather than photosynthetic tissues. To assess the importance of increased carbon allocation to roots for the adaptation of plants to low P availability, carbon budgets were constructed for four common bean genotypes with contrasting adaptation to low phosphorus availability in the field ("phosphorus efficiency"). Solid-phase-buffered silica sand provided low (1 microM), medium (10 microM), and high (30 microM) phosphorus availability. Compared to the high phosphorus treatment, plant growth was reduced by 20% by medium phosphorus availability and by more than 90% by low phosphorus availability. Low phosphorus plants utilized a significantly larger fraction of their daytime net carbon assimilation on root respiration (c. 40%) compared to medium and high phosphorus plants (c. 20%). No significant difference was found among genotypes in this respect. Genotypes also had similar rates of P absorption per unit root weight and plant growth per unit of P absorbed. However, P-efficient genotypes allocated a larger fraction of their biomass to root growth, especially under low P conditions. Efficient genotypes had lower rates of root respiration than inefficient genotypes, which enabled them to maintain greater root biomass allocation than inefficient genotypes without increasing overall root carbon costs.