Query: Water and nutrient uptake in Vriesea

title: Water and nutrient uptake in Vriesea cultivars: Trichomes vs. Roots
abstract: Vriesea species are tank type Bromeliaceae, mainly occurring as epiphytes. With their absorbing trichomes and their leaves arranged into water and nutrient catching tanks, they are able to thrive in tree canopies where water and nutrient uptake by the roots is limited. However, when commercially cultivated in greenhouses as ornamentals these plants grow in a very different environment: they are offered ample water and nutrients, and their roots develop in horticultural substrates. This study shows that under commercial cultivation conditions, Vriesea cultivars take up water and nutrients both by their roots and their leaf trichomes. As plants develop throughout the production cycle the relative share of water and nutrient uptake by the roots diminishes in all cultivars tested, but to a different extent. These cultivar specific differences in water and nutrient uptake can be attributed to differences in tank form, trichome uptake kinetics, trichome densities and ultimately to genetic background.

title: Anomalies in the leaf development of Vriesea and Guzmania linked to disturbances in water and nutrient uptake

title: Microbial activities and foliar uptake of nitrogen in the epiphytic bromeliad Vriesea gigantea.
abstract: In contrast to terrestrial plants, epiphytic tank bromeliads take up nutrients mainly over their tank leaf surface. The form in which nutrients are available in the tanks is determined by the source and the complex interplay between tank microbes, which transform them and the epiphytes that take them up. To elucidate the importance of different nitrogenous compounds for the nitrogen (N) nutrition of Vriesea gigantea from the Atlantic Rainforest, Brazil, N transformation processes in tank water as well as foliar uptake rates were estimated by 15N labelling techniques. Microorganisms actively transformed N compounds in the tank. Specifically, organic N compounds were rapidly mineralized to NH4+ while nitrification was negligible. Plants took up both organic and inorganic N forms, with a clear preference for NH4+ NH4+ comprised the largest and, because of fast mineralization rates, the most constant dissolved N pool in the tank water. Excretion of ureases by the plants together with an unusual uptake kinetic for urea also suggests that urea may be potentially important as an N source.

title: Fertilization effects on biomass production, nutrient leaching and budgets in four stand development stages of short rotation forest poplar
abstract: Dedicated energy poplar plantations have a high biomass production potential in temperate regions, which may be further increased by improved management practices. The aim of this study was to investigate the effects of fertilization on short rotation forest poplar established on former arable land. We examined the effects on biomass production, net nutrient uptake in stems and branches, nutrient leaching fluxes and changes to the nutrient budgets calculated as inputs minus outputs. An experiment was carried out in four stands of different development stages, the establishment (EST) canopy closure (CC) pre thinning (PT) and late aggradation (LAG) stage. After fertilizing with NPK12 5 14 corresponding to 120 kg ha 1 of N we measured the biomass production during three years and analysed biomass samples to assess the net nutrient uptake in stems and branches. We estimated nutrient leaching based on water fluxes modelled with CoupModel and soil solution analyses and calculated the nutrient budgets. Fertilization effects depended on the stage of stand development, but were inconsistent in time. The biomass production increased in EST in the first year after fertilization and in PT in the third year after fertilization, relative to the control. There were no effects in CC and LAG. Nitrogen leaching at 0.9 m depth ranged between 3 and 14 kg ha 1 yr 1 in the control plots of EST and PT and it was negligible in the CC stand. Nitrogen leaching doubled in EST in the year of fertilization with values up to 28 kg ha 1 yr 1 and it tripled in PT in the second year after fertilization, compared to the control. Budgets of N, P and K were negative in all unfertilized and some fertilized treatments, indicating that fertilization may be required to adequately sustain soil nutrient supply in the long term, as large amounts of nutrients will be removed when the biomass is harvested.

title: Changes in Primary Producer and Consumer Communities in Response to Upstream Nutrient Addition in the Kootenai River, Idaho
abstract: The purpose of this study was to assess potential effects of nutrient addition in the previously unassessed lower Kootenai River (Meander Reach) 44 155 km downstream from the nutrient dosing site. We hypothesized that downstream periphyton and plankton densities would increase due to nutrient spiraling and organismal drift following seasonal upstream nutrient addition. Liquid inorganic ammonium polyphosphate fertilizer (10:34:0, N:P:K) was added to the Kootenai River in Idaho immediately downstream from the Idaho Montana border with an in river target concentration of 3.0 ug L 1 total dissolved phosphorus for 16 weeks (01 June 01 October) from 2006 through 2012. As predicted, mean periphyton, phytoplankton, and zooplankton densities increased significantly (P 0.05) post nutrient addition. Periphyton density increased 5.1 times (pre: 685.1 mm 2, post: 3501.0 mm 2) phytoplankton densities increased 1.7 times (pre: 1775.9 L 1, post: 3005.4 L 1) and zooplankton densities increased by 49% (pre: 67.0 L 1, post: 99.7 L 1) While nutrient uptake, water chemistry, algal and chlorophyll accrual, periphyton, macroinvertebrate, and native fish community responses to nutrient addition have been previously published, including results from upstream reaches of the Kootenai River, this study provides the first published account of lower trophic level responses at considerable distances downstream from the dosing site in altered, low velocity habitats which are very different from the upstream gravel bed reaches reported in other studies. Results of this study add to the growing body of empirical knowledge regarding the use of nutrient addition for restoring large culturally denutrified rivers in the Pacific Northwest and provide valuable new insights regarding the longitudinal patterns of response magnitude.

title: Assessment on Cr, Cd, As, Ni and Pb uptake and phyremediation potential of Scirpus mucronatus
abstract: A laboratory experiment was conducted to examine the heavy metals (Cr, Cd, As, Ni and Pb) phytoaccumulation potential of an aquatic macrophytes Scirpus mucronatus. The macrophyte were transferred to the laboratory containing nutrient solution enriched with 1.0, 2.0, 4.0, 8.0 and 16 mg L 1 of Cr, Cd, As, Ni and Pb and were separately harvested after 2, 4, 6, 8 and 10 days. The bioaccumulation study showed a linear relationship for Cr accumulation but curvilinear in the case of the other metals with the exposure time (2 10 d) The accumulation of all the metals was found to be higher in the root than the shoot. The maximum bioconcentration factor (BCF) and translocation factor (TF) value were found in Pb (1387 and 0.95) and minimum BCF and TF values were found in Ni (386) and Cd (0.51) treated plants respectively. The experimental results demonstrated that the S. mucronatus can be used for removal of Cr, Cd and Pb from contaminated water.

title: Effects of Water Soluble Potassium Silicate by Soil Drenching Application on Watermelon (Citrullus lanatus var. lanatus)
abstract: The objective of this study was to determine the effects of soluble potassium silicate by soil drenching application on watermelon growth, yield, and nutrient uptake. The potassium silicate rates were control (No potassium silicate) 1.63mM, 3.25mM, 6.50mM. The potassium silicate were treated 6 times (twice before fruit forming and 4 times after fruit forming per 7 day. Soil chemical properties, such as soil pH, EC, available phosphorus and silicate, exchangeable K, nitrate N levels were increased after potassium silicate treatment, while the concentrations of soil organic matter, exchangeable Ca and Mg were similar to control. The growth characteristics of watermelon, such as stem diameter, fresh and dry weight of watermelon at harvest were thicker and heavier for increased potassium silicate treatment than the control, while number of node, and plant length were same for all treatments. With increased potassium silicate treatment, nutrient concentrations, such as P and K in the watermelon leaf at harvest were increased, N concentration in the leaf was decreased, and Ca and Mg concentrations in the leaf were same. Chlorophyll content was increased with increased potassium silicate application. The occurrence of powdery mildew was lower for the potassium silicate treatments than the control. Fresh watermelon weight for the potassium silicate treatments was 0.1 to 0.5kg per watermelon heavier than the control, sugar content was 0.5 to 0.6Brix higher than control, and merchantable watermelon was 2 to 4% increased compared to the control. These results suggest that potassium silicate application by soil drenching method in the greenhouse can improve watermelon nutrient uptake, merchantable watermelon and suppress the occurrence of powdery mildew.  chlorophyll, dry weight, powdery mildew, sugar content

title: The effect of rotation, tillage, and fertility on rice grain yields and nutrient flows.
abstract: Rice is one of the most intensively cultivated row crops in America. In order to move away from current tillage practices it will be necessary to maintain current yield levels. A key to successful no till rice production will be to maintain plant fertilizer efficiency in a system that is flooded much of the growing season and not increase nutrient runoff. A study was established in 2000 that compares fertility, variety, and conventional and no till rice rotations. Rice grain yields, across all treatments, were between 140 and 195 bu a. Yields were most affected by rotation and tillage. Continuous rice grain yields averaged 34 bu a lower than a rice soybean rotation. Plant P and K uptake varied significantly between rotation treatments but not between tillage, fertility, or variety treatments. Phosphorus concentrations in run off liquid were significantly higher in the no till plots. Total P in runoff was lower in the no till plots because of reduced P being carried in solids. Total nitrogen uptake was lower in the continuous rice rotation compared to the rice soybean rotation with soil N uptake higher for the no till compared to conventional till in both rotations.  Field #8 at the University of Arkansas Rice Research and Extension Center was selected for this study and cut to a 0.15% slope in February, 1999. This site had not been previously used for rice research because irrigation water was not available. Soil at the site is referred to as a Stuttgart silt loam and classified as a fine, smectitic, thermic Albaqultic Hapludolf. Initial soil samples showed a pH range of 5.6 to 6.2 with carbon content averaging 0.84% and nitrogen 0.08% Plots measuring 250' x 40' were laid out in a north south direction. These plots were then divided in half east west with each side randomized as conventional or no till treatments. Each tillage treatment was then split into a standard and high fertility treatment. For rice, 'standard' fertility consisted of a single preflood N application of 100 lbs urea a plus 40 lbs a P2O5, and 60 lbs a K2O applied prior to planting. Rates increased to 150 lbs a N, 60 lbs a P2O5, and 90 lbs a K2O for the 'enhanced' treatment with application times remaining the same. Two varieties of each crop species were planted in a continuous strip across the conventional and no till treatments. In March, soil samples were collected for fertility evaluations. Soil samples were ground and dried. Phosphorus and potassium determinations were made using a Melich III extraction at a 1:10 extraction ratio. Plant samples were collected following physiological maturity but before leaf senescence for nutrient determinations in 1999, 2000, and 2001. Plants were divided into grain, leaf, and stem portions for analysis. Plant analysis was completed using a HNO3 digest and read with a ICP (Spectro Model D) The following rotations were started in 1999: 1) continuous rice, 2) ricesoybean, 3) soybean rice, 4) rice corn, 5) corn rice, 6) rice (wheat) rice (wheat) 7) rice (wheat)soybeans (wheat) 8) soybeans (wheat) rice (wheat) 9) rice corn soybeans, 10) rice corn (wheat)soybeans. Yield data and nutrient uptake will be presented for the continuous rice and rice soybean rotations.

title: Treatment with silicon fertilizer induces changes in root morphological traits in soybean (Glycine max L. during early growth
abstract: Plant roots are key components of plant growth and development by taking up soil water and inorganic nutrients. Therefore, understanding root characteristics such as root length, root angle, root density, and root diameter is very important for improving crop productivity. Here, we investigate the effects of exogenous application of silicon on root morphological traits in two soybean cultivars (Taeseon and Pungsanaeul) The majority of root morphological traits evaluated show a significant (p 0.05) effect of Si treatment. The exceptions to this trend were forks (p 0.8677) and the mean link branching angle (p 0.0632) In Taeseon cultivars, root morphological traits such as length (21.8% diameter (19.3% tips (32.8% and projected area (34.4% were significantly increased by Si treatment compared to plants that received no exogenous Si. Pungsanaeul cultivars showed a similar pattern. The length, mean diameter, tips, and projected area increased in soybean plants that received exogenous Si 21.3% 13.6% 25.9% and 33.0% respectively. In conclusion, exogenous Si application increased root length and root diameter, thereby increasing overall root biomass. Because Si application enhances root growth and development, we anticipate that it will increase soybean productivity by improving water and nutrient uptake. To verify these findings, additional experiments at field conditions are needed.

title: Amino acid uptake and profile in bromeliads with different habits cultivated in vitro
abstract: Bromeliads can have terrestrial and epiphytic habits. Therefore, they have developed probably different mechanisms for the uptake of nutrients from distinct sources such as the pedosphere and the atmosphere. Many bromeliads, such as the epiphytes, absorb water and nutrients almost exclusively via their foliar trichomes. In contrast, terrestrial bromeliads essentially use their roots to withdraw the nutrients from the soil. The aim of this study was to compare nitrogen (N) nutrition between a terrestrial, Ananas comosus (L. Merr. and an epiphytic, Vriesea gigantea Gaudich. bromeliad. The in vitro absorption of [3H]glycine and [3H]glutamine was investigated. Plants were also grown in vitro with NH4+ glutamine (Gln) or glycine (Gly) as N sources, and the amino acid profile was analyzed. Ammonium treatment had little effect upon the A. comosus amino acid profile, while asparagine was the main amino acid accumulated in V. gigantea after 3 d in a medium with this nitrogen source. This suggests that V. gigantea accumulate N in compounds with high N/C ratio, allowing it to store higher N level when it is available in epiphytic environment. The two species were able to take up amino acids in vitro, although V. gigantea had a higher rate of amino acid uptake than the terrestrial bromeliad, A. comosus. For both species, Gly was taken up in a higher rate than Gln. The data support the idea that V. gigantea has a luxury consumption when inorganic and organic N are available in the environment, which does not happen in the case of the terrestrial bromeliad A. comosus. It has a more stable source of nutrients, the soil. We can also suggest that amino acids such as Gly, Gln and others present in the bromeliad tank water may be important N sources for V. gigantea and other epiphytic bromeliads in natural habitats.