Effect of organic and inorganic fertilizers on nutrient concentrations ...

African Journals Online (AJOL)

Effect of organic and inorganic fertilizers on nutrient concentrations in plantain ( Musa spp.) ... Fruit parameters measured were fruit weight, edible proportion and pulp dry matter content; also, the concentrations of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), iron (Fe) and zinc (Zn) in fruits were determined.

Nitrogen and potassium concentrations in the nutrients solution for melon plants growing in coconut fiber without drainage.

Science.gov (United States)

Gratieri, Luiz Augusto; Cecílio Filho, Arthur Bernardes; Barbosa, José Carlos; Pavani, Luiz Carlos

2013-01-01

With the objective of evaluating the effects of N and K concentrations for melon plants, an experiment was carried out from July 1, 2011 to January 3, 2012 in Muzambinho city, Minas Gerais State, Brazil. The "Bonus no. 2" was cultivated at the spacing of 1.1 × 0.4. The experimental design was a randomized complete block with three replications in a 4 × 4 factorial scheme with four N concentrations (8, 12, 16, and 20 mmol L(-1)) and four K concentrations (4, 6, 8, and 10 mmol L(-1)). The experimental plot constituted of eight plants. It was observed that the leaf levels of N and K, of N-NO₃ and of K, and the electrical conductivity (CE) of the substrate increased with the increment of N and K in the nutrients' solution. Substratum pH, in general, was reduced with increments in N concentration and increased with increasing K concentrations in the nutrients' solution. Leaf area increased with increments in N concentration in the nutrients solution. Fertigation with solutions stronger in N (20 mmol L(-1)) and K (10 mmol L(-1)) resulted in higher masses for the first (968 g) and the second (951 g) fruits and crop yield (4,425 gm(-2)).

Human skin condition and its associations with nutrient concentrations in serum and diet

NARCIS (Netherlands)

Boelsma, E.; Vijver, L.P.L. van de; Goldbohm, R.A.; Klöpping-Ketelaars, I.A.A.; Hendriks, H.F.J.; Roza, L.

2003-01-01

Background: Nutritional factors exert promising actions on the skin, but only scant information is available on the modulating effects of physiologic concentrations of nutrients on the skin condition of humans. Objective: The objective was to evaluate whether nutrient concentrations in serum and

The Concentration of Nutrients in Tissues of Plantation-Grown Eastern Cottonwood (Populus deltoides Bart.)

Science.gov (United States)

M. G. Shelton; L. E. Nelson; G. L. Switzer; B. G. Blackmon

1981-01-01

Nutrient concentrations were determined for 10 tissues from each of 24 cottonwood trees that ranged in age from four to 16 years. Highest concentrations occurred in the most physiologically active tissues; i.e., stemtips, current branches and foliage. Tree age had little influence on the variation in nutrient concentration of tissues. Some differences in concentrations...

Nutrient Infiltrate Concentrations from Three Permeable Pavement Types

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While permeable pavement is increasingly being used to control stormwater runoff, field-based, side-by-side investigations on the effects different pavement types have on nutrient concentrations present in stormwater runoff are limited. In 2009, the U.S. EPA constructed a 0.4-ha...

Nitrogen and Potassium Concentrations in the Nutrients Solution for Melon Plants Growing in Coconut Fiber without Drainage

Directory of Open Access Journals (Sweden)

Luiz Augusto Gratieri

2013-01-01

Full Text Available With the objective of evaluating the effects of N and K concentrations for melon plants, an experiment was carried out from July 1, 2011 to January 3, 2012 in Muzambinho city, Minas Gerais State, Brazil. The “Bonus no. 2” was cultivated at the spacing of 1.1 × 0.4. The experimental design was a randomized complete block with three replications in a 4 × 4 factorial scheme with four N concentrations (8, 12, 16, and 20 mmol L−1 and four K concentrations (4, 6, 8, and 10 mmol L−1. The experimental plot constituted of eight plants. It was observed that the leaf levels of N and K, of N-NO3 and of K, and the electrical conductivity (CE of the substrate increased with the increment of N and K in the nutrients' solution. Substratum pH, in general, was reduced with increments in N concentration and increased with increasing K concentrations in the nutrients' solution. Leaf area increased with increments in N concentration in the nutrients solution. Fertigation with solutions stronger in N (20 mmol L−1 and K (10 mmol L−1 resulted in higher masses for the first (968 g and the second (951 g fruits and crop yield (4,425 gm−2.

Differences in nutrient concentrations and resources between seagrass communities on carbonate and terrigenous sediments in South Sulawesi, Indonesia

NARCIS (Netherlands)

Erftemeijer, P.L.A.

1994-01-01

Water column, sediment and plant parameters were studied in six tropical seagrass beds in South Sulawesi, Indonesia, to evaluate the relation between seagrass bed nutrient concentrations and sediment type. Coastal seagrass beds on terrigenous sediments had considerably higher biomass of

High nutrient concentration and temperature alleviated formation of large colonies of Microcystis: Evidence from field investigations and laboratory experiments.

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Zhu, Wei; Zhou, Xiaohua; Chen, Huaimin; Gao, Li; Xiao, Man; Li, Ming

2016-09-15

Correlations between Microcystis colony size and environmental factors were investigated in Meiliang Bay and Gonghu Bay of Lake Taihu (China) from 2011 to 2013. Compared with Gonghu Bay, both nutrient concentrations and Microcystis colony sizes were greater in Meiliang Bay. The median colony size (D50: 50% of the total mass of particles smaller than this size) increased from April to August and then decreased until November. In both bays, the average D50 of Microcystis colonies were 500 μm) dominated in summer. The differences in colony size in Meiliang Bay and Gonghu Bay were probably due to horizontal drift driven by the prevailing south wind in summer. Redundancy analysis (RDA) of field data indicated that colony size was negatively related to nutrient concentrations but positively related to air temperature, suggesting that low nutrient concentrations and high air temperature promoted formation of large colonies. To validate the field survey, Microcystis colonies collected from Lake Taihu were cultured at different temperatures (15, 20, 25 and 30 °C) under high and low nutrient concentrations for 9 days. The size of Microcystis colonies significantly decreased when temperature was above 20 °C but had no significant change at 15 °C. The differences in temperature effects on colony formation shown from field and laboratory suggested that the larger colonies in summer were probably due to the longer growth period rather than the higher air temperature and light intensity. In addition, colony size decreased more significantly at high nutrient levels. Therefore, it could be concluded that high nutrient concentration and temperature may alleviate formation of large colonies of Microcystis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Phytotoxic effects of nickel on yield and concentration of macro- and micro-nutrients in sunflower (Helianthus annuus L.) achenes.

Science.gov (United States)

Ahmad, Muhammad Sajid Aqeel; Ashraf, Muhammad; Hussain, Mumtaz

2011-01-30

The phytotoxic effects of varying levels of nickel (0, 10, 20, 30, and 40 mg L(-1)) on growth, yield and accumulation of macro- and micro-nutrients in leaves and achenes of sunflower (Helianthus annuus L.) were appraised in this study. A marked reduction in root and shoot fresh biomass was recorded at higher Ni levels. Nickel stress also caused a substantial decrease in all macro- and micro-nutrients in leaves and achenes. The lower level of Ni (10 mg L(-1)) had a non-significant effect on various yield attributes, but higher Ni levels considerably decreased these parameters. Higher Ni levels decreased the concentrations of Ca, Mn and Fe in achenes. In contrast, achene N, K, Zn, Mn and Cu decreased consistently with increasing level of Ni, even at lower level (10 mg L(-1)). Sunflower hybrid Hysun-33 had better yield and higher most of the nutrients in achenes as compared with SF-187. The maximum reduction in all parameters was observed at the maximum level of nickel (40 mg L(-1)) where almost all parameters were reduced more than 50% of those of control plants. In conclusion, the pattern of uptake and accumulation of different nutrients in sunflower plants were nutrient- and cultivar-specific under Ni-stress. Copyright © 2010 Elsevier B.V. All rights reserved.

Effects of watershed densities of animal feeding operations on nutrient concentrations and estrogenic activity in agricultural streams

Science.gov (United States)

Ciparis, Serena; Iwanowicz, Luke R.; Voshell, J. Reese

2012-01-01

Application of manures from animal feeding operations (AFOs) as fertilizer on agricultural land can introduce nutrients and hormones (e.g. estrogens) to streams. A landscape-scale study was conducted in the Shenandoah River watershed (Virginia, USA) in order to assess the relationship between densities of AFOs in watersheds of agricultural streams and in-stream nutrient concentrations and estrogenic activity. The effect of wastewater treatment plants (WWTPs) on nutrients and estrogenic activity was also evaluated. During periods of high and low flow, dissolved inorganic nitrogen (DIN) and orthophosphate (PO4-P) concentrations were analyzed and estrogens/estrogenic compounds were extracted and quantified as17β-estradiol equivalents (E2Eq) using a bioluminescent yeast estrogen screen. Estrogenic activity was measurable in the majority of collected samples, and 20% had E2Eq concentrations > 1 ng/L. Relatively high concentrations of DIN (> 1000 μg/L) were also frequently detected. During all sampling periods, there were strong relationships between watershed densities of AFOs and in-stream concentrations of DIN (R2 = 0.56–0.81) and E2Eq (R2 = 0.39–0.75). Relationships between watershed densities of AFOs and PO4-P were weaker, but were also significant (R2 = 0.27–0.57). When combined with the effect of watershed AFO density, streams receiving WWTP effluent had higher concentrations of PO4-P than streams without WWTP discharges, and PO4-P was the only analyte with a consistent relationship to WWTPs. The results of this study suggest that as the watershed density of AFOs increases, there is a proportional increase in the potential for nonpoint source pollution of agricultural streams and their receiving waters by nutrients, particularly DIN, and compounds that can cause endocrine disruption in aquatic organisms.

Effects of watershed densities of animal feeding operations on nutrient concentrations and estrogenic activity in agricultural streams.

Science.gov (United States)

Ciparis, Serena; Iwanowicz, Luke R; Voshell, J Reese

2012-01-01

Application of manures from animal feeding operations (AFOs) as fertilizer on agricultural land can introduce nutrients and hormones (e.g. estrogens) to streams. A landscape-scale study was conducted in the Shenandoah River watershed (Virginia, USA) in order to assess the relationship between densities of AFOs in watersheds of agricultural streams and in-stream nutrient concentrations and estrogenic activity. The effect of wastewater treatment plants (WWTPs) on nutrients and estrogenic activity was also evaluated. During periods of high and low flow, dissolved inorganic nitrogen (DIN) and orthophosphate (PO(4)-P) concentrations were analyzed and estrogens/estrogenic compounds were extracted and quantified as17β-estradiol equivalents (E2Eq) using a bioluminescent yeast estrogen screen. Estrogenic activity was measurable in the majority of collected samples, and 20% had E2Eq concentrations >1 ng/L. Relatively high concentrations of DIN (>1000 μg/L) were also frequently detected. During all sampling periods, there were strong relationships between watershed densities of AFOs and in-stream concentrations of DIN (R(2) = 0.56-0.81) and E2Eq (R(2) = 0.39-0.75). Relationships between watershed densities of AFOs and PO(4)-P were weaker, but were also significant (R(2) = 0.27-0.57). When combined with the effect of watershed AFO density, streams receiving WWTP effluent had higher concentrations of PO(4)-P than streams without WWTP discharges, and PO(4)-P was the only analyte with a consistent relationship to WWTPs. The results of this study suggest that as the watershed density of AFOs increases, there is a proportional increase in the potential for nonpoint source pollution of agricultural streams and their receiving waters by nutrients, particularly DIN, and compounds that can cause endocrine disruption in aquatic organisms. Copyright © 2011 Elsevier B.V. All rights reserved.

Mapping of trophic states based on nutrients concentration and phytoplankton abundance in Jatibarang Reservoir

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Rudiyanti, Siti; Anggoro, Sutrisno; Rahman, Arif

2018-02-01

Jatibarang Reservoir is one of the Indonesian Reservoirs, which used for human activities such as tourism and agriculture. These activities will provide input of organic matter and nutrients into the water. These materials will impact water quality and eutrophication process. Eutrophication is the water enrichment by nutrients, especially nitrogen and phosphorus which can promote the growth of phytoplankton. Some indicators of eutrophication are increasing nutrients, trophic states, and change of phytoplankton composition. The relationship between water quality and phytoplankton community can be used as an indicator of trophic states in Jatibarang Reservoir. The aim of this study was to analyze the effect of nutrients concentration and phytoplankton abundance to the trophic states and mapping trophic states based on nutrients concentration and phytoplankton in Jatibarang Reservoir. This study was conducted in June and July 2017 at 9 stations around Jatibarang Reservoir. The results showed that average concentration of nitrate, phosphate, and chlorophyll-a in Jatibarang Reservoir was 0.69 mg/L, 0.27 mg/L, and 1.66 mg/m3, respectively. The phytoplankton abundance ranged 16-62,200 cells/L, consists of 21 genera of four classes, i.e. Chlorophyceae, Cyanophyceae, Bacillariophyceae, and Dinophyceae. Cyanophyceae was a dominant phytoplankton group based on the composition of abundance (>80%). High nutrient concentrations and phytoplankton dominated by Anabaena (Cyanophyceae) which indicated that the waters in Jatibarang Reservoir were eutrophic.

Detecting terrestrial nutrient limitation: a global meta-analysis of foliar nutrient concentrations after fertilization

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Rebecca eOstertag

2016-03-01

Full Text Available Examining foliar nutrient concentrations after fertilization provides an alternative method for detecting nutrient limitation of ecosystems, which is logistically simpler to measure than biomass change. We present a meta-analysis of response ratios of foliar nitrogen and phosphorus (RRN, RRP after addition of fertilizer of nitrogen (N, phosphorus (P, or the two elements in combination, in relation to climate, ecosystem type, life form, family, and methodological factors. Results support other meta-analyses using biomass, and demonstrate there is strong evidence for nutrient limitation in natural communities. However, because N fertilization experiments greatly outnumber P fertilization trials, it is difficult to discern the absolute importance of N vs. P vs. co-limitation across ecosystems. Despite these caveats, it is striking that results did not follow conventional wisdom that temperate ecosystems are N-limited and tropical ones are P-limited. In addition, the use of ratios of N-to-P rather than response ratios also are a useful index of nutrient limitation, but due to large overlap in values, there are unlikely to be universal cutoff values for delimiting N vs. P limitation. Differences in RRN and RRP were most significant across ecosystem types, plant families, life forms, and between competitive environments, but not across climatic variables.

Effects of soil characteristics on grape juice nutrient concentrations and other grape quality parameters in Shiraz

Science.gov (United States)

Concepción Ramos, Maria; Romero, Maria Paz

2017-04-01

This study investigated the response of grapes to soil properties in the variety Shiraz (SH) cultivated in the Costers de Segre Designation of Origin (NE, Spain). The research was carried out in two areas with differences in vigor, which was examined using the Normalized Difference Vegetation Index (NDVI). Soil properties such as organic matter content, pH, electrical conductivity and nutrients (N, P, K, Ca, Mg, Cu, Zn and Mn) were analysed in the two areas. Soil analyses were limited to the upper 40 cm. Soil N-NO3 was measured in 2M KCl extracts. Assimilable phosphorus was analysed by extraction with 0.5 M NaHCO3 at pH 8.5 using the Olsen method. The available K, Ca and Mg were evaluated in hemaaxinecobalt trichloride extracts and the available fraction of Cu, Zn, Mn and Fe in DTPA- trietanolamine extracts, by spectroscopy atomic emission/absorption. Berry grapes were collected at maturity. Nutrients in grape juice (K, Ca, Mg Cu, Zn, Mn and Fe) were determined after a microwave hydrogen peroxide digestion in a closed vessel microwave digestion system and measured by spectroscopy. Other grape properties that determine grape quality such as pH, berry weight and sugar content were analysed using the methods proposed by the OIV. Differences in soil properties were observed between plots, which determined the differences in vigour. The vines with lower vigour were grown in the soils with higher pH, electrical conductivity and silt content, which had in addition higher Ca, Mg and K available levels as well as higher levels of Fe and Mn than the soil in which vines had higher vigour. However, the available fraction of Cu and Zn was smaller. Similar differences in nutrient concentration in the berry were observed for all nutrients except for Cu. Grape juice pH and total soluble solids (°Brix) were higher in the most vigorous vines. However, the differences in berry weight and total acidity at ripening were not significant. Keywords: acidity; berry weight; nutrients; p

Frequent Canned Food Use is Positively Associated with Nutrient-Dense Food Group Consumption and Higher Nutrient Intakes in US Children and Adults.

Science.gov (United States)

Comerford, Kevin B

2015-07-09

In addition to fresh foods, many canned foods also provide nutrient-dense dietary options, often at a lower price, with longer storage potential. The aim of this study was to compare nutrient-dense food group intake and nutrient intake between different levels of canned food consumption in the US. Consumption data were collected for this cross-sectional study from 9761 American canned food consumers (aged two years and older) from The NPD Group's National Eating Trends® (NET®) database during 2011-2013; and the data were assessed using The NPD Group's Nutrient Intake Database. Canned food consumers were placed into three groups: Frequent Can Users (≥6 canned items/week); n = 2584, Average Can Users (3-5 canned items/week); n = 4445, and Infrequent Can Users (≤2 canned items/week); n = 2732. The results provide evidence that Frequent Can Users consume more nutrient-dense food groups such as fruits, vegetables, dairy products, and protein-rich foods, and also have higher intakes of 17 essential nutrients including the shortfall nutrients-potassium, calcium and fiber-when compared to Infrequent Can Users. Therefore, in addition to fresh foods, diets higher in nutrient-dense canned food consumption can also offer dietary options which improve nutrient intakes and the overall diet quality of Americans.

Can We Manage Nonpoint-Source Pollution Using Nutrient Concentrations during Seasonal Baseflow?

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James A. McCarty

2016-05-01

Full Text Available Nationwide, a substantial amount of resources has been targeted toward improving water quality, particularly focused on nonpoint-source pollution. This study was conducted to evaluate the relationship between nutrient concentrations observed during baseflow and runoff conditions from 56 sites across five watersheds in Arkansas. Baseflow and stormflow concentrations for each site were summarized using geometric mean and then evaluated for directional association. A significant, positive correlation was found for NO–N, total N, soluble reactive P, and total P, indicating that sites with high baseflow concentrations also had elevated runoff concentrations. Those landscape factors that influence nutrient concentrations in streams also likely result in increased runoff, suggesting that high baseflow concentrations may reflect elevated loads from the watershed. The results highlight that it may be possible to collect water-quality data during baseflow to help define where to target nonpoint-source pollution best management practices within a watershed.

Relation of nutrient concentrations, nutrient loading, and algal production to changes in water levels in Kabetogama Lake, Voyageurs National Park, northern Minnesota, 2008-09

Science.gov (United States)

Christensen, Victoria G.; Maki, Ryan P.; Kiesling, Richard L.

2011-01-01

Nutrient enrichment has led to excessive algal growth in Kabetogama Lake, Voyageurs National Park, northern Minnesota. Water- and sediment-quality data were collected during 2008-09 to assess internal and external nutrient loading. Data collection was focused in Kabetogama Lake and its inflows, the area of greatest concern for eutrophication among the lakes of Voyageurs National Park. Nutrient and algal data were used to determine trophic status and were evaluated in relation to changes in Kabetogama Lake water levels following changes to dam operation starting in 2000. Analyses were used to estimate external nutrient loading at inflows and assess the potential contribution of internal phosphorus loading. Kabetogama Lake often was mixed vertically, except for a few occasionally stratified areas, including Lost Bay in the northeastern part of Kabetogama Lake. Stratification, combined with larger bottom-water nutrient concentrations, larger sediment phosphorus concentrations, and estimated phosphorus release rates from sediment cores indicate that Lost Bay may be one of several areas that may be contributing substantially to internal loading. Internal loading is a concern because nutrients may cause excessive algal growth including potentially toxic cyanobacteria. The cyanobacterial hepatotoxin, microcystin, was detected in 7 of 14 cyanobacterial bloom samples, with total concentrations exceeding 1.0 microgram per liter, the World Health Organization's guideline for finished drinking water for the congener, microcystin-LR. Comparisons of the results of this study to previous studies indicate that chlorophyll-a concentrations and trophic state indices have improved since 2000, when the rules governing dam operation changed. However, total-phosphorus concentrations have not changed significantly since 2000.

Modeled sensitivity of Lake Michigan productivity and zooplankton to changing nutrient concentrations and quagga mussels

Science.gov (United States)

Pilcher, Darren J.; McKinley, Galen A.; Kralj, James; Bootsma, Harvey A.; Reavie, Euan D.

2017-08-01

The recent decline in Lake Michigan productivity is often attributed to filter feeding by invasive quagga mussels, but some studies also implicate reductions in lakewide nutrient concentrations. We use a 3-D coupled hydrodynamic-biogeochemical model to evaluate the effect of changing nutrient concentrations and quagga mussel filtering on phytoplankton production and phytoplankton and zooplankton biomass. Sensitivity experiments are used to assess the net effect of each change separately and in unison. Quagga mussels are found to have the greatest impact during periods of isothermal mixing, while nutrients have the greatest impact during thermal stratification. Quagga mussels also act to enhance spatial heterogeneity, particularly between nearshore-offshore regions. This effect produces a reversal in the gradient of nearshore-offshore productivity: from relatively greater nearshore productivity in the prequagga lake to relatively lesser nearshore productivity after quaggas. The combined impact of both processes drives substantial reductions in phytoplankton and zooplankton biomass, as well as significant modifications to the seasonality of surface water pCO2, particularly in nearshore regions where mussel grazing continues year-round. These results support growing concern that considerable losses of phytoplankton and zooplankton will yield concurrent losses at higher trophic levels. Comparisons to observed productivity suggest that both quagga mussel filtration and lower lakewide total phosphorus are necessary to accurately simulate recent changes in primary productivity in Lake Michigan.

Frequent Canned Food Use is Positively Associated with Nutrient-Dense Food Group Consumption and Higher Nutrient Intakes in US Children and Adults

Directory of Open Access Journals (Sweden)

Kevin B. Comerford

2015-07-01

Full Text Available In addition to fresh foods, many canned foods also provide nutrient-dense dietary options, often at a lower price, with longer storage potential. The aim of this study was to compare nutrient-dense food group intake and nutrient intake between different levels of canned food consumption in the US. Consumption data were collected for this cross-sectional study from 9761 American canned food consumers (aged two years and older from The NPD Group’s National Eating Trends® (NET® database during 2011–2013; and the data were assessed using The NPD Group’s Nutrient Intake Database. Canned food consumers were placed into three groups: Frequent Can Users (≥6 canned items/week; n = 2584, Average Can Users (3–5 canned items/week; n = 4445, and Infrequent Can Users (≤2 canned items/week; n = 2732. The results provide evidence that Frequent Can Users consume more nutrient-dense food groups such as fruits, vegetables, dairy products, and protein-rich foods, and also have higher intakes of 17 essential nutrients including the shortfall nutrients—potassium, calcium and fiber—when compared to Infrequent Can Users. Therefore, in addition to fresh foods, diets higher in nutrient-dense canned food consumption can also offer dietary options which improve nutrient intakes and the overall diet quality of Americans.

Decadal and seasonal trends of nutrient concentration and export from highly managed coastal catchments.

Science.gov (United States)

Wan, Yongshan; Wan, Lei; Li, Yuncong; Doering, Peter

2017-05-15

Understanding anthropogenic and hydro-climatic influences on nutrient concentrations and export from highly managed catchments often necessitates trend detection using long-term monitoring data. This study analyzed the temporal trend (1979-2014) of total nitrogen (TN) and total phosphorus (TP) concentrations and export from four adjacent coastal basins in south Florida where land and water resources are highly managed through an intricate canal network. The method of integrated seasonal-trend decomposition using LOESS (LOcally weighted regrESSion) was employed for trend detection. The results indicated that long-term trends in TN and TP concentrations (increasing/decreasing) varied with basins and nutrient species, reflecting the influence of basin specific land and water management practices. These long-term trends were intervened by short-term highs driven by high rainfall and discharges and lows associated with regional droughts. Seasonal variations in TP were more apparent than for TN. Nutrient export exhibited a chemostatic behavior for TN from all the basins, largely due to the biogenic nature of organic N associated with the ubiquity of organic materials in the managed canal network. Varying degrees of chemodynamic export was present for TP, reflecting complex biogeochemical responses to the legacy of long-term fertilization, low soil P holding capacity, and intensive stormwater management. The anthropogenic and hydro-climatic influences on nutrient concentration and export behavior had great implications in nutrient loading abatement strategies for aquatic ecosystem restoration of the downstream receiving waterbody. Published by Elsevier Ltd.

Influence of harvest managements on biomass nutrient concentrations and removal rates of festulolium and tall fescue from a poorly drained nutrient-rich fen peatland

DEFF Research Database (Denmark)

Kandel, Tanka; Elsgaard, Lars; Lærke, Poul Erik

2017-01-01

This study was designed to show the effects of harvest time and frequency on biomass nutrient concentrations (total ash, N, P, K, Ca, Mg, Fe, Mn, Cu and Zn) as well as total nutrient removal potential by festulolium and tall fescue cultivated on a nutrient-rich fen peatland. The harvest managemen...

NUTRIENTS CONCENTRATION AND RETRANSLOCATION IN THE Pinus taeda L. NEEDLES

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Márcio Viera

2010-03-01

Full Text Available Aiming at evaluating nutrients concentration and retranslocation in the Pinus taeda L. needles, this study was developed in two stands, in native grass area and in second rotation area, with same species and same age (7.5 years old in Cambará do Sul, RS. The needles were collected in plants in four orthogonal points (South, North, East and West, sampled new needles, mature needles and old needles. The material was dried in a stove, milled and chemically analyzed (macro and micronutrients. The concentrations of N, P, K, B, Cu and Zn had decreased, of Ca, Fe and Mn increased, and the Mg and S have remained constant with the age of the needles. The retranslocation rate (old-new needles was more than 50% for most nutrients, except for Mn and Fe, showed that cumulative effect and the Ca reference element.

Deciphering relationships between in-stream travel times, nutrient concentrations, and uptake through analysis of hysteretic and non-hysteretic kinetic behavior

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Covino, T. P.; Bowden, W. B.; Gooseff, M. N.; Wollheim, W. M.; McGlynn, B. L.; Whittinghill, K. A.; Wlostowski, A. N.; Herstand, M. R.

2012-12-01

Understanding the relationship between solute travel time, concentration, and nutrient uptake remains a central question in watershed hydrology and biogeochemistry. Theoretical understanding predicts that nutrient uptake should increase as in-stream solute travel time lengthens and/or as concentration increases; however, results from field-based studies have been contradictory. We used a newly developed approach, Tracer Additions for Spiraling Curve Characterization (TASCC), to investigate relationships between solute travel time, nutrient concentration, and nutrient uptake across a range of stream types. This approach allows us to quantify in-stream nutrient uptake across a range of travel times and nutrient concentrations using single instantaneous injections (slugs) of conservative and non-conservative tracers. In some systems we observed counter-clockwise hysteresis loops in the relationship between nutrient uptake and concentration. Greater nutrient uptake on the falling limb of tracer breakthrough curves indicates stronger uptake for a given concentration at longer travel times. However, in other systems we did not observe hysteresis in these relationships. Lack of hysteresis indicates that nutrient uptake kinetics were not influenced by travel time travel time. Here we investigate the potential roles of travel time and in-stream flowpaths that could be responsible for hysteretic behavior.

Effects of thermal discharges on the seasonal patterns of nutrient concentrations in brackish water

International Nuclear Information System (INIS)

Nitchals, D.

1985-05-01

Massiv quantities of water are used in power plant cooling systems, especially nuclear power plants, and are often returned to the donor ecosystem at significantly elevated temperatures. Few studies of the environmental effects of such a situation have looked extensively at the effects on nutrients in the water. The present study examined the effects of cooling water discharges from a nuclear power plant on the seasonal nutrient patterns within and outside a brackish water, research artificial lake, the 0.9 km 2 Biotest Basin on Sweden's east coast. The lack of ice cover in winter is the most apparent effect. In a portion of the lake with a relatively long water residence time, on the order of a few days, the vernal nutrient depletion of phosphate, nitrate, and nitrite apparently began sooner than outside the lake. Benthic influence on nutrient concentrations in the free water mass may be very significant in coastal areas receiving heat inputs. This study's data apparently support the conclusion by other researchers that phosphorus may be the nutrient limiting algal growth in the spring in this area of the central Baltic Sea. Determination of a nutrient budget for the Basin was unachievable because inlet and outlet nutrient concentrations were insufficiently different to override experimental variation. Implications for management of heat inputs to coastal ecosystems include avoidance of areas with high nutrient content, rich organic sediment, or poor flushing. (author)

Prenatal lipid-based nutrient supplements increase cord leptin concentration in pregnant women from rural Burkina Faso.

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Huybregts, Lieven; Roberfroid, Dominique; Lanou, Hermann; Meda, Nicolas; Taes, Youri; Valea, Innocent; D'Alessandro, Umberto; Kolsteren, Patrick; Van Camp, John

2013-05-01

In developing countries, prenatal lipid-based nutrient supplements (LNSs) were shown to increase birth size; however, the mechanism of this effect remains unknown. Cord blood hormone concentrations are strongly associated with birth size. Therefore, we hypothesize that LNSs increase birth size through a change in the endocrine regulation of fetal development. We compared the effect of daily prenatal LNSs with multiple micronutrient tablets on cord blood hormone concentrations using a randomized, controlled design including 197 pregnant women from rural Burkina Faso. Insulin-like growth factors (IGF) I and II, their binding proteins IGFBP-1 and IGFBP-3, leptin, cortisol, and insulin were quantified in cord sera using immunoassays. LNS was associated with higher cord blood leptin mainly in primigravidae (+57%; P = 0.02) and women from the highest tertile of BMI at study inclusion (+41%; P = 0.02). We did not find any significant LNS effects on other measured cord hormones. The observed increase in cord leptin was associated with a significantly higher birth weight. Cord sera from small-for-gestational age newborns had lower median IGF-I (-9 μg/L; P = 0.003), IGF-II (-79 μg/L; P = 0.003), IGFBP-3 (-0.7 μg/L; P = 0.007), and leptin (-1.0 μg/L; P = 0.016) concentrations but higher median cortisol (+18 μg/L; P = 0.037) concentrations compared with normally grown newborns. Prenatal LNS resulted in increased cord leptin concentrations in primigravidae and mothers with higher BMI at study inclusion. The elevated leptin concentrations could point toward a higher neonatal fat mass.

Managed nutrient reduction impacts on nutrient concentrations, water clarity, primary production, and hypoxia in a north temperate estuary

Science.gov (United States)

Oviatt, Candace; Smith, Leslie; Krumholz, Jason; Coupland, Catherine; Stoffel, Heather; Keller, Aimee; McManus, M. Conor; Reed, Laura

2017-12-01

Except for the Providence River and side embayments like Greenwich Bay, Narragansett Bay can no longer be considered eutrophic. In summer 2012 managed nitrogen treatment in Narragansett Bay achieved a goal of reducing effluent dissolved inorganic nitrogen inputs by over 50%. Narragansett Bay represents a small northeast US estuary that had been heavily loaded with sewage effluent nutrients since the late 1800s. The input reduction was reflected in standing stock nutrients resulting in a statistically significant 60% reduction in concentration. In the Providence River estuary, total nitrogen decreased from 100 μm to about 40 μm, for example. We tested four environmental changes that might be associated with the nitrogen reduction. System apparent production was significantly decreased by 31% and 45% in the upper and mid Bay. Nutrient reductions resulted in statistically improved water clarity in the mid and upper Bay and in a 34% reduction in summer hypoxia. Nitrogen reduction also reduced the winter spring diatom bloom; winter chlorophyll levels after nutrient reduction have been significantly lower than before the reduction. The impact on the Bay will continue to evolve over the next few years and be a natural experiment for other temperate estuaries that will be experiencing nitrogen reduction. To provide perspective we review factors effecting hypoxia in other estuaries with managed nutrient reduction and conclude that, as in Narragansett Bay, physical factors can be as important as nutrients. On a positive note managed nutrient reduction has mitigated further deterioration in most estuaries.

Nutrient Concentrations and Stable Isotopes of Runoff from a Midwest Tile-Drained Corn Field

Science.gov (United States)

Wilkins, B. P.; Woo, D.; Li, J.; Michalski, G. M.; Kumar, P.; Conroy, J. L.; Keefer, D. A.; Keefer, L. L.; Hodson, T. O.

2017-12-01

Tile drains are a common crop drainage device used in Midwest agroecosystems. While efficient at drainage, the tiles provide a quick path for nutrient runoff, reducing the time available for microbes to use nutrients (e.g., NO3- and PO43-) and reduce export to riverine systems. Thus, understanding the effects of tile drains on nutrient runoff is critical to achieve nutrient reduction goals. Here we present isotopic and concentration data collected from tile drain runoff of a corn field located near Monticello, IL. Tile flow samples were measured for anion concentrations and stable isotopes of H2O and NO3-, while precipitation was measured for dual isotopes of H2O. Results demonstrate early tile flow from rain events have a low Cl- concentration (60% contribution) in the beginning of the hydrograph. As flow continues H2O isotopic values reflect pre-event water (ground and soil water), and Cl- concentrations increase representing a greater influence by matrix flow (60-90% contribution). Nitrate concentrations change dramatically, especially during the growing season, and do not follow a similar trend as the conservative Cl-, often decreasing days before, which represents missing nitrate in the upper surface portion of the soil. Nitrate isotopic data shows significant changes in 15N (4‰) and 18O (4‰) during individual hydrological events, representing that in addition to plant uptake and leaching, considerate NO3- is lost through denitrification. It is notable, that throughout the season d15N and d18O of nitrate change significantly representing that seasonally, substantial denitrification occurs.

Effects of macro nutrient concentration on biological N2 fixation by Azotobacter vinelandii ATCC 12837

International Nuclear Information System (INIS)

Liew Pauline Woan Ying; Nazalan Najimudin; Jong Bor Chyan; Latiffah Noordin; Khairuddin Abdul Rahim; Amir Hamzah Ahmad Ghazali

2010-01-01

The dynamic changes of biological N 2 fixation by Azotobacter vinelandii ATCC 12837 under the influence of various macro nutrients, specifically phosphorus (P) and potassium (K), was investigated. In this attempt, Oryza sativa L. var. MR 219 was used as the model plant. Results obtained showed changes in the biological N 2 fixation activities with different macro nutrient(s) manipulations. The research activity enables optimisation of macro nutrients concentration for optimal/ enhanced biological N 2 fixation by A. vinelandii ATCC 12837. (author)

Nutrient cycling, connectivity, and free-floating plant abundance in backwater lakes of the Upper Mississippi River

Science.gov (United States)

Houser, Jeff N.; Giblin, Shawn M.; James, William F.; Langrehr, H.A.; Rogala, James T.; Sullivan, John F.; Gray, Brian R.

2013-01-01

River eutrophication may cause the formation of dense surface mats of free floating plants (FFP; e.g., duckweeds and filamentous algae) which may adversely affect the ecosystem. We investigated associations among hydraulic connectivity to the channel, nutrient cycling, FFP, submersed aquatic vegetation (SAV), and dissolved oxygen concentration (DO) in ten backwater lakes of the Upper Mississippi River (UMR) that varied in connectivity to the channel. Greater connectivity was associated with higher water column nitrate (NO3-N) concentration, higher rates of sediment phosphorus (P) release, and higher rates of NO3-N flux to the sediments. Rates of sediment P and N (as NH4-N) release were similar to those of eutrophic lakes. Water column nutrient concentrations were high, and FFP tissue was nutrient rich suggesting that the eutrophic condition of the UMR often facilitated abundant FFP. However, tissue nutrient concentrations, and the associations between FFP biomass and water column nutrient concentrations, suggested that nutrients constrained FFP abundance at some sites. FFP abundance was positively associated with SAV abundance and negatively associated with dissolved oxygen concentration. These results illustrate important connections among hydraulic connectivity, nutrient cycling, FFP, SAV, and DO in the backwaters of a large, floodplain river.

Wind-induced flow velocity effects on nutrient concentrations at Eastern Bay of Lake Taihu, China.

Science.gov (United States)

Jalil, Abdul; Li, Yiping; Du, Wei; Wang, Jianwei; Gao, Xiaomeng; Wang, Wencai; Acharya, Kumud

2017-07-01

Shallow lakes are highly sensitive to respond internal nutrient loading due to wind-induced flow velocity effects. Wind-induced flow velocity effects on nutrient suspension were investigated at a long narrow bay of large shallow Lake Taihu, the third largest freshwater lake in China. Wind-induced reverse/compensation flow and consistent flow field probabilities at vertical column of the water were measured. The probabilities between the wind field and the flow velocities provided a strong correlation at the surface (80.6%) and the bottom (65.1%) layers of water profile. Vertical flow velocity profile analysis provided the evidence of delay response time to wind field at the bottom layer of lake water. Strong wind field generated by the west (W) and west-north-west (WNW) winds produced displaced water movements in opposite directions to the prevailing flow field. An exponential correlation was observed between the current velocities of the surface and the bottom layers while considering wind speed as a control factor. A linear model was developed to correlate the wind field-induced flow velocity impacts on nutrient concentration at the surface and bottom layers. Results showed that dominant wind directions (ENE, E, and ESE) had a maximum nutrient resuspension contribution (nutrient resuspension potential) of 34.7 and 43.6% at the surface and the bottom profile layers, respectively. Total suspended solids (TSS), total nitrogen (TN), and total phosphorus (TP) average concentrations were 6.38, 1.5, and 0.03 mg/L during our field experiment at Eastern Bay of Lake Taihu. Overall, wind-induced low-to-moderate hydrodynamic disturbances contributed more in nutrient resuspension at Eastern Bay of Lake Taihu. The present study can be used to understand the linkage between wind-induced flow velocities and nutrient concentrations for shallow lakes (with uniform morphology and deep margins) water quality management and to develop further models.

Plant response to nutrient availability across variable bedrock geologies

Science.gov (United States)

Castle, S.C.; Neff, J.C.

2009-01-01

We investigated the role of rock-derived mineral nutrient availability on the nutrient dynamics of overlying forest communities (Populus tremuloides and Picea engelmanni-Abies lasiocarpa v. arizonica) across three parent materials (andesite, limestone, and sandstone) in the southern Rocky Mountains of Colorado. Broad geochemical differences were observed between bedrock materials; however, bulk soil chemistries were remarkably similar between the three different sites. In contrast, soil nutrient pools were considerably different, particularly for P, Ca, and Mg concentrations. Despite variations in nutrient stocks and nutrient availability in soils, we observed relatively inflexible foliar concentrations and foliar stoichiometries for both deciduous and coniferous species. Foliar nutrient resorption (P and K) in the deciduous species followed patterns of nutrient content across substrate types, with higher resorption corresponding to lower bedrock concentrations. Work presented here indicates a complex plant response to available soil nutrients, wherein plant nutrient use compensates for variations in supply gradients and results in the maintenance of a narrow range in foliar stoichiometry. ?? 2008 Springer Science+Business Media, LLC.

How to know which food is good for you: bumblebees use taste to discriminate between different concentrations of food differing in nutrient content.

Science.gov (United States)

Ruedenauer, Fabian A; Spaethe, Johannes; Leonhardt, Sara D

2015-07-01

In view of the ongoing pollinator decline, the role of nutrition in bee health has received increasing attention. Bees obtain fat, carbohydrates and protein from pollen and nectar. As both excessive and deficient amounts of these macronutrients are detrimental, bees would benefit from assessing food quality to guarantee an optimal nutrient supply. While bees can detect sucrose and use it to assess nectar quality, it is unknown whether they can assess the macronutrient content of pollen. Previous studies have shown that bees preferentially collect pollen of higher protein content, suggesting that differences in pollen quality can be detected either by individual bees or via feedback from larvae. In this study, we examined whether and, if so, how individuals of the buff-tailed bumblebee (Bombus terrestris) discriminate between different concentrations of pollen and casein mixtures and thus nutrients. Bumblebees were trained using absolute and differential conditioning of the proboscis extension response (PER). As cues related to nutrient concentration could theoretically be perceived by either smell or taste, bees were tested on both olfactory and, for the first time, chemotactile perception. Using olfactory cues, bumblebees learned and discriminated between different pollen types and casein, but were unable to discriminate between different concentrations of these substances. However, when they touched the substances with their antennae, using chemotactile cues, they could also discriminate between different concentrations. Bumblebees are therefore able to discriminate between foods of different concentrations using contact chemosensory perception (taste). This ability may enable them to individually regulate the nutrient intake of their colonies. © 2015. Published by The Company of Biologists Ltd.

Transposing Concentration-Discharge Curves onto Unmonitored Catchments to Estimate Seasonal Nutrient Loads

Science.gov (United States)

Minaudo, C.; Moatar, F.; Abbott, B. W.; Dupas, R.; Gascuel-Odoux, C.; Pinay, G.; Roubeix, V.; Danis, P. A.

2017-12-01

Many lakes and reservoirs in Europe suffer from severe eutrophication. Accurate quantification of nutrient loads are critical for effective mitigation measures, but this information is often unknown. For example, in France, only 50 out of 481 lakes and reservoirs have national monitoring allowing estimation of interannual nitrogen and phosphorus loads, and even these loads are computed from low-frequency data. To address this lack of data, we developed a straightforward method to predict seasonal loads in lake tributaries. First, we analyzed concentration-discharge (C-Q) curves in monitored catchments and identified slopes, intercepts, and coefficient of variation of the log(C)-log(Q) regressions determined for both low and high flows, separated by the median daily flow [Moatar et al., 2017]. Then, we used stepwise multiple linear regression models to empirically link the characteristics of C-Q curves with a set of catchment descriptors such as land use, lithology, morphology indices, climate, and hydrological indicators. Modeled C-Q relationships were then used to estimate annual and seasonal nutrient loads in nearby and similar unmonitored catchments. We implemented this approach on a large dataset from France where stream flow was surveyed daily and water quality (suspended solids, nitrate, total phosphorus, and orthophosphate concentrations) was measured on a monthly basis at 233 stations over the past 20 years in catchments from 10 to 3000 km². The concentration at the median daily flow (seen here as a metric of the general level of contamination in a catchment) was predicted with uncertainty ranging between 30 and 100 %, depending on the variable. C-Q slopes were predicted with large errors, but a sensitivity analysis was conducted to determine the impact of C-Q slopes uncertainties on computed annual and seasonal loads. This approach allows estimation of seasonal and annual nutrient loads and could be potentially implemented to improve protection and

Linking river nutrient concentrations to land use and rainfall in a paddy agriculture-urban area gradient watershed in southeast China.

Science.gov (United States)

Xia, Yongqiu; Ti, Chaopu; She, Dongli; Yan, Xiaoyuan

2016-10-01

The effects of land use and land-use changes on river nutrient concentrations are not well understood, especially in the watersheds of developing countries that have a mixed land use of rice paddy fields and developing urban surfaces. Here, we present a three-year study of a paddy agricultural-urban area gradient watershed in southeast China. The annual anthropogenic nitrogen (N) input from the agricultural region to the urban region was high, yet the results showed that the monthly nutrient concentrations in the river were low in the rainy seasons. The nutrient concentrations decreased continuously as the river water passed through the traditional agriculture region (TAR; paddy rice and wheat rotation) and increased substantially in the city region (CR). The traditional agricultural reference region exported most of the nutrient loads at high flows (>1mmd(-1)), the intensified agricultural region (IAR, aquaculture and poultry farming) exported most of the nutrient loads at moderate flows (between 0.5 and 1mmd(-1)), and the CR reference area exported most of the nutrient loads under low to moderate flows. We developed a statistical model to link variations in the nutrient concentrations to the proportion of land-use types and rainfall. The statistical results showed that impervious surfaces, which we interpret as a proxy for urban activities including sewage disposal, were the most important drivers of nutrient concentrations, whereas water surfaces accounted for a substantial proportion of the nutrient sinks. Therefore, to efficiently reduce water pollution, sewage from urban areas must be addressed as a priority, although wetland restoration could also achieve substantial pollutant removal. Copyright © 2016. Published by Elsevier B.V.

Nutrient and sediment concentrations and loads in the Steele Bayou Basin, northwestern Mississippi, 2010–14

Science.gov (United States)

Hicks, Matthew B.; Murphy, Jennifer C.; Stocks, Shane J.

2017-06-01

The U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers-Vicksburg District, monitored streamflow, water quality, and sediment at two stations on the Steele Bayou in northwestern Mississippi from October 2010 through September 2014 to characterize nutrient and sediment concentrations and loads in areas where substantial implementation of conservation efforts have been implemented. The motivation for this effort was to quantify improvements, or lack thereof, in water quality in the Steele Bayou watershed as a result of implementing large- and small-scale best-management practices aimed at reducing nutrient and sediment concentrations and loads. The results of this study document the hydrologic, water-quality, and sedimentation status of these basins following over two decades of ongoing implementation of conservation practices.Results from this study indicate the two Steele Bayou stations have comparable loads and yields of total nitrogen, phosphorus, and suspended sediment when compared to other agricultural basins in the southeastern and central United States. However, nitrate plus nitrite yields from basins in the Mississippi River alluvial plain, including the Steele Bayou Basin, are generally lower than other agricultural basins in the southeastern and central United States.Seasonal variation in nutrient and sediment loads was observed at both stations and for most constituents. About 50 percent of the total annual nutrient and sediment load was observed during the spring (February through May) and between 25 and 50 percent was observed during late fall and winter (October through January). These seasonal patterns probably reflect a combination of seasonal patterns in precipitation, runoff, streamflow, and in the timing of fertilizer application.Median concentrations of total nitrogen, nitrate plus nitrite, total phosphorus, orthophosphate, and suspended sediment were slightly higher at the upstream station, Steele Bayou near Glen Allan

Effect of Carbohydrate Source and Cottonseed Meal Level in the Concentrate on Feed Intake, Nutrient Digestibility, Rumen Fermentation and Microbial Protein Synthesis in Swamp Buffaloes

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M. Wanapat

2013-07-01

Full Text Available The objective of this study was to investigate the effect of carbohydrate source and cottonseed meal level in the concentrate on feed intake, nutrient digestibility, rumen fermentation and microbial protein synthesis in swamp buffaloes. Four, 4-yr old rumen fistulated swamp buffaloes were randomly assigned to receive four dietary treatments according to a 2×2 factorial arrangement in a 4×4 Latin square design. Factor A was carbohydrate source; cassava chip (CC and CC+rice bran at a ratio 3:1 (CR3:1, and factor B was level of cottonseed meal (CM; 109 g CP/kg (LCM and 328 g CP/kg (HCM in isonitrogenous diets (490 g CP/kg. Buffaloes received urea-treated rice straw ad libitum and supplemented with 5 g concentrate/kg BW. It was found that carbohydrate source did not affect feed intake, nutrient intake, digested nutrients, nutrient digestibility, ammonia nitrogen concentration, fungi and bacterial populations, or microbial protein synthesis (p>0.05. Ruminal pH at 6 h after feeding and the population of protozoa at 4 h after feeding were higher when buffalo were fed with CC than in the CR3:1 treatment (p0.05. Based on this experiment, concentrate with a low level of cottonseed meal could be fed with cassava chips as an energy source in swamp buffalo receiving rice straw.

Substitution of common concentrates with by-products modulated ruminal fermentation, nutrient degradation, and microbial community composition in vitro.

Science.gov (United States)

Ertl, P; Knaus, W; Metzler-Zebeli, B U; Klevenhusen, F; Khiaosa-Ard, R; Zebeli, Q

2015-07-01

A rumen simulation technique was used to evaluate the effects of the complete substitution of a common concentrate mixture (CON) with a mixture consisting solely of by-products from the food industry (BP) at 2 different forage-to-concentrate ratios on ruminal fermentation profile, nutrient degradation, and abundance of rumen microbiota. The experiment was a 2×2 factorial arrangement with 2 concentrate types (CON and BP) and 2 concentrate levels (25 and 50% of diet dry matter). The experiment consisted of 2 experimental runs with 12 fermentation vessels each (n=6 per treatment). Each run lasted for 10d, with data collection on the last 5d. The BP diets had lower starch, but higher neutral detergent fiber (NDF) and fat contents compared with CON. Degradation of crude protein was decreased, but NDF and nonfiber carbohydrate degradation were higher for the BP diets. At the 50% concentrate level, organic matter degradation tended to be lower for BP and CH4 formation per unit of NDF degraded was also lower for BP. The BP mixture led to a higher concentration of propionate and a lower acetate-to-propionate ratio, whereas concentrations of butyrate and caproate decreased. Concentrate type did not affect microbial community composition, except that the abundance of bacteria of the genus Prevotella was higher for BP. Increasing the concentrate level resulted in higher degradation of organic matter and crude protein. At the higher concentrate level, total short-chain fatty acid formation increased and concentrations of isobutyrate and valerate decreased. In addition, at the 50% concentrate level, numbers of protozoa increased, whereas numbers of methanogens, anaerobic fungi, and fibrolytic bacteria decreased. No interaction was noted between the 2 dietary factors on most variables, except that at the higher concentrate level the effects of BP on CH4 and CO2 formation per unit of NDF degraded, crude protein degradation, and the abundance of Prevotella were more prominent. In

[Effect of microbial nutrient concentration on improvement of municipal sewage sludge dewaterability through bioleaching].

Science.gov (United States)

Song, Yong-wei; Liu, Fen-wu; Zhou, Li-xiang

2012-08-01

In this study, shaking flask batch experiments and practical engineering application tests were performed to investigate the effect of microbial nutrient concentration on the dewaterability of municipal sewage sludge with 2%, 3%, 4% and 5% solid contents via bioleaching. Meanwhile, the changes of pH value and the utilization efficiency of microbial nutrients during bioleaching were analyzed in this study. The results showed that the pH value decreased gradually at the beginning and then maintained a stable state in the treatments with different solid contents, and the nutrients were completely used up by the microorganisms after 2 days of bioleaching. It was found that the SRF of 2%, 3%, 4%, 5% sludges decreased quickly and then rose gradually with the extension of bioleaching time. In addition, the higher solid content the greater the increase. It was determined that the optimum microbial nutrient dosage for sludge with solid content of 2%, 3%, 4% and 5% were 3.0 g x L(-1), 4.5 g x L(-1), 8.3 g x L(-1) and 12.8 g x L(-1) respectively. At this point, the lowest SRF of sludge with each solid content were 0.61 x 10(12) m x kg(-1), 1.22 x 10(12) m x kg(-1), 3.09 x 10(12) m x kg(-1) and 4.83 x 10(12) m x kg(-1), respectively. Through the engineering application, it was showed that diluting the solid content of sewage sludge from 5% to 3% before bioleaching was feasible. It could not only improve the dewaterability of bioleached sewage sludge (the SRF declined from 3.29 x 10(12) m x kg(-1) to 1.10 x 10(12) m x kg(-1)), but also shorten the sludge nutrient time (shortened from 4 days to 2.35 days) and reduce the operation costs. Therefore, the results of this study have important significance for the engineering application of bioleaching of municipal sewage sludge with high solid content.

Nutrient and salinity concentrations effects on quality and storability of cherry tomato fruits grown by hydroponic system

Directory of Open Access Journals (Sweden)

Mohammad Zahirul Islam

2018-04-01

Full Text Available ABSTRACT This study was conducted to investigate the effects of nutrient and salinity concentrations on the quality of deepflow technique hydroponic system cultivated cherry tomatoes (Lycopersicon esculentum Mill ‘Unicorn’. The conditions were: (1 control (NS-1 × nutrient Solution, Electrical Conductivity – EC: 2.5 mS∙cm–1; (2 2 × NS (2 × NS-Double NS, EC: 5 mS∙cm–1; (3 NS + 4.23 mM NaCl (NaCl-Sodium Chloride, EC: 5 mS∙cm–1; and (4 NS + 13.70 mM Sea Water – SW (EC: 7.5 mS∙cm–1. NS + 13.70 mM SW treatment showed the lowest fresh weight loss. Visual quality as well as shelf life was the longest in NS (1 × nutrient solution treated tomato fruits. The longest shelf life at 5 °C, 11 °C, and 24 °C were 21, 16, and 8 days, respectively, in NS (1 × nutrient solution treated tomato fruits. The highest firmness was recorded in NS (1 × nutrient solution treated tomato fruits, which was retained after storage. Moreover, NS + 13.70 mM SW treatment increased the cherry tomato fruit’s quality, especially soluble solids and sugar contents. These results indicate that salinity concentration has effect the soluble solids and sugar of cherry tomato fruits. In addition, nutrient concentration influenced the shelf life and firmness of cherry tomato fruits.

Data to support "Boosted Regression Tree Models to Explain Watershed Nutrient Concentrations & Biological Condition"

Data.gov (United States)

U.S. Environmental Protection Agency — Spreadsheets are included here to support the manuscript "Boosted Regression Tree Models to Explain Watershed Nutrient Concentrations and Biological Condition". This...

Litter production and its nutrient concentration in some fuelwood trees grown on sodic soil

Energy Technology Data Exchange (ETDEWEB)

Garg, V.K. (National Botanical Research Inst., Lucknow (India))

1992-01-01

Litter production was estimated in 8-year-old tree plantations of Acacia nilotica, Prosopis juliflora, Dalbergia sisso, and Terminalia arjuna planted in a monoculture tree cropping system on sodic soils of Lucknow Division, India. Mean annual litter fall of these trees amounted to 5.9, 7.4, 5.0 and 5.4 t ha[sup -1], respectively. Irrespective of tree species, the leaf litter concentrations of N, K and Ca were greater than those of P and Mg. The concentration of nutrients in leaf tissues was negatively correlated for N and Ca, with the magnitude of leaf fall in D. sissoo, but was positively correlated for Ca and Mg in A. nilotica; no such correlations were found in P. juliflora and T. arjuna. The variations in the concentration of leaf litter nutrient did not appear to be species specific but depended on adverse edaphic properties including the fertility status of sodic soil. A. nilotica and P. juliflora with bimodal patterns of litter fall return greater amounts of nutrients to the soil surface than D. sissoo and T. arjuna which have unimodal patterns of litter fall. The study indicated the potential benefit of a mixed plantation system having variable leaf fall patterns among the planted trees so providing constant litter mulch to help in conserving soil moisture. (author).

Sudden increase in atmospheric concentration reveals strong coupling between shoot carbon uptake and root nutrient uptake in young walnut trees

International Nuclear Information System (INIS)

Delaire, M.; Sigogne, M.; Beaujard, F.; Frak, E.; Adam, B.; Le Roux, X.

2005-01-01

Short-term effects of a sudden increase in carbon dioxide concentration on nutrient uptake by roots during vegetative growth was studied in young walnut trees. Rates of carbon dioxide uptake and water loss by individual trees were determined by a branch bag method from three days before and six days after carbon dioxide concentration was increased. Nutrient uptake rates were measured concurrently by a hydroponic recirculating nutrient solution system. Carbon dioxide uptake rates increased greatly with increasing atmospheric carbon dioxide; nutrient uptake rates were proportional to carbon dioxide uptake rates, except for the phosphorus ion. Daily water loss rates were only slightly affected by elevated carbon dioxide. Overall, it was concluded that in the presence of non-limiting supplies of water and nutrients, root nutrient uptake and shoot carbon assimilation are strongly coupled in the short term in young walnut trees despite the important carbon and nutrient storage capacities od woody species. 45 refs., 7 figs

Effects of watershed and riparian zone characteristics on nutrient concentrations in the River Scheldt Basin

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J. Meynendonckx

2006-01-01

Full Text Available The relative influence of a set of watershed characteristics on surface water nutrient concentrations was examined in 173 watersheds within two subcatchments (Upper-Scheldt and Nete of the River Scheldt Basin (Flanders, Belgium. Each watershed was described by seasonal rainfall, discharge loading of point sources, morphological characteristics (area, average slope, drainage density, elongation, land use and soil properties (soil texture and drainage. Partial regression analysis revealed that soil drainage variables had the strongest influence on nutrient concentrations. Additional influence was exerted by land use and point source loading variables. Nitrate concentrations were positively correlated with effluent loadings coming from wastewater treatment plants and with the area of agricultural land. Phosphate concentrations were best explained by effluent loadings of industrial point sources and by the area of urban land. Land use close to the river was not a better predictor of nitrate and phosphate concentrations than land use away from the river. This suggests that the mediating impact of riparian zones is rather explained by the hydrologic pathways within the buffer strip.

Cerium enhances germination and shoot growth, and alters mineral nutrient concentration in rice

Science.gov (United States)

García-Morales, Soledad; Pérez-Sato, Juan Antonio

2018-01-01

Cerium (Ce) belongs to the rare earth elements (REEs), and although it is not essential for plants, it can stimulate growth and other physiological processes. The objective of this research was to evaluate the effect of Ce on seed germination, initial seedling growth, and vegetative growth in rice (Oryza sativa L.) cv. Morelos A-98. During the germination process, the seeds were treated with Ce concentrations of 0, 4, 8, and 12 μM; after 5 d, germination percentage was recorded and after 10 d seedling growth was measured. For vegetative growth, a hydroponic system was established where 14-d-old plants without previous Ce treatment were transferred into nutrient solution. After two weeks of acclimatizing, 0, 25, 50, and 100 μM Ce were added to the nutrient solution for 28 d. Ce significantly increased germination and the initial growth variables of the seedlings. During vegetative growth, Ce increased plant height, number of tillers, root volume, and shoot fresh and dry biomass, without affecting root biomass weight. With low Ce concentrations (25 and 50 μM), the concentrations of chlorophylls and amino acids in the shoots were similar to those in the control, like amino acid concentration in the roots at a concentration of 25 μM Ce. Conversely, the concentration of total sugars increased in the shoot with the application of 25, 50, and 100 μM Ce, and in the roots with the application of 50 μM Ce. Also, Ce did not affect the concentration of macro or micronutrients in the shoots. However, in the roots, the high Ce concentration decreased the concentrations of Ca, Fe, Mn, and Zn, while the Mg concentration increased. Our results indicate that Ce, at the right concentrations, can function as a biostimulant in rice germination and growth. PMID:29579100

Effect of phosphorus concentration of the nutrient solution on the volatile constituents of leaves and bracts of Origanum dictamnus.

Science.gov (United States)

Economakis, C; Skaltsa, Helen; Demetzos, Costas; Soković, M; Thanos, Costas A

2002-10-23

The chemical composition of the essential oils obtained from the leaves and bracts of hydroponically cultivated Origanum dictamnus were analyzed by GC-MS techniques. Three different concentrations of phosphorus (5, 30, and 60 mg/L) in the nutrient solution were used for the cultivation, using the nutrient film technique (NFT). A total of 46 different compounds were identified and significant differences (qualitative and quantitative) were observed between the samples. Carvacrol and p-cymene were identified as the main compounds in all samples analyzed, whereas thymoquinone was found in higher percentage in the leaves than in bracts. The essential oils were tested for their antibacterial activity against Gram-positive and Gram-negative bacteria. The oils obtained from the bracts were found to be more active. The results obtained from GC-MS analyses were submitted to chemometric analysis.

Ultraviolet-B Radiation and Nitrogen Affect Nutrient Concentrations and the Amount of Nutrients Acquired by Above-Ground Organs of Maize

OpenAIRE

Correia, Carlos M.; Coutinho, João F.; Bacelar, Eunice A.; Gonçalves, Berta M.; Björn, Lars Olof; Moutinho Pereira, José

2012-01-01

UV-B radiation effects on nutrient concentrations in above-ground organs of maize were investigated at silking and maturity at different levels of applied nitrogen under field conditions. The experiment simulated a 20% stratospheric ozone depletion over Portugal. At silking, UV-B increased N, K, Ca, and Zn concentrations, whereas at maturity Ca, Mg, Zn, and Cu increased and N, P and Mn decreased in some plant organs. Generally, at maturity, N, Ca, Cu, and Mn were lower, while P, K, and Zn con...

Lipid-based nutrient supplements do not affect efavirenz but lower plasma nevirapine concentrations in Ethiopian adult HIV patients

DEFF Research Database (Denmark)

Abdissa, A; Olsen, Mette Frahm; Yilma, D

2015-01-01

OBJECTIVES: Lipid-based nutrient supplements (LNSs) are increasingly used in HIV programmes in resource-limited settings. However, the possible effects of LNSs on the plasma concentrations of antiretroviral drugs have not been assessed. Here, we aimed to assess the effects of LNSs on plasma...... efavirenz and nevirapine trough concentrations in Ethiopian adult HIV-infected patients. METHODS: The effects of LNSs were studied in adults initiating antiretroviral therapy (ART) in a randomized trial. Patients with body mass index (BMI) > 17 kg/m(2) (n = 282) received daily supplementation of an LNS.......9; -0.9 μg/mL; P = 0.01), respectively, compared with the group not receiving supplements. There were no differences between groups with respect to efavirenz plasma concentrations. The CYP2B6 516 G>T polymorphism was associated with a 5 μg/mL higher plasma efavirenz concentration compared with the wild...

NPK fertilization effects on concentration of nutrients in Valencia orange leaves

International Nuclear Information System (INIS)

Basso, C.; Mielniczuk, J.; Bohnen, H.

1983-01-01

The effects of NPK fertilization on the nutrient concentration in the leaves was evaluated in a field experiment of Valencia orange (Citrus sinensis Osbeck) growing in a sandy acid soil, with 4N, 3P and 4K fertilizer levels. N and Cu contents in the leaves were high, while P and Zn levels were low, in all treatments. Increasing the levels of N, P 2 O 5 and K 2 O fertilization resulted in an increase of the N, P and K concentration in the leaves, respectively. Crescent levels of N fertilization raised Mn and decreased Ca concentration in the leaves. P and K contents in the leaves correlated positively. With a great availability and absorption of K, reduction on he foliar contents of Mg and Ca ocurred. (M.A.C.) [pt

THE MAIN NUTRIENTS CONCENTRATION FROM INTRA TISSUE WATER OF BENTHOS ORAGANISMS FROM MURES BASIN

Directory of Open Access Journals (Sweden)

DANA POPA

2008-05-01

Full Text Available In the hydrographic basin of Mures river, aboard an altitude gradient, were taken samples of intra tissue waters from benthonic organisms for research the nutrients concentrations. The reference point was represented by a dairy caw farm where the agricultural fields of this is applied the organic fertilization with manure. The intra tissue water samples from benthonic organisms were prelevated in spring and autumn and the prelevate dates are the same with spread manure dates. At the intra tissue water level, concentrations value of N and P are bigger at the second data prelevations than first data prelevations and we can conclude that the benthonic oligochetas activity increase, more than, they density increase in Mures basin. The high concentrations of NH4 show as that Mures basin is a zone characterized by high degree of anoxia and this fact is supported by significant differences between seasonal prelevations. The explication is the manifestation to the cumulated and at distance effects of introduction in water to some organic products, very probably washed from neighborhoods agricultural field. Were calculated values of Student test for seasonal comparisons and were founded significant differences between nutrients concentration values at first and second prelevations.

Experimental analysis of an effect of the nutrient type and its concentration on the rheological properties of the baker’s yeast suspensions

Directory of Open Access Journals (Sweden)

Major-Godlewska Marta

2015-09-01

Full Text Available The aim of the study presented was to experimentally analyze an effect of the nutrient type and its concentration on the variability of rheological properties of the baker’s yeast suspensions for different time periods. Aqueous suspensions of the baker’s yeast of various concentration (solution I, without nutrient and yeasts suspended in aqueous solution of sucrose or honey as nutrients with different concentration (solution II or solution III were tested. Experiments were carried out using rotational rheoviscometer of type RT10 by a company HAAKE. The measurements were conducted for different time periods (from 1 h up to 144 h at given fluid temperature. On the basis of the obtained data, rheological characteristics of the aqueous solution of baker’s yeast suspensions without and with nutrients of different sucrose or honey concentration were identified and mathematically described.

The Effect of Potassium Concentration in Nutrient Solution on Lycopene, Vitamin C and Qualitative Characteristics of Cherry Tomato in Saline Conditions

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E. Shabani Sangtarashani

2013-06-01

Full Text Available Potassium (K has a special place in improving the quality of agricultural products. To evaluate the effect of K concentration in nutrient solution on lycopene content, vitamin C and qualitative characteristics of cherry tomato in NaCl salinity conditions, an experiment was carried out as a completely randomized design with five treatments and three replications at university of Tabriz, Tabriz, Iran, in 2010. Treatments consisted of four concentrations of K (0.2, 2, 7 and 14 mM in nutrient solution with 60 mM NaCl concentration. A nutrient solution treatment without salinity was considered as control. The experiment was conducted in greenhouse, in a hydroponic system. The results indicated that increasing of K concentration increased lycopene content in fruit. Lycopene content in control treatment showed significant difference (P<0.01 in comparison with salinity treatments. With increasing the K concentration (except at 14 mM concentration, vitamin C content was increased, but indicated no statistically significant difference. Vitamin C content in saline conditions was more than control treatment, but showed no significant difference. Adding potassium concentration in nutrient solution improved yield and enhanced quality parameters such as percentage of dry matter, soluble solids and electrical conductivity of fruit extract. Since in saline conditions, the qualitative characteristics of tomato at 7 mM concentration were in the best situation, therefore using this concentration is recommended.

The biogeochemical role of baleen whales and krill in Southern Ocean nutrient cycling.

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Lavenia Ratnarajah

Full Text Available The availability of micronutrients is a key factor that affects primary productivity in High Nutrient Low Chlorophyll (HNLC regions of the Southern Ocean. Nutrient supply is governed by a range of physical, chemical and biological processes, and there are significant feedbacks within the ecosystem. It has been suggested that baleen whales form a crucial part of biogeochemical cycling processes through the consumption of nutrient-rich krill and subsequent defecation, but data on their contribution are scarce. We analysed the concentration of iron, cadmium, manganese, cobalt, copper, zinc, phosphorus and carbon in baleen whale faeces and muscle, and krill tissue using inductively coupled plasma mass spectrometry. Metal concentrations in krill tissue were between 20 thousand and 4.8 million times higher than typical Southern Ocean HNLC seawater concentrations, while whale faecal matter was between 276 thousand and 10 million times higher. These findings suggest that krill act as a mechanism for concentrating and retaining elements in the surface layer, which are subsequently released back into the ocean, once eaten by whales, through defecation. Trace metal to carbon ratios were also higher in whale faeces compared to whale muscle indicating that whales are concentrating carbon and actively defecating trace elements. Consequently, recovery of the great whales may facilitate the recycling of nutrients via defecation, which may affect productivity in HNLC areas.

Effects of mountain agriculture on nutrient cycling at upstream watersheds

Science.gov (United States)

Lin, T.-C.; Shaner, P. L.; Wang, L.-J.; Shih, Y.-T.; Wang, C.-P.; Huang, G.-H.; Huang, J.-C.

2015-05-01

The expansion of agriculture to rugged mountains can exacerbate negative impacts of agriculture activities on ecosystem function. In this study, we monitored streamwater chemistry of four watersheds with varying proportions of agricultural lands (0.4, 3, 17, 22%) and rainfall chemistry of two of the four watersheds at Feitsui Reservoir Watershed in northern Taiwan to examine the effects of agriculture on watershed nutrient cycling. We found that the greater the proportions of agricultural lands, the higher the ion concentrations, which is evident for fertilizer-associated ions (NO3-, K+) but not for ions that are rich in soils (SO42-, Ca2+, Mg2+), suggesting that agriculture enriched fertilizer-associated nutrients in streamwater. The watershed with the highest proportion of agricultural lands had higher concentrations of ions in rainfall and lower nutrient retention capacity (i.e. higher output-input ratio of ions) compared to the relatively pristine watershed, suggesting that agriculture can influence atmospheric deposition of nutrients and a system's ability to retain nutrients. Furthermore, we found that a forested watershed downstream of agricultural activities can dilute the concentrations of fertilizer-associated ions (NO3-, K+) in streamwater by more than 70%, indicating that specific landscape configurations help mitigate nutrient enrichment to aquatic systems. We estimated that agricultural lands at our study site contributed approximately 400 kg ha-1 yr-1 of NO3-N and 260 kg ha-1 yr-1 of PO4-P output via streamwater, an order of magnitude greater than previously reported around the globe and can only be matched by areas under intense fertilizer use. Furthermore, we re-constructed watershed nutrient fluxes to show that excessive leaching of N and P, and additional loss of N to the atmosphere via volatilization and denitrification, can occur under intense fertilizer use. In summary, this study demonstrated the pervasive impacts of agriculture activities

Biochar and manure affect calcareous soil and corn silage nutrient concentrations and uptake.

Science.gov (United States)

Lentz, R D; Ippolito, J A

2012-01-01

Carbon-rich biochar derived from the pyrolysis of biomass can sequester atmospheric CO, mitigate climate change, and potentially increase crop productivity. However, research is needed to confirm the suitability and sustainability of biochar application to different soils. To an irrigated calcareous soil, we applied stockpiled dairy manure (42 Mg ha dry wt) and hardwood-derived biochar (22.4 Mg ha), singly and in combination with manure, along with a control, yielding four treatments. Nitrogen fertilizer was applied when needed (based on preseason soil test N and crop requirements) in all plots and years, with N mineralized from added manure included in this determination. Available soil nutrients (NH-N; NO-N; Olsen P; and diethylenetriaminepentaacetic acid-extractable K, Mg, Na, Cu, Mn, Zn, and Fe), total C (TC), total N (TN), total organic C (TOC), and pH were evaluated annually, and silage corn nutrient concentration, yield, and uptake were measured over two growing seasons. Biochar treatment resulted in a 1.5-fold increase in available soil Mn and a 1.4-fold increase in TC and TOC, whereas manure produced a 1.2- to 1.7-fold increase in available nutrients (except Fe), compared with controls. In 2009 biochar increased corn silage B concentration but produced no yield increase; in 2010 biochar decreased corn silage TN (33%), S (7%) concentrations, and yield (36%) relative to controls. Manure produced a 1.3-fold increase in corn silage Cu, Mn, S, Mg, K, and TN concentrations and yield compared with the control in 2010. The combined biochar-manure effects were not synergistic except in the case of available soil Mn. In these calcareous soils, biochar did not alter pH or availability of P and cations, as is typically observed for acidic soils. If the second year results are representative, they suggest that biochar applications to calcareous soils may lead to reduced N availability, requiring additional soil N inputs to maintain yield targets. Copyright © by the

Dredging effects on selected nutrient concentrations and ecoenzymatic activity in two drainage ditch sediments in the lower Mississippi River Valley

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Matt Moore

2017-09-01

Full Text Available Agricultural drainage ditches are conduits between production acreage and receiving aquatic systems. Often overlooked for their mitigation capabilities, agricultural drainage ditches provide an important role for nutrient transformation via microbial metabolism. Variations in ecoenzyme activities have been used to elucidate microbial metabolism and resource demand of microbial communities to better understand the relationship between altered nutrient ratios and microbial activity in aquatic ecosystems. Two agricultural drainage ditches, one in the northeast portion of the Arkansas Delta and the other in the lower Mississippi Delta, were monitored for a year. Sediment samples were collected prior to each ditch being dredged (cleaned, and subsequent post-dredging samples occurred as soon as access was available. Seasonal samples were then collected throughout a year to examine effects of dredging on selected nutrient concentrations and ecoenzymatic activity recovery in drainage ditch sediments. Phosphorus concentrations in sediments after dredging decreased 33–66%, depending on ditch and phosphorus extraction methodology. Additionally, ecoenzymatic activity was significantly decreased in most sediment samples after dredging. Fluorescein diacetate hydrolysis activity, an estimate of total microbial activity, decreased 56–67% after dredging in one of the two ditches. Many sample sites also had significant phosphorus and ecoenzymatic activity differences between the post-dredge samples and the year-long follow-up samples. Results indicate microbial metabolism in dredged drainage ditches may take up to a year or more to recover to pre-dredged levels. Likewise, while sediment nutrient concentrations may be decreased through dredging and removal, runoff and erosion events over time tend to quickly replenish nutrient concentrations in replaced sediments. Understanding nutrient dynamics and microbial metabolism within agricultural drainage ditches is

Experimental evidence for enhanced top-down control of freshwater macrophytes with nutrient enrichment.

Science.gov (United States)

Bakker, Elisabeth S; Nolet, Bart A

2014-11-01

The abundance of primary producers is controlled by bottom-up and top-down forces. Despite the fact that there is consensus that the abundance of freshwater macrophytes is strongly influenced by the availability of resources for plant growth, the importance of top-down control by vertebrate consumers is debated, because field studies yield contrasting results. We hypothesized that these bottom-up and top-down forces may interact, and that consumer impact on macrophyte abundance depends on the nutrient status of the water body. To test this hypothesis, experimental ponds with submerged vegetation containing a mixture of species were subjected to a fertilization treatment and we introduced consumers (mallard ducks, for 8 days) on half of the ponds in a full factorial design. Over the whole 66-day experiment fertilized ponds became dominated by Elodea nuttallii and ponds without extra nutrients by Chara globularis. Nutrient addition significantly increased plant N and P concentrations. There was a strong interactive effect of duck presence and pond nutrient status: macrophyte biomass was reduced (by 50%) after the presence of the ducks on fertilized ponds, but not in the unfertilized ponds. We conclude that nutrient availability interacts with top-down control of submerged vegetation. This may be explained by higher plant palatability at higher nutrient levels, either by a higher plant nutrient concentration or by a shift towards dominance of more palatable plant species, resulting in higher consumer pressure. Including nutrient availability may offer a framework to explain part of the contrasting field observations of consumer control of macrophyte abundance.

Nutrient concentrations in leachate and runoff from dairy cattle lots with different surface materials

Science.gov (United States)

Nitrogen (N) and phosphorus (P) loss from agriculture persists as a water quality issue, and outdoor cattle lots can have a high loss potential. We monitored hydrology and nutrient concentrations in leachate and runoff from dairy heifer lots constructed with three surface materials (soil, sand, bark...

Numerical simulations of river discharges, nutrient flux and nutrient dispersal in Jakarta Bay, Indonesia

International Nuclear Information System (INIS)

Wulp, Simon A. van der; Damar, Ario; Ladwig, Norbert; Hesse, Karl-J.

2016-01-01

The present application of numerical modelling techniques provides an overview of river discharges, nutrient flux and nutrient dispersal in Jakarta Bay. A hydrological model simulated river discharges with a total of 90 to 377 m 3 s −1 entering Jakarta Bay. Daily total nitrogen and total phosphorus loads ranged from 40 to 174 tons and 14 to 60 tons, respectively. Flow model results indicate that nutrient gradients are subject to turbulent mixing by tides and advective transport through circulation driven by wind, barotropic and baroclinic pressure gradients. The bulk of nutrient loads originate from the Citarum and Cisadane rivers flowing through predominantly rural areas. Despite lower nutrient loads, river discharges from the urban area of Jakarta exhibit the highest impact of nutrient concentrations in the near shore area of Jakarta Bay and show that nutrient concentrations were not only regulated by nutrient loads but were strongly regulated by initial river concentrations and local flow characteristics. - Highlights: • Full overview of river discharges, nutrient flux and nutrient levels in Jakarta Bay • Important overview of nutrient flux from individual rivers • Simulations identify the principal drivers of water circulation and nutrient gradient. • Nutrient dispersion model includes the local effects of the Java Sea current system.

Numerical simulations of river discharges, nutrient flux and nutrient dispersal in Jakarta Bay, Indonesia.

Science.gov (United States)

van der Wulp, Simon A; Damar, Ario; Ladwig, Norbert; Hesse, Karl-J

2016-09-30

The present application of numerical modelling techniques provides an overview of river discharges, nutrient flux and nutrient dispersal in Jakarta Bay. A hydrological model simulated river discharges with a total of 90 to 377m(3)s(-1) entering Jakarta Bay. Daily total nitrogen and total phosphorus loads ranged from 40 to 174tons and 14 to 60tons, respectively. Flow model results indicate that nutrient gradients are subject to turbulent mixing by tides and advective transport through circulation driven by wind, barotropic and baroclinic pressure gradients. The bulk of nutrient loads originate from the Citarum and Cisadane rivers flowing through predominantly rural areas. Despite lower nutrient loads, river discharges from the urban area of Jakarta exhibit the highest impact of nutrient concentrations in the near shore area of Jakarta Bay and show that nutrient concentrations were not only regulated by nutrient loads but were strongly regulated by initial river concentrations and local flow characteristics. Copyright © 2016 Elsevier Ltd. All rights reserved.

Concentração e conteúdo de nutrientes em lisianto, cultivado em hidroponia, em sistema NFT = Concentration and nutrient content in lisianthus grown in a hydroponic NFT system

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Fernanda Alice Antonello Londero Backes

2008-10-01

Full Text Available O diagnóstico nutricional é fundamental para determinar as exigências das plantas quanto aos nutrientes, de forma a se proceder a um manejo adequado, de acordo com a espécie. Assim, para determinar as concentrações e conteúdos nutricionais adequados à produção e qualidade de plantas de lisianto em cultivo hidropônico, instalou-se um experimento onde as plantas foram cultivadas em sistema NFT, em diferentes soluções nutritivas. O experimento foi conduzido, segundo delineamento experimental em blocos casualizados, em esquema fatorial 4x3, totalizando 12 tratamentos, com três repetições. Ostratamentos foram compostos de quatro cultivares (Echo Champagne, Mariachi Pure White, Balboa Yellow e Ávila Blue Rim e três soluções nutritivas (Teste, Steiner modificada e Barbosa. Foram avaliadas as concentrações e os conteúdos dos nutrientes nas folhas e conteúdos na parte aérea das plantas. As plantas cultivadas nas soluções Barbosa eTeste apresentaram resultados satisfatórios quanto às concentrações e aos conteúdos de nutrientes, enquanto a solução Steiner modificada produziu plantas com limitações nutricionais.The nutritional diagnosis is fundamental for determining plantnutrients, in order to correctly manage the nutritional requirements for each species. Thus, in order to determine the ideal nutrient amount and concentration for obtaining the best yield and quality of lisianthus grown hydroponically, an experiment was conducted inwhich the plants were grown under the NFT system in different nutrient solutions. The experiment was conducted according to a random block design arrangement in a 4x3 factorial scheme, totaling 12 treatments with three repetitions. The treatments werecomprised of four cultivars (Echo Champagne, Mariachi Pure White, Balboa Yellow and Ávila Blue Rim and three nutrient solutions (Test, modified Steiner and Barbosa. In the leaves, nutrient concentration and content were evaluated; in the aerial

Tidal pumping drives nutrient and dissolved organic matter dynamics in a Gulf of Mexico subterranean estuary

Science.gov (United States)

Santos, Isaac R.; Burnett, William C.; Dittmar, Thorsten; Suryaputra, I. G. N. A.; Chanton, Jeffrey

2009-03-01

We hypothesize that nutrient cycling in a Gulf of Mexico subterranean estuary (STE) is fueled by oxygen and labile organic matter supplied by tidal pumping of seawater into the coastal aquifer. We estimate nutrient production rates using the standard estuarine model and a non-steady-state box model, separate nutrient fluxes associated with fresh and saline submarine groundwater discharge (SGD), and estimate offshore fluxes from radium isotope distributions. The results indicate a large variability in nutrient concentrations over tidal and seasonal time scales. At high tide, nutrient concentrations in shallow beach groundwater were low as a result of dilution caused by seawater recirculation. During ebb tide, the concentrations increased until they reached a maximum just before the next high tide. The dominant form of nitrogen was dissolved organic nitrogen (DON) in freshwater, nitrate in brackish waters, and ammonium in saline waters. Dissolved organic carbon (DOC) production was two-fold higher in the summer than in the winter, while nitrate and DON production were one order of magnitude higher. Oxic remineralization and denitrification most likely explain these patterns. Even though fresh SGD accounted for only ˜5% of total volumetric additions, it was an important pathway of nutrients as a result of biogeochemical inputs in the mixing zone. Fresh SGD transported ˜25% of DOC and ˜50% of total dissolved nitrogen inputs into the coastal ocean, with the remainder associated with a one-dimensional vertical seawater exchange process. While SGD volumetric inputs are similar seasonally, changes in the biogeochemical conditions of this coastal plain STE led to higher summertime SGD nutrient fluxes (40% higher for DOC and 60% higher for nitrogen in the summer compared to the winter). We suggest that coastal primary production and nutrient dynamics in the STE are linked.

Gamma radiation and osmotic potential of the nutrient solution differentially affect macronutrient concentrations, pH and EC in chilhuacle pepper fruits

International Nuclear Information System (INIS)

Victor Garcia-Gaytan, Libia Iris Trejo-Tellez; Olga Tejeda-Sartorius; Maribel Ramirez-Martinez; Julian Delgadillo-Martinez; Fernando Carlos Gomez-Merino; Soledad Garcia-Morales

2018-01-01

Chilhuacle pepper (Capsicum annuum L.) seeds were exposed to gamma radiation (GR) doses (0, 10, 80 and 120 Gy), and plants were grown in hydroponics with different osmotic potentials (OP) (- 0.036, - 0.072, - 0.092, and - 0.108 MPa) in the nutrient solution. We measured the nutrient concentrations, pH and electrical conductivity (EC) in fruits at different time points after transplanting (70, 90 and 130 dat), and found the GR, nutrient solution OP and their interactions differentially affected N, P, K, Ca, and Mg concentrations, as well as pH and EC in chilhuacle peppers. (author)

Effect of thymol and carvacrol on nutrient digestibility in rams fed high or low concentrate diets.

Science.gov (United States)

Zamiri, M J; Azizabadi, E; Momeni, Z; Rezvani, M R; Atashi, H; Akhlaghi, A

2015-01-01

Published data on the effects of essential oils (EO) on in vivo nutrient digestibility in sheep are contradictory. In 2 experiments, the effect of thymol and carvacrol on nutrient digestibility was studied in sheep fed with high (70%) or low (52%) concentrate diets, using incomplete Latin Square designs. The essential oils were mixed with the concentrate portion of the diet at the rate of 0.0, 0.3, or 0.6 g per kg dry matter (DM) diet. Supplementation of thymol had no significant effect on digestibility of dry matter (DM), organic matter (OM), crude protein (CP) and acid detergent fiber (ADF). The main effect of thymol on neutral detergent fiber (NDF) and ether extract (EE) digestibility and on nitrogen balance (NB) was significant (Pdigestibility. The main effect of carvacrol on ruminal ammonia levels and NB was significant, but within each level of dietary concentrate no significant differences were observed in ammonia levels and NB. Inclusion of 0.3 g/kg diet DM of carvacrol or thyme was more effective than 0.6 g/kg diet DM in terms of NB but neither dose affected nutrient digestibility. Future research should determine the long-term effects of essential oils on digestibility and performance in sheep, before recommendation can be made for their use under practical husbandry conditions.

Nutrient Mass Balance for the Mobile River Basin in Alabama, Georgia, and Mississippi

Science.gov (United States)

Harned, D. A.; Harvill, J. S.; McMahon, G.

2001-12-01

percent mean). The basins retained from 60 to 87 percent (74 percent mean) of phosphorous inputs. Correlation of basin nutrient output loads and concentrations with the basin inputs and correlation of output loads and concentrations with basin land use were tested using the Spearman rank test. The correlation analysis indicated that higher nitrogen concentrations in the streams are associated with urban areas and higher loads are associated with agriculture; high phosphorus output loads and concentrations are associated with agriculture. Higher nutrient loads in agricultural basins are partly an effect of basin size-- larger basins generate larger nutrient loads. Nutrient loads and concentrations showed no significant correlation to point-source inputs. Nitrogen loads were significantly (p0.5) higher in basins with greater cropland areas. Nitrogen concentrations also increased as residential, commercial, and total urban areas increased. Phosphorus loads were positively correlated with animal-waste inputs, pasture, and total agricultural land. Phosphorus concentrations were highest in basins with the greatest amounts of row-crop agriculture.

Long-Term Trends in Nutrient Concentrations and Fluxes in Streams Draining to Lake Tahoe, California

Science.gov (United States)

Domagalski, J. L.

2017-12-01

Lake Tahoe, situated in the rain shadow of the eastern Sierra Nevada at an elevation of 1,897 meters, has numerous small to medium sized tributaries that are sources of nutrients and fine sediment. The Tahoe watershed is relatively small and the surface area of the lake occupies about 38% of the total watershed area (1,313 km2). Each stream contributing water to the lake therefore also occupies a small watershed, mostly forested, with typical trees being Jeffrey, Ponderosa, or Sugar Pine and White Fir. Outflow from the lake contributes to downstream uses such as water supply and ecological resources. Only about 6% of the watershed is urbanized or residential land, and wastewater is exported to adjacent basins and not discharged to the lake as part of a plan to maintain water clarity. The lake's exceptional clarity has been diminishing due to phytoplankton and fine sediment, prompting development of management plans to improve water quality. Much of the annual discharge and flux of nutrients to the lake results from snowmelt in the spring and summer months, and climatic changes have begun to shift this melt to earlier time frames. Winter rains on urbanized land also contribute to nutrient loads. To understand the relative importance of land use, climate, and other factors affecting stream concentrations and fluxes, a Weighted Regression on Time Discharge and Season (WRTDS) model documented trends over a time frame of greater than 25 years. Ten streams have records of discharge, nutrient (NO3, NH3, OP, TP, TKN) and sediment data to complete this analysis. Both urbanized and non-urbanized locations generally show NO3 trending down in the 1980s. Some locations show initially decreasing orthophosphate trends, followed by small significant increases in concentration and fluxes starting around 2000 to 2005. Although no wastewater enters the streams, ammonia concentrations mimic those of orthophosphate, with initially negative trends in concentration and flux followed by

Effects of mountain tea plantations on nutrient cycling at upstream watersheds

Science.gov (United States)

Lin, T.-C.; Shaner, P.-J. L.; Wang, L.-J.; Shih, Y.-T.; Wang, C.-P.; Huang, G.-H.; Huang, J.-C.

2015-11-01

The expansion of agriculture to rugged mountains can exacerbate negative impacts of agricultural activities on ecosystem function. In this study, we monitored streamwater and rainfall chemistry of mountain watersheds at the Feitsui Reservoir Watershed in northern Taiwan to examine the effects of agriculture on watershed nutrient cycling. We found that the greater the proportion of tea plantation cover, the higher the concentrations of fertilizer-associated ions (NO3-, K+) in streamwater of the four mountain watersheds examined; on the other hand, the concentrations of the ions that are rich in soils (SO42-, Ca2+, Mg2+) did not increase with the proportion of tea plantation cover, suggesting that agriculture enriched fertilizer-associated nutrients in streamwater. Of the two watersheds for which rainfall chemistry was available, the one with higher proportion of tea plantation cover had higher concentrations of ions in rainfall and retained less nitrogen in proportion to input compared to the more pristine watershed, suggesting that agriculture can influence atmospheric deposition of nutrients and a system's ability to retain nutrients. As expected, we found that a forested watershed downstream of agricultural activities can dilute the concentrations of NO3- in streamwater by more than 70 %, indicating that such a landscape configuration helps mitigate nutrient enrichment in aquatic systems even for watersheds with steep topography. We estimated that tea plantation at our study site contributed approximately 450 kg ha-1 yr-1 of NO3-N via streamwater, an order of magnitude greater than previously reported for agricultural lands around the globe, which can only be matched by areas under intense fertilizer use. Furthermore, we constructed watershed N fluxes to show that excessive leaching of N, and additional loss to the atmosphere via volatilization and denitrification can occur under intense fertilizer use. In summary, this study demonstrated the pervasive impacts of

Modeling the interaction of light intensity, nutrient concentration and uranium toxicity in Lemna minor

Energy Technology Data Exchange (ETDEWEB)

Zimmer, E.; Horemans, N.; Vandenhove, H. [Belgian Nuclear Research Centre SCK-CEN (Belgium); Cedergreen, N. [University of Copenhagen (Denmark); Jager, T. [Vrije Universiteit Amsterdam (Netherlands)

2014-07-01

focused on (heterotrophic) animals, where usually only one food source with constant composition is taken into account. Reproduction can in most cases be modeled simplistically as continuous production of offspring in the final developmental stage. A DEB model for a (photoautotrophic) plant should take into account both light and nutrients as energy input. Additionally, reproduction takes place differently than in animals (e.g., vegetative reproduction). Until now, no plant model based on DEB has been developed yet. We here present the first DEB model for a plant. It explicitly takes light as an input of energy into account, which enables us to study the interaction of light intensity and radionuclides. As study organism, we chose Lemna minor,because of its advantages of being a relatively simple higher plant. We discuss the interaction of light intensity, nutrient concentration and radionuclides using uranium toxicity as a case study. Document available in abstract form only. (authors)

Geographic variation in the relationships of temperature, salinity or sigma sub t versus plant nutrient concentrations in the world ocean. [silicic acid, nitrate, and phosphate concentration

Science.gov (United States)

Kamykowski, D.; Zentara, S. J.

1985-01-01

A NODC data set representing all regions of the world ocean was analyzed for temperature and sigma-t relationships with nitrate, phosphate or silicic acid. Six cubic regressions were for each ten degree square of latitude and longitude containing adequate data. World maps display the locations that allow the prediction of plant nutrient concentrations from temperature or sigma-t. Geographic coverage improves along the sequence: nitrate, phosphate, and silicic acid and is better for sigma-t than for temperature. Contour maps of the approximate temperature of sigma-t at which these nitrients are no longer measurable in a parcel of water are generated, based on a percentile analysis of the temperature or sigma-t at which less than a selected amount of plant nutrient occurs. Results are stored on magnetic tape in tabular form. The global potential to predict plant nutrient concentrations from remotely sensed temperature of sigma-t and to emphasize the latitudinally and longitudinally changing phytoplankton growth environment in present and past oceans is demonstrated.

Nutrients and heavy metal distribution in thermally treated pig manure

DEFF Research Database (Denmark)

Kuligowski, Ksawery; Poulsen, Tjalfe G.; Stoholm, Peder

2008-01-01

Ash from pig manure treated by combustion and thermal gasification was characterized and compared in terms of nutrient, i.e., potassium (K), phosphorus (P) and heavy metal, i.e., cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni) and zinc (Zn) contents. Total nutrient and metal concentrations...... that ash from gasified manure contained more water-extractable K in comparison with combusted manure whereas the opposite was the case with respect to P. Heavy metals Ni, Cr and Cd were present in higher concentrations in the fine particle size fractions (

Effects of Dietary Zinc Pectin Oligosaccharides Chelate Supplementation on Growth Performance, Nutrient Digestibility and Tissue Zinc Concentrations of Broilers.

Science.gov (United States)

Wang, Zhongcheng; Yu, Huimin; Wu, Xuezhuang; Zhang, Tietao; Cui, Hu; Wan, Chunmeng; Gao, Xiuhua

2016-10-01

The experiment was conducted to investigate the effects of zinc pectin oligosaccharides (Zn-POS) chelate on growth performance, nutrient digestibility, and tissue zinc concentrations of Arbor Acre broilers aged from 1 to 42 days. A total of 576 1-day-old broilers were randomly assigned into 4 groups with 9 replicates per group and 16 chicks per replicate. Chicks were fed either a basal diet (control) or basal diet supplemented with Zn-POS at 300 (Zn-POS-300), 600 (Zn-POS-600), or 900 mg/kg (Zn-POS-900), respectively, for 42 days. A 3-day metabolism trial was conducted during the last week of the experiment feeding. The average daily gain and the average daily feed intake of Zn-POS-600 were significantly higher (P digestibility of dry matter, crude protein, and metabolic energy among all groups. The control group had the lowest apparent digestibility of dry matter (P digestibility of dry matter in Zn-POS-600 was higher (P digestibility of crude protein in Zn-POS-600 or Zn-POS-900 was higher (P digestibility of metabolic energy in Zn-POS-600 or Zn-POS-900 was higher (P < 0.05) than that of Zn-POS-300. Zn-POS-600 had the highest liver zinc concentrations (P < 0.05), while Zn-POS-900 had the highest pancreatic zinc concentrations (P < 0.05). Our data suggest that the supplementation of 600 mg/kg Zn-POS is optimal in improving the average daily gain and the average daily feed intake, utilization of dietary dry matter and crude protein, and increasing tissue zinc concentrations in liver and pancreas of broilers.

The MANAGE database: nutrient load and site characteristic updates and runoff concentration data.

Science.gov (United States)

Harmel, Daren; Qian, Song; Reckhow, Ken; Casebolt, Pamela

2008-01-01

The "Measured Annual Nutrient loads from AGricultural Environments" (MANAGE) database was developed to be a readily accessible, easily queried database of site characteristic and field-scale nutrient export data. The original version of MANAGE, which drew heavily from an early 1980s compilation of nutrient export data, created an electronic database with nutrient load data and corresponding site characteristics from 40 studies on agricultural (cultivated and pasture/range) land uses. In the current update, N and P load data from 15 additional studies of agricultural runoff were included along with N and P concentration data for all 55 studies. The database now contains 1677 watershed years of data for various agricultural land uses (703 for pasture/rangeland; 333 for corn; 291 for various crop rotations; 177 for wheat/oats; and 4-33 yr for barley, citrus, vegetables, sorghum, soybeans, cotton, fallow, and peanuts). Across all land uses, annual runoff loads averaged 14.2 kg ha(-1) for total N and 2.2 kg ha(-1) for total P. On average, these losses represented 10 to 25% of applied fertilizer N and 4 to 9% of applied fertilizer P. Although such statistics produce interesting generalities across a wide range of land use, management, and climatic conditions, regional crop-specific analyses should be conducted to guide regulatory and programmatic decisions. With this update, MANAGE contains data from a vast majority of published peer-reviewed N and P export studies on homogeneous agricultural land uses in the USA under natural rainfall-runoff conditions and thus provides necessary data for modeling and decision-making related to agricultural runoff. The current version can be downloaded at http://www.ars.usda.gov/spa/manage-nutrient.

Impact of the river Liffey discharge on nutrient and chlorophyll concentrations in the Liffey estuary and Dublin Bay (Irish Sea)

Science.gov (United States)

O'Higgins, T. G.; Wilson, J. G.

2005-08-01

Temperature, salinity, nutrients (total oxidised nitrogen (TON), ammonium (NH 4) and orthophosphate (PO 4)) and chlorophyll a were monitored in the Liffey estuary and Dublin Bay from June 2000 to June 2003. Four groups of sites were defined comprising the upper estuary (Gp. I), the outer estuary (Gp. III) with a small set (Gp. II) of sites between Groups I and III heavily influenced by the sewage treatment works outflow, and the Bay proper (Gp. IV). Riverine inputs of TON and PO 4 were calculated at an average of 826 t N y -1 and 31 t P y -1, respectively, and were largely controlled by flow rate. The sewage treatment works were identified as a major source of PO 4 and NH 4 to the system. Mixing in the upper estuary of nutrient limited saline waters with hypernutrified river water regularly (i.e. annually) produced relatively high concentrations of chlorophyll a (>10 mg chl a m -3), and also sporadic blooms with extremely high chlorophyll a values (max. 121.6 mg chl a m -3). These latter phytoplankton blooms occurred in high salinity waters and were due to mixing of nutrient limited saline waters and nutrient rich river waters. The mean annual flux of phytoplankton carbon from the river Liffey was calculated at 23.5 t C y -1, of which half was accumulated or remineralised in the estuary and did not enter the Bay. In the Bay proper (Gp. IV) summer nutrient concentrations dropped below detection limits, and chlorophyll a concentrations followed the classic pattern with a spring bloom maximum of 5.5 mg chl a m -3. This pattern in nutrients and chlorophyll a came from the advection of waters into the Bay from an offshore source. Overall while there was considerable evidence for eutrophication in the estuary, the bay itself showed little biological response to nutrient loading.

Nutrient supply of plants in aquaponic systems

OpenAIRE

Bittsánszky, András; Uzinger, Nikolett; Gyulai, Gábor; Mathis, Alex; Junge, Ranka; Villarroel, Morris; Kotzen, Benzion; Komives, Tamas

2016-01-01

In this preliminary article we present data on plant nutrient concentrations in aquaponic systems, and compare them to nutrient concentrations in “standard” hydroponic solutions. Our data shows that the nutrient concentrations supplied by the fish in aquaponic system are significantly lower for most nutrients, compared to hydroponic systems. Nevertheless, plants do thrive in solutions that have lower nutrient levels than “standard” hydroponic solutions. This is especially true for green leafy...

Absorption and nutrient concentration in apple (Pyrus mains L.)

OpenAIRE

Trani, P.E.; Haag, H.P.; Sarruge, J.R.; Dechen, A.R.; Catani, CB

1981-01-01

In order to obtain the following informations: a) dry matter production and extraction of nutrients by the fruits at different ages; b) dry matter production and extraction of nutrient by the leaves and "trunk + branches" collected at the flowering stage; c) dry matter production and export of nutrients by pruning (leaves and branches) at the begining dormant stage; A trial was conducted on Latossolo Vermelho Escuro Orto group (Orthox) at Buri, São Paulo State, Brazil. The material was collec...

Quantifying Nutrient and Mercury Concentrations and Loads in Lake Tahoe Snowpack

Science.gov (United States)

Pearson, C.; Obrist, D.; Schumer, R.

2012-12-01

Recent climate models predict a large decrease in Sierra Nevada snowpack over the next fifty years as a result of climate change. This decrease will not only affect the hydrologic balance but also change inputs of nutrients and pollutants through atmospheric deposition. In the Lake Tahoe basin, winter precipitation dominates and snowfall provides approximately 70 percent of the annual water input. From the first snowfall until the end of melting, snowpack acts as a temporary storage for atmospheric deposition that accumulates throughout winter and spring. Through melt and runoff processes, these nutrients and pollutants can enter the aquatic ecosystem where they can have detrimental effects on lake clarity and health. Most previous studies in this basin have focused on direct atmospheric deposition loads to the lake surface, and little temporal and spatial information is available on the dynamics of atmospheric deposition in the basin's snowpack. We here present nitrogen (N), phosphorus (P), and mercury (Hg) concentrations and pool sizes in snowpack along two elevational transects in the Tahoe Basin from January to April of 2012. Total N and P concentrations in the snowpack ranged from 0.07 mg/L to 0.38 mg/L and 0.003 mg/L to 0.109 mg/L, respectively. P concentrations showed strong increases from the west-side to the east-side of the basin which we attribute to local (e.g., urban or road-dust), in-basin sources that are distributed along the dominant west-wind patterns. N species, on the other hand, generally showed little spatial trends, indicating that its sources were more diffuse and possibly from out-of- basin. Hg concentrations ranged from 0.81 ppt to 6.25 ppt and showed similar spatial patterns as N. Hg, however, also showed significant snowpack concentration decreases during storm-free periods which we attribute to gaseous losses of Hg back to the atmosphere from photochemical reduction. These emissions are further supported by lower Hg concentrations in

A multivariate analysis of serum nutrient levels and lung function

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Smit Henriette A

2008-09-01

Full Text Available Abstract Background There is mounting evidence that estimates of intakes of a range of dietary nutrients are related to both lung function level and rate of decline, but far less evidence on the relation between lung function and objective measures of serum levels of individual nutrients. The aim of this study was to conduct a comprehensive examination of the independent associations of a wide range of serum markers of nutritional status with lung function, measured as the one-second forced expiratory volume (FEV1. Methods Using data from the Third National Health and Nutrition Examination Survey, a US population-based cross-sectional study, we investigated the relation between 21 serum markers of potentially relevant nutrients and FEV1, with adjustment for potential confounding factors. Systematic approaches were used to guide the analysis. Results In a mutually adjusted model, higher serum levels of antioxidant vitamins (vitamin A, beta-cryptoxanthin, vitamin C, vitamin E, selenium, normalized calcium, chloride, and iron were independently associated with higher levels of FEV1. Higher concentrations of potassium and sodium were associated with lower FEV1. Conclusion Maintaining higher serum concentrations of dietary antioxidant vitamins and selenium is potentially beneficial to lung health. In addition other novel associations found in this study merit further investigation.

Spatial and temporal shifts in gross primary productivity, respiration, and nutrient concentrations in urban streams impacted by wastewater treatment plant effluent

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Ledford, S. H.; Toran, L.

2017-12-01

Impacts of wastewater treatment plant effluent on nutrient retention and stream productivity are highly varied. The working theory has been that large pulses of nutrients from plants may hinder in-stream nutrient retention. We evaluated nitrate, total dissolved phosphorus, and dissolved oxygen in Wissahickon Creek, an urban third-order stream in Montgomery and Philadelphia counties, PA, that receives effluent from four wastewater treatment plants. Wastewater treatment plant effluent had nitrate concentrations of 15-30 mg N/L and total dissolved phosphorus of 0.3 to 1.8 mg/L. Seasonal longitudinal water quality samples showed nitrate concentrations were highest in the fall, peaking at 22 mg N/L, due to low baseflow, but total dissolved phosphorous concentrations were highest in the spring, reaching 0.6 mg/L. Diurnal dissolved oxygen patterns above and below one of the treatment plants provided estimates of gross primary productivity (GPP) and ecosystem respiration (ER). A site 1 km below effluent discharge had higher GPP in April (80 g O2 m-2 d-1) than the site above the plant (28 g O2 m-2 d-1). The pulse in productivity did not continue downstream, as the site 3 km below the plant had GPP of only 12 g O2 m-2 d-1. Productivity fell in June to 1-2 g O2 m-2 d-1 and the differences in productivity above and below plants were minimal. Ecosystem respiration followed a similar pattern in April, increasing from -17 g O2 m-2 d-1 above the plant to -47 g O2 m-2 d-1 1 km below the plant, then decreasing to -8 g O2 m-2 d-1 3 km below the plant. Respiration dropped to -3 g O2 m-2 d-1 above the plant in June but only fell to -9 to -10 g O2 m-2 d-1 at the two downstream sites. These findings indicate that large nutrient pulses from wastewater treatment plants spur productivity and respiration, but that these increases may be strongly seasonally dependent. Examining in-stream productivity and respiration is critical in wastewater impacted streams to understanding the seasonal and

Nutrient cycling strategies.

NARCIS (Netherlands)

Breemen, van N.

1995-01-01

This paper briefly reviews pathways by which plants can influence the nutrient cycle, and thereby the nutrient supply of themselves and of their competitors. Higher or lower internal nutrient use efficiency positively feeds back into the nutrient cycle, and helps to increase or decrease soil

Assessment of nutrient retention by Natete wetland Kampala, Uganda

Science.gov (United States)

Kanyiginya, V.; Kansiime, F.; Kimwaga, R.; Mashauri, D. A.

Natete wetland which is located in a suburb of Kampala city in Uganda is dominated by C yperus papyrus and covers an area of approximately 1 km 2. The wetland receives wastewater and runoff from Natete town which do not have a wastewater treatment facility. The main objective of this study was to assess nutrient retention of Natete wetland and specifically to: determine the wastewater flow patterns in the wetland; estimate the nutrient loads into and out of the wetland; determine the nutrient retention by soil, plants and water column in the wetland; and assess the above and belowground biomass density of the dominant vegetation. Soil, water and plant samples were taken at 50 m intervals along two transects cut through the wetland; soil and water samples were taken at 10 cm just below the surface. Physico-chemical parameters namely pH, electrical conductivity and temperature were measured in situ. Water samples were analyzed in the laboratory for ammonium-nitrogen, nitrate-nitrogen, total nitrogen, orthophosphate and total phosphorus. Electrical conductivity ranged between 113 μS/cm and 530 μS/cm and the wastewater flow was concentrated on the eastern side of the wetland. pH varied between 6 and 7, temperature ranged from 19 °C to 24 °C. NH 4-N, NO 3-N, and TN concentrations were retained by 21%, 98%, and 35% respectively. Phosphorus concentration was higher at the outlet of the wetland possibly due to release from sediments and leaching. Nutrient loads were higher at the inlet (12,614 ± 394 kgN/day and 778 ± 159 kgP/day) than the outlet (2368 ± 425 kgN/day and 216 ± 56 kgP/day) indicating retention by the wetland. Plants stored most nutrients compared to soil and water. The belowground biomass of papyrus vegetation in the wetland was higher (1288.4 ± 8.3 gDW/m 2) than the aboveground biomass (1019.7 ± 13.8 gDW/m 2). Plant uptake is one of the important routes of nutrient retention in Natete wetland. It is recommended that harvesting papyrus can be an

Source Material and Concentration of Wildfire-Produced Pyrogenic Carbon Influence Post-Fire Soil Nutrient Dynamics

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Lucas A. Michelotti

2015-04-01

Full Text Available Pyrogenic carbon (PyC is produced by the thermal decomposition of organic matter in the absence of oxygen (O. PyC affects nutrient availability, may enhance post-fire nitrogen (N mineralization rates, and can be a significant carbon (C pool in fire-prone ecosystems. Our objectives were to characterize PyC produced by wildfires and examine the influence that contrasting types of PyC have on C and N mineralization rates. We determined C, N, O, and hydrogen (H concentrations and atomic ratios of charred bark (BK, charred pine cones (PC, and charred woody debris (WD using elemental analysis. We also incubated soil amended with BK, PC, and WD at two concentrations for 60 days to measure C and N mineralization rates. PC had greater H/C and O/C ratios than BK and WD, suggesting that PC may have a lesser aromatic component than BK and WD. C and N mineralization rates decreased with increasing PyC concentrations, and control samples produced more CO2 than soils amended with PyC. Soils with PC produced greater CO2 and had lower N mineralization rates than soils with BK or WD. These results demonstrate that PyC type and concentration have potential to impact nutrient dynamics and C flux to the atmosphere in post-fire forest soils.

Yogurt consumption is associated with higher nutrient intake, diet quality and favourable metabolic profile in children: a cross-sectional analysis using data from years 1-4 of the National diet and Nutrition Survey, UK.

Science.gov (United States)

Hobbs, D A; Givens, D I; Lovegrove, J A

2018-01-12

Yogurt consumption has been associated with higher nutrient intakes, better diet quality and improved metabolic profiles in adults. Few studies have investigated these associations in children. This study investigated the association of yogurt consumption with nutrient intakes, diet quality and metabolic profile in British children. Data from  1687 children aged 4-10 and 11-18 years of the National Diet and Nutrition Survey (NDNS) years 1-4 were analysed. Yogurt consumption was determined using a 4-day diet diary. Diet quality was assessed by the Healthy Eating Index 2010 (HEI-2010). Anthropometric measures, blood pressure, pulse pressure, plasma glucose, HbA1c, C-reactive protein, triacylglycerol, total cholesterol, high-and low-density cholesterol from NDNS were used. The highest tertile of yogurt consumption (T3) was associated with higher nutrient intakes, particularly for calcium (children 4-10 years: P consumption was associated with significantly lower pulse pressure in children aged 4-10 years and lower HbA1c concentration, being shorter and having a larger hip circumference in children aged 11-18 years, compared with non-yogurt consumers. This study suggests that British children who are yogurt consumers (> 60 g/day) have higher overall diet quality, nutrient intakes and adequacy, lower pulse pressure (children aged 4-10 years) and HbA1c concentrations (children aged 11-18 years), were shorter and had a smaller hip circumference (children aged 11-18 years).

Nutrient supply of plants in aquaponic systems

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Andras Bittsanszky

2016-10-01

Full Text Available In this preliminary article we present data on plant nutrient concentrations in aquaponics systems, and we compare them to nutrient concentrations in “standard” hydroponic solutions. Our data shows that the nutrient concentrations supplied by the fish in the aquaponics system are significantly lower for most nutrients compared to hydroponic systems. Nevertheless, plants do thrive in solutions that have lower nutrient levels compared to “standard” hydroponic solutions. This is especially true for green leafy vegetables that rarely need additional nutritional supplementation. It is concluded that in the highly complex system of aquaponics, special care has to be taken, via continuous monitoring of the chemical composition of the circulating water, to provide adequate concentrations and ratios of nutrients, and especially for the potentially toxic component, ammonium. If certain plants require nutrient supplementation, we consider that one based on organic substances would be most beneficial. However, protocols for the application of such nutrient amendments still need to be developed.

Effect of CO2 Enrichment on the Growth and Nutrient Uptake of Tomato Seedlings

Institute of Scientific and Technical Information of China (English)

LI Juan; ZHOU Jian-Min; DUAN Zeng-Qiang; DU Chang-Wen; WANG Huo-Yan

2007-01-01

Exposing tomato seedlings to elevated CO2 concentrations may have potentially profound impacts on the tomato yield and quality. A growth chamber experiment was designed to estimate how different nutrient concentrations influenced the effect of elevated CO2 on the growth and nutrient uptake of tomato seedlings. Tomato (Hezuo 906) was grown in pots placed in controlled growth chambers and was subjected to ambient or elevated CO2 (360 or 720 μL L-1), and four nutrient solutions of different strengths (1/2-, 1/4-, 1/8-, and 1/16-strength Japan Yamazaki nutrient solutions) in a completely randomized design. The results indicated that some agricultural characteristics of the tomato seedlings such as the plant height, stem thickness, total dry and fresh weights of the leaves, stems and roots, the G value (G value = total plant dry weight/seedling age),and the seedling vigor index (seedling vigor index = stem thickness/(plant height × total plant dry weight) increased with the elevated CO2, and the increases were strongly dependent on the nutrient solution concentrations, being greater with higher nutrient solution concentrations. The elevated CO2 did not alter the ratio of root to shoot. The total N, P, K, and C absorbed from all the solutions except P in the 1/8- and 1/16-strength nutrient solutions increased in the elevated CO2 treatment. These results demonstrate that the nutrient demands of the tomato seedlings increased at elevated CO2 concentrations.

An Integrated Multimodal Sensor for the On-site Monitoring of the Water Content and Nutrient Concentration of Soil by Measuring the Phase and Electrical Conductivity

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Masato FUTAGAWA

2012-03-01

Full Text Available We have fabricated a new multimodal sensor chip which is capable of simultaneous on-site measurements of the water content and nutrient concentration. Until now, in agriculture, water content sensors, such as TDR sensors, have been unable to provide accurate measurements, since these sensors are affected by the nutrient concentration in the soil solution. Therefore, tensiometers have generally been used. However, these are large-scale sensors and are not suitable for the precise measurements required in agriculture. Our proposed sensors are the world’s first to enable independent measurements of the water content and nutrient concentration.

Early root overproduction not triggered by nutrients decisive for competitive success belowground.

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Francisco M Padilla

Full Text Available Theory predicts that plant species win competition for a shared resource by more quickly preempting the resource in hotspots and by depleting resource levels to lower concentrations than its competitors. Competition in natural grasslands largely occurs belowground, but information regarding root interactions is limited, as molecular methods quantifying species abundance belowground have only recently become available.In monoculture, the grass Festuca rubra had higher root densities and a faster rate of soil nitrate depletion than Plantago lanceolata, projecting the first as a better competitor for nutrients. However, Festuca lost in competition with Plantago. Plantago not only replaced the lower root mass of its competitor, but strongly overproduced roots: with only half of the plants in mixture than in monoculture, Plantago root densities in mixture were similar or higher than those in its monocultures. These responses occurred equally in a nutrient-rich and nutrient-poor soil layer, and commenced immediately at the start of the experiment when root densities were still low and soil nutrient concentrations high.Our results suggest that species may achieve competitive superiority for nutrients by root growth stimulation prior to nutrient depletion, induced by the presence of a competitor species, rather than by a better ability to compete for nutrients per se. The root overproduction by which interspecific neighbors are suppressed independent of nutrient acquisition is consistent with predictions from game theory. Our results emphasize that root competition may be driven by other mechanisms than is currently assumed. The long-term consequences of these mechanisms for community dynamics are discussed.

Concentrations and loads of nutrients in the tributaries of the Lake Okeechobee watershed, south-central Florida, water years 2004-2008

Science.gov (United States)

Byrne, Michael J.; Wood, Molly S.

2011-01-01

Lake Okeechobee in south-central Florida is the second largest freshwater lake in the contiguous United States. Excessive phosphorus loading, harmful high and low water levels, and rapid expansion of non-native vegetation have threatened the health of the lake in recent decades. A study was conducted to monitor discharge and nutrient concentrations from selected tributaries into Lake Okeechobee and to evaluate nutrient loads. The data analysis was performed at 16 monitoring stations from December 2003 to September 2008. Annual and seasonal discharge measured at monitoring stations is affected by rainfall. Hurricanes affected three wet years (2004, 2005, and the latter part of 2008) and resulted in substantially greater discharge than the drought years of 2006, 2007, and the early part of 2008. Rainfall supplies about 50 percent of the water to Lake Okeechobee, discharge from the Kissimmee River supplies about 25 percent, and discharge from tributaries and groundwater seepage along the lake perimeter collectively provide the remaining 25 percent. Annually, tributary discharge from basins located on the west side of the Kissimmee River is about 5 to 6 times greater than that from basins located on the east side. For the purposes of this study, the basins on the east side of the Kissimmee River are called "priority basins" because of elevated phosphorus concentrations, while those on the west side are called "nonpriority" basins. Total annual discharge in the non-priority basins ranged from 245,000 acre-feet (acre-ft) in 2007 to 1,322,000 acre-ft in 2005, while annual discharge from the priority basins ranged from 41,000 acre-ft in 2007 to 219,000 acre-ft in 2005. Mean total phosphorus concentrations ranged from 0.10 to 0.54 milligrams per liter (mg/L) at the 16 tributaries during 2004–2008. Mean concentrations were significantly higher at priority basin sites than at non-priority basin sites, particularly at Arbuckle Creek and C 41A Canal. Concentrations of organic

Synergistic effects and optimization of nitrogen and phosphorus concentrations on the growth and nutrient uptake of a freshwater Chlorella vulgaris.

Science.gov (United States)

Alketife, Ahmed M; Judd, Simon; Znad, Hussein

2017-01-01

The synergistic effects and optimization of nitrogen (N) and phosphorus (P) concentrations on the growth of Chlorella vulgaris (CCAP 211/11B, CS-42) and nutrient removal have been investigated under different concentrations of N (0-56 mg/L) and P (0-19 mg/L). The study showed that N/P ratio has a crucial effect on the biomass growth and nutrient removal. When N/P=10, a complete P and N removal was achieved at the end of cultivation with specific growth rate (SGR) of 1 d -1 and biomass concentration of 1.58 g/L. It was also observed that when the N content <2.5 mg/L, the SGR significantly reduced from 1.04 to 0.23 d -1 and the maximum biomass produced was decreased more than three-fold to 0.5 g/L. The Box-Behnken experimental design and response surface method were used to study the effects of the initial concentrations (P, N and C) on P and N removal efficiencies. The optimized P, N and C concentrations supporting 100% removal of both P and N at an SGR of 0.95 were 7, 55 and 10 mg/L respectively, with desirability value of 0.94. The results and analysis obtained could be very useful when applying the microalgae for efficient wastewater treatment and nutrient removal.

Proposal for a method to estimate nutrient shock effects in bacteria

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Azevedo Nuno F

2012-08-01

Full Text Available Abstract Background Plating methods are still the golden standard in microbiology; however, some studies have shown that these techniques can underestimate the microbial concentrations and diversity. A nutrient shock is one of the mechanisms proposed to explain this phenomenon. In this study, a tentative method to assess nutrient shock effects was tested. Findings To estimate the extent of nutrient shock effects, two strains isolated from tap water (Sphingomonas capsulata and Methylobacterium sp. and two culture collection strains (E. coli CECT 434 and Pseudomonas fluorescens ATCC 13525 were exposed both to low and high nutrient conditions for different times and then placed in low nutrient medium (R2A and rich nutrient medium (TSA. The average improvement (A.I. of recovery between R2A and TSA for the different times was calculated to more simply assess the difference obtained in culturability between each medium. As expected, A.I. was higher when cells were plated after the exposition to water than when they were recovered from high-nutrient medium showing the existence of a nutrient shock for the diverse bacteria used. S. capsulata was the species most affected by this phenomenon. Conclusions This work provides a method to consistently determine the extent of nutrient shock effects on different microorganisms and hence quantify the ability of each species to deal with sudden increases in substrate concentration.

Linking nutrient enrichment, sediment erodibility and biofilms

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Conrad, B.; Mahon, R.; Sojka, S. L.

2014-12-01

Sediment movement in coastal lagoons affects nutrient flux and primary producer growth. Previous research has shown that sediment erodibility is affected by biofilm concentration and that growth of benthic organisms, which produce biofilm, is affected by nutrient enrichment. However, researchers have not examined possible links between nutrient addition and sediment erodibility. We manipulated nutrient levels in the water column of 16 microcosms filled with homogenized sediment from a shallow coastal lagoon and artificial seawater to determine the effects on biofilm growth, measured through chlorophyll a and colloidal carbohydrate concentrations. Erosion tests using a Gust microcosm were conducted to determine the relationship between sediment erodibility and biofilm concentration. Results show that carbohydrate levels decreased with increasing nutrient enrichment and were unrelated to chlorophyll concentrations and erodibility. The nutrient levels did not predictably affect the chlorophyll levels, with lower chlorophyll concentrations in the control and medium enrichment treatments than the low and high enrichment treatments. Controls on biofilm growth are still unclear and the assumed relationship between carbohydrates and erodibility may be invalid. Understanding how biofilms respond to nutrient enrichment and subsequent effects on sediment erodibility is essential for protecting and restoring shallow coastal systems.

EPA's Review of Concentrated Animal Feeding Operation (CAFO) Permits and Nutrient Management Plans in the Chesapeake Bay Watershed

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Starting in 2013, EPA conducted reviews of Concentrated Animal Feeding Operations (CAFOs) permits and nutrient management plans (NMPs) in six of the Bay jurisdictions (Delaware, Maryland, New York, Pennsylvania, Virginia and West Virginia).

Nutrient budgets for large Chinese estuaries

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S. M. Liu

2009-10-01

Full Text Available Chinese rivers deliver about 5–10% of global freshwater input and 15–20% of the global continental sediment to the world ocean. We report the riverine fluxes and concentrations of major nutrients (nitrogen, phosphorus, and silicon in the rivers of the contiguous landmass of China and Korea in the northeast Asia. The rivers are generally enriched with dissolved inorganic nitrogen (DIN and depleted in dissolved inorganic phosphate (PO₄³⁻ with very high DIN: PO₄³⁻ concentration ratios. DIN, phosphorus, and silicon levels and loads in rivers are mainly affected by agriculture activities and urbanization, anthropogenic activities and adsorption on particulates, and rock types, climate and physical denudation intensity, respectively. Nutrient transports by rivers in the summer are 3–4 times higher than those in the winter with the exception of NH₄⁺. The flux of NH₄⁺ is rather constant throughout the year due to the anthropogenic sources such as the sewer discharge. As nutrient composition has changed in the rivers, ecosystems in estuaries and coastal sea have also changed in recent decades. Among the changes, a shift of limiting nutrients from phosphorus to nitrogen for phytoplankton production with urbanization is noticeable and in some areas silicon becomes the limiting nutrient for diatom productivity. A simple steady-state mass-balance box model was employed to assess nutrient budgets in the estuaries. The major Chinese estuaries export <15% of nitrogen, <6% of phosphorus required for phytoplankton production and ~4% of silicon required for diatom growth in the Chinese Seas (Bohai, Yellow Sea, East China Sea, South China Sea. This suggests that land-derived nutrients are largely confined to the immediate estuaries, and ecosystem in the coastal sea beyond the estuaries is mainly supported by other nutrient sources such as regeneration, open ocean and

Doses de N e K no tomateiro sob estresse salino: I. Concentração de nutrientes no solo e na planta Doses of N and K in tomato under saline stress: I. Concentration of nutrients in the soil solution and plant

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Flávio F. Blanco

2008-02-01

Full Text Available Em geral, culturas tolerantes à salinidade geralmente apresentam maiores teores foliares de certos nutrientes, sugerindo que a adubação em culturas sensíveis poderia elevar os teores desses nutrientes nas folhas, aumentando sua tolerância aos sais. Este trabalho teve o objetivo de estudar os efeitos do N e do K na condutividade elétrica, pH e concentração de nutrientes da solução do solo e nos teores de nutrientes e prolina nas folhas do tomateiro irrigado com água salina. Os tratamentos foram compostos da combinação de três níveis de N (7,5; 15,0 e 22,5 g por planta e de K (8, 16 e 24 gK2O por planta aplicados via fertirrigação por gotejamento, no esquema fatorial 3 x 3, com cinco repetições, sendo que à água de irrigação foram adicionados os sais cloreto de sódio e cloreto de cálcio, para obtenção de condutividade elétrica da água de 9,5 dS m-1. As concentrações de NO3 e K na solução do solo e de N e K nas folhas do tomateiro aumentaram com as doses de N e K mas não promoveram redução dos teores de Cl nem de Na nas folhas das plantas. O aumento do teor de prolina com as doses de K e a redução de Cl/N com as doses de N, sugerem que o aumento na adubação potássica e nitrogenada pode ser benéfico para o tomateiro sob condições de salinidade moderada.Crops tolerant to salinity generally present higher concentrations of some nutrients in the leaves, suggesting that the fertilization of sensitive crops could increase the contents of these nutrients in the leaves to increase the crop tolerance to salts. This work had the objective of studying the effects of N and K on electrical conductivity, pH and nutrient concentrations of soil solution and on concentration of nutrients and proline in the leaves of tomatos irrigated with saline water. The treatments were composed of the combination of three levels of N (7.5, 15.0 and 22.5 g per plant and K (8, 16 and 24 g K2O per plant applied by drip fertigation, in a 3

A comparative study on nutrient cycling in wet heathland ecosystems : II. Litter decomposition and nutrient mineralization.

Science.gov (United States)

Berendse, Frank; Bobbink, Roland; Rouwenhorst, Gerrit

1989-03-01

The concept of the relative nutrient requirement (L n ) that was introduced in the first paper of this series is used to analyse the effects of the dominant plant population on nutrient cycling and nutrient mineralization in wet heathland ecosystems. A distinction is made between the effect that the dominant plant species has on (1) the distribution of nutrients over the plant biomass and the soil compartment of the ecosystem and (2) the recirculation rate of nutrients. The first effect of the dominant plant species can be calculated on the basis of the δ/k ratio (which is the ratio of the relative mortality to the decomposition constant). The second effect can be analysed using the relative nutrient requirement (L n ). The mass loss and the changes in the amounts of N and P in decomposing above-ground and below-ground litter produced by Erica tetralix and Molinia caerulea were measured over three years. The rates of mass loss from both above-ground and below-ground litter of Molinia were higher than those from Erica litter. After an initial leaching phase, litter showed either a net release or a net immobilization of nitrogen or phosphorus that depended on the initial concentrations of these nutrients. At the same sites, mineralization of nitrogen and phosphorus were measured for two years both in communities dominated by Molinia and in communities dominated by Erica. There were no clear differences in the nitrogen mineralization, but in one of the two years, phosphate mineralization in the Molinia-community was significantly higher. On the basis of the theory that was developed, mineralization rates and ratios between amounts of nutrients in plant biomass and in the soil were calculated on the basis of parameters that were independently measured. There was a reasonable agreement between predicted and measured values in the Erica-communities. In the Molinia-communities there were large differences between calculated and measured values, which was explained by the

Stormflow influence on nutrient dynamics in micro-catchments under contrasting land use in the Cerrado and Amazon Biomes, Brazil

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Edelmann, Katharina; Nóbrega, Rodolfo L. B.; Gerold, Gerhard

2017-04-01

The Amazon and Cerrado biomes in Brazil have been under intense land-use change during the past few decades. The conversion of native vegetation to pastures and croplands has caused impacts on hydrological processes in these biomes, resulting in increased streamflow and nutrient fluxes. Our aim was to compare the nutrient dynamics during stormflow events in two pairs of adjacent micro-catchments with similar physical characteristics under contrasting land use, i.e. native vegetation (rainforest or cerrado) and pasture. One pair of catchments was located in the Amazon and the other in the Cerrado, both on the Amazon Agricultural Frontier in the Brazilian states of Mato Grosso and Pará. We collected hydrological and hydrochemical data on 50 stormflow events on a sub-hourly resolution during the wet seasons of 2013 and 2014. We compared the dynamics of total inorganic carbon (TIC), total organic carbon (TOC), dissolved organic carbon (DOC), nitrate (NO3), calcium (Ca), potassium (K), and magnesium (Mg) in different hydrograph parts, i.e. rising limb, peak and recession limb, between the catchments within the same biome. For the Cerrado biome, our findings show that the nutrient concentrations in the stormflows were higher in the pasture catchment than in the cerrado catchment. In the Amazon biome, we found an inverse relationship with higher concentrations in the forest catchment than in the pasture catchment, except for TIC and K. Most nutrients in the cerrado catchment had the highest concentrations in the rising limb. Mg, however, reached highest concentrations during peak discharge, and lowest in the recession limb. In the adjacent pasture catchment, in contrast, the highest nutrient concentrations were observed during the peak discharge (TIC, TOC, Ca) or the recession limb (DOC, NO3, K, Mg) with lowest in the rising limb, except for NO3, which showed the lowest concentrations during peak discharge. In the Amazon forest catchment, the peak discharge showed the

Impact of organic carbon and nutrients mobilized during chemical oxidation on subsequent bioremediation of a diesel-contaminated soil.

Science.gov (United States)

Sutton, Nora B; Grotenhuis, Tim; Rijnaarts, Huub H M

2014-02-01

Remediation with in situ chemical oxidation (ISCO) impacts soil organic matter (SOM) and the microbial community, with deleterious effects on the latter being a major hurdle to coupling ISCO with in situ bioremediation (ISB). We investigate treatment of a diesel-contaminated soil with Fenton's reagent and modified Fenton's reagent coupled with a subsequent bioremediation phase of 187d, both with and without nutrient amendment. Chemical oxidation mobilized SOM into the liquid phase, producing dissolved organic carbon (DOC) concentrations 8-16 times higher than the untreated field sample. Higher aqueous concentrations of nitrogen and phosphorous species were also observed following oxidation; NH4(+) increased 14-172 times. During the bioremediation phase, dissolved carbon and nutrient species were utilized for microbial growth-yielding DOC concentrations similar to field sample levels within 56d of incubation. In the absence of nutrient amendment, the highest microbial respiration rates were correlated with higher availability of nitrogen and phosphorus species mobilized by oxidation. Significant diesel degradation was only observed following nutrient amendment, implying that nutrients mobilized by chemical oxidation can increase microbial activity but are insufficient for bioremediation. While all bioremediation occurred in the first 28d of incubation in the biotic control microcosm with nutrient amendment, biodegradation continued throughout 187d of incubation following chemical oxidation, suggesting that chemical treatment also affects the desorption of organic contaminants from SOM. Overall, results indicate that biodegradation of DOC, as an alternative substrate to diesel, and biological utilization of mobilized nutrients have implications for the success of coupled ISCO and ISB treatments. Copyright © 2013 Elsevier Ltd. All rights reserved.

Concentrations of base cations, phosphorous and nitrogen in tree stumps in Sweden, Finland and Denmark; Halter av baskatjoner, fosfor och kvaeve i stubbar i Sverige, Finland och Danmark

Energy Technology Data Exchange (ETDEWEB)

Hellsten, Sofie; Waengberg, Ingvar (The Swedish Environmental Research Institute Ltd., Stockholm (Sweden)); Helmisaari, Heljae-Sisko; Kaakinen, Seija; Kukkola, Mikko; Saarsalmi, Anna (Metla, Vantaa (Finland)); Melin, Ylva; Petersson, Hans (Swedish Univ. of Agriculture, Umeaa (Sweden)); Skovsgaard, Jens Peter (Forest and Landscape Denmark, Univ. of Copenhagen, Hoersholm (Denmark)); Akselsson, Cecilia (Lunds Univ., Lund (Sweden))

2009-05-15

Stump removal is becoming increasingly important in as demand for renewable energy is increasing. Nutrient concentrations in stumps are applied when evaluating the environmental effect of stump removal on acidification and nutrient balances in forest soil. The objectives of this study was to evaluate concentrations of nutrients in stumps in Sweden, Finland and Denmark, and to evaluate how nutrient concentrations vary with site characteristics, stand age and deposition level. Concentrations of N, P, Ca, K, Mg and Na in spruce, pine and birch stumps were assessed in eight sites across Scandinavia. The results of this study indicate that the concentration of nutrients are higher in birch stumps compared with spruce and pine. In Sweden and Finland, the nutrient concentrations were generally higher in the southern sites compared with northern sites in the country, except for P. Nutrient concentrations were significantly higher in the bark of the stump and the roots compared to the wood for all nutrients. Furthermore nutrients concentration increased significantly with decreasing root diameter. In Jaedraaas, Sweden, nutrient concentration of N, K, Mg and P in pine decreased with age of the stump harvested tree, for stumps < 65 years. This relation was not evident for other age spans or sites. Further studies are needed to provide a broader picture of how the nutrient concentrations vary with site characteristics, stand age and forestry management to get a better foundation when setting up recommendations for stump removal

Tomato root growth and phosphorus absorption kinetics by tomato plants as affected by phosphorus concentration in nutrient solution

International Nuclear Information System (INIS)

Fontes, P.C.R.; Barber, S.A.

1984-01-01

To evaluate the effects P concentrations in nutrient solution on root growth and on root physiological characteristics involved in P uptake by tomato Lycopersicon esculentum Mill plants, six seedlings were grown in nutrient solution at initial concentrations of 48.5, 97, 194 and 388 μMP until one day before harvest. They were then transferred to solutions with P at 20 μM and 30 μM, and the depletion curves and Michaelis-Menten parameters were determined. The conclusions were that as P supply increased and as the plant P contents are sufficient for maximum growth, the rate of P uptake tends to be lower. The results also indicate that total P uptake by tomato seedlings depends on the amount of root surface area exposed to P. (M.A.C.) [pt

Soluble organic nutrient fluxes

Science.gov (United States)

Robert G. Qualls; Bruce L. Haines; Wayne Swank

2014-01-01

Our objectives in this study were (i) compare fluxes of the dissolved organic nutrients dissolved organic carbon (DOC), DON, and dissolved organic phosphorus (DOP) in a clearcut area and an adjacent mature reference area. (ii) determine whether concentrations of dissolved organic nutrients or inorganic nutrients were greater in clearcut areas than in reference areas,...

Changing climate and nutrient transfers: Evidence from high temporal resolution concentration-flow dynamics in headwater catchments.

Science.gov (United States)

Ockenden, M C; Deasy, C E; Benskin, C McW H; Beven, K J; Burke, S; Collins, A L; Evans, R; Falloon, P D; Forber, K J; Hiscock, K M; Hollaway, M J; Kahana, R; Macleod, C J A; Reaney, S M; Snell, M A; Villamizar, M L; Wearing, C; Withers, P J A; Zhou, J G; Haygarth, P M

2016-04-01

We hypothesise that climate change, together with intensive agricultural systems, will increase the transfer of pollutants from land to water and impact on stream health. This study builds, for the first time, an integrated assessment of nutrient transfers, bringing together a) high-frequency data from the outlets of two surface water-dominated, headwater (~10km(2)) agricultural catchments, b) event-by-event analysis of nutrient transfers, c) concentration duration curves for comparison with EU Water Framework Directive water quality targets, d) event analysis of location-specific, sub-daily rainfall projections (UKCP, 2009), and e) a linear model relating storm rainfall to phosphorus load. These components, in combination, bring innovation and new insight into the estimation of future phosphorus transfers, which was not available from individual components. The data demonstrated two features of particular concern for climate change impacts. Firstly, the bulk of the suspended sediment and total phosphorus (TP) load (greater than 90% and 80% respectively) was transferred during the highest discharge events. The linear model of rainfall-driven TP transfers estimated that, with the projected increase in winter rainfall (+8% to +17% in the catchments by 2050s), annual event loads might increase by around 9% on average, if agricultural practices remain unchanged. Secondly, events following dry periods of several weeks, particularly in summer, were responsible for high concentrations of phosphorus, but relatively low loads. The high concentrations, associated with low flow, could become more frequent or last longer in the future, with a corresponding increase in the length of time that threshold concentrations (e.g. for water quality status) are exceeded. The results suggest that in order to build resilience in stream health and help mitigate potential increases in diffuse agricultural water pollution due to climate change, land management practices should target

The relationship between transpiration and nutrient uptake in wheat changes under elevated atmospheric CO2.

Science.gov (United States)

Houshmandfar, Alireza; Fitzgerald, Glenn J; O'Leary, Garry; Tausz-Posch, Sabine; Fletcher, Andrew; Tausz, Michael

2017-12-04

The impact of elevated [CO 2 ] (e[CO 2 ]) on crops often includes a decrease in their nutrient concentrations where reduced transpiration-driven mass flow of nutrients has been suggested to play a role. We used two independent approaches, a free-air CO 2 enrichment (FACE) experiment in the South Eastern wheat belt of Australia and a simulation study employing the agricultural production systems simulator (APSIM), to show that transpiration (mm) and nutrient uptake (g m -2 ) of nitrogen (N), potassium (K), sulfur (S), calcium (Ca), magnesium (Mg) and manganese (Mn) in wheat are correlated under e[CO 2 ], but that nutrient uptake per unit water transpired is higher under e[CO 2 ] than under ambient [CO 2 ] (a[CO 2 ]). This result suggests that transpiration-driven mass flow of nutrients contributes to decreases in nutrient concentrations under e[CO 2 ], but cannot solely explain the overall decline. © 2017 Scandinavian Plant Physiology Society.

Nutrient and secondary metabolite concentrations in a savanna are independently affected by large herbivores and shoot growth rate

CSIR Research Space (South Africa)

Scogings, PF

2014-01-01

Full Text Available Carbon-based secondary metabolites (CBSMs) such as tannins are assumed to function as plant defences against herbivores. CBSMs are thought to be inversely related to growth rate and nutrient concentrations because a physiological trade-off exists...

Oxygen and diverse nutrients influence the water kefir fermentation process.

Science.gov (United States)

Laureys, David; Aerts, Maarten; Vandamme, Peter; De Vuyst, Luc

2018-08-01

Eight water kefir fermentation series differing in the presence of oxygen, the nutrient concentration, and the nutrient source were studied during eight consecutive backslopping steps. The presence of oxygen allowed the proliferation of acetic acid bacteria, resulting in high concentrations of acetic acid, and decreased the relative abundance of Bifidobacterium aquikefiri. Low nutrient concentrations resulted in slow water kefir fermentation and high pH values, which allowed the growth of Comamonas testosteroni/thiooxydans. Further, low nutrient concentrations favored the growth of Lactobacillus hilgardii and Dekkera bruxellensis, whereas high nutrient concentrations favored the growth of Lactobacillus nagelii and Saccharomyces cerevisiae. Dried figs, dried apricots, and raisins resulted in stable water kefir fermentation. Water kefir fermentation with dried apricots resulted in the highest pH and water kefir grain growth, whereas that with raisins resulted in the lowest pH and water kefir grain growth. Further, water kefir fermentation with raisins resembled fermentations with low nutrient concentrations, that with dried apricots resembled fermentations with normal nutrient concentrations, and that with fresh figs or a mixture of yeast extract and peptone resembled fermentations with high nutrient concentrations. Copyright © 2018 Elsevier Ltd. All rights reserved.

Limitation of multi-elemental fingerprinting of wheat grains: Effect of cultivar, sowing date, and nutrient management

DEFF Research Database (Denmark)

Suarez-Tapia, Alfonso; Kucheryavskiy, Sergey V.; Christensen, Bent Tolstrup

2017-01-01

Multi-element fingerprinting demonstrates some potential for tracing the origin of agricultural products but not for discriminating among crop cultivars and nutrient management (source, rate). With principal component analysis (PCA) and univariate statistics, we examined 19 elements in grains from...... two winter wheat cultivars (Hereford, Mariboss) grown with different rates of animal manure (AM) or mineral fertilisers (NPK) in a long-term field experiment and two sowing dates (early, timely). Nitrogen, Cd and Mn related to NPK, and Mo and Na to AM. Barium, Fe, and P reflected nutrient rate......; these elements increased with nutrient rate regardless of source. Unmanured grains were enriched in Cu. Mariboss was characterized by higher concentrations of Sr, Ba and Sc compared to Hereford with Sr in grain as the main separator. Univariate statistics showed higher concentrations of N, P, Mg, Ba, Cu, Mo...

Circulating fat-soluble vitamin concentrations and nutrient composition of aquatic prey eaten by American oystercatchers (Haematopus palliatus) in the southeastern United States

Science.gov (United States)

Carlson-Bremer, Daphne; Norton, Terry M.; Sanders, Felicia J.; Winn, Brad; Spinks, Mark D.; Glatt, Batsheva A.; Mazzaro, Lisa; Jodice, Patrick G.R.; Chen, Tai C.; Dierenfeld, Ellen S.

2014-01-01

The American oystercatcher (Haematopus palliatus palliatus) is currently listed as a species of high concern by the United States Shorebird Conservation Plan. Because nutritional status directly impacts overall health and reproduction of individuals and populations, adequate management of a wildlife population requires intimate knowledge of a species' diet and nutrient requirements. Fat-soluble vitamin concentrations in blood plasma obtained from American oystercatchers and proximate, vitamin, and mineral composition of various oystercatcher prey species were determined as baseline data to assess nutritional status and nutrient supply. Bird and prey species samples were collected from the Cape Romain region, South Carolina, USA, and the Altamaha River delta islands, Georgia, USA, where breeding populations appear relatively stable in recent years. Vitamin A levels in blood samples were higher than ranges reported as normal for domestic avian species, and vitamin D concentrations were lower than anticipated based on values observed in poultry. Vitamin E levels were within ranges previously reported for avian groups with broadly similar feeding niches such as herons, gulls, and terns (eg, aquatic/estuarine/marine). Prey species (oysters, mussels, clams, blood arks [Anadara ovalis], whelks [Busycon carica], false angel wings [Petricola pholadiformis]) were similar in water content to vertebrate prey, moderate to high in protein, and moderate to low in crude fat. Ash and macronutrient concentrations in prey species were high compared with requirements of carnivores or avian species. Prey items analyzed appear to meet nutritional requirements for oystercatchers, as estimated by extrapolation from domestic carnivores and poultry species; excesses, imbalances, and toxicities—particularly of minerals and fat-soluble vitamins—may warrant further investigation.

Effect of mycorrhiza and phosphorus content in nutrient solution on the yield and nutritional status of tomato plants grown on rockwool or coconut coir

Directory of Open Access Journals (Sweden)

Iwona Kowalska

2015-03-01

Full Text Available Effects of P level in nutrient solution and the colonization of roots by arbuscular mycorrhizal fungi (AMF on P uptake by tomato plants, their nutritional status, yield and quality of fruits were studied. Plants were grown on rockwool or coconut coir. Inoculation by a mixture of several AMF species was performed three times during the growing period. The mycorrhizal frequency in roots inoculated with AMF amounted to 35.79 – 50.82%. The highest level of mycorrhiza was found in plants receiving nutrient solution with a lower concentration of P. Among the experimental factors, only P level influenced the fruit yield, being higher from plants receiving a nutrient solution with a higher P level. A higher concentration of P in nutrient solution imposed better nutritional status of plants. Higher contents of ascorbic acid and total soluble sugars were found in fruits collected from inoculated plants, grown on rockwool.

Nitrogen regulation of transpiration controls mass-flow acquisition of nutrients.

Science.gov (United States)

Matimati, Ignatious; Verboom, G Anthony; Cramer, Michael D

2014-01-01

Transpiration may enhance mass-flow of nutrients to roots, especially in low-nutrient soils or where the root system is not extensively developed. Previous work suggested that nitrogen (N) may regulate mass-flow of nutrients. Experiments were conducted to determine whether N regulates water fluxes, and whether this regulation has a functional role in controlling the mass-flow of nutrients to roots. Phaseolus vulgaris were grown in troughs designed to create an N availability gradient by restricting roots from intercepting a slow-release N source, which was placed at one of six distances behind a 25 μm mesh from which nutrients could move by diffusion or mass-flow (termed 'mass-flow' treatment). Control plants had the N source supplied directly to their root zone so that N was available through interception, mass-flow, and diffusion (termed 'interception' treatment). 'Mass-flow' plants closest to the N source exhibited 2.9-fold higher transpiration (E), 2.6-fold higher stomatal conductance (gs), 1.2-fold higher intercellular [CO2] (Ci), and 3.4-fold lower water use efficiency than 'interception' plants, despite comparable values of photosynthetic rate (A). E, gs, and Ci first increased and then decreased with increasing distance from the N source to values even lower than those of 'interception' plants. 'Mass-flow' plants accumulated phosphorus and potassium, and had maximum concentrations at 10mm from the N source. Overall, N availability regulated transpiration-driven mass-flow of nutrients from substrate zones that were inaccessible to roots. Thus when water is available, mass-flow may partially substitute for root density in providing access to nutrients without incurring the costs of root extension, although the efficacy of mass-flow also depends on soil nutrient retention and hydraulic properties.

Nutrient dynamics across a dissolved organic carbon and burn gradient in central Siberia

Science.gov (United States)

Rodriguez-Cardona, B.; Coble, A. A.; Prokishkin, A. S.; Kolosov, R.; Spencer, R. G.; Wymore, A.; McDowell, W. H.

2016-12-01

In stream ecosystems, dissolved organic carbon (DOC) and nitrogen (N) processing are tightly linked. In temperate streams, greater DOC concentrations and higher DOC:NO3- ratios promote the greatest nitrate (NO3-) uptake. However, less is known about this relationship in other biomes including the arctic which is undergoing changes due to climate change contributing to thawing of permafrost and alterations in biogeochemical cycles in soils and streams. Headwater streams draining into the N. Tunguska River in the central Siberian plateau are affected by forest fires but little is known about the aquatic biogeochemical implications in both a thawing and burning landscape. There are clear patterns between carbon concentration and fire history where generally DOC concentration in streams decrease after fires and older burn sites have shown greater DOC concentrations and more bioavailable DOC that could promote greater heterotrophic uptake of NO3-. However, the relationship between nutrient dynamics, organic matter composition, and fire history in streams is not very clear. In order to assess the influence of organic matter composition and DOC concentration on nutrient uptake in arctic streams, we conducted a series of short-term nutrient addition experiments following the tracer addition for spiraling curve characterization (TASCC) method, consisting of NO3- and NH4++PO43- additions, across 4 streams that comprise a fire gradient that spans 3- >100 years since the last burn with DOC concentrations ranging between 12-23 mg C/L. We hypothesized that nutrient uptake would be greatest in older burn sites due to greater DOC concentrations and availability. We will specifically examine how nutrient uptake relates to DOC concentration and OM composition (analyzed via FTICR-MS) across the burn gradient. Across the four sites DOC concentration and DOC:NO3- ratios decreased from old burn sites to recently burned sites. Results presented here can elucidate on the potential impacts

Growth and nutrient efficiency of Betula alnoides clones in response to phosphorus supply

Directory of Open Access Journals (Sweden)

Lin Chen

2016-12-01

Full Text Available As phosphorus deficiency limits the productivity of many plantation forests in Asia, there is considerable interest in developing phosphorus-efficient clones for the region through targeted breeding programs. Therefore, we determined growth, nutrient concentrations and nutrient absorption and utility efficiencies of four Betula alnoides clones (C5, C6, 1-202 and BY1 in response to six phosphorus levels of 0, 17, 52, 70, 140 and 209 mg P plant-1 coded as P1 to P6, respectively. Maximum growth occurred in the P4, P5 and P6 plants since they had the largest height, biomass, leaf area and branch number. Phosphorus application increased the phosphorus concentrations of all clones. Nutrient loading was achieved with the P6 treatment because growth and biomass were not significantly higher, but root, stem and leaf phosphorus concentrations were approximately twice those of P4 plants. Clone BY1 had the highest phosphorus-efficiency, and is recommended for field application due to its maximum root collar diameter, biomass, root/shoot ratio, leaf area, nutrient absorption and utility efficiency among the four clones. The findings will help to improve the nutrient efficiency of this species in plantation forestry in Asia.

Nutrient Leaching When Soil Is Part of Plant Growth Media

Directory of Open Access Journals (Sweden)

Sally D. Logsdon

2017-07-01

Full Text Available Soils can serve as sorbents for phosphorus (P, negating the need for artificial sorbents. The purpose of this study was to compare soils with different properties for their effect on nutrient levels in effluent. Four soils were mixed with sand and packed into columns 0.5 m long, with or without compost on the surface. Infiltration and effluent concentrations were measured before and after growing plants [Buffalograss (Buchloe dactyloides (Nutt. Engelm. and bluegrama grasses (Bouteloua gracilis H.B.K. and red clover (Trifolium pratense L.]. The growth media with compost at the surface had higher nutrient levels than the media without the compost, but the final effluent nitrate concentrations post-harvest were significantly lower for columns with the compost blanket (59 vs. 86 mg L−1. All of the nitrate concentrations were high (many >100 mg L−1 due to mineralization and nitrogen fixation. The final effluent P concentrations before planting were significantly higher in the soil with the most sand (0.71 mg L−1, and after harvest in the mixture that contained the high soil P levels (0.58 mg L−1. Some soils (high in aluminum or calcium were adequate sorbents for P without additions of other sorbents, but soils often generated too much nitrate in effluent.

Cast Stone Formulation At Higher Sodium Concentrations

International Nuclear Information System (INIS)

Fox, K. M.; Edwards, T. A.; Roberts, K. B.

2013-01-01

concentration in the salt solution reduced the time to peak heat flow, and reducing the amount of slag in the premix increased the time to peak heat flow. These observations may help to describe some of the cured properties of the samples, in particular the differences in compressive strength observed after 28 and 90 days of curing. Samples were cured for at least 28 days at ambient temperature in the laboratory prior to cured properties analyses. The low activity waste form for disposal at the Hanford Site is required to have a compressive strength of at least 500 psi. After 28 days of curing, several of the test mixes had mean compressive strengths that were below the 500 psi requirement. Higher sodium concentrations and higher water to premix ratios led to reduced compressive strength. Higher fly ash concentrations decreased the compressive strength after 28 days of curing. This may be explained in that the cementitious phases matured more quickly in the mixes with higher concentrations of slag, as evidenced by the data for the time to peak heat generation. All of the test mixes exhibited higher mean compressive strengths after 90 days of curing, with only one composition having a mean compressive strength of less than 500 psi. Leach indices were determined for the test mixes for contaminants of interest. The leaching performance of the mixes evaluated in this study was not particularly sensitive to the factors used in the experimental design. This may be beneficial in demonstrating that the performance of the waste form is robust with respect to changes in the mix composition. The results of this study demonstrate the potential to achieve significantly higher waste loadings in Cast Stone and other low temperature, cementitious waste forms. Additional work is needed to elucidate the hydration mechanisms occurring in Cast Stone formulated with highly concentrated salt solutions since these reactions are responsible for determining the performance of the cured waste form. The

Cast Stone Formulation At Higher Sodium Concentrations

International Nuclear Information System (INIS)

Fox, K. M.; Roberts, K. A.; Edwards, T. B.

2014-01-01

concentration in the salt solution reduced the time to peak heat flow, and reducing the amount of slag in the premix increased the time to peak heat flow. These observations may help to describe some of the cured properties of the samples, in particular the differences in compressive strength observed after 28 and 90 days of curing. Samples were cured for at least 28 days at ambient temperature in the laboratory prior to cured properties analyses. The low activity waste form for disposal at the Hanford Site is required to have a compressive strength of at least 500 psi. After 28 days of curing, several of the test mixes had mean compressive strengths that were below the 500 psi requirement. Higher sodium concentrations and higher water to premix ratios led to reduced compressive strength. Higher fly ash concentrations decreased the compressive strength after 28 days of curing. This may be explained in that the cementitious phases matured more quickly in the mixes with higher concentrations of slag, as evidenced by the data for the time to peak heat generation. All of the test mixes exhibited higher mean compressive strengths after 90 days of curing, with only one composition having a mean compressive strength of less than 500 psi. Leachability indices were determined for the test mixes for contaminants of interest. The leaching performance of the mixes evaluated in this study was not particularly sensitive to the factors used in the experimental design. This may be beneficial in demonstrating that the performance of the waste form is robust with respect to changes in the mix composition. The results of this study demonstrate the potential to achieve significantly higher waste loadings in Cast Stone and other low temperature, cementitious waste forms. Additional work is needed to elucidate the hydration mechanisms occurring in Cast Stone formulated with highly concentrated salt solutions since these reactions are responsible for determining the performance of the cured waste

Cast Stone Formulation At Higher Sodium Concentrations

Energy Technology Data Exchange (ETDEWEB)

Fox, K. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Roberts, K. A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Edwards, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2014-02-28

concentration in the salt solution reduced the time to peak heat flow, and reducing the amount of slag in the premix increased the time to peak heat flow. These observations may help to describe some of the cured properties of the samples, in particular the differences in compressive strength observed after 28 and 90 days of curing. Samples were cured for at least 28 days at ambient temperature in the laboratory prior to cured properties analyses. The low activity waste form for disposal at the Hanford Site is required to have a compressive strength of at least 500 psi. After 28 days of curing, several of the test mixes had mean compressive strengths that were below the 500 psi requirement. Higher sodium concentrations and higher water to premix ratios led to reduced compressive strength. Higher fly ash concentrations decreased the compressive strength after 28 days of curing. This may be explained in that the cementitious phases matured more quickly in the mixes with higher concentrations of slag, as evidenced by the data for the time to peak heat generation. All of the test mixes exhibited higher mean compressive strengths after 90 days of curing, with only one composition having a mean compressive strength of less than 500 psi. Leachability indices were determined for the test mixes for contaminants of interest. The leaching performance of the mixes evaluated in this study was not particularly sensitive to the factors used in the experimental design. This may be beneficial in demonstrating that the performance of the waste form is robust with respect to changes in the mix composition. The results of this study demonstrate the potential to achieve significantly higher waste loadings in Cast Stone and other low temperature, cementitious waste forms. Additional work is needed to elucidate the hydration mechanisms occurring in Cast Stone formulated with highly concentrated salt solutions since these reactions are responsible for determining the performance of the cured waste

Cast Stone Formulation At Higher Sodium Concentrations

Energy Technology Data Exchange (ETDEWEB)

Fox, K. M.; Edwards, T. A.; Roberts, K. B.

2013-10-02

concentration in the salt solution reduced the time to peak heat flow, and reducing the amount of slag in the premix increased the time to peak heat flow. These observations may help to describe some of the cured properties of the samples, in particular the differences in compressive strength observed after 28 and 90 days of curing. Samples were cured for at least 28 days at ambient temperature in the laboratory prior to cured properties analyses. The low activity waste form for disposal at the Hanford Site is required to have a compressive strength of at least 500 psi. After 28 days of curing, several of the test mixes had mean compressive strengths that were below the 500 psi requirement. Higher sodium concentrations and higher water to premix ratios led to reduced compressive strength. Higher fly ash concentrations decreased the compressive strength after 28 days of curing. This may be explained in that the cementitious phases matured more quickly in the mixes with higher concentrations of slag, as evidenced by the data for the time to peak heat generation. All of the test mixes exhibited higher mean compressive strengths after 90 days of curing, with only one composition having a mean compressive strength of less than 500 psi. Leach indices were determined for the test mixes for contaminants of interest. The leaching performance of the mixes evaluated in this study was not particularly sensitive to the factors used in the experimental design. This may be beneficial in demonstrating that the performance of the waste form is robust with respect to changes in the mix composition. The results of this study demonstrate the potential to achieve significantly higher waste loadings in Cast Stone and other low temperature, cementitious waste forms. Additional work is needed to elucidate the hydration mechanisms occurring in Cast Stone formulated with highly concentrated salt solutions since these reactions are responsible for determining the performance of the cured waste form. The

Cast Stone Formulation At Higher Sodium Concentrations

Energy Technology Data Exchange (ETDEWEB)

Fox, K. M.; Roberts, K. A.; Edwards, T. B.

2013-09-17

concentration in the salt solution reduced the time to peak heat flow, and reducing the amount of slag in the premix increased the time to peak heat flow. These observations may help to describe some of the cured properties of the samples, in particular the differences in compressive strength observed after 28 and 90 days of curing. Samples were cured for at least 28 days at ambient temperature in the laboratory prior to cured properties analyses. The low activity waste form for disposal at the Hanford Site is required to have a compressive strength of at least 500 psi. After 28 days of curing, several of the test mixes had mean compressive strengths that were below the 500 psi requirement. Higher sodium concentrations and higher water to premix ratios led to reduced compressive strength. Higher fly ash concentrations decreased the compressive strength after 28 days of curing. This may be explained in that the cementitious phases matured more quickly in the mixes with higher concentrations of slag, as evidenced by the data for the time to peak heat generation. All of the test mixes exhibited higher mean compressive strengths after 90 days of curing, with only one composition having a mean compressive strength of less than 500 psi. Leach indices were determined for the test mixes for contaminants of interest. The leaching performance of the mixes evaluated in this study was not particularly sensitive to the factors used in the experimental design. This may be beneficial in demonstrating that the performance of the waste form is robust with respect to changes in the mix composition. The results of this study demonstrate the potential to achieve significantly higher waste loadings in Cast Stone and other low temperature, cementitious waste forms. Additional work is needed to elucidate the hydration mechanisms occurring in Cast Stone formulated with highly concentrated salt solutions since these reactions are responsible for determining the performance of the cured waste form. The

Technical Note: A comparison of two empirical approaches to estimate in-stream net nutrient uptake

Science.gov (United States)

von Schiller, D.; Bernal, S.; Martí, E.

2011-04-01

To establish the relevance of in-stream processes on nutrient export at catchment scale it is important to accurately estimate whole-reach net nutrient uptake rates that consider both uptake and release processes. Two empirical approaches have been used in the literature to estimate these rates: (a) the mass balance approach, which considers changes in ambient nutrient loads corrected by groundwater inputs between two stream locations separated by a certain distance, and (b) the spiralling approach, which is based on the patterns of longitudinal variation in ambient nutrient concentrations along a reach following the nutrient spiralling concept. In this study, we compared the estimates of in-stream net nutrient uptake rates of nitrate (NO3) and ammonium (NH4) and the associated uncertainty obtained with these two approaches at different ambient conditions using a data set of monthly samplings in two contrasting stream reaches during two hydrological years. Overall, the rates calculated with the mass balance approach tended to be higher than those calculated with the spiralling approach only at high ambient nitrogen (N) concentrations. Uncertainty associated with these estimates also differed between both approaches, especially for NH4 due to the general lack of significant longitudinal patterns in concentration. The advantages and disadvantages of each of the approaches are discussed.

Response of dissolved carbon and nitrogen concentrations to moderate nutrient additions in a tropical montane forest of south Ecuador

Science.gov (United States)

Velescu, Andre; Valarezo, Carlos; Wilcke, Wolfgang

2016-05-01

In the past two decades, the tropical montane rain forests in south Ecuador experienced increasing deposition of reactive nitrogen mainly originating from Amazonian forest fires, while Saharan dust inputs episodically increased deposition of base metals. Increasing air temperature and unevenly distributed rainfall have allowed for longer dry spells in a perhumid ecosystem. This might have favored mineralization of dissolved organic matter (DOM) by microorganisms and increased nutrient release from the organic layer. Environmental change is expected to impact the functioning of this ecosystem belonging to the biodiversity hotspots of the Earth. In 2007, we established a nutrient manipulation experiment (NUMEX) to understand the response of the ecosystem to moderately increased nutrient inputs. Since 2008, we have continuously applied 50 kg ha-1 a-1 of nitrogen (N), 10 kg ha-1 a-1 of phosphorus (P), 50 kg + 10 kg ha-1 a-1 of N and P and 10 kg ha-1 a-1 of calcium (Ca) in a randomized block design at 2000 m a.s.l. in a natural forest on the Amazonia-exposed slopes of the south Ecuadorian Andes. Nitrogen concentrations in throughfall increased following N+P additions, while separate N amendments only increased nitrate concentrations. Total organic carbon (TOC) and dissolved organic nitrogen (DON) concentrations showed high seasonal variations in litter leachate and decreased significantly in the P and N+P treatments, but not in the N treatment. Thus, P availability plays a key role in the mineralization of DOM. TOC/DON ratios were narrower in throughfall than in litter leachate but their temporal course did not respond to nutrient amendments. Our results revealed an initially fast, positive response of the C and N cycling to nutrient additions which declined with time. TOC and DON cycling only change if N and P supply are improved concurrently, while NO3-N leaching increases only if N is separately added. This indicates co-limitation of the microorganisms by N and P

Response of dissolved carbon and nitrogen concentrations to moderate nutrient additions in a tropical montane forest of south Ecuador

Directory of Open Access Journals (Sweden)

Andre eVelescu

2016-05-01

Full Text Available In the past two decades, the tropical montane rain forests in south Ecuador experienced increasing deposition of reactive nitrogen mainly originating from Amazonian forest fires, while Saharan dust inputs episodically increased deposition of base metals. Increasing air temperature and unevenly distributed rainfall have allowed for longer dry spells in a perhumid ecosystem. This might have favored mineralization of dissolved organic matter (DOM by microorganisms and increased nutrient release from the organic layer. Environmental change is expected to impact the functioning of this ecosystem belonging to the biodiversity hotspots of the Earth.In 2007, we established a nutrient manipulation experiment (NUMEX to understand the response of the ecosystem to moderately increased nutrient inputs. Since 2008, we have continuously applied 50 kg ha-1 a-1 of nitrogen (N, 10 kg ha-1 a-1 of phosphorus (P, 50 kg + 10 kg ha-1 a-1 of N and P and 10 kg ha-1 a-1 of calcium (Ca in a randomized block design at 2000 m a.s.l. in a natural forest on the Amazonia-exposed slopes of the south Ecuadorian Andes.Nitrogen concentrations in throughfall increased following N+P additions, while separate N amendments only increased nitrate concentrations. Total organic carbon (TOC and dissolved organic nitrogen (DON concentrations showed high seasonal variations in litter leachate and decreased significantly in the P and N+P treatments, but not in the N treatment. Thus, P availability plays a key role in the mineralization of DOM. TOC/DON ratios were narrower in throughfall than in litter leachate but their temporal course did not respond to nutrient amendments.Our results revealed an initially fast, positive response of the C and N cycling to nutrient additions which declined with time. TOC and DON cycling only change if N and P supply are improved concurrently, while NO3-N leaching increases only if N is separately added. This indicates co-limitation of the microorganisms by N

Micro and Macroscale Drivers of Nutrient Concentrations in Urban Streams in South, Central and North America.

Science.gov (United States)

Loiselle, Steven A; Gasparini Fernandes Cunha, Davi; Shupe, Scott; Valiente, Elsa; Rocha, Luciana; Heasley, Eleanore; Belmont, Patricia Pérez; Baruch, Avinoam

Global metrics of land cover and land use provide a fundamental basis to examine the spatial variability of human-induced impacts on freshwater ecosystems. However, microscale processes and site specific conditions related to bank vegetation, pollution sources, adjacent land use and water uses can have important influences on ecosystem conditions, in particular in smaller tributary rivers. Compared to larger order rivers, these low-order streams and rivers are more numerous, yet often under-monitored. The present study explored the relationship of nutrient concentrations in 150 streams in 57 hydrological basins in South, Central and North America (Buenos Aires, Curitiba, São Paulo, Rio de Janeiro, Mexico City and Vancouver) with macroscale information available from global datasets and microscale data acquired by trained citizen scientists. Average sub-basin phosphate (P-PO4) concentrations were found to be well correlated with sub-basin attributes on both macro and microscales, while the relationships between sub-basin attributes and nitrate (N-NO3) concentrations were limited. A phosphate threshold for eutrophic conditions (>0.1 mg L-1 P-PO4) was exceeded in basins where microscale point source discharge points (eg. residential, industrial, urban/road) were identified in more than 86% of stream reaches monitored by citizen scientists. The presence of bankside vegetation covaried (rho = -0.53) with lower phosphate concentrations in the ecosystems studied. Macroscale information on nutrient loading allowed for a strong separation between basins with and without eutrophic conditions. Most importantly, the combination of macroscale and microscale information acquired increased our ability to explain sub-basin variability of P-PO4 concentrations. The identification of microscale point sources and bank vegetation conditions by citizen scientists provided important information that local authorities could use to improve their management of lower order river ecosystems.

Effects of Feeding Corn-lablab Bean Mixture Silages on Nutrient Apparent Digestibility and Performance of Dairy Cows

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Yongli Qu

2013-04-01

Full Text Available This study estimated the fermentation characteristics and nutrient value of corn-lablab bean mixture silages relative to corn silages. The effects of feeding corn-lablab bean mixture silages on nutrient apparent digestibility and milk production of dairy cows in northern China were also investigated. Three ruminally cannulated Holstein cows were used to determine the ruminal digestion kinetics and ruminal nutrient degradability of corn silage and corn-lablab bean mixture silages. Sixty lactating Holstein cows were randomly divided into two groups of 30 cows each. Two diets were formulated with a 59:41 forage: concentrate ratio. Corn silage and corn-lablab bean mixture silages constituted 39.3% of the forage in each diet, with Chinese wildrye hay constituting the remaining 60.7%. Corn-lablab bean mixture silages had higher lactic acid, acetic acid, dry matter (DM, crude protein (CP, ash, Ca, ether extract concentrations and ruminal nutrient degradability than monoculture corn silage (p<0.05. Neutral detergent fiber (NDF and acid detergent fiber (ADF concentrations of corn-lablab bean mixture silages were lower than those of corn silage (p<0.05. The digestibility of DM, CP, NDF, and ADF for cows fed corn-lablab bean mixture silages was higher than for those fed corn silage (p<0.05. Feeding corn-lablab bean mixture silages increased milk yield and milk protein of dairy cows when compared with feeding corn silage (p<0.05. The economic benefit for cow fed corn-lablab bean mixture silages was 8.43 yuan/day/cow higher than that for that fed corn silage. In conclusion, corn-lablab bean mixture improved the fermentation characteristics and nutrient value of silage compared with monoculture corn. In this study, feeding corn-lablab bean mixture silages increased milk yield, milk protein and nutrient apparent digestibility of dairy cows compared with corn silage in northern China.

Effects of a specific blend of essential oils on apparent nutrient digestion, rumen fermentation and rumen microbial populations in sheep fed a 50:50 alfalfa hay:concentrate diet

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N. Khateri

2017-03-01

Full Text Available Objective An experiment was conducted to investigate the effects of a specific mixture of essential oils (MEO, containing thyme, clove and cinnamon EO, on rumen microbial fermentation, nutrient apparent digestibility and blood metabolites in fistulated sheep. Methods Six sheep fitted with ruminal fistulas were used in a repeated measurement design with two 24-d periods to investigate the effect of adding MEO at 0 (control, 0.8, and 1.6 mL/d on apparent nutrient digestibility, rumen fermentation characteristics, rumen microbial population and blood chemical metabolites. Animals were fed with a 50:50 alfalfa hay:concentrate diet. Results Ruminal pH, total volatile fatty acids (VFA concentration, molar proportion of individual VFA, acetate: propionate ratio and methane production were not affected with MEO. Relative to the control, Small peptides plus amino acid nitrogen and large peptides nitrogen concentration in rumen fluid were not affected with MEO supplementation; while, rumen fluid ammonia nitrogen concentration at 0 and 6 h after morning feeding in sheep fed with 1.6 mL/d of MEO was lower (p<0.05 compared to the control and 0.8 mL/d of MEO. At 0 h after morning feeding, ammonia nitrogen concentration was higher (p<0.05 in sheep fed 0.8 mL/d of MEO relative to 1.6 mL/d and control diet. Ruminal protozoa and hyper ammonia producing (HAP bacteria counts were not affected by addition of MEO in the diet. Relative to the control, no changes were observed in the red and white blood cells, hemoglobin, hematocrit, glucose, beta-hydroxybutyric acid, cholesterol, total protein, albumin, blood urea nitrogen and aspartate aminotransferase and alanine aminotransferase concentration. Apparent total tract digestibility of dry matter, crude proten, organic matter, and neutral detergent fiber were not influenced by MEO supplementation. Conclusion The results of the present study suggested that supplementation of MEO may have limited effects on apparent

Distributions of nutrients, dissolved organic carbon and carbohydrates in the western Arctic Ocean

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Wang, Deli; Henrichs, Susan M.; Guo, Laodong

2006-09-01

Seawater samples were collected from stations along a transect across the shelf-basin interface in the western Arctic Ocean during September 2002, and analyzed for nutrients, dissolved organic carbon (DOC), and total dissolved carbohydrate (TDCHO) constituents, including monosaccharides (MCHO) and polysaccharides (PCHO). Nutrients (nitrate, ammonium, phosphate and dissolved silica) were depleted at the surface, especially nitrate. Their concentrations increased with increasing depth, with maxima centered at ˜125 m depth within the halocline layer, then decreased with increasing depth below the maxima. Both ammonium and phosphate concentrations were elevated in shelf bottom waters, indicating a possible nutrient source from sediments, and in a plume that extended into the upper halocline waters offshore. Concentrations of DOC ranged from 45 to 85 μM and had an inverse correlation with salinity, indicating that mixing is a control on DOC concentrations. Concentrations of TDCHO ranged from 2.5 to 19 μM-C, comprising 13-20% of the bulk DOC. Higher DOC concentrations were found in the upper water column over the shelf along with higher TDCHO concentrations. Within the TDCHO pool, the concentrations of MCHO ranged from 0.4 to 8.6 μM-C, comprising 20-50% of TDCHO, while PCHO concentrations ranged from 0.5 to 13.6 μM-C, comprising 50-80% of the TDCHO. The MCHO/TDCHO ratio was low in the upper 25 m of the water column, followed by a high MCHO/TDCHO ratio between 25 and 100 m, and a low MCHO/TDCHO ratio again below 100 m. The high MCHO/TDCHO ratio within the halocline layer likely resulted from particle decomposition and associated release of MCHO, whereas the low MCHO/TDCHO (or high PCHO/TDCHO) ratio below the halocline layer could have resulted from slow decomposition and additional particulate CHO sources.

Effect of Carbohydrate Sources and Levels of Cotton Seed Meal in Concentrate on Feed Intake, Nutrient Digestibility, Rumen Fermentation and Microbial Protein Synthesis in Young Dairy Bulls

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M. Wanapat

2013-04-01

Full Text Available The objective of this study was to investigate the effect of levels of cottonseed meal with various carbohydrate sources in concentrate on feed intake, nutrient digestibility, rumen fermentation and microbial protein synthesis in dairy bulls. Four, 6 months old dairy bulls were randomly assigned to receive four dietary treatments according to a 2×2 factorial arrangement in a 4×4 Latin square design. Factor A was carbohydrate source; cassava chip (CC and cassava chip+rice bran in the ratio of 3:1 (CR3:1, and factor B was cotton seed meal levels in the concentrate; 109 g CP/kg (LCM and 328 g CP/kg (HCM at similar overall CP levels (490 g CP/kg. Bulls received urea-lime treated rice straw ad libitum and were supplemented with 10 g of concentrate/kg BW. It was found that carbohydrate source and level of cotton seed meal did not have significant effects on ruminal pH, ammonia nitrogen concentration, microbial protein synthesis or feed intake. Animals which received CC showed significantly higher BUN concentration, ruminal propionic acid and butyric acid proportions, while dry matter, organic matter digestibility, populations of total viable bacteria and proteolytic bacteria were lower than those in the CR3:1 treatment. The concentration of total volatile fatty acids was higher in HCM than LCM treatments, while the concentration of butyric acid was higher in LCM than HCM treatments. The population of proteolytic bacteria with the LCM treatments was higher than the HCM treatments; however other bacteria groups were similar among the different levels of cotton seed meal. Bulls which received LCM had higher protein digestibility than those receiving HCM. Therefore, using high levels of cassava chip and cotton seed meal might positively impact on energy and nitrogen balance for the microbial population in the rumen of the young dairy bull.

Ultrasonic waste activated sludge disintegration for recovering multiple nutrients for biofuel production.

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Xie, Guo-Jun; Liu, Bing-Feng; Wang, Qilin; Ding, Jie; Ren, Nan-Qi

2016-04-15

Waste activated sludge is a valuable resource containing multiple nutrients, but is currently treated and disposed of as an important source of pollution. In this work, waste activated sludge after ultrasound pretreatment was reused as multiple nutrients for biofuel production. The nutrients trapped in sludge floc were transferred into liquid medium by ultrasonic disintegration during first 30 min, while further increase of pretreatment time only resulted in slight increase of nutrients release. Hydrogen production by Ethanoligenens harbinense B49 from glucose significantly increased with the concentration of ultrasonic sludge, and reached maximum yield of 1.97 mol H2/mol glucose at sludge concentration of 7.75 g volatile suspended solids/l. Without addition of any other chemicals, waste molasses rich in carbohydrate was efficiently turned into hydrogen with yield of 189.34 ml H2/g total sugar by E. harbinense B49 using ultrasonic sludge as nutrients. The results also showed that hydrogen production using pretreated sludge as multiple nutrients was higher than those using standard nutrients. Acetic acid produced by E. harbinense B49 together with the residual nutrients in the liquid medium were further converted into hydrogen (271.36 ml H2/g total sugar) by Rhodopseudomonas faecalis RLD-53 through photo fermentation, while ethanol was the sole end product with yield of 220.26 mg/g total sugar. Thus, pretreated sludge was an efficient nutrients source for biofuel production, which could replace the standard nutrients. This research provided a novel strategy to achieve environmental friendly sludge disposal and simultaneous efficient biofuel recovery from organic waste. Copyright © 2016 Elsevier Ltd. All rights reserved.

Influence of Wheat and Maize Starch on Fermentation in the Rumen, Duodenal Nutrient Flow and Nutrient Digestibility

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Milan Šimko

2010-01-01

Full Text Available We investigated the effects of feeding diets with different starch sources on fermentation in the rumen, duodenal nutrient flow and nutrient digestibility. The basis of the diets was maize silage and alfalfa hay supplemented with wheat meal in diet W, or maize meal in diet M. The experiment was performed on four Black-Spotted bulls with mean live weight of 525 kg, which were fed twice daily at 06.30 and 18.30 h. Experimental animals were fitted with ruminal fistulae and duodenal T-shaped cannulae. Cr2O3 was used as a marker of nutrient flow to the duodenum. Rations were formulated so that the ratio of starch to crude fibre (CF was 2.1:1 and the percentage of CF was maintained at 17% (DM. Duodenal chymus was collected at 2-h time intervals. Starch origin significantly affected ruminal fermentation. Concentration of propionic, butyric and lactic acid was higher with wheat than with maize meal. When the maize meal was the source of starch there was a significantly higher flow of fat, CF, nitrogen-free extract, and starch into duodenum. Differences in duodenal flow of crude protein were not significant across the starch sources. Intake of wheat meal or maize meal increased duodenal flow relative to intake by 33% or 42 % respectively. The apparent digestibility of dry matter (76 ± 2%, crude protein (67 ± 0.9%, CF (64 ± 1.9%, nitrogen-free extract (82 ± 1.5% and organic matter (76 ± 1.3% was significantly higher by offering wheat meal.

Pelagic community production and carbon-nutrient stoichiometry under variable ocean acidification in an Arctic fjord

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A. Silyakova

2013-07-01

Full Text Available Net community production (NCP and carbon to nutrient uptake ratios were studied during a large-scale mesocosm experiment on ocean acidification in Kongsfjorden, western Svalbard, during June–July 2010. Nutrient depleted fjord water with natural plankton assemblages, enclosed in nine mesocosms of ~ 50 m3 in volume, was exposed to pCO2 levels ranging initially from 185 to 1420 μatm. NCP estimations are the cumulative change in dissolved inorganic carbon concentrations after accounting for gas exchange and total alkalinity variations. Stoichiometric coupling between inorganic carbon and nutrient net uptake is shown as a ratio of NCP to a cumulative change in inorganic nutrients. Phytoplankton growth was stimulated by nutrient addition half way through the experiment and three distinct peaks in chlorophyll a concentration were observed during the experiment. Accordingly, the experiment was divided in three phases. Cumulative NCP was similar in all mesocosms over the duration of the experiment. However, in phases I and II, NCP was higher and in phase III lower at elevated pCO2. Due to relatively low inorganic nutrient concentration in phase I, C : N and C : P uptake ratios were calculated only for the period after nutrient addition (phase II and phase III. For the total post-nutrient period (phase II + phase III ratios were close to Redfield, however they were lower in phase II and higher in phase III. Variability of NCP, C : N and C : P uptake ratios in different phases reflects the effect of increasing CO2 on phytoplankton community composition and succession. The phytoplankton community was composed predominantly of haptophytes in phase I, prasinophytes, dinoflagellates, and cryptophytes in phase II, and haptophytes, prasinophytes, dinoflagellates and chlorophytes in phase III (Schulz et al., 2013. Increasing ambient inorganic carbon concentrations have also been shown to promote primary production and carbon assimilation. For this study, it is

SPATIAL UNCERTAINTY OF NUTRIENT LOSS BY EROSION IN SUGARCANE HARVESTING SCENARIOS

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Patrícia Gabarra Mendonça

2015-08-01

Full Text Available The assessment of spatial uncertainty in the prediction of nutrient losses by erosion associated with landscape models is an important tool for soil conservation planning. The purpose of this study was to evaluate the spatial and local uncertainty in predicting depletion rates of soil nutrients (P, K, Ca, and Mg by soil erosion from green and burnt sugarcane harvesting scenarios, using sequential Gaussian simulation (SGS. A regular grid with equidistant intervals of 50 m (626 points was established in the 200-ha study area, in Tabapuã, São Paulo, Brazil. The rate of soil depletion (SD was calculated from the relation between the nutrient concentration in the sediments and the chemical properties in the original soil for all grid points. The data were subjected to descriptive statistical and geostatistical analysis. The mean SD rate for all nutrients was higher in the slash-and-burn than the green cane harvest scenario (Student’s t-test, pMg>K>P. The SD rate was highest in areas with greater slope. Lower uncertainties were associated to the areas with higher SD and steeper slopes. Spatial uncertainties were highest for areas of transition between concave and convex landforms.

Major nutrients, heavy metals and PBDEs in soils after long-term sewage sludge application

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Wu, Longhua; Li, Zhu; Ren, Jing; Shen, Libo; Wang, Songfeng; Luo, Yongming [Chinese Academy of Sciences, Nanjing (China). Key Lab. of Soil Environment and Pollution Remediation; Cheng, Miaomiao [Chinese Academy of Sciences, Nanjing (China). Key Lab. of Soil Environment and Pollution Remediation; Chinese Academy of Sciences, Beijing (China). Graduate School; Christie, Peter [Agri-Food and Biosciences Institute, Belfast (United Kingdom). Agri-Environment Branch

2012-04-15

Purpose: Two contrasting soils receiving long-term application of commercial sewage sludge fertilizers in China were investigated to determine the concentrations of selected nutrients, heavy metals (HMs) and polybrominated diphenyl ethers (PBDEs) present to evaluate the impact of sewage sludge fertilizer on soil fertility and environmental risk. Materials and methods: Soil samples were collected from Tangshan City, Hebei province and Ningbo City, Zhejiang province and divided into two portions, one of which was air-dried and sieved through 2-, 0.25- and 0.149-mm nylon mesh for determination of nutrients and heavy metals. The other portion was frozen at -20 C, freeze-dried and sieved through 2-mm nylon mesh for PBDE analysis. The concentrations of nutrients, heavy metals and PBDEs were determined in all samples. Results and discussion: Concentrations of nutrients and heavy metals in soils amended with low rates of sewage sludge fertilizer (SSF) and conventional fertilizer were compared. After long-term excessive amendment with SSF from Ningbo City (SSF-N), the concentrations of soil total N, P, aqua regia-extractable HMs and DTPA extractable HMs were higher than the control, especially in the arable layer. Moreover, the concentration of aqua regia-extractable Zn (457 mg kg{sup -1}) exceeded the recommended China Environmental Quality Standard for soils (GB15618-1995). All 8 target PBDE congeners were found in fertilizer SSF-N and soil with excessive amendment with SSF-N for 12 years, but the concentrations of 8 different PBDEs in SSF-N-amended soil were not significantly different from control soil. Conclusions: Both economic and environmental benefits can be obtained by careful application of sewage sludge fertilizer to recycle plant nutrients. Repeated and excessive application rates of sewage sludge fertilizer may pose environmental risk, especially in respect of soil heavy metal and PBDE contamination, and high concentrations of phosphorus may also be

Assessment of Nutrient Concentration in Sokori River, Southwest ...

African Journals Online (AJOL)

Nutrient enrichment leads to excessive growth of primary producers as well as heterotrophic bacteria and fungi, which increases the metabolic activities of stream water leading to a depletion of dissolved oxygen. The low discharge of stream and its fairly flat terrain nature also influenced the metabolic activities in the mid- ...

A field study to evaluate the impact of different factors on the nutrient pollutant concentrations in green roof runoff.

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Wang, Xiaochen; Zhao, Xinhua; Peng, Chenrui; Zhang, Xinbo; Wang, Jianghai

2013-01-01

The objectives of this study are to investigate the impact of different factors on the nutrient pollutant concentrations in green roof runoff and to provide reference data for the engineering design of dual substrate layer green roofs. The data were collected from eight different trays under three kinds of artificial rains. The results showed that except for total phosphorus, dual substrate layer green roofs behaved as a sink for most of the nutrient pollutants (significant at p green roof and the depth of the adsorption substrates. Compared with the influence of the substrates, the influence of the plant density and drainage systems was small.

The role of nutrients, productivity and climate in determining tree fruit production in European forests.

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Fernández-Martínez, Marcos; Vicca, Sara; Janssens, Ivan A; Espelta, Josep Maria; Peñuelas, Josep

2017-01-01

Fruit production (NPP f ), the amount of photosynthates allocated to reproduction (%GPP f ) and their controls for spatial and species-specific variability (e.g. nutrient availability, climate) have been poorly studied in forest ecosystems. We characterized fruit production and its temporal behaviour for several tree species and resolved the effects of gross primary production (GPP), climate and foliar nutrient concentrations. We used data for litterfall and foliar nutrient concentration from 126 European forests and related them to climatic data. GPP was estimated for each forest using a regression model. Mean NPP f ranged from c. 10 to 40 g C m -2  yr -1 and accounted for 0.5-3% of GPP. Forests with higher GPPs produced larger fruit crops. Foliar zinc (Zn) and phosphorus (P) concentrations were associated positively with NPP f , whereas foliar Zn and potassium (K) were negatively related to its temporal variability. Maximum NPP f and interannual variability of NPP f were higher in Fagaceae than in Pinaceae species. NPP f and %GPP f were similar amongst the studied species despite the different reproductive temporal behaviour of Fagaceae and Pinaceae species. We report that foliar concentrations of P and Zn are associated with %GPP f , NPP f and its temporal behaviour. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Effect of Nitrogen Form and pH of Nutrient Solution on the Shoot Concentration of Phosphorus, Nitrate, and Nitrogen of Spinach in Hydroponic Culture

OpenAIRE

N. Najafi; M. Parsazadeh

2010-01-01

In order to study the effect of nitrogen form and pH of nutrient solution on the shoot concentration of P, nitrate, organic N + inorganic ammonium, and total N of spinach, a factorial experiment was conducted with two factors including pH of nutrient solution in three levels (4.5, 6.5 and 8.0) and nitrate to ammonium ratio of nutrient solution in five levels (100:0, 75:25, 50:50, 25:75 and 0:100). This factorial experiment was carried out in a completely randomized design with four replicatio...

Trends in nutrients

Science.gov (United States)

Heathwaite, A.L.; Johnes, P.J.; Peters, N.E.

1996-01-01

The roles of nitrogen (N) and phosphorus (P) as key nutrients determining the trophic status of water bodies are examined, and evidence reviewed for trends in concentrations of N and P species which occur in freshwaters, primarily in northern temperate environments. Data are reported for water bodies undergoing eutrophication and acidification, especially water bodies receiving increased nitrogen inputs through the atmospheric deposition of nitrogen oxides (NOx). Nutrient loading on groundwaters and surface freshwaters is assessed with respect to causes and rates of (change, relative rates of change for N and P, and implications of change for the future management of lakes, rivers and groundwaters. In particular, the nature and emphasis of studies for N species and P fractions in lakes versus rivers and groundwaters are contrasted. This review paper primarily focuses on results from North America and Europe, particularly for the UK where a wide range of data sets exists. Few nutrient loading data have been published on water bodies in less developed countries; however, some of the available data are presented to provide a global perspective. In general, N and P concentrations have increased dramatically (>20 times background concentrations) in many areas and causes vary considerably, ranging from urbanization to changes in agricultural practices.

Changes in nutrients and decay rate of Ginkgo biloba leaf litter exposed to elevated O3 concentration in urban area

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Wei Fu

2018-03-01

Full Text Available Ground-level ozone (O3 pollution has been widely concerned in the world, particularly in the cities of Asia, including China. Elevated O3 concentrations have potentially influenced growth and nutrient cycling of trees in urban forest. The decomposition characteristics of urban tree litters under O3 exposure are still poorly known. Ginkgo biloba is commonly planted in the cities of northern China and is one of the main tree species in the urban forest of Shenyang, where concentrations of ground-level O3 are very high in summer. Here, we hypothesized that O3 exposure at high concentrations would alter the decomposition rate of urban tree litter. In open-top chambers (OTCs, 5-year-old G. biloba saplings were planted to investigate the impact of elevated O3 concentration (120 ppb on changes in nutrient contents and decomposition rate of leaf litters. The results showed that elevated O3 concentration significantly increased K content (6.31 ± 0.29 vs 17.93 ± 0.40, P < 0.01 in leaves of G. biloba, significantly decreased the contents of total phenols (2.82 ± 0.93 vs 1.60 ± 0.44, P < 0.05 and soluble sugars (86.51 ± 19.57 vs 53.76 ± 2.40, P < 0.05, but did not significantly alter the contents of C, N, P, lignin and condensed tannins, compared with that in ambient air. Furthermore, percent mass remaining in litterbags after 150 days under ambient air and elevated O3 concentration was 56.0% and 52.8%, respectively. No significant difference between treatments was observed in mass remaining at any sampling date during decomposition. The losses of the nutrients in leaf litters of G. biloba showed significant seasonal differences regardless of O3 treatment. However, we found that elevated O3 concentration slowed down the leaf litter decomposition only at the early decomposition stage, but slightly accelerated the litter decomposition at the late stage (after 120 days. This study provides our understanding of the ecological processes regulating

Effect of humic acid on the growth, yield, nutrient composition, photosynthetic pigment and total sugar contents of peas (pisum sativum l)

International Nuclear Information System (INIS)

Khan, A.; Khan, M.Z.; Hussain, F.; Akhtar, M.E.; Gurmani, A.R.; Khan, S.

2013-01-01

Summary: A pot experiment was conducted to evaluate the effects of humic acid (HA) applied as soil and foliar at 15, 30 and 45 ppm on the growth, biochemical content, nutrient concentrations and yield of peas. Soil as well as foliar application of HA increased the plant growth and grain yield of peas; however magnitude of increase was higher in soil application than foliar. Highest plant growth and grain yield was achieved with soil application of 15 ppm HA followed by 30 ppm and foliar application of 45 ppm HA respectively. Percentage increase in dry grain yield due to 15 ppm was 37%, with 30 ppm was 29% and foliar application of 45 ppm was 25%. Nutrient concentrations (P, K, Fe, Zn, Mn and Cu) were increased with soil and foliar application of HA. The concentrations of nutrients were relatively higher in shelf than grain. Maximum concentration of P, K and Fe was obtained with the soil application of HA at 15 ppm. Humic acid applied at 15, 30 as soil as well as foliar application at 45 ppm significantly increased chlorophyll, carotenoid and total sugar content. Our results indicate that soil application of HA at 15 and 30 ppm, while foliar application at 45 ppm can increase growth, nutrients concentration, chlorophyll content and yield of Peas in calcareous soil conditions. (author)

Effect of Integrated Water-Nutrient Management Strategies on Soil Erosion Mediated Nutrient Loss and Crop Productivity in Cabo Verde Drylands

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Baptista, Isaurinda; Ritsema, Coen; Geissen, Violette

2015-01-01

Soil erosion, runoff and related nutrient losses are a big risk for soil fertility in Cabo Verde drylands. In 2012, field trials were conducted in two agro-ecological zones to evaluate the effects of selected techniques of soil-water management combined with organic amendments (T1: compost/manure + soil surfactant; T2: compost/animal or green manure + pigeon-pea hedges + soil surfactant; T3: compost/animal or green manure + mulch + pigeon-pea hedges) on nitrogen (N) and phosphorus (P) losses in eroded soil and runoff and on crop yields. Three treatments and one control (traditional practice) were tested in field plots at three sites with a local maize variety and two types of beans. Runoff and eroded soil were collected after each erosive rain, quantified, and analysed for NO3-N and PO4-P concentrations. In all treatments runoff had higher concentrations of NO3-N (2.20-4.83 mg L-1) than of PO4-P (0.02-0.07 mg L-1), and the eroded soil had higher content of PO4-P (5.27-18.8 mg g-1) than of NO3-N (1.30-8.51 mg g-1). The control had significantly higher losses of both NO3-N (5.4, 4.4 and 19 kg ha-1) and PO4-P (0.2, 0.1 and 0.4 kg ha-1) than the other treatments. T3 reduced soil loss, runoff and nutrient losses to nearly a 100% while T1 and T2 reduced those losses from 43 to 88%. The losses of NO3-N and PO4-P were highly correlated with the amounts of runoff and eroded soil. Nutrient losses from the applied amendments were low (5.7% maximum), but the losses in the control could indicate long-term nutrient depletion in the soil (19 and 0.4 kg ha-1 of NO3-N and PO4-P, respectively). T1-T3 did not consistently increase crop yield or biomass in all three sites, but T1 increased both crop yield and biomass. We conclude that T3 (combining crop-residue mulch with organic amendment and runoff hedges) is the best treatment for steep slope areas but, the pigeon-pea hedges need to be managed for higher maize yield. T1 (combining organic amendment with soil surfactant) could be a

Effect of Integrated Water-Nutrient Management Strategies on Soil Erosion Mediated Nutrient Loss and Crop Productivity in Cabo Verde Drylands.

Science.gov (United States)

Baptista, Isaurinda; Ritsema, Coen; Geissen, Violette

2015-01-01

Soil erosion, runoff and related nutrient losses are a big risk for soil fertility in Cabo Verde drylands. In 2012, field trials were conducted in two agro-ecological zones to evaluate the effects of selected techniques of soil-water management combined with organic amendments (T1: compost/manure + soil surfactant; T2: compost/animal or green manure + pigeon-pea hedges + soil surfactant; T3: compost/animal or green manure + mulch + pigeon-pea hedges) on nitrogen (N) and phosphorus (P) losses in eroded soil and runoff and on crop yields. Three treatments and one control (traditional practice) were tested in field plots at three sites with a local maize variety and two types of beans. Runoff and eroded soil were collected after each erosive rain, quantified, and analysed for NO3-N and PO4-P concentrations. In all treatments runoff had higher concentrations of NO3-N (2.20-4.83 mg L-1) than of PO4-P (0.02-0.07 mg L-1), and the eroded soil had higher content of PO4-P (5.27-18.8 mg g-1) than of NO3-N (1.30-8.51 mg g-1). The control had significantly higher losses of both NO3-N (5.4, 4.4 and 19 kg ha-1) and PO4-P (0.2, 0.1 and 0.4 kg ha-1) than the other treatments. T3 reduced soil loss, runoff and nutrient losses to nearly a 100% while T1 and T2 reduced those losses from 43 to 88%. The losses of NO3-N and PO4-P were highly correlated with the amounts of runoff and eroded soil. Nutrient losses from the applied amendments were low (5.7% maximum), but the losses in the control could indicate long-term nutrient depletion in the soil (19 and 0.4 kg ha-1 of NO3-N and PO4-P, respectively). T1-T3 did not consistently increase crop yield or biomass in all three sites, but T1 increased both crop yield and biomass. We conclude that T3 (combining crop-residue mulch with organic amendment and runoff hedges) is the best treatment for steep slope areas but, the pigeon-pea hedges need to be managed for higher maize yield. T1 (combining organic amendment with soil surfactant) could be a

Short-Term Effects of Drying-Rewetting and Long-Term Effects of Nutrient Loading on Periphyton N:P Stoichiometry

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Andres D. Sola

2018-01-01

Full Text Available Nitrogen (N and phosphorus (P concentrations and N:P ratios critically influence periphyton productivity and nutrient cycling in aquatic ecosystems. In coastal wetlands, variations in hydrology and water source (fresh or marine influence nutrient availability, but short-term effects of drying and rewetting and long-term effects of nutrient exposure on periphyton nutrient retention are uncertain. An outdoor microcosm experiment simulated short-term exposure to variation in drying-rewetting frequency on periphyton mat nutrient retention. A 13-year dataset from freshwater marshes of the Florida Everglades was examined for the effect of long-term proximity to different N and P sources on mat-forming periphyton nutrient standing stocks and stoichiometry. Field sites were selected from one drainage with shorter hydroperiod and higher connectivity to freshwater anthropogenic nutrient supplies (Taylor Slough/Panhandle, TS/Ph and another drainage with longer hydroperiod and higher connectivity to marine nutrient supplies (Shark River Slough, SRS. Total P, but not total N, increased in periphyton mats exposed to both low and high drying-rewetting frequency with respect to the control mats in our experimental microcosm. In SRS, N:P ratios slightly decreased downstream due to marine nutrient supplies, while TS/Ph increased. Mats exposed to short-term drying-rewetting had higher nutrient retention, similar to nutrient standing stocks from long-term field data. Periphyton mat microbial communities may undergo community shifts upon drying-rewetting and chronic exposure to nutrient loads. Additional work on microbial species composition may further explain how periphyton communities interact with drying-rewetting dynamics to influence nutrient cycling and retention in wetlands.

Polymer-Coated Urea Delays Growth and Accumulation of Key Nutrients in Aerobic Rice but Does Not Affect Grain Mineral Concentrations

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Terry J. Rose

2016-01-01

Full Text Available Enhanced efficiency nitrogen (N fertilizers (EEFs may improve crop recovery of fertilizer-N, but there is evidence that some EEFs cause a lag in crop growth compared to growth with standard urea. Biomass and mineral nutrient accumulation was investigated in rice fertilized with urea, urea-3,4-dimethylpyrazole phosphate (DMPP and polymer-coated urea (PCU to determine whether any delays in biomass production alter the accumulation patterns, and subsequent grain concentrations, of key mineral nutrients. Plant growth and mineral accumulation and partitioning to grains did not differ significantly between plants fertilized with urea or urea-DMPP. In contrast, biomass accumulation and the accumulation of phosphorus, potassium, calcium, magnesium, copper, zinc and manganese were delayed during the early growth phase of plants fertilized with PCU. However, plants in the PCU treatment ultimately compensated for this by increasing growth and nutrient uptake during the latter vegetative stages so that no differences in biomass or nutrient accumulation generally existed among N fertilizer treatments at anthesis. Delayed biomass accumulation in rice fertilized with PCU does not appear to reduce the total accumulation of mineral nutrients, nor to have any impact on grain mineral nutrition when biomass and grain yields are equal to those of rice grown with urea or urea-DMPP.

Intercropping of green garlic (Allium sativum L.) induces nutrient concentration changes in the soil and plants in continuously cropped cucumber (Cucumis sativus L.) in a plastic tunnel.

Science.gov (United States)

Xiao, Xuemei; Cheng, Zhihui; Meng, Huanwen; Liu, Lihong; Li, Hezi; Dong, Yinxin

2013-01-01

A pot-based experiment was conducted to investigate nutrient concentrations in cucumber plants intercropped with various amounts of green garlic. In addition, the soil nutrient contents were studied over two consecutive growing seasons. The results revealed that the accumulation of biomass and the nutritional elements nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and manganese (Mn) in cucumber plants were significantly increased for intercropping treatments during the two growing seasons compared to monoculture. Conversely, magnesium (Mg) concentrations were decreased in the cucumber plants. Shoot iron (Fe) concentrations decreased whereas root Fe concentrations increased in the intercropping system. Shoot and root zinc (Zn) concentrations decreased during the fall of 2011 but increased during the spring of 2012. Soil organic matter and available N, P and K were significantly increased as the proportion of intercropped green garlic increasing. Medium levels of intercropping green garlic improved cucumber nutrient concentrations the most. The regression analysis showed that the concentrations of most elements were significantly related to the amounts of garlic bulbs, especially the microelements in the spring 2011. The available soil N and organic matter were linearly related to the amounts of garlic bulbs. The results indicate that the nutritional status of the soil and plants of continuously cropped cucumber could be improved by intercropping with green garlic.

The influence of gadolinium and yttrium on biomass production and nutrient balance of maize plants

International Nuclear Information System (INIS)

Saatz, Jessica; Vetterlein, Doris; Mattusch, Jürgen; Otto, Matthias; Daus, Birgit

2015-01-01

Rare earth elements (REE) are expected to become pollutants by enriching in the environment due to their wide applications nowadays. The uptake and distribution of gadolinium and yttrium and its influence on biomass production and nutrient balance was investigated in hydroponic solution experiments with maize plants using increasing application doses of 0.1, 1 and 10 mg L −1 . It could be shown that concentrations of up to 1 mg L −1 of Gd and Y did not reduce or enhance the plant growth or alter the nutrient balance. 10 mg L −1  Gd or Y resulted in REE concentrations of up to 1.2 weight-% in the roots and severe phosphate deficiency symptoms. Transfer rates showed that there was only little transport of Gd and Y from roots to shoots. Significant correlations were found between the concentration of Gd and Y in the nutrient solution and the root tissue concentration of Ca, Mg and P. - Highlights: • Roots accumulate REE in very high concentrations. • Transfer factors from root to shoot tissue are very low, with HREE higher than MREE. • The nutrient balance of the plant is severely influenced by REE addition. • Phosphate deficiency appears at high concentrations of REE addition. - The addition of the rare-earth elements Gd and Y results in less Ca and Mg uptake and phosphate deficiency in maize plants grown in hydroponics

Diagnosis of the nutrient compositional space of fruit crops

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Léon-Étienne Parent

2011-03-01

Full Text Available Tissue analysis is a useful tool for the nutrient management of fruit orchards. The mineral composition of diagnostic tissues expressed as nutrient concentration on a dry weight basis has long been used to assess the status of 'pure' nutrients. When nutrients are mixed and interact in plant tissues, their proportions or concentrations change relatively to each other as a result of synergism, antagonism, or neutrality, hence producing resonance within the closed space of tissue composition. Ternary diagrams and nutrient ratios are early representations of interacting nutrients in the compositional space. Dual and multiple interactions were integrated by the Diagnosis and Recommendation Integrated System (DRIS into nutrient indexes and by Compositional Nutrient Diagnosis into centered log ratios (CND-clr. DRIS has some computational flaws such as using a dry matter index that is not a part as well as nutrient products (e.g. NxCa instead of ratios. DRIS and CND-clr integrate all possible nutrient interactions without defining an ad hoc interactive model. They diagnose D components while D-1 could be diagnosed in the D-compositional Hilbert space. The isometric log ratio (ilr coordinates overcome these problems using orthonormal binary nutrient partitions instead of dual ratios. In this study, it is presented a nutrient interactive model as well as computation methods for DRIS and CND-clr and CND-ilr coordinates (CND-ilr using leaf analytical data from an experimental apple orchard in Southwestern Quebec, Canada. It was computed the Aitchison and Mahalanobis distances across ilr coordinates as measures of nutrient imbalance. The effect of changing nutrient concentrations on ilr coordinates are simulated to identify the ones contributing the most to nutrient imbalance.

Effect of Nutrient Solution Concentration, Time and Frequency of Foliar Application on Growth of Leaf and Daughter Corms of Saffron (Crocus sativus L.

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R Khorasani

2015-07-01

Full Text Available In order to investigate the effect of different levels of nutrient solution concentration and times and frequencies of foliar applications on dry weight, nitrogen, phosphorus and potassium concentrations of leaf and corm of saffron, a pot experiment was conducted as a completely randomized design with factorial arrangement and three replications under open door conditions in research garden of ferdowsi university, faculty of agriculture. The experimental treatments were included 4 levels of solution concentration (0, 4, 8 and 12 per 1000 and 7 levels of time and frequency of foliar applications (F1: foliar application on 3th February, F2: foliar application on 18th February, F3: foliar application on 5th March, F4: foliar applications on 3th and 18th February, F5: foliar applications on 3th February and 5th March, F6: foliar applications on 18th February and 5th March, F7: foliar applications on 3th and 18th February and 5th March. Results of variance analysis showed that fresh and dry weight of corm and leaf were not influenced by concentration, time and frequency of foliar applications. Also, comparison of nitrogen, phosphorus and potassium concentrations of leaf and corm showed that there was no significant difference between levels of foliar treatments and control. Therefore, it seems that due attention to pattern of leaf and low nutrient demand of saffron, foliar applications in different levels of nutrient solution concentrations and times and frequencies of foliar applications could not increase vegetative growth and consequently, could not improve the growth and nutritional properties of saffron corms.

Nutrient fluxes at the landscape level and the R* rule

Science.gov (United States)

Ju, Shu; DeAngelis, Donald L.

2010-01-01

Nutrient cycling in terrestrial ecosystems involves not only the vertical recycling of nutrients at specific locations in space, but also biologically driven horizontal fluxes between different areas of the landscape. This latter process can result in net accumulation of nutrients in some places and net losses in others. We examined the effects of such nutrient-concentrating fluxes on the R* rule, which predicts that the species that can survive in steady state at the lowest level of limiting resource, R*, can exclude all competing species. To study the R* rule in this context, we used a literature model of plant growth and nutrient cycling in which both nutrients and light may limit growth, with plants allocating carbon and nutrients between foliage and roots according to different strategies. We incorporated the assumption that biological processes may concentrate nutrients in some parts of the landscape. We assumed further that these processes draw nutrients from outside the zone of local recycling at a rate proportional to the local biomass density. Analysis showed that at sites where there is a sufficient biomass-dependent accumulation of nutrients, the plant species with the highest biomass production rates (roughly corresponding to the best competitors) do not reduce locally available nutrients to a minimum concentration level (that is, minimum R*), as expected from the R* rule, but instead maximize local nutrient concentration. These new results require broadening of our understanding of the relationships between nutrients and vegetation competition on the landscape level. The R* rule is replaced by a more complex criterion that varies across a landscape and reduces to the R* rule only under certain limiting conditions.

Nutrient enrichment effects on photosynthesis in the wetland plants Typha orientalis and Phormium tenax

DEFF Research Database (Denmark)

Sorrell, Brian Keith; Brix, Hans; Tanner, Chris

-growing species raupo (Typha orientalis) and slower-growing flax (Phormium tenax). Photosynthesis was compared between 9 field locations differing in nutrient availability where the two species co-existed, and in an outdoor growth experiment. Raupo accumulated higher concentrations of nitrogen (N) and especially...

Effect of organic and inorganic fertilizers on nutrient concentrations ...

African Journals Online (AJOL)

Yomi

2012-01-24

Jan 24, 2012 ... food energy and basic nutrients for proper nutrition of man. ... 2008). Irrespective of the variety, crop yield is a direct ..... had recently formed the research drive of scientists so as .... Bioresource Technology for Sustainable.

Nutrient Management in Recirculating Hydroponic Culture

Science.gov (United States)

Bugbee, Bruce

2004-01-01

There is an increasing need to recirculate and reuse nutrient solutions in order to reduce environmental and economic costs. However, one of the weakest points in hydroponics is the lack of information on managing the nutrient solution. Many growers and research scientists dump out nutrient solutions and refill at weekly intervals. Other authors have recommended measuring the concentrations of individual nutrients in solution as a key to nutrient control and maintenance. Dumping and replacing solution is unnecessary. Monitoring ions in solution is not always necessary; in fact the rapid depletion of some nutrients often causes people to add toxic amounts of nutrients to the solution. Monitoring ions in solution is interesting, but it is not the key to effective maintenance.

Nutrient dynamics and plant assemblages of Macrotermes falciger mounds in a savanna ecosystem

Science.gov (United States)

Muvengwi, Justice; Ndagurwa, Hilton G. T.; Nyenda, Tatenda; Mbiba, Monicah

2016-10-01

Termites through mound construction and foraging activities contribute significantly to carbon and nutrient fluxes in nutrient-poor savannas. Despite this recognition, studies on the influence of termite mounds on carbon and nitrogen dynamics in sub-tropical savannas are limited. In this regard, we examined soil nutrient concentrations, organic carbon and nitrogen mineralization in incubation experiments in mounds of Macrotermes falciger and surrounding soils of sub-tropical savanna, northeast Zimbabwe. We also addressed whether termite mounds altered the plant community and if effects were similar across functional groups i.e. grasses, forbs or woody plants. Mound soils had significantly higher silt and clay content, pH and concentrations of calcium (Ca), magnesium (Mg), potassium (K), organic carbon (C), ammonium (NH4+) and nitrate (NO3-) than surrounding soils, with marginal differences in phosphorus (P) and sodium (Na) between mounds and matrix soils. Nutrient enrichment increased by a factor ranging from 1.5 for C, 4.9 for Mg up to 10.3 for Ca. Although C mineralization, nitrification and nitrification fraction were similar between mounds and matrix soils, nitrogen mineralization was elevated on mounds relative to surrounding matrix soils. As a result, termite mounds supported unique plant communities rich and abundant in woody species but less diverse in grasses and forbs than the surrounding savanna matrix in response to mound-induced shifts in soil parameters specifically increased clay content, drainage and water availability, nutrient status and base cation (mainly Ca, Mg and Na) concentration. In conclusion, by altering soil properties such as texture, moisture content and nutrient status, termite mounds can alter the structure and composition of sub-tropical savanna plant communities, and these results are consistent with findings in other savanna systems suggesting that increase in soil clay content, nutrient status and associated changes in the plant

Determination of the algal growth-limiting nutrients in strip mine ponds

International Nuclear Information System (INIS)

Bucknavage, M.J.; Aharrah, E.C.

1984-01-01

Using both a test organism, Ankistrodesmus falcatus, and natural phytoplankton, the Printz Algal Assay Bottle Test was used to determine the algal growth limiting nutrients in two strip mine ponds. Nitrogen, phosphorus, and iron were investigated, singly and in combination, as possible limiting nutrients. A synthetic chelator, Na 2 EDTA, was also used in the assay to test for the presence of metal toxicants and/or trace metal limitation. Because bacteria have a major influence on water chemistry, a separate assay incorporating the natural bacteria population was performed. In both ponds, assay results using test alga indicate phosphorus to be the primary limiting nutrient and nitrogen as a secondary factor. The presence of EDTA in combination with phosphate containing treatment promoted a higher algal concentration in both ponds. Iron was determined to be a secondary limiting nutrient in only one of the ponds. Natural phytoplankton of the two ponds responded in a similar manner to nutrient increases. Only one pond had the same results produced by both assays. Nutrient availability was influenced by the presence of bacteria in one pond but not in the other

Contribution of fish farming to the nutrient loading of the Mediterranean

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Ioannis Karakassis

2005-06-01

Full Text Available Mediterranean fish farming has grown exponentially during the last 20 years. Although there is little evidence of the impact on the trophy status around fish farms, there are concerns that the release of solute wastes from aquaculture might affect larger scales in the ecosystem by changing the nutrient load. After combining information from various sources on waste production and on nutrient loads, it was concluded that the overall N and P waste from fish farms in the Mediterranean represents less than 5% of the total annual anthropogenic discharge, and the overall annual increase in P and N pools in the Mediterranean, under a production rate of 150000 tons, is less than 0.01%. The proportion of fish farming discharged nutrients was slightly higher in the eastern Mediterranean. A simple model was used to assess the long-term effects of nutrients released from various sources taking into account the water renewal rate in the Mediterranean. We conclude that, in the long term, fish farm waste could cause a 1% increase in nutrient concentrations in contrast to other anthropogenic activities which might double the Mediterranean nutrient pool.

Frequent Canned Food Use is Positively Associated with Nutrient-Dense Food Group Consumption and Higher Nutrient Intakes in US Children and Adults

OpenAIRE

Comerford, Kevin B.

2015-01-01

In addition to fresh foods, many canned foods also provide nutrient-dense dietary options, often at a lower price, with longer storage potential. The aim of this study was to compare nutrient-dense food group intake and nutrient intake between different levels of canned food consumption in the US. Consumption data were collected for this cross-sectional study from 9761 American canned food consumers (aged two years and older) from The NPD Group’s National Eating Trends® (NET®) database during...

Nutrient and Bacteria Concentrations in the Coastal Waters off ...

African Journals Online (AJOL)

ammonium, nitrate, nitrite, soluble reactive phosphorous) and bacteria (total and faecal coliforms) in the waters off Zanzibar Town. The study covered both the SE and NE monsoon and the two transition periods for a total of one year. Nutrient ...

Trace element concentrations in higher fungi

International Nuclear Information System (INIS)

Byrne, A.R.; Ravnik, V.; Kosta, L.

1976-01-01

The concentrations of ten trace elements, As, Br, Cd, Cu, Hg, I, Mn, Se, Zn and V, have been determined in up to 27 species of higher fungi from several sites in Slovenia, Yugoslavia. Analyses were based on destructive neutron activation techniques. Data are presented and compared with the concentrations found in soils. Previously values were non-existent or scanty for these elements, so that the data represent typical levels for basidiomycetes. In addition to confirming high levels of mercury in many species, the survey also found that cadmium is accumulated to a surprising extent by most fungi, the average value being 5 ppm. Among other accumulations found was bromine by the genus Amanita, and selenium by edible Boletus. Correlation analysis between all pairs of trace elements gave values for r of from 0.75 to 0.43 for 7 pairs (Cu and Hg, 0.75; Se and As, 0.69). As well as these features of biochemical interest, the values found and the pattern of accumulation suggest potential uses of fungi in environmental studies

Grand Fir Nutrient Management in the Inland Northwestern USA

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Dennis R. Parent

2016-11-01

Full Text Available Grand fir (Abies grandis (Douglas ex D. Don Lindley is widely distributed in the moist forests of the Inland Northwest. It has high potential productivity, its growth being nearly equal to western white pine, the most productive species in the region. There are large standing volumes of grand fir in the region. Nutritionally, the species has higher foliage cation concentrations than associated conifers, especially potassium (K and calcium (Ca. In contrast, it has lower nitrogen (N foliage concentrations, which creates favorable nutrient balance on N-limited sites. Despite concentration differences, grand fir stores proportionally more nutrients per tree than associated species because of greater crown biomass. Although few fertilization trials have examined grand fir specifically, its response is inferred from its occurrence in many monitored mixed conifer stands. Fertilization trials including grand fir either as a major or minor component show that it has a strong diameter and height growth response ranging from 15% to 50% depending in part on site moisture availability and soil geology. Grand fir tends to have a longer response duration than other inland conifers. When executed concurrently with thinning, fertilization often increases the total response. Late rotation application of N provides solid investment returns in carefully selected stands. Although there are still challenges with the post-fertilization effects on tree mortality, grand fir will continue to be an important species with good economic values and beneficial responses to fertilization and nutrient management.

Intercropping of Green Garlic (Allium sativum L.) Induces Nutrient Concentration Changes in the Soil and Plants in Continuously Cropped Cucumber (Cucumis sativus L.) in a Plastic Tunnel

Science.gov (United States)

Xiao, Xuemei; Cheng, Zhihui; Meng, Huanwen; Liu, Lihong; Li, Hezi; Dong, Yinxin

2013-01-01

A pot-based experiment was conducted to investigate nutrient concentrations in cucumber plants intercropped with various amounts of green garlic. In addition, the soil nutrient contents were studied over two consecutive growing seasons. The results revealed that the accumulation of biomass and the nutritional elements nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and manganese (Mn) in cucumber plants were significantly increased for intercropping treatments during the two growing seasons compared to monoculture. Conversely, magnesium (Mg) concentrations were decreased in the cucumber plants. Shoot iron (Fe) concentrations decreased whereas root Fe concentrations increased in the intercropping system. Shoot and root zinc (Zn) concentrations decreased during the fall of 2011 but increased during the spring of 2012. Soil organic matter and available N, P and K were significantly increased as the proportion of intercropped green garlic increasing. Medium levels of intercropping green garlic improved cucumber nutrient concentrations the most. The regression analysis showed that the concentrations of most elements were significantly related to the amounts of garlic bulbs, especially the microelements in the spring 2011. The available soil N and organic matter were linearly related to the amounts of garlic bulbs. The results indicate that the nutritional status of the soil and plants of continuously cropped cucumber could be improved by intercropping with green garlic. PMID:23637994

Intercropping of green garlic (Allium sativum L. induces nutrient concentration changes in the soil and plants in continuously cropped cucumber (Cucumis sativus L. in a plastic tunnel.

Directory of Open Access Journals (Sweden)

Xuemei Xiao

Full Text Available A pot-based experiment was conducted to investigate nutrient concentrations in cucumber plants intercropped with various amounts of green garlic. In addition, the soil nutrient contents were studied over two consecutive growing seasons. The results revealed that the accumulation of biomass and the nutritional elements nitrogen (N, phosphorus (P, potassium (K, calcium (Ca and manganese (Mn in cucumber plants were significantly increased for intercropping treatments during the two growing seasons compared to monoculture. Conversely, magnesium (Mg concentrations were decreased in the cucumber plants. Shoot iron (Fe concentrations decreased whereas root Fe concentrations increased in the intercropping system. Shoot and root zinc (Zn concentrations decreased during the fall of 2011 but increased during the spring of 2012. Soil organic matter and available N, P and K were significantly increased as the proportion of intercropped green garlic increasing. Medium levels of intercropping green garlic improved cucumber nutrient concentrations the most. The regression analysis showed that the concentrations of most elements were significantly related to the amounts of garlic bulbs, especially the microelements in the spring 2011. The available soil N and organic matter were linearly related to the amounts of garlic bulbs. The results indicate that the nutritional status of the soil and plants of continuously cropped cucumber could be improved by intercropping with green garlic.

Nutrient fluxes from coastal California catchments with suburban development

Science.gov (United States)

Melack, J. M.; Leydecker, A.; Beighley, E.; Robinson, T.; Coombs, S.

2005-12-01

Numerous streams originate in the mountains fringing California's coast and transport nutrients into coastal waters. In central California, these streams traverse catchments with land covers including chaparral, grazed grasslands, orchards, industrial agriculture and suburban and urban development. Fluvial nutrient concentrations and fluxes vary as a function of these land covers and as a function of considerable fluctuations in rainfall. As part of a long-term investigation of mobilization and fluvial transport of nutrients in catchments bordering the Santa Barbara Channel we have intensively sampled nutrient concentrations and measured discharge during storm and base flows in multiple catchments and subcatchments. Volume-weighted mean concentrations of nitrate generally ranged from 5 to 25 micromolar in undeveloped areas, increased to about 100 micromolar for suburban and most agricultural catchments, and were in excess of 1000 micromolar in catchments with greenhouse-based agriculture. Phosphate concentrations ranged from 2 to 20 micromolar among the catchments. These data are used to examine the premise that the suburbanized portion of the catchments is the primary source of nutrients to the streams.

Wheat cultivar tolerance to boron deficiency and toxicity in nutrient solution

Directory of Open Access Journals (Sweden)

Furlani Ângela Maria Cangiani

2003-01-01

Full Text Available Field symptoms of open spikelets in wheat were observed in specific cultivars and supposedly related to low B soils and differential B requirement among cultivars. This study aimed to evaluate the response of four wheat (Triticum aestivum L. cultivars, IAC 24, IAC 60, IAC 287 and IAC 289, to increasing B concentrations in nutrient solution. The experiment was set up in a randomized complete block design, with four replicates and five B concentrations (0.0, 0.05, 0.2, 0.8 and 2.0 mg L-1, during 1997/1998, in a greenhouse. Plants were grown to maturity and evaluated for plant height, spike number and length, open spikelet number, grains per spike, plant parts dry matter, B, P, K, Ca and Mg leaf concentrations and total nutrient contents. The visual symptoms of B deficiency consisted of open spikelets, distorted spikes without grains. 'IAC 60' and 'IAC 287' had higher B efficiency, with the highest grain yields in lower B concentrations. The 'IAC 287' and 'IAC 24' were more tolerant to the highest B concentrations. 'IAC 24' required more B for grain production as compared to the other cultivars. The critical leaf B concentration for deficiency was 25 mg kg-1 of dry matter tissue for all cultivars, and for toxicity were: 44 to 45 mg kg-1 for 'IAC 60' and 'IAC 289'; 228 and 318 mg kg-1 for 'IAC 24' and 'IAC 287', respectively. Except for the highest B level in the nutrient solution, the leaf P, K, Ca and Mg concentrations and whole plant contents were in an adequate range in the plants and did not vary among cultivars.

The Relative Concentrations of Nutrients and Toxins Dictate Feeding by a Vertebrate Browser, the Greater Glider Petauroides volans.

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Lora M Jensen

Full Text Available Although ecologists believe that vertebrate herbivores must select a diet that allows them to meet their nutritional requirements, while avoiding intoxication by plant secondary metabolites, this is remarkably difficult to show. A long series of field and laboratory experiments means that we have a good understanding of the factors that affect feeding by leaf-eating marsupials. This knowledge and the natural intraspecific variation in Eucalyptus chemistry allowed us to test the hypothesis that the feeding decisions of greater gliders (Petauroides volans depend on the concentrations of available nitrogen (incorporating total nitrogen, dry matter digestibility and tannins and of formylated phloroglucinol compounds (FPCs, potent antifeedants unique to Eucalyptus. We offered captive greater gliders foliage from two species of Eucalyptus, E. viminalis and E. melliodora, which vary naturally in their concentrations of available nitrogen and FPCs. We then measured the amount of foliage eaten by each glider and compared this with our laboratory analyses of foliar total nitrogen, available nitrogen and FPCs for each tree offered. The concentration of FPCs was the main factor that determined how much gliders ate of E. viminalis and E. melliodora, but in gliders fed E. viminalis the concentration of available nitrogen was also a significant influence. In other words, greater gliders ate E. viminalis leaves with a particular combination of FPCs and available nitrogen that maximised the nutritional gain but minimised their ingestion of toxins. In contrast, the concentration of total nitrogen was not correlated with feeding. This study is among the first to empirically show that browsing herbivores select a diet that balances the potential gain (available nutrients and the potential costs (plant secondary chemicals of eating leaves. The major implication of the study is that it is essential to identify the limiting nutrients and relevant toxins in a system in

Response of non-added solutes during nutrient addition experiments in streams

Science.gov (United States)

Rodriguez-Cardona, B.; Wymore, A.; Koenig, L.; Coble, A. A.; McDowell, W. H.

2015-12-01

Nutrient addition experiments, such as Tracer Additions for Spiraling Curve Characterization (TASCC), have become widely popular as a means to study nutrient uptake dynamics in stream ecosystems. However, the impact of these additions on ambient concentrations of non-added solutes is often overlooked. TASCC addition experiments are ideal for assessing interactions among solutes because it allows for the characterization of multiple solute concentrations across a broad range of added nutrient concentrations. TASCC additions also require the addition of a conservative tracer (NaCl) to track changes in conductivity during the experimental manipulation. Despite its use as a conservative tracer, chloride (Cl) and its associated sodium (Na) might change the concentrations of other ions and non-added nutrients through ion exchange or other processes. Similarly, additions of biologically active solutes might change the concentrations of other non-added solutes. These methodological issues in nutrient addition experiments have been poorly addressed in the literature. Here we examine the response of non-added solutes to pulse additions (i.e. TASCC) of NaCl plus nitrate (NO3-), ammonium, and phosphate across biomes including temperate and tropical forests, and arctic taiga. Preliminary results demonstrate that non-added solutes respond to changes in the concentration of these added nutrients. For example, concentrations of dissolved organic nitrogen (DON) in suburban headwater streams of New Hampshire both increase and decrease in response to NO3- additions, apparently due to biotic processes. Similarly, cations such as potassium, magnesium, and calcium also increase during TASCC experiments, likely due to cation exchange processes associated with Na addition. The response of non-added solutes to short-term pulses of added nutrients and tracers needs to be carefully assessed to ensure that nutrient uptake metrics are accurate, and to detect biotic interactions that may

Lichen substances prevent lichens from nutrient deficiency.

Science.gov (United States)

Hauck, Markus; Willenbruch, Karen; Leuschner, Christoph

2009-01-01

The dibenzofuran usnic acid, a widespread cortical secondary metabolite produced by lichen-forming fungi, was shown to promote the intracellular uptake of Cu(2+) in two epiphytic lichens, Evernia mesomorpha and Ramalina menziesii, from acidic, nutrient-poor bark. Higher Cu(2+) uptake in the former, which produces the depside divaricatic acid in addition to usnic acid, suggests that this depside promotes Cu(2+) uptake. Since Cu(2+) is one of the rarest micronutrients, promotion of Cu(2+) uptake by lichen substances may be crucial for the studied lichens to survive in their nutrient-poor habitats. In contrast, study of the uptake of other metals in E. mesomorpha revealed that the intracellular uptake of Mn(2+), which regularly exceeds potentially toxic concentrations in leachates of acidic tree bark, was partially inhibited by the lichen substances produced by this species. Inhibition of Mn(2+) uptake by lichen substances previously has been demonstrated in lichens. The uptake of Fe(2+), Fe(3+), Mg(2+), and Zn(2+), which fail to reach toxic concentrations in acidic bark at unpolluted sites, although they are more common than Cu(2+), was not affected by lichen substances of E. mesomorpha.

Report Assesses Nutrient Pollution in U.S. Streams and Aquifers

Science.gov (United States)

Showstack, Randy

2010-10-01

Concentrations of nutrients in many U.S. streams and aquifers have remained the same or have increased since the early 1990s, according to a new decadal assessment entitled “Nutrients in the nation's streams and groundwater, 1992-2004,” released by the U.S. Geological Survey (USGS) on 24 September. “Despite improvements in water quality made by reducing point sources of nutrients, our data show that nonpoint sources of nutrients have resulted in concentrations of both nitrogen and phosphorus far above criteria recommended by [the U.S. Environmental Protection Agency] for the protection of aquatic life,” Neil Dubrovsky, project chief for USGS's National Water-Quality Assessment (NAWQA) Program, said at a briefing when the report was released. While USGS continues to sample for nutrient concentrations, the report assessment period concluded in 2004.

Reuse potential of laundry greywater for irrigation based on growth, water and nutrient use of tomato

Science.gov (United States)

Misra, R. K.; Patel, J. H.; Baxi, V. R.

2010-05-01

SummaryGreywater is considered as a valuable resource with a high reuse potential for irrigation of household lawns and gardens. However, there are possibilities of surfactant and sodium accumulation in soil from reuse of greywater which may affect agricultural productivity and environmental sustainability adversely. We conducted a glasshouse experiment to examine variation in growth, water and nutrient use of tomato ( Lycopersicon esculentum Mill. cv. Grosse Lisse) using tap water (TW), laundry greywater (GW) and solutions of low and high concentration of a detergent surfactant (LC and HC, respectively) as irrigation treatments. Each treatment was replicated five times using a randomised block design. Measurements throughout the experiment showed greywater to be significantly more alkaline and saline than the other types of irrigation water. Although all plants received 16 irrigations over a period of 9 weeks until flowering, there were little or no significant effects of irrigation treatments on plant growth. Soil water retention following irrigation reduced significantly when plants were irrigated with GW or surfactant solutions on only three of 12 occasions. On one occasion, water use measured as evapotranspiration (ET) with GW irrigation was similar to TW, but it was significantly higher than the plants receiving HC irrigation. At harvest, various components of plant biomass and leaf area for GW irrigated plants were found to be similar or significantly higher than the TW irrigated plants with a common trend of GW ⩾ TW > LC ⩾ HC. Whole-plant concentration was measured for 12 essential plant nutrients (N, P, K, Ca, Mg, S, Fe, Cu, Mn, Zn, Mo and B) and Na (often considered as a beneficial nutrient). Irrigation treatments affected the concentration of four nutrients (P, Fe, Zn and Na) and uptake of seven nutrients (P, K, Ca, Mg, Na, Fe and B) significantly. Uptake of these seven nutrients by tomato was generally in the order GW ⩾ TW > HC ⩾ LC. GW

Review on Periphyton as Mediator of Nutrient Transfer in Aquatic Ecosystems

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Surjya K. Saikia

2011-12-01

Full Text Available In the studies of aquatic ecology, periphyton has been uncared for despite its vital role in nutrient uptake and transfer to the upper trophic organisms. Being the component of food chain as attached organism it takes part in nutrient cycling in the ecosystem like that of suspended planktonic counterparts. The present review, with an aim to understand the role of periphyton in nutrient transfer from benthic environment to upper trophic level, focuses many aspects of periphyton-nutrient relationship based on available literatures. It also attempts to redefine periphyton, as a part of biofilm, harboring nutrient components like protein, fat and carbohydrate preferably in its extracellular polymeric substance (EPS, cyanobacteria, diatom and other algal communities. In addition to physical processes, nutrient uptake by periphyton is catalyzed by enzymes like Nitrogen Reductase and Alkaline Phosphatase from the environment. This uptake and transfer is further regulated by periphytic C: nutrient (N or P stoichiometry, colonization time, distribution of periphyton cover on sediments and macrophytes, macronutrient concentration, grazing, sloughing, temperature, and advective transport. The Carbon (C sources of periphyton are mainly dissolve organic matter and photosynthetic C that enters into higher trophic levels through predation and transfers as C-rich nutrient components. Despite of emerging interests on utilizing periphyton as nutrient transfer tool in aquatic ecosystem, the major challenges ahead for modern aquatic biologists lies on determining nutrient uptake and transfer rate of periphyton, periphytic growth and simulating nutrient models of periphyton to figure a complete energy cycle in aquatic ecosystem.

TEORES DE NUTRIENTES EM POVOAMENTOS MONOESPECÍFICOS E MISTOS DE Eucalyptus urograndis e Acacia mearnsii em SISTEMA AGROSSILVICULTURAL

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Márcio Viera

2013-01-01

Full Text Available The study had as objective compare the nutrients content in the different species involved in monospecific and mixed stands of Eucalyptus urograndis and Acacia mearnsii and in a consortium with Zea mays. The determination for forest species nutrients concentration, the treatments 100E (100 % eucalyptus + maize; 100A (100 % black-wattle + maize and 50E:50A (50 % eucalyptus + 50 % black-wattle + maize, and in the maize were done in treatments 100E; 100A, 50E:50A; 75E:25A (75 % eucalyptus + 25 % black-wattle + maize and 25E:75A (25 % eucalyptus + 75 % black-wattle + maize. The experimental design was a randomized block design with three replications. Forests species sampling was made in average tree in each plot, based on diameter at breast height (DBH, in three trees six month-old per treatment. Within all treatments and your replicates, installed one subplot with long 3.0 m by three corn-rows as wide, where the plants were harvested in stem, leaf, grain, cob and straw. With the exception of Ca, which was more concentrated in the bark fraction and Mg and B in the bark and leaves, the other nutrients in Eucalyptus urograndis, so in monoculture much in mixed stands, contained higher concentration just in leaves. The grain component has the highest concentrations of nitrogen and phosphorus, as straw and cob have the highest potassium concentration and the leaf component has the largest concentrations of other nutrients. The forest species did not influence significantly the levels of nutrients in components of aboveground biomass of maize.

Concentration of nutrient solution in the hydroponic production of potato minitubers Concentração da solução nutritiva na produção hidropônica de minitubérculos de batata

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Manuel Benito Novella

2008-09-01

Full Text Available The effect of the nutrient solution concentration on potato plant growth and minituber yield were determined in a sand closed hydroponic system. Minitubers and micropropagated plantlets of the cv. 'Macaca' were used. Treatments were five nutrient solution concentrations at electrical conductivities (EC of 1.0 (T1, 2.2 (T2, 3.4 (T3, 4.7 (T4 and 5.8dS m-1 (T5. The split plot randomised experimental design was used with three replications. Plants from minitubers produced higher fresh and mean weight of minitubers, shoot dry mass and leaf area index than the micropropagated ones. However, higher dry mass of minitubers was found with micropropagated plantlets compared to minitubers. The concentration of the nutrient solution did not affect minituber number. Increasing the nutrient solution concentration decreased total and minituber dry mass production of micropropagated plantlets and plant growth and minituber production of minituber-originated plants. Low concentration of nutrient solution at an EC of about 1.0dS m-1 can be used in the hydroponic production of potato minitubers of both micropropagated and minituber-originated plants.Neste trabalho foi determinado o efeito da concentração da solução nutritiva no crescimento e na produtividade de minitubérculos de batata em um sistema hidropônico fechado empregando areia como substrato. Plântulas micropropagadas e minitubérculos foram plantados em 24 de março de 2004. Os tratamentos foram cinco soluções nutritivas com condutividades elétricas (CE de 1,0 (T1, 2,2 (T2, 3,4 (T3, 4,7 (T4 e 5,8dS m-1 (T5. O experimento foi conduzido em parcelas subdivididas no delineamento inteiramente casualizado com três repetições. Plantas originadas de minitubérculos produziram mais massa fresca total e média de minitubérculos, massa seca da parte aérea e maior índice de área foliar que plantas micropropagadas. Entretanto, maior massa seca dos minitubérculos foi obtida em plantas micropropagadas

Coastal Acidification as Nutrients Over Enrichment Impact: A Case Study in Ambon Bay, Indonesia

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Idha Yulia Ikhsani

2017-05-01

Full Text Available Ambon Bay is a silled bay on Ambon Island consisting of two regions, Inner Ambon Bay (IAB and Outer Ambon Bay (OAB that are separated by shallow sill. Ambon bay and its surrounding have economically important ecosystem since the utilization for many activities. The bay is affected by anthropogenic impacts associated with urbanization, climate change, and nutrients over enrichment. The “deep water-rich nutrients” from Banda Sea that enter the bay during Southeast monsoon also contribute to this enrichment as well as the nutrients transport from the land. The high concentration of nutrients increases carbon dioxide level and promotes acidifications. There are literatures about nutrients over enrichment in Ambon Bay, however, little is known about coastal acidification as nutrients over enrichment impact. In order to study the effect of nutrients distribution on the acidity of Ambon Bay, the researchers measured pH and concentrations of nutrients {nitrate + nitrite (N+N and Soluble Reactive Phosphate (SRP} from water samples collected in 7 stations on both IAB and OAB during Southeast monsoon. The results showed that in surface water, nutrients concentrations is increased from May to June due to the “deep water flushing” occurrence on May and increased precipitations from May to June. From July to August, the nutrients concentrations on surface layer decreased, due to the decreased precipitations. In column and bottom water, the nutrients concentrations were increased from May to August. While the acidity have reverse pattern from the nutrients, when nutrient concentrations increased the acidity was decreased. From correlation test, pH was not significantly correlated with the concentrations of nutrients on surface water, but showed significantly correlated on column and bottom water. The results indicated that the distribution of nutrients on column and bottom water might be an important environmental factor affecting the acidification of

Effects of arsenic on concentration and distribution of nutrients in the fronds of the arsenic hyperaccumulator Pteris vittata L

International Nuclear Information System (INIS)

Tu Cong; Ma, Lena Q.

2005-01-01

Pteris vittata was the first terrestrial plant known to hyperaccumulate arsenic (As). However, it is unclear how As hyperaccumulation influences nutrient uptake by this plant. P. vittata fern was grown in soil spiked with 0-500 mg As kg -1 in the greenhouse for 24 weeks. The concentrations of essential macro- (P, K, Ca, and Mg) and micro- (Fe, Mn, Cu, Zn, B and Mo) elements in the fronds of different age were examined. Both macro- and micronutrients in the fronds were found to be within the normal concentration ranges for non-hyperaccumulators. However, As hyperaccumulation did influence the elemental distribution among fronds of different age of P. vittata. Arsenic-induced P and K enhancements in the fronds contributed to the As-induced growth stimulation at low As levels. The frond P/As molar ratios of 1.0 can be used as the threshold value for normal growth of P. vittata. Potassium may function as a counter-cation for As in the fronds as shown by the As-induced K increases in the fronds. The present findings not only demonstrate that P. vittata has the ability to maintain adequate concentrations of essential nutrients while hyperaccumulating As from the soil, but also have implications for soil management (fertilization in particular) of P. vittata in As phytoextraction practice

Nutrient uptake and biomass accumulation for eleven different field crops

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K. HAKALA

2008-12-01

Full Text Available Oil hemp (Cannabis sativa L., quinoa (Chenopodium quinoa Willd., false flax (Camelina sativa (L. Crantz, caraway (Carum carvi L., dyer’s woad (Isatis tinctoria L., nettle (Urtica dioica L., reed canary grass (RCG (Phalaris arundinacea L., buckwheat (Fagopyrum esculentum Moench, linseed (Linum usitatissimum L., timothy (Phleum pratense L. and barley (Hordeum vulgare L. were grown under uniform conditions in pots containing well fertilised loam soil. Dry matter (DM accumulation was measured repeatedly, and contents of minerals N, P, K, Ca and Mg at maturity. Annual crops accumulated above-ground biomass faster than perennials, while perennials had higher DM accumulation rates below ground. Seeds had high concentrations of N and P, while green biomass had high concentrations of K and Ca. Stems and roots had low concentrations of minerals. Concentrations of K and P were high in quinoa and caraway, and that of P in buckwheat. Hemp and nettle had high Ca concentrations, and quinoa had high Mg concentration. N and P were efficiently harvested with seed, Ca and K with the whole biomass. Perennials could prevent soil erosion and add carbon to the soil in the long term, while annuals compete better with weeds and prevent erosion during early growth. Nutrient balances in a field could be modified and nutrient leaching reduced by careful selection of the crop and management practices.;

Effects of forest fire on soil nutrients in Turkish pine (Pinus brutia, Ten) ecosystems.

Science.gov (United States)

Yildiz, Oktay; Esen, Derya; Sarginci, Murat; Toprak, Bulent

2010-01-01

Fire is a long-standing and poorly understood component of the Mediterranean forestlands in Turkey. Fire can alter plant composition, destroy biomass, alter soil physical and chemical properties and reduce soil nutrient pools. However fire can also promote productivity of certain ecosystems by mineralizing soil nutrients and promoting fast growing nitrogen fixing plant species. Fire effects on soils and ecosystems in Turkey and Mediterranean regions are not well understood. This study uses a retrospective space-for-time substitution to study soil macro-nutrient changes on sites which were burned at different times during the last 8 years. The study sites are in the Fethiye Forest Management Directorate in the western Mediterranean Sea region of Turkey. Our samples show 40% less Soil C, and cation exchange capacity (CEC) at 0-20 cm soil depth two weeks after the fire. Soil C and CEC appear to recover to pre-fire level in one year. Concentrations of Mg were significantly lower on new-burn sites, but returned to pre-fire levels in one year. Total soil N concentrations one and two years after fire were 90% higher than other sites, and total P was 9 times higher on new-burn site than averages from other sites. Some implications of these results for forest managers are discussed.

Protection from wintertime rainfall reduces nutrient losses and greenhouse gas emissions during the decomposition of poultry and horse manure-based amendments.

Science.gov (United States)

Maltais-Landry, Gabriel; Neufeld, Katarina; Poon, David; Grant, Nicholas; Nesic, Zoran; Smukler, Sean

2018-04-01

Manure-based soil amendments (herein "amendments") are important fertility sources, but differences among amendment types and management can significantly affect their nutrient value and environmental impacts. A 6-month in situ decomposition experiment was conducted to determine how protection from wintertime rainfall affected nutrient losses and greenhouse gas (GHG) emissions in poultry (broiler chicken and turkey) and horse amendments. Changes in total nutrient concentration were measured every 3 months, changes in ammonium (NH 4 + ) and nitrate (NO 3 - ) concentrations every month, and GHG emissions of carbon dioxide (CO 2 ), methane (CH 4 ), and nitrous oxide (N 2 O) every 7-14 days. Poultry amendments maintained higher nutrient concentrations (except for K), higher emissions of CO 2 and N 2 O, and lower CH 4 emissions than horse amendments. Exposing amendments to rainfall increased total N and NH 4 + losses in poultry amendments, P losses in turkey and horse amendments, and K losses and cumulative N 2 O emissions for all amendments. However, it did not affect CO 2 or CH 4 emissions. Overall, rainfall exposure would decrease total N inputs by 37% (horse), 59% (broiler chicken), or 74% (turkey) for a given application rate (wet weight basis) after 6 months of decomposition, with similar losses for NH 4 + (69-96%), P (41-73%), and K (91-97%). This study confirms the benefits of facilities protected from rainfall to reduce nutrient losses and GHG emissions during amendment decomposition. The impact of rainfall protection on nutrient losses and GHG emissions was monitored during the decomposition of broiler chicken, turkey, and horse manure-based soil amendments. Amendments exposed to rainfall had large ammonium and potassium losses, resulting in a 37-74% decrease in N inputs when compared with amendments protected from rainfall. Nitrous oxide emissions were also higher with rainfall exposure, although it had no effect on carbon dioxide and methane emissions

Evaluation of high nutrient diets on litter performance of heat-stressed lactating sows

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Yohan Choi

2017-11-01

Full Text Available Objective The present study investigated the litter performance of multiparous sows fed 3% and 6% densified diets at farrowing to weaning during summer with mean maximum room temperature of 30.5°C. Methods A total of 60 crossbred multiparous sows were allotted to one of three treatments based on body weight according to a completely randomized design. Three different nutrient levels based on NRC were applied as standard diet (ST; metabolizable energy, 3,300 kcal/kg, high nutrient level 1 (HE1; ST+3% higher energy and 16.59% protein and high nutrient level 2 (HE2; ST+6% higher energy and 17.04% protein. Results There was no variation in the body weight change. However, backfat thickness change tended to reduce in HE1 in comparison to ST treatment. Dietary treatments had no effects on feed intake, daily energy intake and weaning-to-estrus interval in lactating sows. Litter size, litter weight at weaning and average daily gain of piglets were significantly greater in sows in HE1 compared with ST, however, no difference was observed between HE2 and ST. Increasing the nutrient levels had no effects on the blood urea nitrogen, glucose, triglyceride, and creatinine at post-farrowing and weaning time. The concentration of follicle stimulating hormone, cortisol and insulin were not affected by dietary treatments either in post-farrowing or weaning time. The concentration of blood luteinizing hormone of sows in ST treatment was numerically less than sows in HE2 treatment at weaning. Milk and colostrum compositions such as protein, fat and lactose were not affected by the treatments. Conclusion An energy level of 3,400 kcal/kg (14.23 MJ/kg with 166 g/kg crude protein is suggested as the optimal level of dietary nutrients for heat stressed lactating sows with significant beneficial effects on litter size.

Nutrient removal from swine lagoon effluent by duckweed

Energy Technology Data Exchange (ETDEWEB)

Bergmann, B.A.; Cheng, J.; Classen, J.; Stomp, A.M.

2000-04-01

Three duckweed geographic isolates were grown on varying concentrations of swine lagoon effluent in a greenhouse to determine their ability to remove nutrients from the effluent. Duckweed biomass was harvested every other day over a 12-day period. Duckweed biomass production, nutrient loss from the swine lagoon effluent, and nutrient content of duckweed biomass were used to identify effluent concentrations/geographic isolate combinations that are effective in terms of nutrient utilization from swine lagoon effluent and production of healthy duckweed biomass. When Lemna minor geographic isolate 8627 was grown on 50% swine lagoon effluent, respective losses of TKN, NH{sub 3}-N, TP, OPO{sub 4}-P, TOC, K, Cu, and Zn were 83, 100, 49, 31, 68, 21, 28 and 67%.

Fisheries management under nutrient influence

DEFF Research Database (Denmark)

Hammarlund, Cecilia; Nielsen, Max; Waldo, Staffan

2018-01-01

A fisheries management model that identifies the economic optimal management of fisheries under the influence of nutrients is presented. The model starts from the idea that growth in fish biomass increases with increasing availability of nutrients owing to higher food availability up to a peak...

High sugar consumption and poor nutrient intake among drug addicts in Oslo, Norway.

Science.gov (United States)

Saeland, M; Haugen, M; Eriksen, F-L; Wandel, M; Smehaugen, A; Böhmer, T; Oshaug, A

2011-02-01

Poor dietary habits among drug addicts represent health hazards. However, very few studies have focused on dietary intake as an independent health risk factor in relation to this group. The objective of the present study was to examine the dietary habits of drug addicts living on the fringes of an affluent society. The study focused on food access, food preferences, intake of energy and nutrients, and related nutrient blood concentrations. The respondent group consisted of 123 male and seventy-two female drug addicts, who participated in a cross-sectional study that included a 24 h dietary recall, blood samples, anthropometrical measurements and a semi-structured interview concerning food access and preferences. Daily energy intake varied from 0 to 37 MJ. Food received from charitable sources and friends/family had a higher nutrient density than food bought by the respondents. Added sugar accounted for 30 % of the energy intake, which was mirrored in biomarkers. Sugar and sugar-sweetened food items were preferred by 61 % of the respondents. Of the respondents, 32 % had a TAG concentration above the reference values, while 35 % had a cholesterol concentration beneath the reference values. An elevated serum Cu concentration indicated inflammation among the respondents. Further research on problems related to the diets of drug addicts should focus on dietary habits and aim to uncover connections that may reinforce inebriation and addiction.

Intake and nutrient digestibilies of all-concentrate diet form forage ...

African Journals Online (AJOL)

A total or 20 animals comprising 10 rams and 10 bucks were involved in a digestibility study to assess the nutritive value of a combination of yam peel, ... The dry matter intakes in the all-concentrate diet by the sheep and goat ( > 4% of body weight) were higher (p<0.05) than obtained for the conventional diet of grass hay ...

Relationships between nutrient enrichment, pleurocerid snail density and trematode infection rate in streams

Science.gov (United States)

Ciparis, Serena; Iwanowicz, Deborah D.; Voshell, J. Reese

2013-01-01

Summary 1. Nutrient enrichment is a widespread environmental problem in freshwater ecosystems. Eutrophic conditions caused by nutrient enrichment may result in a higher prevalence of infection by trematode parasites in host populations, due to greater resource availability for the molluscan first intermediate hosts. 2. This study examined relationships among land use, environmental variables indicating eutrophication, population density of the pleurocerid snail, Leptoxis carinata, and trematode infections. Fifteen study sites were located in streams within the Shenandoah River catchment (Virginia, U.S.A.), where widespread nutrient enrichment has occurred. 3. Snail population density had a weak positive relationship with stream water nutrient concentration. Snail population density also increased as human activities within stream catchments increased, but density did not continue to increase in catchments where anthropogenic disturbance was greatest. 4. Cercariae from five families of trematodes were identified in L. carinata, and infection rate was generally low (<10%). Neither total infection rate nor the infection rate of individual trematode types showed a positive relationship with snail population density, nutrients or land use. 5. There were statistically significant but weak relationships between the prevalence of infection by two trematode families and physical and biological variables. The prevalence of Notocotylidae was positively related to water depth, which may be related to habitat use by definitive hosts. Prevalence of Opecoelidae had a negative relationship with orthophosphate concentration and a polynomial relationship with chlorophyll a concentration. Transmission of Opecoelid trematodes between hosts may be inhibited by eutrophic conditions. 6. Leptoxis carinata appears to be a useful species for monitoring the biological effects of eutrophication and investigating trematode transmission dynamics in lotic systems.

Hyperspectral remote sensing techniques for grass nutrient estimations in savannah ecosystems

CSIR Research Space (South Africa)

Ramoelo, Abel

2010-03-01

Full Text Available Information on the distribution of grass quality (nutrient concentration) is crucial in understanding rangeland vitality and facilitates effective management of wildlife and livestock. The spatial distribution of grass nutrient concentration occurs...

Upland and in-stream controls on baseflow nutrient dynamics in tile-drained agroecosystem watersheds

Science.gov (United States)

Ford, William I.; King, Kevin; Williams, Mark R.

2018-01-01

In landscapes with low residence times (e.g., rivers and reservoirs), baseflow nutrient concentration dynamics during sensitive timeframes can contribute to deleterious environmental conditions downstream. This study assessed upland and in-stream controls on baseflow nutrient concentrations in a low-gradient, tile-drained agroecosystem watershed. We conducted time-series analysis using Empirical mode decomposition of seven decade-long nutrient concentration time-series in the agricultural Upper Big Walnut Creek watershed (Ohio, USA). Four tributaries of varying drainage areas and three main-stem sites were monitored, and nutrient grab samples were collected weekly from 2006 to 2016 and analyzed for dissolved reactive phosphorus (DRP), nitrate-nitrogen (NO3-N), total nitrogen (TN), and total phosphorus (TP). Statistically significant seasonal fluctuations were compared with seasonality of baseflow, watershed characteristics (e.g., tile-drain density), and in-stream water quality parameters (pH, DO, temperature). Findings point to statistically significant seasonality of all parameters with peak P concentrations in summer and peak N in late winter-early spring. Results suggest that upland processes exert strong control on DRP concentrations in the winter and spring months, while coupled upland and in-stream conditions control watershed baseflow DRP concentrations during summer and early fall. Conversely, upland flow sources driving streamflow exert strong control on baseflow NO3-N, and in-stream attenuation through transient and permanent pathways impacts the magnitude of removal. Regarding TN and TP, we found that TN was governed by NO3-N, while TP was governed by DRP in summer and fluvial erosion of P-rich benthic sediments during higher baseflow conditions. Findings of the study highlight the importance of coupled in-stream and upland management for mitigating eutrophic conditions during environmentally sensitive timeframes.

Impact of Temperature and Nutrients on Carbon: Nutrient Tissue Stoichiometry of Submerged Aquatic Plants: An Experiment and Meta-Analysis

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Mandy Velthuis

2017-05-01

Full Text Available Human activity is currently changing our environment rapidly, with predicted temperature increases of 1–5°C over the coming century and increased nitrogen and phosphorus inputs in aquatic ecosystems. In the shallow parts of these ecosystems, submerged aquatic plants enhance water clarity by resource competition with phytoplankton, provide habitat, and serve as a food source for other organisms. The carbon:nutrient stoichiometry of submerged aquatic plants can be affected by changes in both temperature and nutrient availability. We hypothesized that elevated temperature leads to higher carbon:nutrient ratios through enhanced nutrient-use efficiency, while nutrient addition leads to lower carbon:nutrient ratios by the luxurious uptake of nutrients. We addressed these hypotheses with an experimental and a meta-analytical approach. We performed a full-factorial microcosm experiment with the freshwater plant Elodea nuttallii grown at 10, 15, 20, and 25°C on sediment consisting of pond soil/sand mixtures with 100, 50, 25, and 12.5% pond soil. To address the effect of climatic warming and nutrient addition on the carbon:nutrient stoichiometry of submerged freshwater and marine plants we performed a meta-analysis on experimental studies that elevated temperature and/or added nutrients (nitrogen and phosphorus. In the microcosm experiment, C:N ratios of Elodea nuttallii decreased with increasing temperature, and this effect was most pronounced at intermediate nutrient availability. Furthermore, higher nutrient availability led to decreased aboveground C:P ratios. In the meta-analysis, nutrient addition led to a 25, 22, and 16% reduction in aboveground C:N and C:P ratios and belowground C:N ratios, accompanied with increased N content. No consistent effect of elevated temperature on plant stoichiometry could be observed, as very few studies were found on this topic and contrasting results were reported. We conclude that while nutrient addition

Temporal Changes in the Spatial Variability of Soil Nutrients

Energy Technology Data Exchange (ETDEWEB)

Hoskinson, Reed Louis; Hess, John Richard; Alessi, Randolph Samuel

1999-07-01

This paper reports the temporal changes in the spatial variability of soil nutrient concentrations across a field during the growing season, over a four-year period. This study is part of the Site-Specific Technologies for Agriculture (SST4Ag) precision farming research project at the INEEL. Uniform fertilization did not produce a uniform increase in fertility. During the growing season, several of the nutrients and micronutrients showed increases in concentration although no additional fertilization had occurred. Potato plant uptake did not explain all of these changes. Some soil micronutrient concentrations increased above levels considered detrimental to potatoes, but the plants did not show the effects in reduced yield. All the nutrients measured changed between the last sampling in the fall and the first sampling the next spring prior to fertilization. The soil microbial community may play a major role in the temporal changes in the spatial variability of soil nutrient concentrations. These temporal changes suggest potential impact when determining fertilizer recommendations, and when evaluating the results of spatially varying fertilizer application.

Can radiocaesium be used as a tracer for vegetal nutrients?

International Nuclear Information System (INIS)

Anjos, R. M.; Mosquera, B.; Carvalho, C.; Sanches, N.; Bastos, J.; Macario, K.; Vezzone, M.; Gomes, P.R.S.

2007-01-01

In recent years, there has been a growing interest in the evaluation of nutrient fluxes and radioactive contaminants in forest and agricultural ecosystems. Several studies on forest ecosystems have been carried out, mostly in Europe, after the Chernobyl accident. These studies have been performed mainly in the development of models for predicting the radiocaesium behavior in the soil and plant compartments of forest systems. However, research on the use of radiocaesium as a tracer for vegetal nutrients has shown that, despite the fact that caesium is a weakly hydrated alkaline metal and has chemical similarities to potassium and ammonium, this is still a complex problem requiring, then, more experimental results. Additionally, very little is known about the mechanisms involved in the radionuclide uptake and retention by tropical plants. In order to contribute to the understanding of the relative behavior of caesium, potassium and ammonium and to investigate whether radiocaesium can be used as a tracer for vegetal nutrients, the Laboratory of Radioecology (LARA) of the Federal Fluminense University has been performing analysis of 137 Cs, 40 K and NH 4 concentrations in several vegetal compartments of agricultural tropical plants, such as guava (Psidium guajava), mango (Mangifera indica), avocado (Persea americana), pomegranate (Punica granatum), papaya (Carica Papaya), banana (Musa paradisiaca), manioc (Manihot Esculenta), and chili pepper (Capsicum fructescens) trees. Measurements of 137 Cs, 40 K and NH 4 concentrations show that these elements can be very mobile within a plant, exhibiting the highest values of concentration in the growing parts of the trees: fruits, leaves, twigs, barks and the outer growth layers. On the other hand, our results indicate that for wood trees (such as guava, mango, avocado, pomegranate and chili pepper trees) do both caesium and the vegetal nutrients have simultaneously higher concentrations in the youngest rather than in the oldest

Nutrient and carbohydrate partitioning in sorghum stover

International Nuclear Information System (INIS)

Powell, J.M.; Hons, F.M.; McBee, G.G.

1991-01-01

Sorghum [Sorghum bicolor (L.) Moench] stover has been demonstrated to be a potential biomass energy source. Complete aboveground crop removal, however, can result in soil degradation. Differential dry matter, nutrient, and carbohydrate partitioning by sorghum cultivars may allow management strategies that return certain parts to the field while removing other portions for alternative uses, such as energy production. A field study was conducted to determine N,P,K, nonstructural carbohydrate, cellulose hemicellulose, and lignin distributions in stover of three diverse sorghum cultivars of differing harvest indices. Determinations were based on total vegetative biomass; total blades; total stalks; and upper middle, and lower blades and stalks. Concentrations of N and P were higher in blades than stalks and generally declines from upper to lower stover parts. Large carbohydrate and lignin concentration differences were observed on the basis of cultivar and stover part. Greater nutrient partitioning to the upper third of the intermediate and forage-type sorghum stovers was observed as compared to the conventional grain cultivar. Stover carbohydrates for all cultivars were mainly contained in the lower two-thirds of the stalk fraction. A system was proposed for returning upper stover portion to soil, while removing remaining portions for alternative uses

Enhanced nutrition improves growth and increases blood adiponectin concentrations in very low birth weight infants

Directory of Open Access Journals (Sweden)

Elin W. Blakstad

2016-12-01

Full Text Available Background: Adequate nutrient supply is essential for optimal postnatal growth in very low birth weight (VLBW, birth weight<1,500 g infants. Early growth may influence the risk of metabolic syndrome later in life. Objective: To evaluate growth and blood metabolic markers (adiponectin, leptin, and insulin-like growth factor-1 (IGF-1 in VLBW infants participating in a randomized nutritional intervention study. Design: Fifty VLBW infants were randomized to an enhanced nutrient supply or a standard nutrient supply. Thirty-seven infants were evaluated with growth measurements until 2 years corrected age (CA. Metabolic markers were measured at birth and 5 months CA. Results: Weight gain and head growth were different in the two groups from birth to 2 years CA (weight gain: pinteraction=0.006; head growth: pinteraction=0.002. The intervention group improved their growth z-scores after birth, whereas the control group had a pronounced decline, followed by an increase and caught up with the intervention group after discharge. At 5 months CA, adiponectin concentrations were higher in the intervention group and correlated with weight gain before term (r=0.35 and nutrient supply (0.35≤r≤0.45. Leptin concentrations correlated with weight gain after term and IGF-1 concentrations with length growth before and after term and head growth after term (0.36≤r≤0.53. Conclusion: Enhanced nutrient supply improved early postnatal growth and may have prevented rapid catch-up growth later in infancy. Adiponectin concentration at 5 months CA was higher in the intervention group and correlated positively with early weight gain and nutrient supply. Early nutrition and growth may affect metabolic markers in infancy.Clinical Trial Registration (ClinicalTrials.gov no.: NCT01103219

Quantifying stream nutrient uptake from ambient to saturation with instantaneous tracer additions

Science.gov (United States)

Covino, T. P.; McGlynn, B. L.; McNamara, R.

2009-12-01

Stream nutrient tracer additions and spiraling metrics are frequently used to quantify stream ecosystem behavior. However, standard approaches limit our understanding of aquatic biogeochemistry. Specifically, the relationship between in-stream nutrient concentration and stream nutrient spiraling has not been characterized. The standard constant rate (steady-state) approach to stream spiraling parameter estimation, either through elevating nutrient concentration or adding isotopically labeled tracers (e.g. 15N), provides little information regarding the stream kinetic curve that represents the uptake-concentration relationship analogous to the Michaelis-Menten curve. These standard approaches provide single or a few data points and often focus on estimating ambient uptake under the conditions at the time of the experiment. Here we outline and demonstrate a new method using instantaneous nutrient additions and dynamic analyses of breakthrough curve (BTC) data to characterize the full relationship between spiraling metrics and nutrient concentration. We compare the results from these dynamic analyses to BTC-integrated, and standard steady-state approaches. Our results indicate good agreement between these three approaches but we highlight the advantages of our dynamic method. Specifically, our new dynamic method provides a cost-effective and efficient approach to: 1) characterize full concentration-spiraling metric curves; 2) estimate ambient spiraling metrics; 3) estimate Michaelis-Menten parameters maximum uptake (Umax) and the half-saturation constant (Km) from developed uptake-concentration kinetic curves, and; 4) measure dynamic nutrient spiraling in larger rivers where steady-state approaches are impractical.

Seasonality of nutrients in leaves and fruits of apple trees

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Nachtigall Gilmar Ribeiro

2006-01-01

Full Text Available The nutrient accumulation curves of apple trees are good indicators of plant nutrient demand for each developmental stage. They are also a useful tool to evaluate orchard nutritional status and to estimate the amount of soil nutrient removal. This research aimed at evaluating the seasonality of nutrients in commercial apple orchards during the agricultural years of 1999, 2000, and 2001. Therefore, apple tree leaves and fruits of three cultivars 'Gala', 'Golden Delicious' and 'Fuji' were weekly collected and evaluated for fresh and dry matter, fruit diameter and macronutrient (N, P, K, Ca and Mg and micronutrient (B, Cu, Fe, Mn, and Zn concentrations. Leaf and fruit sampling started one or two weeks after full bloom, depending on the cultivar, and ended at fruit harvest or four weeks later (in the case of leaf sampling. In general, leaf concentrations of N, P, K, Cu, and B decreased; Ca increased; and Mg, Fe, Mn, and Zn did vary significantly along the plant vegetative cycle. In fruits, the initial nutrient concentrations decreased quickly, undergoing slow and continuous decreases and then remaining almost constant until the end of fruit maturation, indicating nutrient dilution, once the total nutrient accumulation increased gradually with fruit growth. Potassium was the nutrient present in highest quantities in apple tree fruits and thus, the most removed from the soil.

Nutrients versus emerging contaminants–Or a dynamic match between subsidy and stress effects on stream biofilms

International Nuclear Information System (INIS)

Aristi, I.; Casellas, M.; Elosegi, A.; Insa, S.; Petrovic, M.; Sabater, S.; Acuña, V.

2016-01-01

Freshwater ecosystems are threatened by multiple anthropogenic stressors, which might be differentiated into two types: those that reduce biological activity at all concentrations (toxic contaminants), and those that subsidize biological activity at low concentrations and reduce it at high concentrations (assimilable contaminants). When occurring in mixtures, these contaminants can have either antagonistic, neutral or synergistic effects; but little is known on their joint effects. We assessed the interaction effects of a mixture of assimilable and toxic contaminants on stream biofilms in a manipulative experiment using artificial streams, and following a factorial design with three nutrient levels (low, medium or high) and either presence or absence of a mixture of emerging contaminants (ciprofloxacin, erythromycin, diclofenac, methylparaben, and sulfamethoxazole). We measured biofilm biomass, basal fluorescence, gross primary production and community respiration. Our initial hypotheses were that biofilm biomass and activity would: increase with medium nutrient concentrations (subsidy effect), but decrease with high nutrient concentrations (stress effect) (i); decrease with emerging contaminants, with the minimum decrease at medium nutrient concentrations (antagonistic interaction between nutrients subsidy and stress by emerging contaminants) and the maximum decrease at high nutrient concentrations (synergistic interaction between nutrients and emerging contaminants stress) (ii). All the measured variables responded linearly to the available nutrients, with no toxic effect at high nutrient concentrations. Emerging contaminants only caused weak toxic effects in some of the measured variables, and only after 3–4 weeks of exposure. Therefore, only antagonistic interactions were observed between nutrients and emerging contaminants, as medium and high nutrient concentrations partly compensated the harmful effects of emerging contaminants during the first weeks of the

Soil nutrient assessment for urban ecosystems in Hubei, China.

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Zhi-Guo Li

Full Text Available Recent urban landscape vegetation surveys conducted in many cities in China identified numerous plant nutrient deficiencies, especially in newly developed cities. Soil nutrients and soil nutrient management in the cities of Hubei province have not received adequate attention to date. The aims of this study were to characterize the available nutrients of urban soils from nine cities in Hubei province, China, and to assess how soil nutrient status is related to land use type and topography. Soil nutrients were measured in 405 sites from 1,215 soil samples collected from four land use types (park, institutional [including government building grounds, municipal party grounds, university grounds, and garden city institutes], residential, and roadside verges and three topographies (mountainous [142-425 m a.s.l], hilly [66-112 m a.s.l], and plain [26-30 m a.s.l]. Chemical analyses showed that urban soils in Hubei had high pH and lower soil organic matter, available nitrogen (N, available phosphorus (P, and available boron (B concentrations than natural soils. Nutrient concentrations were significantly different among land use types, with the roadside and residential areas having greater concentrations of calcium (Ca, sulfur (S, copper (Cu, manganese (Mn, and zinc (Zn that were not deficient against the recommended ranges. Topographic comparisons showed statistically significant effects for 8 of the 11 chemical variables (p < 0.05. Concentrations of N, Ca, Mg, S, Cu, and Mn in plain cities were greater than those in mountainous cities and show a negative correlation with city elevation. These results provide data on urban soils characteristics in land use types and topography, and deliver significant information for city planners and policy makers.

Groundwater – The disregarded component in lake water and nutrient budgets. Part 2: effects of groundwater on nutrients

Science.gov (United States)

Lewandowski, Jörg; Meinikmann, Karin; Nützmann, Gunnar; Rosenberry, Donald O.

2015-01-01

Lacustrine groundwater discharge (LGD) transports nutrients from a catchment to a lake, which may fuel eutrophication, one of the major threats to our fresh waters. Unfortunately, LGD has often been disregarded in lake nutrient studies. Most measurement techniques are based on separate determinations of volume and nutrient concentration of LGD: Loads are calculated by multiplying seepage volumes by concentrations of exfiltrating water. Typically low phosphorus (P) concentrations of pristine groundwater often are increased due to anthropogenic sources such as fertilizer, manure or sewage. Mineralization of naturally present organic matter might also increase groundwater P. Reducing redox conditions favour P transport through the aquifer to the reactive aquifer-lake interface. In some cases, large decreases of P concentrations may occur at the interface, for example, due to increased oxygen availability, while in other cases, there is nearly no decrease in P. The high reactivity of the interface complicates quantification of groundwater-borne P loads to the lake, making difficult clear differentiation of internal and external P loads to surface water. Anthropogenic sources of nitrogen (N) in groundwater are similar to those of phosphate. However, the environmental fate of N differs fundamentally from P because N occurs in several different redox states, each with different mobility. While nitrate behaves essentially conservatively in most oxic aquifers, ammonium's mobility is similar to that of phosphate. Nitrate may be transformed to gaseous N2 in reducing conditions and permanently removed from the system. Biogeochemical turnover of N is common at the reactive aquifer-lake interface. Nutrient loads from LGD were compiled from the literature. Groundwater-borne P loads vary from 0.74 to 2900 mg PO4-P m−2 year−1; for N, these loads vary from 0.001 to 640 g m−2 year−1. Even small amounts of seepage can carry large nutrient loads due to often high

Nutrients versus emerging contaminants-Or a dynamic match between subsidy and stress effects on stream biofilms.

Science.gov (United States)

Aristi, I; Casellas, M; Elosegi, A; Insa, S; Petrovic, M; Sabater, S; Acuña, V

2016-05-01

Freshwater ecosystems are threatened by multiple anthropogenic stressors, which might be differentiated into two types: those that reduce biological activity at all concentrations (toxic contaminants), and those that subsidize biological activity at low concentrations and reduce it at high concentrations (assimilable contaminants). When occurring in mixtures, these contaminants can have either antagonistic, neutral or synergistic effects; but little is known on their joint effects. We assessed the interaction effects of a mixture of assimilable and toxic contaminants on stream biofilms in a manipulative experiment using artificial streams, and following a factorial design with three nutrient levels (low, medium or high) and either presence or absence of a mixture of emerging contaminants (ciprofloxacin, erythromycin, diclofenac, methylparaben, and sulfamethoxazole). We measured biofilm biomass, basal fluorescence, gross primary production and community respiration. Our initial hypotheses were that biofilm biomass and activity would: increase with medium nutrient concentrations (subsidy effect), but decrease with high nutrient concentrations (stress effect) (i); decrease with emerging contaminants, with the minimum decrease at medium nutrient concentrations (antagonistic interaction between nutrients subsidy and stress by emerging contaminants) and the maximum decrease at high nutrient concentrations (synergistic interaction between nutrients and emerging contaminants stress) (ii). All the measured variables responded linearly to the available nutrients, with no toxic effect at high nutrient concentrations. Emerging contaminants only caused weak toxic effects in some of the measured variables, and only after 3-4 weeks of exposure. Therefore, only antagonistic interactions were observed between nutrients and emerging contaminants, as medium and high nutrient concentrations partly compensated the harmful effects of emerging contaminants during the first weeks of the

Effects of Nitrogen and Nutrient Removal on Nitrate Accumulation and Growth Characteristics of Spinach (Spinacia oleraceae L.

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mohammadsadegh sadeghi

2017-12-01

Full Text Available Introduction: Spinach is a leafy vegetable which is rich source of vitamins, antioxidant compounds (e.g. flavonoids, acid ascorbic and essential elements (e.g. Fe, and Se. Spinach is capable of accumulating large amounts of nitrogen in the form of nitrate in shoot tissues which is undesirablein the human diet. The concentration of nitrate in plants is affected by species, fertilizer use, and growing conditions. Green leafy vegetables such as spinach, generally contain higher levels of nitrate than other foods. Nitrate ofplant tissueslevels are clearly related to both form and concentration of N fertilizers applied. Nitrogen fertilizers have been known as the major factors that influence nitrate content in vegetables. Ideally, the N fertility level must be managed to produce optimum crop yield without leading to excessive accumulation of nitrate in the harvested tissues.Usinghigh amounts ofN fertilizer produced higher yield with higher nitrate inleaves but the highest amount of nitrate was accumulated in the petioles.There are several plant species that may accumulate nitrate, including the Brassica plants, green cereal grains (barley, wheat, rye and maize, sorghum and Sudan grasses, corn, beets, rape, docks, sweet clover and nightshades. The presence of nitrate in vegetables, as in water and generally in other foods, is a serious threat to man’s health. Nitrate is relatively non-toxic, but approximately 5% of all ingested nitrate is converted in saliva and the gastrointestinal tract to the more toxic nitrite. This study was aimed to investigate theeffects of nitrogen and nutrient removal on nitrate accumulation and growth characteristics of spinach (Spinacia oleraceae L.. Materials and Methods: A pot hydroponic experiment was carried out to evaluate the effect of different levels of nitrogen and nutrient removal (one week before harvest on nitrate accumulation and growth characters. A factorial experiment based on completely randomized design

Nutrient Removal Efficiency of Rhizophora mangle (L. Seedlings Exposed to Experimental Dumping of Municipal Waters

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Claudia Maricusa Agraz-Hernández

2018-03-01

Full Text Available Mangrove forests are conspicuous components of tropical wetlands that sustain continuous exposure to wastewater discharges commonly of municipal origins. Mangroves can remove nutrients from these waters to fulfill their nutrients demand, although the effects of continuous exposure are unknown. An experimental greenhouse imitating tidal regimes was built to measure the efficiency of mangrove seedlings to incorporate nutrients, growth and above biomass production when exposed to three periodic wastewater discharges. The experiment totaled 112 d. Nutrient removal by the exposed group, such as phosphates, ammonia, nitrites, nitrates and dissolved inorganic nitrogen (97%, 98.35%, 71.05%, 56.57% and 64.36%, respectively was evident up to the second dumping. By the third dumping, all nutrient concentrations increased in the interstitial water, although significant evidence of removal by the plants was not obtained (p > 0.05. Nutrient concentrations in the control group did not change significantly throughout the experiment (p > 0.05. Treated plants increased two-fold in stem girth when compared to the control (p < 0.05, although control plants averaged higher heights (p < 0.05. Biomass of treated group increased up to 45% against 37% of the control during the duration of the experiment (p < 0.05. We suggest that nutrient removal efficiency of mangroves is linked to the maintenance of oxic conditions in the pore-water because of oxygen transference from their aerial to their subterranean radicular system that facilitates the oxidation of reduced nitrogen compounds and plants uptake. Nevertheless, continuous inflows of wastewater would lead to eutrophication, establishment of anoxic conditions in water and soil, and lessening of nutrient absorption of mangroves.

Dynamics of inorganic nutrients in intertidal sediments: porewater, exchangeable and intracellular pools

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Emilio eGarcia-Robledo

2016-05-01

Full Text Available The study of inorganic nutrients dynamics in shallow sediments usually focuses on two main pools: the porewater (PW nutrients and the exchangeable (EX ammonium and phosphate. Recently, it has been found that microphytobenthos (MPB and other microorganisms can accumulate large amounts of nutrients intracellularly (IC, highlighting the biogeochemical importance of this nutrient pool. Storing nutrients could support the growth of autotrophs when nutrients are not available, and could also provide alternative electron acceptors for dissimilatory processes such as nitrate reduction. Here, we studied the magnitude and relative importance of these three nutrient pools (PW, IC and EX and their relation to chlorophylls (used as a proxy for MPB abundance and organic matter (OM contents in an intertidal mudflat of Cadiz Bay (Spain. MPB was localized in the first 4 mm of the sediment and showed a clear seasonal pattern; highest chlorophylls content was found during autumn and lowest during spring-summer. The temporal and spatial distribution of nutrients pools and MPB were largely correlated. Ammonium was higher in the IC and EX fractions, representing on average 59 and 37% of the total ammonium pool, respectively. Similarly, phosphate in the IC and EX fractions accounted on average for 40 and 31% of the total phosphate pool, respectively. Nitrate in the PW was low, suggesting low nitrification activity and rapid consumption. Nitrate accumulated in the IC pool during periods of moderate MPB abundance, being up to 66% of the total nitrate pool, whereas it decreased when chlorophyll concentration peaked likely due to a high nitrogen demand. EX-Nitrate accounted for the largest fraction of total sediment nitrate, 66% on average. The distribution of EX-Nitrate was significantly correlated with chlorophyll and OM, which probably indicates a relation of this pool to an increased availability of sites for ionic adsorption. This EX-Nitrate pool could represent an

The effects of feeding rations that differ in neutral detergent fiber and starch concentration within a day on rumen digesta nutrient concentration, pH, and fermentation products in dairy cows.

Science.gov (United States)

Ying, Y; Rottman, L W; Crawford, C; Bartell, P A; Harvatine, K J

2015-07-01

There is a daily pattern of feed intake in the dairy cow, and feeding a single total mixed ration results in variation in the amount of fermentable substrate entering the rumen over the day. The object of this study was to determine if feeding multiple rations over the day that complement the pattern of feed intake would stabilize rumen pool sizes and fermentation. Nine ruminally cannulated cows were used in a 3×3 Latin square design with 23-d periods. Diets were a control diet [33.3% neutral detergent fiber (NDF)], a low-fiber diet (LF; 29.6% NDF), and a high-fiber diet (HF; 34.8% NDF). The LF and HF diets were balanced to provide the same nutrient composition as the control diet when cows were fed 3 parts of LF and 7 parts of HF. Cows on the control treatment (CON) were fed at 0900h, cows on the high/low treatment (H/L) were fed HF at 70% of daily offering at 0900h and LF at 30% of daily offering at 2200h, and cows on the low/high (L/H) treatment were fed LF at 30% of daily offering at 0900h and HF at 70% of daily offering at 1300h. All treatments were fed at 110% of daily intake. Preplanned contrasts compared CON with H/L and H/L with L/H. Feeding the LF diet in the evening resulted in a large increase in the amount of feed consumed immediately after feed delivery at that feeding. Rumen digesta starch concentration increased and NDF concentration decreased following feeding of the LF diet in both the L/H and H/L treatments. Starch pool size also increased following feeding of the LF diet in the evening and tended to increase after feeding the LF diet in the morning. Rumen ammonia concentration was increased following feeding of the HF diet in the morning and the LF diet in the evening in the H/L treatment. Additionally, cis-9 C18:1 and cis-9,cis-12 18:2 are higher in concentrate feeds and were increased after feeding the LF diet in both treatments. Trans fatty acid isomers of the normal and alternate biohydrogenation pathways followed a daily pattern, and the H

Monitoring TASCC Injections Using A Field-Ready Wet Chemistry Nutrient Autoanalyzer

Science.gov (United States)

Snyder, L. E.; Herstand, M. R.; Bowden, W. B.

2011-12-01

Quantification of nutrient cycling and transport (spiraling) in stream systems is a fundamental component of stream ecology. Additions of isotopic tracer and bulk inorganic nutrient to streams have been frequently used to evaluate nutrient transfer between ecosystem compartments and nutrient uptake estimation, respectively. The Tracer Addition for Spiraling Curve Characterization (TASCC) methodology of Covino et al. (2010) instantaneously and simultaneously adds conservative and biologically active tracers to a stream system to quantify nutrient uptake metrics. In this method, comparing the ratio of mass of nutrient and conservative solute recovered in each sample throughout a breakthrough curve to that of the injectate, a distribution of spiraling metrics is calculated across a range of nutrient concentrations. This distribution across concentrations allows for both a robust estimation of ambient spiraling parameters by regression techniques, and comparison with uptake kinetic models. We tested a unique sampling strategy for TASCC injections in which samples were taken manually throughout the nutrient breakthrough curves while, simultaneously, continuously monitoring with a field-ready wet chemistry autoanalyzer. The autoanalyzer was programmed to measure concentrations of nitrate, phosphate and ammonium at the rate of one measurement per second throughout each experiment. Utilization of an autoanalyzer in the field during the experiment results in the return of several thousand additional nutrient data points when compared with manual sampling. This technique, then, allows for a deeper understanding and more statistically robust estimation of stream nutrient spiraling parameters.

Vegetated treatment area (VTAs efficiencies for E. coli and nutrient removal on small-scale swine operations

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R. Daren Harmel

2018-06-01

Full Text Available As small-scale animal feeding operations work to manage their byproducts and avoid regulation, they need practical, cost-effective methods to reduce environmental impact. One such option is using vegetative treatment areas (VTAs with perennial grasses to treat runoff; however, research is limited on VTA effectiveness as a waste management alternative for smaller operations. This study evaluated the efficiencies of VTAs in reducing bacteria and nutrient runoff from small-scale swine operations in three counties in Central Texas. Based on 4 yr of runoff data, the Bell and Brazos VTAs significantly reduced loads and concentrations of E. coli and nutrients (except NO3-N and had treatment efficiencies of 73–94%. Most notably, the Bell VTA reduced loads of E. coli, NH4-N, PO4-P, total N, and total P similar to that of the background (control. In spite of significant reductions, runoff from the Brazos VTA had higher concentrations and loads than the control site, especially following installation of concrete pens and increased pen washing, which produced standing water and increased E. coli and nutrient influx. The Robertson VTA produced fewer significant reductions and had lower treatment efficiencies (29–69%; however, E. coli and nutrient concentrations and loads leaving this VTA were much lower than observed at the Bell and Brazos County sites due to alternative solids management and enclosed pens. Based on these results and previous research, VTAs can be practical, effective waste management alternatives for reducing nutrient and bacteria losses from small-scale animal operations, but only if properly designed and managed. Keywords: Bacteria, Nutrients, Swine manure, Waste management, Water quality

Diversidade funcional em sistemas de montado: fluxo de nutrientes em Quercus rotundifolia Lam. Functional diversity in “montado” systems: nutrients fluxes in Quercus rotundifolia Lam.

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J. D. Nunes

2007-01-01

Full Text Available Os componentes dos ciclos de nutrientes em montados de Quercus rotundifolia Lam., relacionados com a precipitação foram estudados na região de Évora, de Novembro de 1996 a Dezembro de 2000. A precipitação bruta, o gotejo a diferentes distâncias do tronco e o escorrimento ao longo do tronco das árvores foram quantificados de modo contínuo, sendo colhidas amostras semanalmente para se proceder à respectiva caracterização química. A quantidade de nutrientes transferidos para o solo através das diferentes soluções foi também determinada. Verificou-se um acréscimo da concentração das espécies iónicas no gotejo em relação à precipitação bruta, o qual foi ainda mais manifesto no escorrimento ao longo do tronco. Estudaram-se, igualmente, as características físico-químicas do solo sob e fora da influência da copa destas árvores, num montado relativamente esparso. Além disso, também se avaliou a quantidade das camadas orgânicas e a quantidade de nutrientes aí retidos. As características físicas e químicas do solo apresentaram, de um modo geral, uma diferenciação positiva em resultado da presença das árvores. Avaliou-se a taxa de mineralização de N nas áreas sob e fora da acção do coberto das árvores, tendo-se observado uma mais elevada disponibilidade deste nutriente nas áreas do sob coberto.Nutrient cycling in Quercus rotundifolia Lam. systems, regarding precipitation was studied at Évora (Southern Portugal, since November of 1996 until December of 2000. The amounts of gross rainfall, throughfall (at different distances from the tree trunk and stemflow were measured continuously and samples for chemical analysis were collected weekly. The concentration of nutrients was higher in the throughfall than in the gross rainfall, especially in the areas closer to the tree trunk. Nutrients transferred to soil, through bulk rainfall, throughfall and stemflow were quantified. The highest concentration of nutrients

Higher intake of vitamin B-6 and dairy products and lower intake of green and oolong tea are independently associated with lower serum homocysteine concentration in young Japanese women.

Science.gov (United States)

Murakami, Kentaro; Sasaki, Satoshi; Uenishi, Kazuhiro

2013-08-01

Little is known about the relation of modifiable dietary factors to circulating homocysteine concentrations, particularly in young adults and non-Western populations. We investigated the hypothesis that intakes of nutrients and foods are associated with serum homocysteine concentration in a group of young Japanese women. This cross-sectional study included 1050 female Japanese dietetic students aged 18 to 22 years. Dietary intake was assessed using a validated, self-administered, comprehensive diet history questionnaire. Fasting blood samples were collected, and serum homocysteine concentrations were measured. Adjustment was made for survey year, region, municipality level, current smoking, current alcohol drinking, dietary supplement use, physical activity, body mass index, energy intake, and intakes of other nutrients or foods. After adjustment for nondietary confounding factors, intakes of all B vitamins (folate, vitamin B-6, vitamin B-12, and riboflavin) were inversely associated with homocysteine concentration. However, only vitamin B-6 remained significant after further adjustment for other B vitamins. Marine-origin n-3 polyunsaturated fatty acid intake showed an inverse association, but this was not independent of intakes of B vitamins. For foods, pulses, fish and shellfish, and vegetables were independently and inversely associated with homocysteine concentration, but these associations disappeared after adjustment for intakes of other foods. Conversely, an inverse association for dairy products and a positive association for green and oolong tea remained even after adjustment for other foods. To conclude, in a group of young Japanese women, higher intake of vitamin B-6 and dairy products and lower intake of green and oolong tea were independently associated with lower serum homocysteine concentration. Copyright © 2013 Elsevier Inc. All rights reserved.

Nutrient and metal pollution of the eastern Gulf of Finland coastline: Sediments, macroalgae, microbiota

International Nuclear Information System (INIS)

Gubelit, Yulia; Polyak, Yulia; Dembska, Grazyna; Pazikowska-Sapota, Grazyna; Zegarowski, Lukasz; Kochura, Dmitry; Krivorotov, Denis; Podgornaya, Elena; Burova, Olga; Maazouzi, Chafik

2016-01-01

The anthropogenic pollution along the coastline of the eastern Gulf of Finland was studied through a range of methods, including analyses of metal contamination in water, surface sediments, accumulated algal biomass and its correlation with resistant microbiota. According to concentrations, the main pollutants in water were copper and manganese. Influence of Nuclear Power Plant was remarkable in adjacent areas and was expressed in high concentrations of molybdenum, nickel, copper and other elements in the water. Relatively high concentrations of copper, lead and zinc were found in sediments. Microbial tolerance appeared to be correlated with the concentration of the metals in sediments. Higher tolerance levels were found in sediment samples from more polluted stations. Macroalgae, which were massively developed in the coastal zone, had shown high level of metal bioaccumulation. Analyses of carbon, nitrogen and phosphorus content of algal tissues allowed the estimation of additional nutrient loading from accumulated decaying algal biomass on the coastal zone of the eastern Gulf of Finland. Mass development of algae in coastal area may contribute to accumulation of organic matter and associated metals. In our study the highest metal concentrations in sediments were found at the sites with dense and continuous layer of fresh and decaying macroalgal biomass, accompanied by hypoxic conditions. Also our study has shown that accumulated biomass may be a significant source of nutrients in the coastal ecosystem. - Highlights: • We studied heavy metal pollution in the coastline of the eastern Gulf of Finland. • Sediments, water, mass macroalgae and microbiota were included into analyses. • Eutrophication and nutrient loading remain the main problem of the studied area. • Macroalgae contribute to accumulation of organic matter, nutrient, and heavy metal. • Pollution in the studied area is caused by a combination of different factors.

Nutrient and metal pollution of the eastern Gulf of Finland coastline: Sediments, macroalgae, microbiota

Energy Technology Data Exchange (ETDEWEB)

Gubelit, Yulia, E-mail: Gubelit@list.ru [Zoological Institute of the Russian Academy of Sciences, St. Petersburg (Russian Federation); Polyak, Yulia [Scientific Research Center for Ecological Safety of the Russian Academy of Sciences, St. Petersburg (Russian Federation); Dembska, Grazyna; Pazikowska-Sapota, Grazyna; Zegarowski, Lukasz [Maritime Institute in Gdansk, Department of Environmental Protection, Gdansk (Poland); Kochura, Dmitry; Krivorotov, Denis; Podgornaya, Elena; Burova, Olga [Research Institute of Hygiene, Occupational Pathology and Human Ecology (RIHOPHE), Federal Medical Biological Agency, St. Petersburg (Russian Federation); Maazouzi, Chafik [Université Claude Bernard Lyon 1, Laboratoire d' Écologie des Hydrosystèmes Naturels et Anthropisés (LEHNA), Lyon (France)

2016-04-15

The anthropogenic pollution along the coastline of the eastern Gulf of Finland was studied through a range of methods, including analyses of metal contamination in water, surface sediments, accumulated algal biomass and its correlation with resistant microbiota. According to concentrations, the main pollutants in water were copper and manganese. Influence of Nuclear Power Plant was remarkable in adjacent areas and was expressed in high concentrations of molybdenum, nickel, copper and other elements in the water. Relatively high concentrations of copper, lead and zinc were found in sediments. Microbial tolerance appeared to be correlated with the concentration of the metals in sediments. Higher tolerance levels were found in sediment samples from more polluted stations. Macroalgae, which were massively developed in the coastal zone, had shown high level of metal bioaccumulation. Analyses of carbon, nitrogen and phosphorus content of algal tissues allowed the estimation of additional nutrient loading from accumulated decaying algal biomass on the coastal zone of the eastern Gulf of Finland. Mass development of algae in coastal area may contribute to accumulation of organic matter and associated metals. In our study the highest metal concentrations in sediments were found at the sites with dense and continuous layer of fresh and decaying macroalgal biomass, accompanied by hypoxic conditions. Also our study has shown that accumulated biomass may be a significant source of nutrients in the coastal ecosystem. - Highlights: • We studied heavy metal pollution in the coastline of the eastern Gulf of Finland. • Sediments, water, mass macroalgae and microbiota were included into analyses. • Eutrophication and nutrient loading remain the main problem of the studied area. • Macroalgae contribute to accumulation of organic matter, nutrient, and heavy metal. • Pollution in the studied area is caused by a combination of different factors.

Effect of algal density in bead, bead size and bead concentrations ...

African Journals Online (AJOL)

Laboratory experiments were performed to study nitrogen and phosphorus uptake by the unicellular green microalga Chlorella vulgaris immobilized in calcium alginate beads. Different cell stockings in beads, different bead sizes and different algal bead concentrations in wastewaters were tested. Significant higher nutrients ...

Nutrient and metal uptake in wetland plants at stormwater detension ponds

DEFF Research Database (Denmark)

Istenic, Darja; Arias, Carlos Alberto; Brix, Hans

2011-01-01

Nutrients and metals were analysed in tissues of various wetland plants growing in stormwater detention ponds in Denmark. Nutrient and metal concentrations in below and aboveground tissues were compared to the concentrations of the adjacent sediment. The results showed accumulation of heavy metal...

Nutrients distribution and trophic status assessment in the northern Beibu Gulf, China

Science.gov (United States)

Lai, Junxiang; Jiang, Fajun; Ke, Ke; Xu, Mingben; Lei, Fu; Chen, Bo

2014-09-01

Using historical and 2010 field data, the distribution of nutrients in the northern Beibu Gulf of China is described. There was a decreasing trend in the concentration of nutrients from the north coast to offshore waters of the northern Beibu Gulf, reflecting the influence of inputs from land-based sources. High concentrations of dissolved inorganic nitrogen (DIN) and phosphate (PO4-P) occurred mainly at Fangchenggang Bay, Qinzhou Bay, and Lianzhou Bay. Four different methods were used to assess eutrophication. The trophic status of the Beibu Gulf was characterized using the single factor, Eutrophication index (EI), Trophic index (TRIX) and Assessment of Estuarine Trophic Status (ASSETS) methods. Based on nutrient concentrations, 73.9% of DIN and 26.7% of PO4-P samples exceeded the fourth grade Seawater Quality Standard of China. Eutrophication index values varied widely, but higher levels of eutrophication were generally found in bays and estuaries. TRIX values ranged from 2.61 to 7.27, with an average of 4.98, indicating a mesotrophic and moderately productive system. A positive correlation between TRIX and harmful algal species richness and abundance was observed. The ASSETS model evaluates eutrophication status based on a Pressure-State-Response approach, including three main indices: influencing factors, overall eutrophic condition, and future outlook. The Beibu Gulf was graded as moderate using ASSETS. The single factor and Chinese nutrient index methods were considered inadequate for the assessment of trophic status. TRIX can be used as an indicator of trophic state and ASSETS showed good potential to assess eutrophication. The results of TRIX and ASSETS depend on threshold values. To establish these values, further research is required within the northern Beibu Gulf.

Effect of Ni and Urea on Growth, Nitrate and Nutrients Concentration in Lettuce (Lactuca sativa Grown in Hydroponics

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Hosein Nazari Mamaqani

2017-02-01

and each separate simultaneous freshweight wasmeasured. Dry weight of organs wasmeasured afterit was oven-dried at 80ºCfor 72h. Leavesoven-dried andthenpowdered, and weredigested(usingacid tomeasure theelements. Extracts from thedigestionmethodwere used for determination ofnickelusingDimethylglyoximemethod.Spectrophotometer used to cover the wavelength at 530nm. Potassium was measured by Flame Photometer410.Totalnitrogenwas measuredbyKjeldahlmethod.Thehomogeneouspowders of dried leaves with hot water were extractedwithnitratemeter(Horiba, Japanand they were used to measuretheirnitrate content. Analysis was performed usingthe Software Statistical Package for the Social Science (SPSS v. 16.0. Individual treatment means were compared with a Duncan’s test to determine whether they were significantly different at the 0.05 probability. Results and Discussion: U50treatedwith 1.8 fold increasecompared with thecontrol groupshowed thehighestfresh weight. The yield increased with increasing concentration to 50 mg/l urea, butat higher urea concentrations, 50 mg/l,yieldsignificantlydecreased, althoughitwas significantlyhighercompared to control. .Enhanced growth and yield in two levels of U25 and U50were coerced. It was duo tohydrolysis urea with the help nickel stored in seed endosperm and also contamination application of nickel fertilizers in nutrient solutionsthat led to release of urea nitrogen.The highestandthelowest concentration ofnickelinleaveswith11-fold increase,were observedatconcentrations ofU50andU100, respectively. Dilution phenomenon occurred with increasingurea concentrationmore than U50.Nickelconcentration inleaveswassignificantlyincreased that this is theopposite offresh weightanddry weight. In U50 treated K concentration was 1.6-fold higher compared to control. With increasing urea concentration more than U50,K concentration decreased. Applyingthe Ni, 8 percent decreased K concentration in leaf tissues. With increasing urea innutrientsolution

Carbonate system and nutrients in the Pearl River estuary, China: Seasonal and inter-annual variations

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Guo, X.

2017-12-01

Located in southern China and surrounded by several metropolis, the Pearl River estuary is a large subtropical estuary under significant human perturbation. We examined the impact of sewage treatment rate on the water environmental factors. Carbonate system parameters (Dissolved inorganic carbon or DIC, Total alkalinity or TA, and pH), and nutrients were surveyed in the Pearl River estuary from 2000 to 2015. Spatially, concentrations of nutrients were high at low salinity and decreased with salinity in both wet and dry seasons although seasonal variation occurred. However, distribution patterns of DIC and TA differed in wet and dry seasons. In wet season, both DIC and TA were low at low salinity (600-1500 umol kg-1) and increased with salinity, but in dry season they were high at low salinity (3000-3500 umol kg-1) and decreased with salinity. Compared with the years before 2010, both values and distribution patterns of DIC, TA and pH were similar among the years in wet season, but they were conspicuously different in the upper estuary in dry season. Both DIC and TA were more than 1000 umol kg-1 lower than those in the years before 2010. For nutrients at low salinity, the ammonia concentration was much lower in the years after 2010 (200 vs. 400 umol kg-1 in wet season and 400 vs. 800 umol kg-1 in dry season), but nitrate concentration was slightly higher (180 vs 120 mmol kg-1 in wet season and 200 vs 180 mmol kg-1 in dry season). As a reference, carbonate system parameters and nutrients were stable among the 16 years in the adjacent northern South China Sea. The variations in biogeochemical processes induced by nutrients concentration and structure as a result of sewage discharge will be discussed in detail. The decrease in DIC, TA and nutrients in the upper Pearl River estuary after 2010 was due mainly to the improvement of sewage treatment rate and capacity.

Metal and nutrient dynamics on an aged intensive green roof

International Nuclear Information System (INIS)

Speak, A.F.; Rothwell, J.J.; Lindley, S.J.; Smith, C.L.

2014-01-01

Runoff and rainfall quality was compared between an aged intensive green roof and an adjacent conventional roof surface. Nutrient concentrations in the runoff were generally below Environmental Quality Standard (EQS) values and the green roof exhibited NO 3 − retention. Cu, Pb and Zn concentrations were in excess of EQS values for the protection of surface water. Green roof runoff was also significantly higher in Fe and Pb than on the bare roof and in rainfall. Input–output fluxes revealed the green roof to be a potential source of Pb. High concentrations of Pb within the green roof soil and bare roof dusts provide a potential source of Pb in runoff. The origin of the Pb is likely from historic urban atmospheric deposition. Aged green roofs may therefore act as a source of legacy metal pollution. This needs to be considered when constructing green roofs with the aim of improving pollution remediation. -- Highlights: • Runoff from an aged intensive green roof was characterised. • Nutrient levels were not problematic for runoff quality. • High concentrations of Cu, Pb and Zn were found in the runoff. • Soil contamination was a likely source of metals in roof runoff. • Historic Pb atmospheric deposition may be the source of contamination. -- Aged green roofs may act as a store of legacy lead pollution

The potential use of treated brewery effluent as a water and nutrient source in irrigated crop production

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Richard P. Taylor

2018-06-01

Full Text Available Brewery effluent (BE needs to be treated before it can be released into the environment, reused or used in down-stream activities. This study demonstrated that anaerobic digestion (AD followed by treatment in an integrated tertiary effluent treatment system transformed BE into a suitable solution for crop irrigation. Brewery effluent can be used to improve crop yields: Cabbage (Brassica oleracea cv. Star 3301, grew significantly larger when irrigated with post-AD, post-primary-facultative-pond (PFP effluent, compared with those irrigated with post-constructed-wetland (CW effluent or tap water only (p < 0.0001. However, cabbage yield when grown using BE was 13% lower than that irrigated with a nutrient-solution and fresh water; the electrical conductivity of BE (3019.05 ± 48.72 µs/cm2 may have been responsible for this. Post-CW and post-high-rate-algal-pond (HRAP BE was least suitable due to their higher conductivity and lower nutrient concentration. After three months, soils irrigated with post-AD and post-PFP BE had a significantly higher sodium concentration and sodium adsorption ratio (3919 ± 94.77 & 8.18 ± 0.17 mg/kg than soil irrigated with a commercial nutrient-solution (920.58 ± 27.46 & 2.20 ± 0.05 mg/kg. However, this was not accompanied by a deterioration in the soil's hydro-physical properties, nor a change in the metabolic community structure of the soil. The benefits of developing this nutrient and water resource could contribute to cost-reductions at the brewery, more efficient water, nutrient and energy management, and job creation. Future studies should investigate methods to reduce the build-up of salt in the soil when treated BE is used to irrigate crops. Keywords: Wastewater irrigation, Nutrient recovery, Agriculture, Brewery effluent

Growth and accumulation of carotenoids and nitrogen compounds in Gracilaria domingensis (Kütz. Sonder ex Dickie (Gracilariales, Rhodophyta cultured under different irradiance and nutrient levels

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Fernanda Ramlov

2011-05-01

Full Text Available Effects of the interaction of irradiance and nutrient levels on growth and contents of photosynthetic pigments, carotenoids and proteins in Gracilaria domingensis (Kütz. Sonder ex Dickie (Gracilariales, Rhodophyta were investigated experimentally. Nutrient availability provided by dilutions of the nutrient solution of von Stosch (25 and 50%, which corresponded to nitrate concentrations of 125 and 250 μmol, respectively and two photon flux densities [low PFD (50±5 and high PFD (100±5 μmol photons.m-2.s-1] were tested. Growth rates of G. domingensis were stimulated by high PFD. The interaction between high nutrient availability (50% VSES and high PFD stimulated the accumulation of total soluble protein. Phycobiliprotein concentrations (phycoerythrin, phycocyanin, and allophycocyanin and carotenoid contents were influenced by irradiance levels. Phycobiliprotein concentrations were higher at low PFD and high irradiances stimulated carotenoid accumulation. These results reflect the function of these pigments in photoprotection and the acclimation of G. domingensis to changes in irradiance levels. Our results indicate that light is a limiting factor for G. domingensis growth, that variations in phycobiliprotein contents under different irradiance levels are related to photoacclimation process, and that higher carotenoid contents at high irradiances are due to a photoprotection mechanism.

Growth and accumulation of carotenoids and nitrogen compounds in Gracilaria domingensis (Kütz. Sonder ex Dickie (Gracilariales, Rhodophyta cultured under different irradiance and nutrient levels

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Fernanda Ramlov

2011-04-01

Full Text Available Effects of the interaction of irradiance and nutrient levels on growth and contents of photosynthetic pigments, carotenoids and proteins in Gracilaria domingensis (Kütz. Sonder ex Dickie (Gracilariales, Rhodophyta were investigated experimentally. Nutrient availability provided by dilutions of the nutrient solution of von Stosch (25 and 50%, which corresponded to nitrate concentrations of 125 and 250 μmol, respectively and two photon flux densities [low PFD (50±5 and high PFD (100±5 μmol photons.m-2.s-1] were tested. Growth rates of G. domingensis were stimulated by high PFD. The interaction between high nutrient availability (50% VSES and high PFD stimulated the accumulation of total soluble protein. Phycobiliprotein concentrations (phycoerythrin, phycocyanin, and allophycocyanin and carotenoid contents were influenced by irradiance levels. Phycobiliprotein concentrations were higher at low PFD and high irradiances stimulated carotenoid accumulation. These results reflect the function of these pigments in photoprotection and the acclimation of G. domingensis to changes in irradiance levels. Our results indicate that light is a limiting factor for G. domingensis growth, that variations in phycobiliprotein contents under different irradiance levels are related to photoacclimation process, and that higher carotenoid contents at high irradiances are due to a photoprotection mechanism.

Wildfire Effects on In-stream Nutrient Processing and Hydrologic Transport

Science.gov (United States)

Rhea, A.; Covino, T. P.; Rhoades, C.; Fegel, T.

2017-12-01

In many forests throughout the Western U.S., drought, climate change, and growing fuel loads are contributing to increased fire frequency and severity. Wildfires can influence watershed nutrient retention as they fundamentally alter the biological composition and physical structure in upland landscapes, riparian corridors, and stream channels. While numerous studies have documented substantial short-term increases in stream nutrient concentrations and export (particularly reactive nitrogen, N) following forest fires, the long-term implications for watershed nutrient cycling remain unclear. For example, recent work indicates that nitrate concentrations and export can remain elevated for a decade or more following wildfire, yet the controls on these processes are unknown. In this research, we use empirical observations from nutrient tracer injections, nutrient diffusing substrates, and continuous water quality monitoring to isolate biological and physical controls on nutrient export across a burn-severity gradient. Tracer results demonstrate substantial stream-groundwater exchange, but little biological nutrient uptake in burned streams. This in part explains patterns of elevated nutrient export. Paired nutrient diffusing substrate experiments allow us to further investigate shifts in N, phosphorus, and carbon limitation that may suppress post-fire stream nutrient uptake. By isolating the mechanisms that reduce the capacity of fire-affected streams to retain and transform nutrient inputs, we can better predict dynamics in post-fire water quality and help prioritize upland and riparian restoration.

Food and Nutrient Intake and Nutritional Status of Finnish Vegans and Non-Vegetarians.

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Anna-Liisa Elorinne

Full Text Available Vegetarian and vegan diets have become more popular among adolescents and young adults. However, few studies have investigated the nutritional status of vegans, who may be at risk of nutritional deficiencies.To compare dietary intake and nutritional status of Finnish long-term vegans and non-vegetarians.Dietary intake and supplement use were estimated using three-day dietary records. Nutritional status was assessed by measuring biomarkers in plasma, serum, and urine samples. Vegans' (n = 22 data was compared with those of sex- and age-matched non-vegetarians (n = 19.All vegans adhered strictly to their diet; however, individual variability was marked in food consumption and supplementation habits. Dietary intakes of key nutrients, vitamins B12 and D, were lower (P < 0.001 in vegans than in non-vegetarians. Nutritional biomarker measurements showed lower concentrations of serum 25-hydroxyvitamin D3 (25(OHD3, iodine and selenium (corrected for multiple comparisons, P < 0.001, Vegans showed more favorable fatty acid profiles (P < 0.001 as well as much higher concentrations of polyphenols such as genistein and daidzein (P < 0.001. Eicosapentaenoic acid proportions in vegans were higher than expected. The median concentration of iodine in urine was below the recommended levels in both groups.Long-term consumption of a vegan diet was associated with some favorable laboratory measures but also with lowered concentrations of key nutrients compared to reference values. This study highlights the need for nutritional guidance to vegans.

Modeling nutrient in-stream processes at the watershed scale using Nutrient Spiralling metrics

Science.gov (United States)

Marcé, R.; Armengol, J.

2009-07-01

One of the fundamental problems of using large-scale biogeochemical models is the uncertainty involved in aggregating the components of fine-scale deterministic models in watershed applications, and in extrapolating the results of field-scale measurements to larger spatial scales. Although spatial or temporal lumping may reduce the problem, information obtained during fine-scale research may not apply to lumped categories. Thus, the use of knowledge gained through fine-scale studies to predict coarse-scale phenomena is not straightforward. In this study, we used the nutrient uptake metrics defined in the Nutrient Spiralling concept to formulate the equations governing total phosphorus in-stream fate in a deterministic, watershed-scale biogeochemical model. Once the model was calibrated, fitted phosphorus retention metrics where put in context of global patterns of phosphorus retention variability. For this purpose, we calculated power regressions between phosphorus retention metrics, streamflow, and phosphorus concentration in water using published data from 66 streams worldwide, including both pristine and nutrient enriched streams. Performance of the calibrated model confirmed that the Nutrient Spiralling formulation is a convenient simplification of the biogeochemical transformations involved in total phosphorus in-stream fate. Thus, this approach may be helpful even for customary deterministic applications working at short time steps. The calibrated phosphorus retention metrics were comparable to field estimates from the study watershed, and showed high coherence with global patterns of retention metrics from streams of the world. In this sense, the fitted phosphorus retention metrics were similar to field values measured in other nutrient enriched streams. Analysis of the bibliographical data supports the view that nutrient enriched streams have lower phosphorus retention efficiency than pristine streams, and that this efficiency loss is maintained in a wide

Metal(loid) allocation and nutrient retranslocation in Pinus halepensis trees growing on semiarid mine tailings

Energy Technology Data Exchange (ETDEWEB)

Parraga-Aguado, Isabel, E-mail: isabel.parraga@upct.es [Universidad Politecnica de Cartagena, Departamento de Ciencia y Tecnología Agraria Paseo Alfonso XIII, Cartagena 48. 30203 (Spain); Querejeta, Jose-Ignacio [Water and Soil Conservation Department, Centro de Edafología y Biología Aplicada del Segura CEBAS-CSIC Campus Universitario de Espinardo, PO Box 164, Espinardo-Murcia ES-30100 (Spain); González-Alcaraz, María Nazaret; Conesa, Hector M. [Universidad Politecnica de Cartagena, Departamento de Ciencia y Tecnología Agraria Paseo Alfonso XIII, Cartagena 48. 30203 (Spain)

2014-07-01

The goal of this study was to evaluate internal metal(loid) cycling and the risk of metal(loid) accumulation in litter from Pinus halepensis trees growing at a mine tailing disposal site in semiarid Southeast Spain. Internal nutrient retranslocation was also evaluated in order to gain insight into the ability of pine trees to cope with the low-fertility soil conditions at the tailings. We measured metal(loid) concentrations in the foliage (young and old needles), woody stems and fresh leaf litter of pine trees growing on tailings. The nutrient status and stable isotope composition of pine foliage (δ{sup 13}C, δ{sup 15}N, δ{sup 18}O as indicators of photosynthesis and water use efficiency) were also analyzed. Tailing soil properties in vegetation patches and in adjacent bare soil patches were characterized as well. Significant amounts of metal(loid)s such us Cd, Cu, Pb and Sb were immobilized in the woody stems of Pinus halepensis trees growing on tailings. Leaf litterfall showed high concentrations of As, Cd, Sb, Pb and Zn, which thereby return to the soil. However, water extractable metal(loid) concentrations in tailing soils were similar between vegetation patches (mineral soil under the litter layer) and bare soil patches. The pines growing on mine tailings showed very low foliar P concentrations in all leaf age classes, which suggests severe P deficiency. Young (current year) needles showed lower accumulation of metal(loid)s, higher nutrient concentrations (P and K), and higher water use efficiency (as indicated by and δ{sup 13}C and δ{sup 18}O data) than older needles. Substantial nutrient resorption occurred before leaf litterfall, with 46% retranslocation efficiency for P and 89% for K. In conclusion, phytostabilization of semiarid mine tailings with Pinus halepensis is feasible but would require careful monitoring of the trace elements released from litterfall, in order to assess the long term risk of metal(loid) transfer to the food chain

Metal(loid) allocation and nutrient retranslocation in Pinus halepensis trees growing on semiarid mine tailings

International Nuclear Information System (INIS)

Parraga-Aguado, Isabel; Querejeta, Jose-Ignacio; González-Alcaraz, María Nazaret; Conesa, Hector M.

2014-01-01

The goal of this study was to evaluate internal metal(loid) cycling and the risk of metal(loid) accumulation in litter from Pinus halepensis trees growing at a mine tailing disposal site in semiarid Southeast Spain. Internal nutrient retranslocation was also evaluated in order to gain insight into the ability of pine trees to cope with the low-fertility soil conditions at the tailings. We measured metal(loid) concentrations in the foliage (young and old needles), woody stems and fresh leaf litter of pine trees growing on tailings. The nutrient status and stable isotope composition of pine foliage (δ 13 C, δ 15 N, δ 18 O as indicators of photosynthesis and water use efficiency) were also analyzed. Tailing soil properties in vegetation patches and in adjacent bare soil patches were characterized as well. Significant amounts of metal(loid)s such us Cd, Cu, Pb and Sb were immobilized in the woody stems of Pinus halepensis trees growing on tailings. Leaf litterfall showed high concentrations of As, Cd, Sb, Pb and Zn, which thereby return to the soil. However, water extractable metal(loid) concentrations in tailing soils were similar between vegetation patches (mineral soil under the litter layer) and bare soil patches. The pines growing on mine tailings showed very low foliar P concentrations in all leaf age classes, which suggests severe P deficiency. Young (current year) needles showed lower accumulation of metal(loid)s, higher nutrient concentrations (P and K), and higher water use efficiency (as indicated by and δ 13 C and δ 18 O data) than older needles. Substantial nutrient resorption occurred before leaf litterfall, with 46% retranslocation efficiency for P and 89% for K. In conclusion, phytostabilization of semiarid mine tailings with Pinus halepensis is feasible but would require careful monitoring of the trace elements released from litterfall, in order to assess the long term risk of metal(loid) transfer to the food chain. - Highlights: • Significant

Effect of fish on water quality and nutrients cycle from an outdoor pond experiment; Sakana no suishitsu, busshitsu junkan ni oyobosu eikyo ni kansuru jikkenteki kenkyu

Energy Technology Data Exchange (ETDEWEB)

Fukushima, T.; Matsushige, K.; Aizaki, M. [National Inst. for Environmental Studies, Tsukuba (Japan); Park, J.; Goma, R. [Tokyo University of Fisheries, Tokyo (Japan); Kong, D. [Korea National Institute of Environmental Research, Seoul (Korea, Republic of)

1995-11-10

The influences of fish (goldfish) on water quality and nutrients cycle (carbon, nitrogen, phosphorus) were investigated during 39 days in the summer of 1993, using six outdoor experimental ponds (36 m{sup 3}) with the same water residence times and nutrient inputs. Blue-been algae dominated the ponds with fish. Compared with ponds without fish, the ponds with high densities of fish had standing stocks of zooplankton and macrozoobenthos nearly one order of magnitude lower, about twice the concentrations of chlorophyll a and twice the rate of primary production. Settling rates of particulate substances in the high density ponds were nearly half those observed in ponds with no fish. The processes of sedimentation and exchange with air played important roles in the nutrient budgets as well as the in- and outflows and the changes in nutrient standing stocks. The high concentrations of chlorophyll a in the fish ponds were attributed in part to the lower zooplankton grazing pressure and in part to the higher nutrient concentrations due to lower settling rates and rapid nutrient recycling between biomass and dissolved components. 28 refs., 8 figs., 6 tabs.

Long-term trends in nutrient budgets of the western Dutch Wadden Sea (1976-2012)

Science.gov (United States)

Jung, A. S.; Brinkman, A. G.; Folmer, E. O.; Herman, P. M. J.; van der Veer, H. W.; Philippart, C. J. M.

2017-09-01

Long-term field observations of nitrogen [N] and phosphorus [P] concentrations were used to construct nutrient budgets for the western Dutch Wadden Sea between 1976 and 2012. Nutrients come into the western Dutch Wadden Sea via river runoff, through exchange with the coastal zone of the North Sea, neighbouring tidal basins and through atmospheric deposition (for N). The highest concentrations in phosphorus and nitrogen were observed in the mid-1980s. Improved phosphorus removal at waste water treatment plants, management of fertilization in agriculture and removal of phosphates from detergents led to reduced riverine nutrient inputs and, consequently, reduced nutrient concentrations in the Wadden Sea. The budgets suggest that the period of the initial net import of phosphorus and nitrogen switched to a net export in 1981 for nitrogen and in 1992 for phosphorus. Such different behaviour in nutrient budgets during the rise and fall of external nutrient concentrations may be the result of different sediment-water exchange dynamics for P and N. It is hypothesized that during the period of increasing eutrophication (1976-1981) P, and to a lesser degree N, were stored in sediments as organic and inorganic nutrients. In the following period (1981-1992) external nutrient concentrations (especially in the North Sea) decreased, but P concentrations in the Wadden Sea remained high due to prolonged sediment release, whilst denitrification removed substantial amounts of N. From 1992 onwards, P and N budgets were closed by net loss, most probably because P stores were then depleted and denitrification continued. Under the present conditions (lower rates of sediment import and depleted P stores), nutrient concentrations in this area are expected to be more strongly influenced by wind-driven exchange with the North Sea and precipitation-driven discharge from Lake IJssel. This implies that the consequences of climate change will be more important, than during the 1970s and 1980s.

Submarine Ground Water Discharge and Fate Along the Coast of Kaloko-Honokohau National Historical Park, Hawai'i:Part 2, Spatial and Temporal Variations in Salinity, Radium-Isotope Activity, and Nutrient Concentrations in Coastal Waters, December 2003-April 2006

Science.gov (United States)

Knee, Karen; Street, Joseph; Grossman, Eric E.; Paytan, Adina

2008-01-01

The aquatic resources of Kaloko-Honokohau National Historical Park, including rocky shoreline, fishponds, and anchialine pools, provide habitat to numerous plant and animal species and offer recreational opportunities to local residents and tourists. A considerable amount of submarine groundwater discharge was known to occur in the park, and this discharge was suspected to influence the park's water quality. Thus, the goal of this study was to characterize spatial and temporal variations in the quality and quantity of groundwater discharge in the park. Samples were collected in December 2003, November 2005, and April 2006 from the coastal ocean, beach pits, three park observation wells, anchialine pools, fishponds, and Honokohau Harbor. The activities of two Ra isotopes commonly used as natural ground-water tracers (223Ra and 224Ra), salinity, and nutrient concentrations were measured. Fresh ground water composed a significant proportion (8-47 volume percent) of coastal-ocean water. This percentage varied widely between study sites, indicating significant spatial variation in submarine groundwater discharge at small (meter to kilometer) scales. Nitrate + nitrite, phosphate, and silica concentrations were significantly higher in nearshore coastal-ocean samples relative to samples collected 1 km or more offshore, and linear regression showed that most of this difference was due to fresh ground-water discharge. High-Ra-isotope-activity, higher-salinity springs were a secondary source of nutrients, particularly phosphate, at Honokohau Harbor and Aiopio Fishtrap. Salinity, Ra-isotope activity, and nutrient concentrations appeared to vary in response to the daily tidal cycle, although little seasonal variation was observed, indicating that submarine ground-water discharge may buffer the park's water quality against the severe seasonal changes that would occur in a system where freshwater inputs were dominated by rivers and runoff. Ra-isotope-activity ratios indicated

Effect of organic substrates on available elemental contents in nutrient solution

Energy Technology Data Exchange (ETDEWEB)

Ao, Y.S.; Sun, M.; Li, Y.Q. [Shanghai Jiao Tong University, Shanghai (China). School for Agriculture & Biology

2008-07-15

In this paper, the changes of available elemental contents in the nutrient solution extracts of organic substrates (peat moss, charred rice husk, chicken manure, sawdust, turfgrass clipping and weathered coal) were studied and compared with that in the water extracts. Results showed that available elemental contents in the nutrient solution extracts are significantly different between organic substrates, whereas ionic concentrations are basically under steady condition after treatment for 36-108 h. Ionic contents in the nutrient solution extracts are not equal to the value of adding ionic concentrations in the supplied nutrient solution to that in the water extract. Thus, a mathematical model was proposed for adjusting the composition of supplied nutrient solution to match plant requirements in the organic soilless culture system.

Cadmium toxicity to two marine phytoplankton under different nutrient conditions

International Nuclear Information System (INIS)

Miao, A.-J.; Wang, W.-X.

2006-01-01

Cd accumulation and toxicity in two marine phytoplankton (diatom Thalassiosira weissflogii and dinoflagellate Prorocentrum minimum) under different nutrient conditions (nutrient-enriched, N- and P-starved conditions) were examined in this study. Strong interactions between the nutrients and Cd uptake by the two algal species were found. Cd accumulation as well as N and P starvation themselves inhibited the assimilation of N, P, and Si by the phytoplankton. Conversely, N starvation strongly inhibited Cd accumulation but no influence was observed under P starvation. However, the Cd accumulation difference between nutrient-enriched and N-starved cells was smaller when [Cd 2+ ] was increased in the medium, indicating that net Cd accumulation was less dependent on the N-containing ligands at high-Cd levels. As for the subcellular distribution of the accumulated Cd, most was distributed in the insoluble fraction of T. weissflogii while it was evenly distributed in the soluble and insoluble fractions of P. minimum at low-Cd levels. A small percentage of cellular Cd ( 2+ ], which increased when the [Cd 2+ ] increased. Cd toxicity in phytoplankton was quantified as depression of growth and maximal photosynthetic system II quantum yield, and was correlated with the [Cd 2+ ], intracellular Cd concentration, and Cd concentrations in the cell-surface-adsorbed, soluble, and insoluble fractions. According to the estimated median inhibition concentration (IC50) based on the different types of Cd concentration, the toxicity difference among the different nutrient-conditioned cells was the smallest when the Cd concentration in the soluble fraction was used, suggesting that it may be the best predictor of Cd toxicity under different nutrient conditions

Effects of dietary brown propolis on nutrient intake and digestibility in feedlot lambs

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Jonilson Araújo da Silva

2014-07-01

Full Text Available The present study tested brown propolis in crude or extract form as a feed supplement for feedlot lambs to identify the type that most improves in vivo nutrient digestibility. Digestibility was assessed by both total fecal collection and internal markers and the results obtained by these techniques were compared. The completely randomized design was used to compare feed intake and nutrient digestibility of 24 male lambs aged seven months among four dietary treatments (crude brown propolis, propolis ethanol extract, monensin sodium, and control. Methods of feces collection were compared using a completely randomized split-plot design, with experimental diets corresponding to the main factor and the methods to estimate fecal production as the sub-factor. The diets had a roughage:concentrate ratio of 50:50, with Tifton-85 bermudagrass hay (Cynodon spp. as roughage, and ground corn, soybean meal and minerals as concentrate. The lambs fed diets with crude propolis had higher feed intake than those fed diets containing monensin sodium. The different diets did not affect dry matter, organic matter, crude protein, neutral detergent fiber, or acid detergent fiber digestibility, but crude propolis supplementation provided higher ether extract digestibility than monensin sodium. Nutrient digestibility, as indicated by indigestible neutral detergent fiber, indigestible acid detergent fiber and sequentially-determined indigestible acid detergent fiber, was lower than that found with the fecal collection method. The addition of brown propolis has the same effect as monensin, but neither maximized nutrient availability in the diet of feedlot lambs at 7 months of age. Digestibility assessment using the internal markers indigestible neutral detergent fiber, indigestible acid detergent fiber and sequentially-determined indigestible acid detergent fiber is not an efficient method compared with total feces collection.

Production of gherkin seedlings in coconut fiber fertirrigated with different nutrient solutions

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Francisco de Assis de Oliveira

Full Text Available ABSTRACT Seedling quality is a key factor to achieve success in vegetable production. The present work aimed to evaluate the production of gherkin seedlings in substrate of coconut fiber fertirrigated with different concentrations of nutrients. The experimental design was completely randomized in a 3 × 5 factorial with four replications. The treatments consisted of combinations of three cultivars of gherkin (Do Norte, Liso de Calcutá, e Liso Gibão with five concentrations of nutrients in the solution (0, 25, 50, 75, and 100%. The nutrient solution, considered standard, matches the recommended solution for melon in hydroponic systems. We evaluated the variables: chlorophyll index, shoot length, number of leaves, stem diameter, main root length, dry weight of leaves, roots, and stem, mass of total dry matter, leaf area, specific leaf area, and leaf area ratio. All variables were affected by the ionic concentration in nutrient solutions. The use of coconut fiber in the production of gherkin seedlings is more efficient with nutrient solutions in concentrations ranging from 75 to 100% of the recommended solution for melon cultivation.

Nutrient depletion in Bacillus subtilis biofilms triggers matrix production

International Nuclear Information System (INIS)

Zhang, Wenbo; Seminara, Agnese; Suaris, Melanie; Angelini, Thomas E; Brenner, Michael P; Weitz, David A

2014-01-01

Many types of bacteria form colonies that grow into physically robust and strongly adhesive aggregates known as biofilms. A distinguishing characteristic of bacterial biofilms is an extracellular polymeric substance (EPS) matrix that encases the cells and provides physical integrity to the colony. The EPS matrix consists of a large amount of polysaccharide, as well as protein filaments, DNA and degraded cellular materials. The genetic pathways that control the transformation of a colony into a biofilm have been widely studied, and yield a spatiotemporal heterogeneity in EPS production. Spatial gradients in metabolites parallel this heterogeneity in EPS, but nutrient concentration as an underlying physiological initiator of EPS production has not been explored. Here, we study the role of nutrient depletion in EPS production in Bacillus subtilis biofilms. By monitoring simultaneously biofilm size and matrix production, we find that EPS production increases at a critical colony thickness that depends on the initial amount of carbon sources in the medium. Through studies of individual cells in liquid culture we find that EPS production can be triggered at the single-cell level by reducing nutrient concentration. To connect the single-cell assays with conditions in the biofilm, we calculate carbon concentration with a model for the reaction and diffusion of nutrients in the biofilm. This model predicts the relationship between the initial concentration of carbon and the thickness of the colony at the point of internal nutrient deprivation. (paper)

The influence of change of concentration of sum of nutrient elements on uptake 137Cs from inert substrate to the lettuce

International Nuclear Information System (INIS)

Alipbekov, O.A.; Dlimbetova, G.K.

2002-01-01

Radiation ecology has become the science of applied character after the numbers of great accidents at the nuclear fuel cycle enterprises (United Kingdom, 1957; Russia,1957; Ukraine, 1986). The success of the fight on the consequences liquidations of the uncontrolled fallen artificial radionuclides on the agricultural fields depends a lot on the correct use of accumulated division products in the soil-plant system in the field migration appropriateness. The considerable lowering of radionuclides uptake into the plants from the soil can be achieved by increase of disability of products fastening of soil division. At the same time the addition of the stuff with high sorption and fixing characteristics into the soil, as a rule, gives a considerable effect only in the first period of their use. Later the fixed isotopes can come into ion-exchange process again after the achievement of the balance condition with the soil-absorbing complex, i.e. pass in the more mobile forms. Entering of mineral fertilizers into the soil often leads to the contradictory results, so the search in this direction is going on. The given information emphasizes the actuality of the further studying the methods of regulation of long living radionuclides availability from the soil to the plants with the help of the nutrient mineral elements. The aim of the present work is the study of the influence of concentration of sum of basic nutrient elements (nitrogen, phosphorus, potassium, calcium, magnesium, iron, copper, zinc, manganese, cobalt, molybdenum, boron) on the uptake of 137 Cs from the inert substrate to the Lettuce plants. The vegetation experiments were carried out in one liter polyethylene vascular. One liter of milled quartz sand (size of the fractions was 0.5-1.0 mm) was put into each vascular specially cleaned from admixtures. The nutrient elements were added according to Rinkis. The results of the carried out researches have shown that the decrease of the concentration of sum of macro

Consequences of warming and resource quality on the stoichiometry and nutrient cycling of a stream shredder.

Directory of Open Access Journals (Sweden)

Esther Mas-Martí

Full Text Available As a result of climate change, streams are warming and their runoff has been decreasing in most temperate areas. These changes can affect consumers directly by increasing their metabolic rates and modifying their physiology and indirectly by changing the quality of the resources on which organisms depend. In this study, a common stream detritivore (Echinogammarus berilloni Catta was reared at two temperatures (15 and 20°C and fed Populus nigra L. leaves that had been conditioned either in an intermittent or permanent reach to evaluate the effects of resource quality and increased temperatures on detritivore performance, stoichiometry and nutrient cycling. The lower quality (i.e., lower protein, soluble carbohydrates and higher C:P and N:P ratios of leaves conditioned in pools resulted in compensatory feeding and lower nutrient retention capacity by E. berilloni. This effect was especially marked for phosphorus, which was unexpected based on predictions of ecological stoichiometry. When individuals were fed pool-conditioned leaves at warmer temperatures, their growth rates were higher, but consumers exhibited less efficient assimilation and higher mortality. Furthermore, the shifts to lower C:P ratios and higher lipid concentrations in shredder body tissues suggest that structural molecules such as phospholipids are preserved over other energetic C-rich macromolecules such as carbohydrates. These effects on consumer physiology and metabolism were further translated into feces and excreta nutrient ratios. Overall, our results show that the effects of reduced leaf quality on detritivore nutrient retention were more severe at higher temperatures because the shredders were not able to offset their increased metabolism with increased consumption or more efficient digestion when fed pool-conditioned leaves. Consequently, the synergistic effects of impaired food quality and increased temperatures might not only affect the physiology and survival of

Temperature sensitivity of extracellular enzyme kinetics in subtropical wetland soils under different nutrient and water level conditions

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Goswami, S.; Inglett, K.; Inglett, P.

2012-12-01

Microbial extracellular enzymes play an important role in the initial steps of soil organic matter decomposition and are involved in regulating nutrient cycle processes. Moreover, with the recent concern of climate change, microbial extracellular enzymes may affect the functioning (C losses, C sequestration, greenhouse gas emissions, vegetation changes) of different ecosystems. Hence, it is imperative to understand the biogeochemical processes that may be climate change sensitive. Here, we have measured the Michaelis Menten Kinetics [maximal rate of velocity (Vmax) and half-saturation constant (Km)] of 6 enzymes involved in soil organic matter decomposition (phosphatase, phosphodiesterase, β-D-glucosidase, cellobiohydrolase, leucine aminopeptidase, N-Acetyl-β-D glucosaminidase) in different nutrient(P) concentration both aerobically and anaerobically in Everglade water conservation area 2A (F1, F4-slough and U3-slough). Temperature sensitivity of different enzymes is assessed within soil of different P concentrations. We hypothesized that the temperature sensitivity of the enzyme changes with the biogeochemical conditions including water level and nutrient condition. Furthermore, we have tested specific hypothesis that higher P concentration will initiate more C demand for microbes leading to higher Vmax value for carbon processing enzymes in high P site. We found temperature sensitivity of all enzymes for Vmax and Km under both aerobic and anaerobic condition ranges from 0.6 to 3.2 for Vmax and 0.5 to 2.5 for Km. Q10 values of Km for glucosidase indicate more temperature sensitivity under anaerobic condition. Under aerobic condition higher temperature showed significant effect on Vmax for bisphosphatase between high P and low P site. Decreasing P concentration from F1 site to U3-S site had showed significant effect in all temperature on carbon processing enzyme. This suggests that in high P site, microbes will use more carbon-processing enzyme to get more carbon

Evidence of chronic anthropogenic nutrient within coastal lagoon reefs adjacent to urban and tourism centers, Kenya: A stable isotope approach.

Science.gov (United States)

Mwaura, Jelvas; Umezawa, Yu; Nakamura, Takashi; Kamau, Joseph

2017-06-30

The source of anthropogenic nutrient and its spatial extent in three fringing reefs with differing human population gradients in Kenya were investigated using stable isotope approaches. Nutrient concentrations and nitrate-δ 15 N in seepage water indicated that population density and tourism contributed greatly to the extent of nutrient loading to adjacent reefs. Although water-column nutrient analyses did not show any significant difference among the reefs, higher δ 15 N and N contents in macrophytes showed terrestrial nutrients affected primary producers in onshore areas in Nyali and Bamburi reefs, but were mitigated by offshore water intrusion especially at Nyali. On the offshore reef flat, where the same species of macroalgae were not available, complementary use of δ 15 N in sedimentary organic matter suggested inputs of nutrients originated from the urban city of Mombasa. If population increases in the future, nutrient conditions in the shallower reef, Vipingo, may be dramatically degraded due to lower water exchange ratio. Copyright © 2017 Elsevier Ltd. All rights reserved.

Heavy metal toxicities in vegetable crops. VI. The effect of potassium and calcium concentration in the nutrient solution on manganese toxicities in vegetable crops

Energy Technology Data Exchange (ETDEWEB)

Osawa, T; Ikeda, H

1977-01-01

Eight species of vegetable crops were grown in solution culture in order to investigate the effect of potassium and calcium concentration in the nutrient solution on manganese toxicities in vegetable crops. Manganese was supplied at levels of 0.5, 30, and 100 ppm. At each manganese level potassium or calcium was supplied at rates of 2, 6, and 18 me/l. The pH of the nutrient solution was adjusted to 5. Manganese excess induced interveinal chlorosis on upper leaves in bean, eggplant, pepper, and spinach, and marginal chlorosis on lower leaves in cabbage, lettuce, and celery. In Welsh onions chlorosis was induced on lower leaves. Increasing the supply of potassium and calcium reduced the severity of manganese-induced chlorosis. This beneficial effect was generally more marked with calcium than with potassium. Increasing the supply of potassium and calcium was effective in alleviating the growth reduction of vegetable crops due to manganese excess. This effect also was more marked with calcium than with potassium. With increasing manganese level in the nutrient solution the manganese concentration in leaves of vegetable crops increased. Increasing the supply of potassium and calcium inhibited excessive accumulation of manganese in leaves. The influence of calcium was stronger than that of potassium. In any of the vegetable crops tested, regardless of potassium and calcium treatments, manganese concentration in leaves was closely related to manganese toxicities; the more the accumulation of manganese in leaves increased, the more the severity of manganese-induced chlorosis and growth reduction increased.

Effects of Elevated CO2 Concentration on the Biomasses and Nitrogen Concentrations in the Organs of Sainfoin(Onobrychis viciaefolia Scop.)

Institute of Scientific and Technical Information of China (English)

ZHOU Zheng-chao; SHANGGUAN Zhou-ping

2009-01-01

In forage grasses,the nitrogen concentration is directly related to the nutritional value.The studies examined the hypothesis that global elevation of CO2 concentration probably affects the biomass,nitrogen(N)concentration,and allocation and distribution patterns in the organs of forage grasses.While sainfoin(Onobrychis viciaefolia Scop.)seedlings grew on a low nutrient soil in closed chambers for 90 days,they were exposed to two CO2 concentrations(ambient or ambient+350μmol mol-1 CO2)without adding nutrients to them.After 90 days exposure to CO2,the biomasses of leaves,stems,and roots,and N concentrations and contents of different parts were measured.Compared with the ambient CO2 concentration,the elevated CO2 concentration increased the total dry matter by 25.07%,mainly due to the root and leaf having positive response to the elevated CO2 concentration.However,the elevated CO2 concentration did not change the proportions of the dry matters in different parts and the total plants compared with the ambient CO2 concentration.The elevated CO2 concentration lowered the N concentrations of the plant parts.Because the dry matter was higher,the elevated CO2 concentration had no effect on the N content in the plants compared to the ambient CO2 concentration.The elevated CO2 concentration promoted N allocations of the different parts significantly and increased N allocation of the underground part.The results have confirmed the previous suggestions that the elevated CO2 concentration stimulates plant biomass production and decreases the N concentrations of the plant parts.

Nutrient sequestration in Aquitaine lakes (SW France) limits nutrient flux to the coastal zone

Science.gov (United States)

Buquet, Damien; Anschutz, Pierre; Charbonnier, Céline; Rapin, Anne; Sinays, Rémy; Canredon, Axel; Bujan, Stéphane; Poirier, Dominique

2017-12-01

Oligotrophic coastal zones are disappearing from increased nutrient loading. The quantity of nutrients reaching the coast is determined not only by their original source (e.g. fertilizers used in agriculture, waste water discharges) and the land use, but also by the pathways through which nutrients are cycled from the source to the river mouth. In particular, lakes sequester nutrients and, hence, reduce downstream transfer of nutrients to coastal environments. Here, we quantify the impact of Aquitaine great lakes on the fluxes of dissolved macro-nutrients (N, P, Si) to the Bay of Biscay. For that, we have measured nutrient concentrations and fluxes in 2014 upstream and downstream lakes of Lacanau and Carcans-Hourtin, which belongs to the catchment of the Arcachon Bay, which is the largest coastal lagoon of the Bay of Biscay French coast. Data were compared to values obtained from the Leyre river, the main freshwater and nutrient source for the lagoon. Results show that processes in lakes greatly limit nutrient flux to the lagoon compared to fluxes from Leyre river, although the watershed is similar in terms of land cover. In lakes, phosphorus and silicon are trapped for long term in the sediment, silicon as amorphous biogenic silica and phosphorus as organic P and P associated with Fe-oxides. Nitrogen that enters lakes mostly as nitrate is used for primary production. N is mineralized in the sediment; a fraction diffuses as ammonium. N2 production through benthic denitrification extracts only 10% of dissolved inorganic nitrogen from the aquatic system. The main part is sequestered in organic-rich sediment that accumulates below 5 m depth in both lakes.

Comparative growth behaviour and leaf nutrient status of native trees planted on mine spoil with and without nutrient amendment

Energy Technology Data Exchange (ETDEWEB)

Singh, A.; Singh, J.S. [Banaras Hindu University, Varanasi (India). Dept. of Botany

2001-07-01

The effect of nutrient amendment on growth of nine indigenous tree species planted on coal mine spoil was studied. Greater growth in fertilized plots was accompanied by greater foliar N and P concentrations in all species. The response to fertilization varied among species and was greater in non-leguminous than in leguminous species. Furthermore, leguminous species exhibited higher growth rates compared to non-leguminous species. Acacia catechu, Dalbergia sissoo, Gmelina arborea and Azadirachta indica fitted the elastic similarity model of tree growth; whereas Pongamia pinnata and Phyllanthus emblica followed the constant stress model. Tectona grandis was the only species which fitted the geometric similarity model.

Traditional food consumption is associated with higher nutrient intakes in Inuit children attending childcare centres in Nunavik

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Doris Gagné

2012-07-01

Full Text Available Objectives. To describe traditional food (TF consumption and to evaluate its impact on nutrient intakes of preschool Inuit children from Nunavik. Design. A cross-sectional study. Methods. Dietary intakes of children were assessed with a single 24-hour recall (n=217. TF consumption at home and at the childcare centres was compared. Differences in children's nutrient intakes when consuming or not consuming at least 1 TF item were examined using ANCOVA. Results. A total of 245 children attending childcare centres in 10 communities of Nunavik were recruited between 2006 and 2010. The children's mean age was 25.0±9.6 months (11–54 months. Thirty-six percent of children had consumed at least 1 TF item on the day of the recall. TF contributed to 2.6% of total energy intake. Caribou and Arctic char were the most reported TF species. Land animals and fish/shellfish were the main contributors to energy intake from TF (38 and 33%, respectively. In spite of a low TF intake, children who consumed TF had significantly (p<0.05 higher intakes of protein, omega-3 fatty acids, iron, phosphorus, zinc, copper, selenium, niacin, pantothenic acid, riboflavin, and vitamin B12, and lower intakes of energy and carbohydrate compared with non-consumers. There was no significant difference in any of the socio-economic variables between children who consumed TF and those who did not. Conclusion. Although TF was not eaten much, it contributed significantly to the nutrient intakes of children. Consumption of TF should be encouraged as it provides many nutritional, economic, and sociocultural benefits.

Urban trees reduce nutrient leaching to groundwater.

Science.gov (United States)

Nidzgorski, Daniel A; Hobbie, Sarah E

2016-07-01

Many urban waterways suffer from excess nitrogen (N) and phosphorus (P), feeding algal blooms, which cause lower water clarity and oxygen levels, bad odor and taste, and the loss of desirable species. Nutrient movement from land to water is likely to be influenced by urban vegetation, but there are few empirical studies addressing this. In this study, we examined whether or not urban trees can reduce nutrient leaching to groundwater, an important nutrient export pathway that has received less attention than stormwater. We characterized leaching beneath 33 trees of 14 species, and seven open turfgrass areas, across three city parks in Saint Paul, Minnesota, USA. We installed lysimeters at 60 cm depth to collect soil water approximately biweekly from July 2011 through October 2013, except during winter and drought periods, measured dissolved organic carbon (C), N, and P in soil water, and modeled water fluxes using the BROOK90 hydrologic model. We also measured soil nutrient pools (bulk C and N, KCl-extractable inorganic N, Brays-P), tree tissue nutrient concentrations (C, N, and P of green leaves, leaf litter, and roots), and canopy size parameters (leaf biomass, leaf area index) to explore correlations with nutrient leaching. Trees had similar or lower N leaching than turfgrass in 2012 but higher N leaching in 2013; trees reduced P leaching compared with turfgrass in both 2012 and 2013, with lower leaching under deciduous than evergreen trees. Scaling up our measurements to an urban subwatershed of the Mississippi River (~17 400 ha, containing ~1.5 million trees), we estimated that trees reduced P leaching to groundwater by 533 kg in 2012 (0.031 kg/ha or 3.1 kg/km 2 ) and 1201 kg in 2013 (0.069 kg/ha or 6.9 kg/km 2 ). Removing these same amounts of P using stormwater infrastructure would cost $2.2 million and $5.0 million per year (2012 and 2013 removal amounts, respectively). © 2016 by the Ecological Society of America.

Marine-derived nutrients, bioturbation, and ecosystem metabolism: reconsidering the role of salmon in streams.

Science.gov (United States)

Holtgrieve, Gordon W; Schindler, Daniel E

2011-02-01

In coastal areas of the North Pacific Ocean, annual returns of spawning salmon provide a substantial influx of nutrients and organic matter to streams and are generally believed to enhance the productivity of recipient ecosystems. Loss of this subsidy from areas with diminished salmon runs has been hypothesized to limit ecosystem productivity in juvenile salmon rearing habitats (lakes and streams), thereby reinforcing population declines. Using five to seven years of data from an Alaskan stream supporting moderate salmon densities, we show that salmon predictably increased stream water nutrient concentrations, which were on average 190% (nitrogen) and 390% (phosphorus) pre-salmon values, and that primary producers incorporated some of these nutrients into tissues. However, benthic algal biomass declined by an order of magnitude despite increased nutrients. We also measured changes in stream ecosystem metabolic properties, including gross primary productivity (GPP) and ecosystem respiration (ER), from three salmon streams by analyzing diel measurements of oxygen concentrations and stable isotopic ratios (delta O-O2) within a Bayesian statistical model of oxygen dynamics. Our results do not support a shift toward higher primary productivity with the return of salmon, as is expected from a nutrient fertilization mechanism. Rather, net ecosystem metabolism switched from approximately net autotrophic (GPP > or = ER) to a strongly net heterotrophic state (GPP disturbance enhanced in situ heterotrophic respiration. Salmon also changed the physical properties of the stream, increasing air-water gas exchange by nearly 10-fold during peak spawning. We suggest that management efforts to restore salmon ecosystems should consider effects on ecosystem metabolic properties and how salmon disturbance affects the incorporation of marine-derived nutrients into food webs.

Measuring calcium, potassium, and nitrate in plant nutrient solutions using ion-selective electrodes in hydroponic greenhouse of some vegetables.

Science.gov (United States)

Vardar, Gökay; Altıkatoğlu, Melda; Ortaç, Deniz; Cemek, Mustafa; Işıldak, İbrahim

2015-01-01

Generally, the life cycle of plants depends on the uptake of essential nutrients in a balanced manner and on toxic elements being under a certain concentration. Lack of control of nutrient levels in nutrient solution can result in reduced plant growth and undesired conditions such as blossom-end rot. In this study, sensitivity and selectivity tests for various polyvinylchloride (PVC)-based ion-selective membranes were conducted to identify those suitable for measuring typical concentration ranges of macronutrients, that is, NO(3-), K(+), and Ca(2+), in hydroponic solutions. The sensitivity and selectivity of PVC-membrane-based ion-selective sensors prepared with tetradodecylammoniumnitrate for NO(3-), valinomycin for K(+), and Ca ionophore IV for Ca(2+) were found to be satisfactory for measuring NO(3-), K(+), and Ca(2+) ions in nutrient solutions over typical ranges of hydroponic concentrations. Potassium, calcium, and nitrate levels that were utilized by cucumber and tomato seedlings in the greenhouse were different. The findings show that tomato plants consumed less amounts of nitrate than cucumber plants over the first 2 months of their growth. We also found that the potassium intake was higher than other nutritional elements tested for all plants. © 2014 International Union of Biochemistry and Molecular Biology, Inc.

Influence of Acacia trees on soil nutrient levels in arid lands

Science.gov (United States)

De Boever, Maarten; Gabriels, Donald; Ouessar, Mohamed; Cornelis, Wim

2014-05-01

The potential of scattered trees as keystone structures in restoring degraded environments is gaining importance. Scattered trees have strong influence on their abiotic environment, mainly causing changes in microclimate, water budget and soil properties. They often function as 'nursing trees', facilitating the recruitment of other plants. Acacia raddiana is such a keystone species which persists on the edge of the Sahara desert. The study was conducted in a forest-steppe ecosystem in central Tunisia where several reforestation campaigns with Acacia took place. To indentify the impact of those trees on soil nutrients, changes in nutrient levels under scattered trees of three age stages were examined for the upper soil layer (0-10 cm) at five microsites with increasing distance from the trunk. In addition, changes in soil nutrient levels with depth underneath and outside the canopy were determined for the 0-30 cm soil layer. Higher concentrations of organic matter (OM) were found along the gradient from underneath to outside the canopy for large trees compared to medium and small trees, especially at microsites close to the trunk. Levels of soluble K, electrical conductivity (EC), available P, OM, total C and N decreased whereas pH and levels of soluble Mg increased with increasing distance from tree. Levels of soluble Ca and Na remained unchanged along the gradient. At the microsite closest to the trunk a significant decrease in levels of soluble K, EC, OM, available P, total C and N, while a significant increase in pH was found with increasing depth. The concentration of other nutrients remained unchanged or declined not differently underneath compared to outside the canopy with increasing depth. Differences in nutrient levels were largely driven by greater inputs of organic matter under trees. Hence, Acacia trees can affect the productivity and reproduction of understory species with the latter in term an important source of organic matter. This positive feedback

Two-Phase Flow Modeling of Solid Dissolution in Liquid for Nutrient Mixing Improvement in Algal Raceway Ponds

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Haider Ali

2018-04-01

Full Text Available Achieving optimal nutrient concentrations is essential to increasing the biomass productivity of algal raceway ponds. Nutrient mixing or distribution in raceway ponds is significantly affected by hydrodynamic and geometric properties. The nutrient mixing in algal raceway ponds under the influence of hydrodynamic and geometric properties of ponds is yet to be explored. Such a study is required to ensure optimal nutrient concentrations in algal raceway ponds. A novel computational fluid dynamics (CFD model based on the Euler–Euler numerical scheme was developed to investigate nutrient mixing in raceway ponds under the effects of hydrodynamic and geometric properties. Nutrient mixing was investigated by estimating the dissolution of nutrients in raceway pond water. Experimental and CFD results were compared and verified using solid–liquid mass transfer coefficient and nutrient concentrations. Solid–liquid mass transfer coefficient, solid holdup, and nutrient concentrations in algal pond were estimated with the effects of pond aspect ratios, water depths, paddle wheel speeds, and particle sizes of nutrients. From the results, it was found that the proposed CFD model effectively simulated nutrient mixing in raceway ponds. Nutrient mixing increased in narrow and shallow raceway ponds due to effective solid–liquid mass transfer. High paddle wheel speeds increased the dissolution rate of nutrients in raceway ponds.

Biomass and nutrient allocation strategies in a desert ecosystem in the Hexi Corridor, northwest China.

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Zhang, Ke; Su, YongZhong; Yang, Rong

2017-07-01

The allocation of biomass and nutrients in plants is a crucial factor in understanding the process of plant structures and dynamics to different environmental conditions. In this study, we present a comprehensive scaling analysis of data from a desert ecosystem to determine biomass and nutrient (carbon (C), nitrogen (N), and phosphorus (P)) allocation strategies of desert plants from 40 sites in the Hexi Corridor. We found that the biomass and levels of C, N, and P storage were higher in shoots than in roots. Roots biomass and nutrient storage were concentrated at a soil depth of 0-30 cm. Scaling relationships of biomass, C storage, and P storage between shoots and roots were isometric, but that of N storage was allometric. Results of a redundancy analysis (RDA) showed that soil nutrient densities were the primary factors influencing biomass and nutrient allocation, accounting for 94.5% of the explained proportion. However, mean annual precipitation was the primary factor influencing the roots biomass/shoots biomass (R/S) ratio. Furthermore, Pearson's correlations and regression analyses demonstrated that although the biomass and nutrients that associated with functional traits primarily depended on soil conditions, mean annual precipitation and mean annual temperature had greater effects on roots biomass and nutrient storage.

Effect of nutrient enrichment on the source and composition of sediment organic carbon in tropical seagrass beds in the South China Sea

International Nuclear Information System (INIS)

Liu, Songlin; Jiang, Zhijian; Zhang, Jingping; Wu, Yunchao; Lian, Zhonglian; Huang, Xiaoping

2016-01-01

To assess the effect of nutrient enrichment on the source and composition of sediment organic carbon (SOC) beneath Thalassia hemprichii and Enhalus acoroides in tropical seagrass beds, Xincun Bay, South China Sea, intertidal sediment, primary producers, and seawater samples were collected. No significant differences on sediment δ 13 C, SOC, and microbial biomass carbon (MBC) were observed between T. hemprichii and E. acoroides. SOC was mainly of autochthonous origin, while the contribution of seagrass to SOC was less than that of suspended particulate organic matter, macroalgae and epiphytes. High nutrient concentrations contributed substantially to SOC of seagrass, macroalgae, and epiphytes. The SOC, MBC, and MBC/SOC ratio in the nearest transect to fish farming were the highest. This suggested a more labile composition of SOC and shorter turnover times in higher nutrient regions. Therefore, the research indicates that nutrient enrichment could enhance plant-derived contributions to SOC and microbial use efficiency. - Highlights: • Response of sources and composition of SOC to nutrient enrichment was observed. • Similar SOC sources and composition were observed in the two seagrass communities. • Nutrient enrichment enhanced seagrass and macroalgae and epiphytes contribution to SOC. • High nutrient concentration stimulated the MBC and the MBC/SOC ratio.

Organic foods contain higher levels of certain nutrients, lower levels of pesticides, and may provide health benefits for the consumer.

Science.gov (United States)

Crinnion, Walter J

2010-04-01

The multi-billion dollar organic food industry is fueled by consumer perception that organic food is healthier (greater nutritional value and fewer toxic chemicals). Studies of the nutrient content in organic foods vary in results due to differences in the ground cover and maturity of the organic farming operation. Nutrient content also varies from farmer to farmer and year to year. However, reviews of multiple studies show that organic varieties do provide significantly greater levels of vitamin C, iron, magnesium, and phosphorus than non-organic varieties of the same foods. While being higher in these nutrients, they are also significantly lower in nitrates and pesticide residues. In addition, with the exception of wheat, oats, and wine, organic foods typically provide greater levels of a number of important antioxidant phytochemicals (anthocyanins, flavonoids, and carotenoids). Although in vitro studies of organic fruits and vegetables consistently demonstrate that organic foods have greater antioxidant activity, are more potent suppressors of the mutagenic action of toxic compounds, and inhibit the proliferation of certain cancer cell lines, in vivo studies of antioxidant activity in humans have failed to demonstrate additional benefit. Clear health benefits from consuming organic dairy products have been demonstrated in regard to allergic dermatitis.

Nutrients and clam contamination by Escherichia coli in a meso-tidal coastal lagoon: Seasonal variation in counter cycle to external sources

International Nuclear Information System (INIS)

Botelho, Maria João; Soares, Florbela; Matias, Domitília; Vale, Carlos

2015-01-01

Highlights: • Sources of nutrients and E. coli in Ria Formosa linked to tourism in summer. • Lower nutrient values and clam contamination by E. coli in summer. • Bactericide effect of temperature and solar radiation causes lower E. coli. • Higher biological consumption of nutrients in warmer periods. • Results mirror possible effects of climate changes on coastal lagoons. - Abstract: The clam Ruditapes decussatus was transplanted from a natural recruitment area of Ria Formosa to three sites, surveyed for nutrients in water and sediments. Specimens were sampled monthly for determination of Escherichia coli, condition index and gonadal index. Higher nutrient values in low tide reflect drainage, anthropogenic sources or sediment regeneration, emphasising the importance of water mixing in the entire lagoon driven by the tide. Despite the increase of effluent discharges in summer due to tourism, nutrient concentrations and E. coli in clams were lower in warmer periods. The bactericide effect of temperature and solar radiation was better defined in clams from the inlet channel site than from sites closer to urban effluents. High temperature in summer and torrential freshwater inputs to Ria Formosa may anticipate climate change scenarios for south Europe. Seasonal variation of nutrients and clam contamination may thus point to possible alterations in coastal lagoons and their ecosystem services

Late gestational nutrient restriction

DEFF Research Database (Denmark)

Tygesen, Malin Plumhoff; Nielsen, Mette Olaf; Nørgaard, Peder

2008-01-01

We investigated the effect of 50% nutrient restriction during the last 6 weeks of gestation on twin-pregnant ewes' plasma glucose, non-esterified fatty acid, ß-hydroxybutyrate, insulin, IGF-1 and leptin concentrations and the effects on lamb birth weight and ewes' lactation performance. Plasma...

Relations of biological indicators to nutrient data for lakes and streams in Pennsylvania and West Virginia, 1990-98

Science.gov (United States)

Brightbill, Robin A.; Koerkle, Edward H.

2003-01-01

The Clean Water Action Plan of 1998 provides a blueprint for federal agencies to work with states, tribes, and other stakeholders to protect and restore the Nation's water resources. The plan includes an initiative that addresses the nutrient-enrichment problem of lakes and streams across the United States. The U.S. Environmental Protection Agency (USEPA) is working to set nutrient criteria by nationwide nutrient ecoregions that are an aggregation of the Omernik level III ecoregions. Because low levels of nutrients are necessary for healthy streams and elevated concentrations can cause algal blooms that deplete available oxygen and kill off aquatic organisms, criteria levels are to be set, in part, using the relation between chlorophyll a and concentrations of total nitrogen and total phosphorus.Data from Pennsylvania and West Virginia, collected between 1990 and 1998, were analyzed for relations between chlorophyll a, nutrients, and other explanatory variables. Both phytoplankton and periphyton chlorophyll a concentrations from lakes and streams were analyzed separately within each of the USEPA nutrient ecoregions located within the boundaries of the two states. These four nutrient ecoregions are VII (Mostly Glaciated Dairy), VIII (Nutrient Poor, Largely Glaciated Upper Midwest and Northeast), IX (Southeastern Temperate Forested Plains and Hills), and XI (Central and Eastern Forested Uplands).Phytoplankton chlorophyll a concentrations in lakes were related to total nitrogen, total phosphorus, Secchi depth, concentration of dissolved oxygen, pH, water temperature, and specific conductivity. In nutrient ecoregion VII, nutrients were not significant predictors of chlorophyll a concentrations. Total nitrogen, Secchi depth, and pH were significantly related to phytoplankton chlorophyll a concentrations in nutrient ecoregion IX. Lake periphyton chlorophyll a concentrations from nutrient ecoregion XI were related to total phosphorus rather than total nitrogen, Secchi

Distribution of nutrients in the western Bay of Bengal

Digital Repository Service at National Institute of Oceanography (India)

De; Naqvi, S.W.A; Reddy, C.V.G.

and low nutrient concentrations increased in thickness from north to south. The intermediate water layer was marked by a steep rise of nutrients associated with oxygen minimum suggesting active decomposition of organic matter.N:P in the upper 75 m...

Emergence of nutrient limitation in tropical dry forests: hypotheses from simulation models

Science.gov (United States)

Medvigy, D.; Waring, B. G.; Xu, X.; Trierweiler, A.; Werden, L. K.; Wang, G.; Zhu, Q.; Powers, J. S.

2017-12-01

It is unclear to what extent tropical dry forest productivity may be limited by nutrients. Direct assessment of nutrient limitation through fertilization experiments has been rare, and paradigms pertaining to other ecosystems may not extend to tropical dry forests. For example, because dry tropical forests have a lower water supply than moist tropical forests, dry forests can have lower decomposition rates, higher soil carbon and nitrogen concentrations, and a more open nitrogen cycle than moist forests. We used a mechanistic, numerical model to generate hypotheses about nutrient limitation in tropical dry forests. The model dynamically couples ED2 (vegetation dynamics), MEND (biogeochemistry), and N-COM (plant-microbe competition for nutrients). Here, the MEND-component of the model has been extended to include nitrogen (N) and phosphorus (P) cycles. We focus on simulation of sixteen 25m x 25m plots in Costa Rica where a fertilization experiment has been underway since 2015. Baseline simulations are characterized by both nitrogen and phosphorus limitation of vegetation. Fertilization with N and P increased vegetation biomass, with N fertilization having a somewhat stronger effect. Nutrient limitation was also sensitive to climate and was more pronounced during drought periods. Overflow respiration was identified as a key process that mitigated nutrient limitation. These results suggest that, despite often having richer soils than tropical moist forests, tropical dry forests can also become nutrient-limited. If the climate becomes drier in the next century, as is expected for Central America, drier soils may decrease microbial activity and exacerbate nutrient limitation. The importance of overflow respiration underscores the need for appropriate treatment of microbial dynamics in ecosystem models. Ongoing and new nutrient fertilization experiments will present opportunities for testing whether, and how, nutrient limitation may indeed be emerging in tropical dry

Zinc deficiency in field-grown pecan trees: changes in leaf nutrient concentrations and structure.

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Ojeda-Barrios, Dámaris; Abadía, Javier; Lombardini, Leonardo; Abadía, Anunciación; Vázquez, Saúl

2012-06-01

Zinc (Zn) deficiency is a typical nutritional disorder in pecan trees [Carya illinoinensis (Wangenh.) C. Koch] grown under field conditions in calcareous soils in North America, including northern Mexico and south-western United States. The aim of this study was to assess the morphological and nutritional changes in pecan leaves affected by Zn deficiency as well as the Zn distribution within leaves. Zinc deficiency led to decreases in leaf chlorophyll concentrations, leaf area and trunk cross-sectional area. Zinc deficiency increased significantly the leaf concentrations of K and Ca, and decreased the leaf concentrations of Zn, Fe, Mn and Cu. All nutrient values found in Zn-deficient leaves were within the sufficiency ranges, with the only exception of Zn, which was approximately 44, 11 and 9 µg g(-1) dry weight in Zn-sufficient, moderately and markedly Zn-deficient leaves, respectively. Zinc deficiency led to decreases in leaf thickness, mainly due to a reduction in the thickness of the palisade parenchyma, as well as to increases in stomatal density and size. The localisation of Zn was determined using the fluorophore Zinpyr-1 and ratio-imaging technique. Zinc was mainly localised in the palisade mesophyll area in Zn-sufficient leaves, whereas no signal could be obtained in Zn-deficient leaves. The effects of Zn deficiency on the leaf characteristics of pecan trees include not only decreases in leaf chlorophyll and Zn concentrations, but also a reduction in the thickness of the palisade parenchyma, an increase in stomatal density and pore size and the practical disappearance of Zn leaf pools. These characteristics must be taken into account to design strategies to correct Zn deficiency in pecan tree in the field. Copyright © 2012 Society of Chemical Industry.

Suppression of the invasive plant mile-a-minute (Mikania micrantha) by local crop sweet potato (Ipomoea batatas) by means of higher growth rate and competition for soil nutrients.

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Shen, Shicai; Xu, Gaofeng; Clements, David Roy; Jin, Guimei; Chen, Aidong; Zhang, Fudou; Kato-Noguchi, Hisashi

2015-01-28

There are a variety of ways of increasing crop diversity to increase agricultural sustainability and in turn having a positive influence on nearby natural ecosystems. Competitive crops may provide potent management tools against invasive plants. To elucidate the competitive mechanisms between a sweet potato crop (Ipomoea batatas) and an invasive plant, mile-a-minute (Mikania micrantha), field experiments were carried out in Longchuan County of Yunnan Province, Southwest China, utilizing a de Wit replacement series. The trial incorporated seven ratios of sweet potato and mile-a-minute plants in 25 m(2) plots. In monoculture, the total biomass, biomass of adventitious root, leafstalk length, and leaf area of sweet potato were all higher than those of mile-a-minute, and in mixed culture the plant height, branch, leaf, stem node, adventitious root, flowering and biomass of mile-a-minute were suppressed significantly (P competition was less than interspecific competition. The competitive balance index of sweet potato demonstrated a higher competitive ability than mile-a-minute. Except pH, other soil nutrient contents of initial soil (CK) were significantly higher than those of seven treatments. The concentrations of soil organic matter, total N, total K, available N, available P, available K, exchange Ca, exchange Mg, available Mn, and available B were significantly greater (P competition of sweet potato in the mixture. Evidently sweet potato has a competitive advantage in terms of plant growth characteristics and greater absorption of soil nutrients. Thus, planting sweet potato is a promising technique for reducing infestations of mile-a-minute, providing weed management benefits and economic returns from harvest of sweet potatoes. This study also shows the potential value of replacement control methods which may apply to other crop-weed systems or invaded natural ecosystems.

Effects of increased atmospheric CO2 on small and intermediate sized osmotrophs during a nutrient induced phytoplankton bloom

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A. Larsen

2008-05-01

Full Text Available We report the transient population dynamic response of the osmotrophic community initiated by a nutrient pulse in mesocosms exposed to different pCO2 levels. Differences in phytoplankton and heterotrophic bacteria abundances associated with the CO2 treatment are also described. Coastal seawater was enclosed in floating mesocosms (27 m3 and nutrients were supplied initially in order to stimulate growth of microbial organisms, including the coccolitophorid Emiliania huxleyi. The mesocosms were modified to achieve 350 μatm (1×CO2, 700 μatm (2×CO2 and 1050 μatm (3×CO2 CO2 pressure. The temporal dynamics was related to nutrient conditions in the enclosures. Numerically small osmotrophs (picoeukaryotes and Synechoccocus sp. dominated initially and towards the end of the experiment, whereas intermediate sized osmotrophs bloomed as the initial bloom of small sized osmotrophs ceased. Maximum concentrations of E. huxleyi were approximately 4.6×103 cells ml−1 whereas other intermediate sized osmotrophs reached approximately twice as high concentrations. The osmotrophic succession pattern did not change, and neither were we able to detect differences with regard to presence or absence of specific osmotrophic taxa as a consequence of altered pCO2. Towards the end of the experiment we did, however, record significantly higher picoeukaryotic- and lower Synechococcus-abundances in the higher CO2 treatments. Slightly increased cell concentrations of E. huxleyi and other nanoeukaryotes were also recorded at elevated pCO2 on certain days.

Improving fermented quality of cider vinegar via rational nutrient feeding strategy.

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Qi, Zhengliang; Dong, Die; Yang, Hailin; Xia, Xiaole

2017-06-01

This work aimed to find a rational nutrient feeding strategy for cider vinegar fermentation based on adequate information on the nutritional requirement of acetic acid bacteria. Through single nutrient lack experiment assay, necessary nutrient recipe for Acetobacter pasteurianus CICIM B7003 in acetous fermentation was confirmed. Compounds from the essential nutrient recipe were tested further to find out the key substrates significantly influencing cider vinegar fermentation. The findings showed that aspartate, glutamate, proline and tryptophan should be considered in detail for optimizing nutritional composition of cider. Finally, a nutrient feeding strategy that simultaneously adds proline, glutamate, aspartate and tryptophan to form final concentrations of 0.02g/L, 0.03g/L, 0.01g/L and 0.005g/L in cider was achieved by orthogonal experiment design. Comparing to the original fermentation, the yield of acetic acid from alcohol reached 93.3% and the concentration of most volatile flavor compounds increased with the rational nutrient feeding strategy. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of interactions between carbon dioxide enrichment and NH4+/NO3- ratio on pH of culturing nutrient solution,growth and vigor of tomato root system

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Juan LI; Jianmin ZHOU

2008-01-01

A growth chamber experiment was conducted to investigate the influence of NH4+/NO3- ratio and elevated CO2 concentration on the pH in nutrient solution,growth and root vigor system of tomato seedling roots,which attempts to understand whether the elevated CO2 concentration can alleviate the harmful effects of higher NH4+-N concentration in nutrient solutions on the tomato root system.Tomato (Lycopersicon esculenturn Mill.var.Hezuo 906) was grown in pots with nutrient solutions varying in NH4+/NO3- ratio (0:1,1:3,1:1,3:1and 1:0) and the growth chambers were supplied with with the growth process and CO2 concentration increased.At both CO2 levels,pH increased when 100% NO3--N was supplied and decreased in other treatments.The pH decrease in the nutrient solution was directly correlated to the NH4+-N proportion.The pH value was more reduced in 100% NH4+-N nutrient solution than increased in the 100% NO3--N nutrient solution.CO2 enrichment increased the dry weight of shoots and roots,root vigor system,total absorbing area and active absorbing area of tomato seedlings.All the measurement indexes above were increased in the elevated CO2 concentration treatment with the NO3- proportion increase in the nutrient solutions.Thus,under the elevated CO2 concentration,the dry weights of shoots and roots,root vigor system,total root absorbing area and active absorbing area were found to be inversely correlated to NH4+/NO3- ratio,leading to about 65.8%,78.0%,18.9%,12.9% and 18.9% increase,respectively,compared with that under the ambient CO2 concentration.Our results indicated that tomato seedling roots may benefit mostly from CO2 enrichment when 100% NO3--N nutrient solutions was supplied,but the CO2 concentration elevation did not alleviate the harmful effects when 100% NHa+-N was supplied.

Effect of mineral nutrients on cell growth and self-flocculation of Tolypothrix tenuis for the production of a biofertilizer.

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Silva, P G; Silva, H J

2007-02-01

The influence of mineral nutrients on the growth and self-flocculation of Tolypothrix tenuis was studied. The identification of possible limiting nutrients in the culture medium was performed by the biomass elemental composition approach. A factorial experimental design was used in order to estimate the contribution of macronutrients and micronutrients, as well as their interactions. Iron was identified to be limiting in the culture medium. The micronutrients influenced mainly cellular growth without effects on self-flocculation. Conversely, the self-flocculation capacity of the biomass increased at higher concentrations of macronutrients. The optimization of mineral nutrition of T. tenuis allowed a 73% increase in the final biomass level and 3.5 times higher flocculation rates.

Effect of feeding a by-product feed-based silage on nutrients intake, apparent digestibility, and nitrogen balance in sheep.

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Seok, J S; Kim, Y I; Lee, Y H; Choi, D Y; Kwak, W S

2016-01-01

Literature is lacking on the effects of feeding by-product feed (BF)-based silage on rumen fermentation parameters, nutrient digestion and nitrogen (N) retention in sheep. Therefore, this study was conducted to determine the effect of replacing rye straw with BF-based silage as a roughage source on ruminal parameters, total-tract apparent nutrient digestibility, and N balance in sheep. The by-product feed silage was composed of spent mushroom substrate (SMS) (45 %), recycled poultry bedding (RPB) (21 %), rye straw (11 %), rice bran (10.8 %), corn taffy residue (10 %), protected fat (1.0 %), bentonite (0.6 %), and mixed microbial additive (0.6 %). Six sheep were assigned randomly to either the control (concentrate mix + rye straw) or a treatment diet (concentrate mix + BF-based silage). Compared with the control diet, feeding a BF-based silage diet resulted in similar ruminal characteristics (pH, acetate, propionate, and butyrate concentrations, and acetate: propionate ratio), higher (p < 0.05) ruminal NH3-N, higher (p < 0.05) ether extract digestibility, similar crude protein digestibility, lower (p < 0.05) dry matter, fiber, and crude ash digestibilities, and higher (p < 0.05) N retention (g/d). The BF-based silage showed similar energy value, higher protein metabolism and utilization, and lower fiber digestion in sheep compared to the control diet containing rye straw.

Sulphate, more than a nutrient, protects the microalga Chlamydomonas moewusii from cadmium toxicity

Energy Technology Data Exchange (ETDEWEB)

Mera, Roi; Torres, Enrique, E-mail: torres@udc.es; Abalde, Julio

2014-03-01

Highlights: • Sulphate effect on cadmium toxicity in the microalga Chlamydomonas moewusii Gerloff. • Cadmium increases the sulphur requirements in Chlamydomonas moewusii. • Kinetic coefficients for sulphate utilization and cadmium effect on them. • Sulphate and cadmium influence on the biosynthesis of low-molecular mass thiols. • Cadmium toxicity reduction by sulphate due to higher biosynthesis of thiols. - Abstract: Sulphur is an essential macroelement that plays important roles in living organisms. The thiol rich sulphur compounds, such as cysteine, γ-Glu–Cys, glutathione and phytochelatins participate in the tolerance mechanisms against cadmium toxicity. Plants, algae, yeasts and most prokaryotes cover their demand for reduced sulphur by reduction of inorganic sulphate. The aim of this study was to investigate, using a bifactorial experimental design, the effect of different sulphate concentrations in the nutrient solution on cadmium toxicity in the freshwater microalga Chlamydomonas moewusii. Cell growth, kinetic parameters of sulphate utilization and intracellular concentrations of low-molecular mass thiol compounds were determined. A mathematical model to describe the growth of this microalga based on the effects of sulphate and cadmium was obtained. An ANOVA revealed an interaction between them, 16% of the effect sizes was explained by this interaction. A higher amount of sulphate in the culture medium allowed a higher cadmium tolerance due to an increase in the thiol compound biosynthesis. The amount of low-molecular mass thiol compounds, mainly phytochelatins, synthesized by this microalga was significantly dependent on the sulphate and cadmium concentrations; the higher phytochelatin content was obtained in cultures with 4 mg Cd/L and 1 mM sulphate. The maximum EC{sub 50} value (based on nominal cadmium concentration) reached for this microalga was 4.46 ± 0.42 mg Cd/L when the sulphate concentration added to the culture medium was also 1 m

Growth and physiological responses to water and nutrient stress in ...

African Journals Online (AJOL)

Growth and physiological responses to water and nutrient stress in oil palm. ... changes in growth, physiology and nutrient concentration in response to two watering regimes (well-watered and water-stress conditions) and ... from 32 Countries:.

Nutrient Addition Leads to a Weaker CO2 Sink and Higher CH4 Emissions through Vegetation-Microclimate Feedbacks at Mer Bleue Bog, Canada

Science.gov (United States)

Bubier, J. L.; Arnkil, S.; Humphreys, E.; Juutinen, S.; Larmola, T.; Moore, T. R.

2015-12-01

Atmospheric nitrogen (N) deposition has led to nutrient enrichment in wetlands globally, affecting plant community composition, carbon (C) cycling, and microbial dynamics. Nutrient-limited boreal bogs are long-term sinks of carbon dioxide (CO2), but sources of methane (CH4), an important greenhouse gas. We fertilized Mer Bleue Bog, a Sphagnum moss and evergreen shrub-dominated ombrotrophic bog near Ottawa, Ontario, for 10-15 years with N as NO3 and NH4 at 5, 10 and 20 times ambient N deposition (0.6-0.8 g N m-2 y-1), with and without phosphorus (P) and potassium (K). Treatments were applied to triplicate plots (3 x 3 m) from May - August 2000-2015 and control plots received distilled water. We measured net ecosystem CO2 exchange (NEE), ecosystem photosynthesis and respiration, and CH4 flux with climate-controlled chambers; leaf-level CO2 exchange and biochemistry; substrate-induced respiration, CH4 production and consumption potentials with laboratory incubations; plant species composition and abundance; and microclimate (peat temperature, moisture, light interception). After 15 years, we have found that NEE has decreased, and CH4 emissions have increased, in the highest nutrient treatments owing to changes in vegetation, microtopography, and peat characteristics. Vegetation changes include a loss of Sphagnum moss and introduction of new deciduous species. Simulated atmospheric N deposition has not benefitted the photosynthetic apparatus of the dominant evergreen shrubs, but resulted in higher foliar respiration, contributing to a weaker ecosystem CO2 sink. Loss of moss has led to wetter near-surface substrate, higher rates of decomposition and CH4 emission, and a shift in microbial communities. Thus, elevated atmospheric deposition of nutrients may endanger C storage in peatlands through a complex suite of feedbacks and interactions among vegetation, microclimate, and microbial communities.

Effect of feeding guar meal on nutrient utilization and growth performance in Mahbubnagar local kids.

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Janampet, Razia Sultana; Malavath, Kishan Kumar; Neeradi, Rajanna; Chedurupalli, Satyanarayana; Thirunahari, Raghunandan

2016-10-01

This study was conducted to evaluate the growth performance and nutrient digestibility of guar meal, an unconventional protein-rich feed ingredient in kids in comparison to conventional groundnut cake. A total of 18 kids were randomly allotted to three groups, and T1 group was fed on basal diet, T2 and T3 groups were offered diet replacing groundnut cake at 50% and 100% with guar meal, respectively, for a period of 120-day. At the end of the growth trial, a digestibility trial was conducted to evaluate the nutrient utilization. There was no significant difference in dry matter intake among three groups. Nutrient digestibilities were significantly higher (preplacement of groundnut cake with guar meal. It can be concluded that guar meal can be incorporated at 50% level in the concentrate mixture of goats replacing groundnut cake without any adverse effects.

Influence of nutrient solutions in an open-field soilless system on the quality characteristics and shelf life of fresh-cut red and green lettuces (Lactuca sativa L.) in different seasons.

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Luna, María C; Martínez-Sánchez, Ascensión; Selma, María V; Tudela, Juan A; Baixauli, Carlos; Gil, María I

2013-01-01

Little information is available about the impact of nutrient solution ion concentration on quality characteristics and shelf life of fresh-cut lettuce grown in soilless systems in open field. Three lettuce genotypes, lollo rosso and red oak leaf as red-leafed genotypes and butterhead as green-leafed genotype, were studied. The influence of three nutrient solutions with low, medium and high ion concentrations, which varied in the macroanion (NO₃⁻) and macrocations (K⁺, Ca²⁺ and NH₄⁺), were compared in summer and winter. The nutrient solutions evaluated in this study for the production of lettuce in a soilless system did not strongly influence the quality characteristics of the raw material. When the ion concentration of the nutrient solution was increased, fresh weight decreased, although it depended on the genotype and season. Maturity index and dry matter content varied with the season but independently of the nutrient solution. In summer, maturity index was higher and dry matter lower than in winter. Initial texture and visual quality were not influenced by the nutrient solution. Medium ion concentration provided the highest content of vitamin C and phenolic compounds. Our observations pointed out that the genotype had a strong influence on the shelf life of the fresh-cut product with minor differences among nutrient solutions. In general, red-leafed lettuces showed the highest antioxidant content, helping the maintenance of sensory characteristics throughout storage. The combination of optimal nutrient solution ion concentration and suitable cultivar is considered essential to ensure lettuce post-cutting life. Copyright © 2012 Society of Chemical Industry.

Energy and nutrient density of foods in relation to their carbon footprint.

Science.gov (United States)

Drewnowski, Adam; Rehm, Colin D; Martin, Agnes; Verger, Eric O; Voinnesson, Marc; Imbert, Philippe

2015-01-01

A carbon footprint is the sum of greenhouse gas emissions (GHGEs) associated with food production, processing, transporting, and retailing. We examined the relation between the energy and nutrient content of foods and associated GHGEs as expressed as g CO2 equivalents. GHGE values, which were calculated and provided by a French supermarket chain, were merged with the Composition Nutritionnelle des Aliments (French food-composition table) nutrient-composition data for 483 foods and beverages from the French Agency for Food, Environmental and Occupational Health and Safety. Foods were aggregated into 34 food categories and 5 major food groups as follows: meat and meat products, milk and dairy products, frozen and processed fruit and vegetables, grains, and sweets. Energy density was expressed as kcal/100 g. Nutrient density was determined by using 2 alternative nutrient-density scores, each based on the sum of the percentage of daily values for 6 or 15 nutrients, respectively. The energy and nutrient densities of foods were linked to log-transformed GHGE values expressed per 100 g or 100 kcal. Grains and sweets had lowest GHGEs (per 100 g and 100 kcal) but had high energy density and a low nutrient content. The more-nutrient-dense animal products, including meat and dairy, had higher GHGE values per 100 g but much lower values per 100 kcal. In general, a higher nutrient density of foods was associated with higher GHGEs per 100 kcal, although the slopes of fitted lines varied for meat and dairy compared with fats and sweets. Considerations of the environmental impact of foods need to be linked to concerns about nutrient density and health. The point at which the higher carbon footprint of some nutrient-dense foods is offset by their higher nutritional value is a priority area for additional research. © 2015 American Society for Nutrition.

Relationships between nutrients and chlorophyll a concentration in the international Alma Gol Wetland, Iran

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Saeed Balali

2013-05-01

Full Text Available This study investigated the relationships between nutrients and chlorophyll, a concentration in the International Alma Gol Wetland. Chlorophyll a is the major photosynthetic pigment in lots of phytoplanktons and has been used as a trophy index in aquatic ecosystems. Water samples were collected fortnightly from five stations in the wetland during summer and autumn. Chlorophyll-a ranged between 4.38 to 156.55 mg/m3, sulfate ranged between 138 to 190 mg/l, total alkalinity ranged between 80 to 280 mg/l, silica ranged between 3.80 to 35.00 mg/l, phosphate ranged between 0.02 to 3.70 mg/l, ammonia ranged between 0.10 to 11.90 mg/l, nitrate ranged between 0.01 to 2.75 mg/l and nitrite ranged between 0.01 to 0.39 mg/l. There was a significant correlation between chlorophyll a and nitrate, nitrite and ammonia but there was no significant correlation between chlorophyll a and silica, total alkalinity, sulfate and phosphorus.

Nutrient Shielding in Clusters of Cells

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Lavrentovich, Maxim O.; Koschwanez, John H.; Nelson, David R.

2014-01-01

Cellular nutrient consumption is influenced by both the nutrient uptake kinetics of an individual cell and the cells’ spatial arrangement. Large cell clusters or colonies have inhibited growth at the cluster's center due to the shielding of nutrients by the cells closer to the surface. We develop an effective medium theory that predicts a thickness ℓ of the outer shell of cells in the cluster that receives enough nutrient to grow. The cells are treated as partially absorbing identical spherical nutrient sinks, and we identify a dimensionless parameter ν that characterizes the absorption strength of each cell. The parameter ν can vary over many orders of magnitude between different cell types, ranging from bacteria and yeast to human tissue. The thickness ℓ decreases with increasing ν, increasing cell volume fraction ϕ, and decreasing ambient nutrient concentration ψ∞. The theoretical results are compared with numerical simulations and experiments. In the latter studies, colonies of budding yeast, Saccharomyces cerevisiae, are grown on glucose media and imaged under a confocal microscope. We measure the growth inside the colonies via a fluorescent protein reporter and compare the experimental and theoretical results for the thickness ℓ. PMID:23848711

Differences in energy expenditures and growth dilution explain higher PCB concentrations in male summer flounder

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Madenjian, Charles P.; Jensen, Olaf P.; Rediske, Richard R.; O'Keefe, James P.; Vastano, Anthony R.; Pothoven, Steven A.

2016-01-01

Comparison of polychlorinated biphenyl (PCB) concentrations between the sexes of mature fish may reveal important behavioral and physiological differences between the sexes. We determined whole-fish PCB concentrations in 23 female summer flounder Paralichthys dentatus and 27 male summer flounder from New Jersey coastal waters. To investigate the potential for differences in diet or habitat utilization between the sexes, carbon and nitrogen stable isotope ratios were also determined. In 5 of the 23 female summer flounder, PCB concentrations in the somatic tissue and ovaries were determined. In addition, we used bioenergetics modeling to assess the contribution of the growth dilution effect to the observed difference in PCB concentrations between the sexes. Whole-fish PCB concentrations for females and males averaged 87 and 124 ng/g, respectively; thus males were 43% higher in PCB concentration compared with females. Carbon and nitrogen stable isotope ratios did not significantly differ between the sexes, suggesting that diet composition and habitat utilization did not vary between the sexes. Based on PCB determinations in the somatic tissue and ovaries, we predicted that PCB concentration of females would increase by 0.6%, on average, immediately after spawning due to release of eggs. Thus, the change in PCB concentration due to release of eggs did not explain the higher PCB concentrations observed in males. Bioenergetics modeling results indicated that the growth dilution effect could account for males being 19% higher in PCB concentration compared with females. Thus, the bulk of the observed difference in PCB concentrations between the sexes was not explained by growth dilution. We concluded that a higher rate of energy expenditure in males, stemming from greater activity and a greater resting metabolic rate, was most likely the primary driver for the observed difference in PCB concentrations between the sexes.

Differences in Energy Expenditures and Growth Dilution Explain Higher PCB Concentrations in Male Summer Flounder.

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Charles P Madenjian

Full Text Available Comparison of polychlorinated biphenyl (PCB concentrations between the sexes of mature fish may reveal important behavioral and physiological differences between the sexes. We determined whole-fish PCB concentrations in 23 female summer flounder Paralichthys dentatus and 27 male summer flounder from New Jersey coastal waters. To investigate the potential for differences in diet or habitat utilization between the sexes, carbon and nitrogen stable isotope ratios were also determined. In 5 of the 23 female summer flounder, PCB concentrations in the somatic tissue and ovaries were determined. In addition, we used bioenergetics modeling to assess the contribution of the growth dilution effect to the observed difference in PCB concentrations between the sexes. Whole-fish PCB concentrations for females and males averaged 87 and 124 ng/g, respectively; thus males were 43% higher in PCB concentration compared with females. Carbon and nitrogen stable isotope ratios did not significantly differ between the sexes, suggesting that diet composition and habitat utilization did not vary between the sexes. Based on PCB determinations in the somatic tissue and ovaries, we predicted that PCB concentration of females would increase by 0.6%, on average, immediately after spawning due to release of eggs. Thus, the change in PCB concentration due to release of eggs did not explain the higher PCB concentrations observed in males. Bioenergetics modeling results indicated that the growth dilution effect could account for males being 19% higher in PCB concentration compared with females. Thus, the bulk of the observed difference in PCB concentrations between the sexes was not explained by growth dilution. We concluded that a higher rate of energy expenditure in males, stemming from greater activity and a greater resting metabolic rate, was most likely the primary driver for the observed difference in PCB concentrations between the sexes.

The effect of nutrient enrichment on the growth, nucleic acid concentrations, and elemental stoichiometry of coral reef macroalgae.

Science.gov (United States)

Reef, Ruth; Pandolfi, John M; Lovelock, Catherine E

2012-08-01

The growth rate hypothesis (GRH) links growth rates with organism elemental stoichiometry. Support for the GRH was found for many animal species, but less so for plants. This is the first study to test the GRH in macroalgae. Tropical coral reef macroalgae from three lineages, Caulerpa serrulata (Chlorophyta), Laurencia intricata (Rhodophyta), and Sargassum polyphyllum (Phaeophyceae) were grown enriched with nitrogen or phosphorous and under control conditions at Heron Island on the Great Barrier Reef, Australia. Growth rate, photosynthesis, nucleic acid composition, and elemental stoichiometry were measured. Nutrient enrichment had positive effects on photosynthetic rates and on investment in RNA. However, growth rate was not correlated with either photosynthetic rates or RNA content; thus, we did not find support for the GRH in tropical macroalgae. Macroalgae, especially L. intricata, accumulated P to very high levels (>0.6% of dry weight). The growth rate response to tissue P concentrations was unimodal. Above 0.21%, P accumulation had negative effects on growth. Nitrogen was not stored, but evidence of futile cycling was observed. The capacity to store large amounts of P is probably an adaptation to the low and patchy nutrient environment of the tropical oceans.

Trends in nutrient concentrations, loads, and yields in streams in the Sacramento, San Joaquin, and Santa Ana Basins, California, 1975-2004

Science.gov (United States)

Kratzer, Charles R.; Kent, Robert; Seleh, Dina K.; Knifong, Donna L.; Dileanis, Peter D.; Orlando, James L.

2011-01-01

A comprehensive database was assembled for the Sacramento, San Joaquin, and Santa Ana Basins in California on nutrient concentrations, flows, and point and nonpoint sources of nutrients for 1975-2004. Most of the data on nutrient concentrations (nitrate, ammonia, total nitrogen, orthophosphate, and total phosphorus) were from the U.S. Geological Survey's National Water Information System database (35.2 percent), the California Department of Water Resources (21.9 percent), the University of California at Davis (21.6 percent), and the U.S. Environmental Protection Agency's STOrage and RETrieval database (20.0 percent). Point-source discharges accounted for less than 1 percent of river flows in the Sacramento and San Joaquin Rivers, but accounted for close to 80 percent of the nonstorm flow in the Santa Ana River. Point sources accounted for 4 and 7 percent of the total nitrogen and total phosphorus loads, respectively, in the Sacramento River at Freeport for 1985-2004. Point sources accounted for 8 and 17 percent of the total nitrogen and total phosphorus loads, respectively, in the San Joaquin River near Vernalis for 1985-2004. The volume of wastewater discharged into the Santa Ana River increased almost three-fold over the study period. However, due to improvements in wastewater treatment, the total nitrogen load to the Santa Ana River from point sources in 2004 was approximately the same as in 1975 and the total phosphorus load in 2004 was less than in 1975. Nonpoint sources of nutrients estimated in this study included atmospheric deposition, fertilizer application, manure production, and tile drainage. The estimated dry deposition of nitrogen exceeded wet deposition in the Sacramento and San Joaquin Valleys and in the basin area of the Santa Ana Basin, with ratios of dry to wet deposition of 1.7, 2.8, and 9.8, respectively. Fertilizer application increased appreciably from 1987 to 2004 in all three California basins, although manure production increased in the

Associação micorrízica e teores de nutrientes nas folhas de cupuaçuzeiro (Theobroma grandiflorum e guaranazeiro (Paullinia cupana de um sistema agroflorestal em Manaus, Amazonas Arbuscular mycorrhizal association and foliar nutrient concentrations of cupuassu (Theobroma grandiflorum and guaraná (Paullinia cupana plants in an agroforestry system in Manaus, AM, Brazil

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A. N. Oliveira

2004-12-01

Full Text Available As micorrizas arbusculares podem ser importantes na nutrição das plantas em solos ácidos e de baixa fertilidade, como são os da Amazônia de modo geral. Avaliaram-se a colonização radicular por fungos micorrízicos arbusculares (FMAs nativos e os teores de nutrientes em cupuaçuzeiro e guaranazeiro em um sistema agroflorestal no município de Manaus, Amazonas. Dez plantas de cada espécie foram selecionadas, das quais foram coletadas amostras de raiz, folha e solo durante o período seco e chuvoso da região de Manaus. Os guaranazeiros e os cupuaçuzeiros apresentaram maior colonização radicular por FMAs na época chuvosa. Os teores foliares de Ca, Mg, K, P, Zn, Cu e Mn nas duas espécies não foram influenciados pelas épocas de amostragem. O teor de Fe nas folhas dos cupuaçuzeiros foi maior na época chuvosa, enquanto o dos guaranazeiros, na época seca. A colonização micorrízica correlacionou-se com a concentração foliar de Ca, Mg, P e Cu nos cupuaçuzeiros e com a de Ca, Fe, Zn e Cu nos guaranazeiros.Arbuscular mycorrhiza can be important for plant nutrition in acid and low fertility soils such as those of the Amazon. The present study evaluated the mycorrhizal colonization by native arbuscular mycorrhizal fungi (AMF and nutrient concentrations of cupuassu and guarana leaves in an agroforestry system in Manaus, Amazonas State, Brazil. Ten plants of each species were selected, of which the roots, soil and leaves were sampled during the rainy and dry seasons. Guarana and cupuassu trees presented higher levels of AMF colonization during the rainy season. Ca, Mg, K, P, Zn, Cu, and Mn concentrations in both species were not affected by the season. Fe concentration was higher during the rainy season in the cupuassu leaves, but higher in the dry season in the guarana leaves. Mycorrhizal colonization correlated with Ca, Mg, P, and Cu concentrations in cupuassu plants and with Ca, Fe, Zn, and Cu in guarana plants.

Accumulation of nutrients and heavy metals in Phragmites australis (Cav.) Trin. ex Steudel and Bolboschoenus maritimus (L.) Palla in a constructed wetland of the Venice lagoon watershed

International Nuclear Information System (INIS)

Bragato, Claudia; Brix, Hans; Malagoli, Mario

2006-01-01

A recently constructed wetland, located in the Venice lagoon watershed, was monitored to investigate growth dynamics, nutrient and heavy metal shoot accumulation of the two dominating macrophytes: Phragmites australis and Bolboschoenus maritimus. Investigations were conducted over a vegetative season at three locations with different distance to the inlet point to assess effects on vegetation. The distance from the inlet did not affect either shoot biomass or nutrients (N, P, K and Na) and heavy metals (Cr, Ni, Cu and Zn) shoot content. With the exception of Na, nutrient and heavy metal concentrations were higher in shoots of P. australis than in B. maritimus. Heavy metal concentration in the incoming water and in the soil was not correlated to the plant content of either species. Shoot heavy metal concentrations were similar to those reported in the current literature, but accumulation generally increased towards the end of the growing season. - Heavy metal shoot concentration in Phragmites australis and Bolboschoenus maritimus increased significantly at the end of the growing season

The effect of anethole containing essentials oils on nutrients digestibility of pigs

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Ladislav Zeman

2009-01-01

Full Text Available The plant additives and their functional components can selectively influence the intestinal microorganism growth in positive or negative direction. If the growth promotion relates with positive microorganisms and growth elimination is connected with pathogens the results is nutrients utilization improvement, stimulation of immunologic system or positive influence of intermedial metabolism. Anethole is one of these important plant metabolites. There are described following positive effects of anethole in human medicine: vasorelaxant, antithrombotic, releasing of heart function, fytoestrogenic (it mean improving of milk secretion, menstruation, promotion of menses, birth improvement, men’s hormonal changes improving, sexual libido improving, antioxidative, antifungal, improvement of derma permeability, antihelmintic, insecticidal, yeast elimination, antibacterial, antipyretic.In our work the effect of anise and fennel essential oils on nutrients utilization in pig experiment was evaluated. The trial was organized in accredited experimental stable Žabčice of Mendel University of Agriculture and Forestry Brno. The high level efficiency of experimental animals is mentioned through general parameters (average daily gain, feed intake and feed conversion. The results of nutrients utilization rate show slightly higher digestibility of nutrients in treatment with anise oil, this improvement is not higher then 1.0 %. We can see also improvement of nitrogen retention in body mass on level of 5.6 % (anise treatment compared with control group. There is low variability between experimental animals (except nitrogen retention coefficient but we can not see any statistical significance. On base of these results we can say the used phytogenic additives do not affect negatively the nutrient utilization in used concentration (0.1 % of essential oil in feed mixture and are fully eligible for animal nutrition. These results are also supported by few

Upland and in-stream controls on baseflow nutrient dynamics in tile-drained agroecosystem watersheds

Science.gov (United States)

Controls on baseflow nutrient concentrations in agroecosystems are poorly characterized in comparison with storm events. However, in landscapes with low residence times (e.g., rivers and reservoirs), baseflow nutrient concentration dynamics during sensitive timeframes can drive deleterious environm...

Application of NMR-based metabonomics suggests a relationship between betaine absorption and elevated creatine plasma concentrations in catheterised sows

DEFF Research Database (Denmark)

Yde, Christian Clement; Westerhuis, Johan A.; Bertram, Hanne Christine S.

2012-01-01

of these metabolites from the small intestine. The LF diet resulted in a higher betaine concentration in the blood than the two high-fibre diets (P¼0·008). This leads to higher plasma concentrations of methionine (P¼0·0028) and creatine (P¼0·020) of endogenous origin. In conclusion, the use of NMR spectroscopy...... for measuring nutrient uptake in the present study elucidated the relationship between betaine uptake and elevated creatine plasma concentrations....

Recovery of nutrients from biogas digestate with biochar and clinoptilolite

NARCIS (Netherlands)

Kocaturk, N.P.

2016-01-01

The liquid fraction of digestate contains nutrients which makes it a valuable fertiliser in agricultural crop production systems. However, direct application of digestate may raise practical and environmental problems. Therefore, processes to concentrate nutrients have been proposed aiming not

Rhizosphere priming: a nutrient perspective

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Feike Auke Dijkstra

2013-07-01

Full Text Available Rhizosphere priming is the change in decomposition of soil organic matter (SOM caused by root activity. Rhizosphere priming plays a crucial role in soil carbon (C dynamics and their response to global climate change. Rhizosphere priming may be affected by soil nutrient availability, but rhizosphere priming itself can also affect nutrient supply to plants. These interactive effects may be of particular relevance in understanding the sustained increase in plant growth and nutrient supply in response to a rise in atmospheric CO2 concentration. We examined how these interactions were affected by elevated CO2 in two similar semiarid grassland field studies. We found that an increase in rhizosphere priming enhanced the release of nitrogen (N through decomposition of a larger fraction of SOM in one study, but not in the other. We postulate that rhizosphere priming may enhance N supply to plants in systems that are N limited, but that rhizosphere priming may not occur in systems that are phosphorus (P limited. Under P limitation, rhizodeposition may be used for mobilisation of P, rather than for decomposition of SOM. Therefore, with increasing atmospheric CO2 concentrations, rhizosphere priming may play a larger role in affecting C sequestration in N poor than in P poor soils.

Nutrient fluctuations in the Quatipuru river: A macrotidal estuarine mangrove system in the Brazilian Amazonian basin

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Pamplona, Fábio Campos; Paes, Eduardo Tavares; Nepomuceno, Aguinaldo

2013-11-01

The temporal and spatial variability of dissolved inorganic nutrients (NO3-, NO2-, NH4+, PO43- and DSi), total nitrogen (TN), total phosphorus (TP), nutrient ratios, suspended particulate matter (SPM) and Chlorophyll-a (Chl-a) were evaluated for the macrotidal estuarine mangrove system of the Quatipuru river (QUATIES), east Amazon coast, North Brazil. Temporal variability was assessed by fortnightly sampling at a fixed station within the middle portion of the estuary, from November 2009 to November 2010. Spatial variability was investigated from two field surveys conducted in November 2009 (dry season) and May 2010 (rainy season), along the salinity gradient of the system. The average DIN (NO3- + NO2- + NH4+) concentration of 9 μM in the dry season was approximately threefold greater in comparison to the rainy season. NH4+ was the main form of DIN in the dry season, while NO3- predominated in the rainy season. The NH4+ concentrations in the water column during the dry season are largely attributed to release by tidal wash-out of the anoxic interstitial waters of the surficial mangrove sediments. On the other hand, the higher NO3- levels during the wet season, suggested that both freshwater inputs and nitrification processes in the water column acted in concert. The river PO43- concentrations (DIP mangrove forests also played a relevant role as a nutrient source as established by the high variability of the nutrient behaviour along the estuarine gradient, consequently affecting the productivity in QUATIES.

The quality of our Nation's waters-Nutrients in the Nation's streams and groundwater, 1992-2004

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Dubrovsky, N.M.; Burow, K.R.; Clark, G.M.; Gronberg, J.M.; Hamilton, P.A.; Hitt, K.J.; Mueller, D.K.; Munn, M.D.; Nolan, B.T.; Puckett, L.J.; Rupert, M.G.; Short, T.M.; Spahr, N.E.; Sprague, L.A.; Wilber, W.G.

2010-01-01

National Findings and Their Implications Although the use of artificial fertilizer has supported increasing food production to meet the needs of a growing population, increases in nutrient loadings from agricultural and, to a lesser extent, urban sources have resulted in nutrient concentrations in many streams and parts of aquifers that exceed standards for protection of human health and (or) aquatic life, often by large margins. Do NAWQA findings substantiate national concerns for aquatic and human health? National Water-Quality Assessment (NAWQA) findings indicate that nutrient concentrations in streams and groundwater in basins with significant agricultural or urban development are substantially greater than naturally occurring or ?background? levels. For example, median concentrations of total nitrogen and phosphorus in agricultural streams are about 6 times greater than background levels. Findings also indicate that concentrations in streams routinely were 2 to 10 times greater than regional nutrient criteria recommended by the U.S. Environmental Protection Agency (USEPA) to protect aquatic life. Such large differences in magnitude suggest that significant reductions in sources of nutrients, as well as greater use of land management strategies to reduce the transport of nutrients to streams, are needed to meet recommended criteria for streams draining areas with significant agricultural and urban development. Nitrate concentrations above the Federal drinking-water standard-or Maximum Contaminant Level (MCL)-of 10 milligrams per liter (mg/L, as nit-ogen) are relatively uncommon in samples from streams used for drinking water or from relatively deep aquifers; the MCL is exceeded, however, in more than 20 percent of shallow (less than 100 feet below the water table) domestic wells in agricultural areas. This finding raises concerns for human health in rural agricultural areas where shallow groundwater is used for domestic supply and may warn of future

Analysis of Dissolved Organic Nutrients in the Interstitial Water of Natural Biofilms.

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Tsuchiya, Yuki; Eda, Shima; Kiriyama, Chiho; Asada, Tomoya; Morisaki, Hisao

2016-07-01

In biofilms, the matrix of extracellular polymeric substances (EPSs) retains water in the interstitial region of the EPS. This interstitial water is the ambient environment for microorganisms in the biofilms. The nutrient condition in the interstitial water may affect microbial activity in the biofilms. In the present study, we measured the concentrations of dissolved organic nutrients, i.e., saccharides and proteins, contained in the interstitial water of biofilms formed on the stones. We also analyzed the molecular weight distribution, chemical species, and availability to bacteria of some saccharides in the interstitial water. Colorimetric assays showed that the concentrations of saccharides and proteins in the biofilm interstitial water were significantly higher (ca. 750 times) than those in the surrounding lake waters (p Chromatographic analyses demonstrated that the saccharides in the interstitial waters were mainly of low molecular-weight saccharides such as glucose and maltose, while proteins in the interstitial water were high molecular-weight proteins (over 7000 Da). Bacterial growth and production of EPS occurred simultaneously with the decrease in the low molecular-weight saccharide concentrations when a small portion of biofilm suspension was inoculated to the collected interstitial water, suggesting that the dissolved saccharides in the interstitial water support bacterial growth and formation of biofilms.

Simultaneous remediation of nutrients from liquid anaerobic digestate and municipal wastewater by the microalga Scenedesmus sp. AMDD grown in continuous chemostats.

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Dickinson, K E; Bjornsson, W J; Garrison, L L; Whitney, C G; Park, K C; Banskota, A H; McGinn, P J

2015-01-01

The primary aim of this study was to investigate the capacity of a microalga, Scenedesmus sp. AMDD, to remediate nutrients from municipal wastewater, either as the sole nutrient source or after blending with wastewater obtained from the anaerobic digestion of swine manure. A complimentary aim was to study and define the effects of these wastewaters on microalgal growth, biomass productivity and composition which have important implications for a commercial biofuels production system. A microalga, Scenedesmus sp. AMDD, was grown in continuous chemostats in municipal wastewater or wastewater supplemented with 1·6× or 2·4× higher levels of nitrogen (N) obtained through supplementation with anaerobic digestates. Biomass productivity increased with increasing nutrient supplementation, but was limited by light at high cell densities. Cellular quotas of carbon (C), nitrogen and phosphorus (P) all increased in direct proportion to their concentrations in the combined wastewaters. At higher cell densities, total carbohydrate decreased while protein increased. Fatty acid content remained relatively constant. Under high nutrient levels, the fatty acid profiles contained a higher concentration of polyunsaturated fatty acids at the expense of monounsaturated fatty acids. Chlorophyll a was 2·5 times greater in the treatment of greatest nutrient supplementation compared to the treatment with the least. Ammonium (NH4(+)) and phosphate (PO4(3-)) were completely removed by algal growth in all treatments and with maximal removal rates of 41·2 mg N l(-1) d(-1) and 6·7 mg P l(-1) d(-1) observed in wastewater amended with 2·4× higher N level. The study is the first to report stable, long-term continuous algal growth and productivity obtained by combining wastewaters of different sources. The study is supported by detailed analyses of the composition of the cultivated biomass and links composition to the nutrient and light availabilities in the cultures. Simultaneous remediation

δ15N of seagrass leaves for monitoring anthropogenic nutrient increases in coral reef ecosystems

International Nuclear Information System (INIS)

Yamamuro, M.; Kayanne, H.; Yamano, H.

2003-01-01

In a coral reef environment, a slight increase in dissolved inorganic nitrogen (DIN;≥1.0 μM) can alter the ecosystem via macroalgal blooms. We collected seagrass leaves from the tropical and subtropical Pacific Ocean in five countries and examined the interactions between nutrient concentrations (C, N, P), molar ratios of nutrients, and δ 15 N to find a possible indicator of the DIN conditions. Within most sites, the concentrations of nutrients and their molar ratios showed large variations owing to species-specific values. On the other hand, almost identical δ 15 N values were found in seagrass leaves of several species at each site. The correlations between δ 15 N and nutrient concentrations and between δ 15 N and molar ratios of nutrients suggested that nutrient availability did not affect the δ 15 N value of seagrass leaves by altering the physiological condition of the plants. Increases in δ 15 N of seagrass leaves mostly matched increases in DIN concentrations in the bottom water. We suggest that δ 15 N in seagrass leaves can be a good tool to monitor time-integrated decrease/increase of DIN concentrations at a site, both in the water column and the interstitial water

Biochar-enhanced composts reduce the potential leaching of nutrients and heavy metals and suppress plant-parasitic nematodes in excessively fertilized cucumber soils.

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Cao, Yune; Gao, Yanming; Qi, Yanbin; Li, Jianshe

2018-03-01

Excessive fertilization is a common agricultural practice that has largely reduced soil nutrient retention capacity and led to nutrient leaching in China. To reduce nutrient leaching, in this study, we evaluated the application of biochar, compost, and biochar-compost on soil properties, leaching water quality, and cucumber plant growth in soils with different nutrient levels. In general, the concentrations of nutrients and heavy metals in leaching water were higher under high-nutrient conditions than under low-nutrient conditions. Both biochar and compost efficiently enhanced soil cation exchange capacity (CEC), water holding capacity (WHC), and microbial biomass carbon (MBC), nitrogen (MBN), and phosphorus (MBP), reduced the potential leaching of nutrients and heavy metals, and improved plant growth. The efficiency of biochar and compost in soil CEC, WHC, MBC, MBN, and MBP and plant growth was enhanced when applied jointly. In addition, biochar and biochar-enhanced compost efficiently suppressed plant-parasitic nematode infestation in a soil with high levels of both N and P. Our results suggest that biochar-enhanced compost can reduce the potential environmental risks in excessively fertilized vegetable soils.

Proximate and ultimate controls on carbon and nutrient dynamics of small agricultural catchments

Science.gov (United States)

Thomas, Zahra; Abbott, Benjamin W.; Troccaz, Olivier; Baudry, Jacques; Pinay, Gilles

2016-03-01

Direct and indirect effects from human activity have dramatically increased nutrient loading to aquatic inland and estuarine ecosystems. Despite an abundance of studies investigating the impact of agricultural activity on water quality, our understanding of what determines the capacity of a watershed to remove or retain nutrients remains limited. The goal of this study was to identify proximate and ultimate controls on dissolved organic carbon and nutrient dynamics in small agricultural catchments by investigating the relationship between catchment characteristics, stream discharge, and water chemistry. We analyzed a 5-year, high-frequency water chemistry data set from three catchments in western France ranging from 2.3 to 10.8 km2. The relationship between hydrology and solute concentrations differed between the three catchments and was associated with hedgerow density, agricultural activity, and geology. The catchment with thicker soil and higher surface roughness had relatively invariant carbon and nutrient chemistry across hydrologic conditions, indicating high resilience to human disturbance. Conversely, the catchments with smoother, thinner soils responded to both intra- and interannual hydrologic variation with high concentrations of phosphate (PO43-) and ammonium (NH4+) in streams during low flow conditions and strong increases in dissolved organic carbon (DOC), sediment, and particulate organic matter during high flows. Despite contrasting agricultural activity between catchments, the physical context (geology, topography, and land-use configuration) appeared to be the most important determinant of catchment solute dynamics based on principle components analysis. The influence of geology and accompanying topographic and geomorphological factors on water quality was both direct and indirect because the distribution of agricultural activity in these catchments is largely a consequence of the geologic and topographic context. This link between inherent

Coupled nutrient removal and biomass production with mixed algal culture: impact of biotic and abiotic factors.

Science.gov (United States)

Su, Yanyan; Mennerich, Artur; Urban, Brigitte

2012-08-01

The influence of biotic (algal inoculum concentration) and abiotic factors (illumination cycle, mixing velocity and nutrient strength) on the treatment efficiency, biomass generation and settleability were investigated with selected mixed algal culture. Dark condition led to poor nutrient removal efficiency. No significant difference in the N, P removal and biomass settleability between continuous and alternating illumination was observed, but a higher biomass generation capability for the continuous illumination was obtained. Different mixing velocity led to similar phosphorus removal efficiencies (above 98%) with different retention times. The reactor with 300 rpm mixing velocity had the best N removal capability. For the low strength wastewater, the N rates were 5.4±0.2, 9.1±0.3 and 10.8±0.3 mg/l/d and P removal rates were 0.57±0.03, 0.56±0.03 and 0.72±0.05 mg/l/d for reactors with the algal inoculum concentration of 0.2, 0.5 and 0.8 g/l, respectively. Low nutrient removal efficiency and poor biomass settleability were obtained for high strength wastewater. Copyright © 2012 Elsevier Ltd. All rights reserved.

Ultrastructural biomarkers in symbiotic algae reflect the availability of dissolved inorganic nutrients and particulate food to the reef coral holobiont

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Sabrina eRosset

2015-11-01

Full Text Available Reef building corals associated with symbiotic algae (zooxanthellae can access environmental nutrients from different sources, most significantly via the uptake of dissolved inorganic nutrients by the algal symbiont and heterotrophic feeding of the coral host. Climate change is expected to alter the nutrient environment in coral reefs with the potential to benefit or disturb coral reef resilience. At present, the relative importance of the two major nutrient sources is not well understood, making predictions of the responses of corals to changes in their nutrient environment difficult. Therefore, we have examined the long-term effects of the availability of different concentrations of dissolved inorganic nutrients and of nutrients in particulate organic form on the model coral Euphyllia paradivisa. Coral and algal biomass showed a significantly stronger increase in response to elevated levels of dissolved inorganic nutrients as compared to the supply with particulate food. Also, changes in the zooxanthellae ultrastructure, determined by transmission electron microscopy (TEM, were mostly driven by the availability of dissolved inorganic nutrients under the present experimental conditions. The larger size of symbiont cells, their increased accumulation of lipid bodies, a higher number of starch granules and the fragmentation of their accumulation body could be established as reliable biomarkers of low availability of dissolved inorganic nutrients to the coral holobiont.

Diagnosis of nutrient imbalances with vector analysis in agroforestry systems.

Science.gov (United States)

Isaac, Marney E; Kimaro, Anthony A

2011-01-01

Agricultural intensification has had unintended environmental consequences, including increased nutrient leaching and surface runoff and other agrarian-derived pollutants. Improved diagnosis of on-farm nutrient dynamics will have the advantage of increasing yields and will diminish financial and environmental costs. To achieve this, a management support system that allows for site-specific rapid evaluation of nutrient production imbalances and subsequent management prescriptions is needed for agroecological design. Vector diagnosis, a bivariate model to depict changes in yield and nutritional response simultaneously in a single graph, facilitates identification of nutritional status such as growth dilution, deficiency, sufficiency, luxury uptake, and toxicity. Quantitative data from cocoa agroforestry systems and pigeonpea intercropping trials in Ghana and Tanzania, respectively, were re-evaluated with vector analysis. Relative to monoculture, biomass increase in cocoa ( L.) under shade (35-80%) was accompanied by a 17 to 25% decline in P concentration, the most limiting nutrient on this site. Similarly, increasing biomass with declining P concentrations was noted for pigeonpea [ (L). Millsp.] in response to soil moisture availability under intercropping. Although vector analysis depicted nutrient responses, the current vector model does not consider non-nutrient resource effects on growth, such as ameliorated light and soil moisture, which were particularly active in these systems. We revisit and develop vector analysis into a framework for diagnosing nutrient and non-nutrient interactions in agroforestry systems. Such a diagnostic technique advances management decision-making by increasing nutrient precision and reducing environmental issues associated with agrarian-derived soil contamination. American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.

Long-term effects of rainforest disturbance on the nutrient composition of throughfall, organic layer percolate and soil solution at Mt. Kilimanjaro.

Science.gov (United States)

Schrumpf, Marion; Axmacher, Jan C; Zech, Wolfgang; Lehmann, Johannes; Lyaruu, Herbert V C

2007-04-15

At the lower parts of the forest belt at Mt. Kilimanjaro, selective logging has led to a mosaic of mature forest, old secondary forests ( approximately 60 years), and old clearings ( approximately 10 years) covered by shrub vegetation. These variations in the vegetation are reflected by differences in nutrient leaching from the canopy and in both amount and quality of litter reaching the ground, thereby also influencing mineralization rates and the composition of seepage water in litter percolate and soil solution. The aim of this study was to investigate how above- and belowground nutrient dynamics vary between regeneration stages, and if forest regeneration at the clearings is hampered by a deterioration of abiotic site conditions. K, Mg, Ca, Na and N compounds were analysed in rainfall, throughfall, organic layer percolate and the soil solution to a depth of 1.00 m at three clearings, three secondary forest and four mature forest sites. Element fluxes via throughfall showed only small variations among regeneration stages except for K and NO(3)-N. With 57-83 kg ha(-1) a(-1)and 2.6-4.1 kg ha(-1) a(-1) respectively, K and NO(3)-N fluxes via throughfall were significantly higher at the clearings than at the mature forest sites (32-37 and 0.7-1.0 kg ha(-1) a(-1) for K and NO(3)-N). In organic layer percolate and in soil solution at 0.15-m soil depth, concentrations of K, Mg, Ca and N were highest at the clearings. In the organic layer percolate, median K concentrations were e.g. 7.4 mg l(-1) for the clearings but only 1.4 mg l(-1) for the mature forests, and for NO(3)-N, median concentrations were 3.1 mg l(-1) for the clearings but only 0.92 mg l(-1) for the mature forest sites. Still, differences in annual means between clearings and mature forests were not always significant due to a high variability within the clearings. With the exception of NO(3)-N, belowground nutrient concentrations in secondary forests ranged between concentrations in mature forests and

Cool tadpoles from Arctic environments waste fewer nutrients - high gross growth efficiencies lead to low consumer-mediated nutrient recycling in the North.

Science.gov (United States)

Liess, Antonia; Guo, Junwen; Lind, Martin I; Rowe, Owen

2015-11-01

Endothermic organisms can adapt to short growing seasons, low temperatures and nutrient limitation by developing high growth rates and high gross growth efficiencies (GGEs). Animals with high GGEs are better at assimilating limiting nutrients and thus should recycle (or lose) fewer nutrients. Longer guts in relation to body mass may facilitate higher GGE under resource limitation. Within the context of ecological stoichiometry theory, this study combines ecology with evolution by relating latitudinal life-history adaptations in GGE, mediated by gut length, to its ecosystem consequences, such as consumer-mediated nutrient recycling. In common garden experiments, we raised Rana temporaria tadpoles from two regions (Arctic/Boreal) under two temperature regimes (18/23 °C) crossed with two food quality treatments (high/low-nitrogen content). We measured tadpole GGEs, total nutrient loss (excretion + egestion) rates and gut length during ontogeny. In order to maintain their elemental balance, tadpoles fed low-nitrogen (N) food had lower N excretion rates and higher total phosphorous (P) loss rates than tadpoles fed high-quality food. In accordance with expectations, Arctic tadpoles had higher GGEs and lower N loss rates than their low-latitude conspecifics, especially when fed low-N food, but only in ambient temperature treatments. Arctic tadpoles also had relatively longer guts than Boreal tadpoles during early development. That temperature and food quality interacted with tadpole region of origin in affecting tadpole GGEs, nutrient loss rates and relative gut length, suggests evolved adaptation to temperature and resource differences. With future climate change, mean annual temperatures will increase. Additionally, species and genotypes will migrate north. This will change the functioning of Boreal and Arctic ecosystems by affecting consumer-mediated nutrient recycling and thus affect nutrient dynamics in general. Our study shows that evolved latitudinal adaption can

Heterogeneity and loss of soil nutrient elements under aeolian processes in the Otindag Desert, China

Science.gov (United States)

Li, Danfeng; Wang, Xunming; Lou, Junpeng; Liu, Wenbin; Li, Hui; Ma, Wenyong; Jiao, Linlin

2018-02-01

The heterogeneity of the composition of surface soils that are affected by aeolian processes plays important roles in ecological evolution and the occurrence of aeolian desertification in fragile ecological zones, but the associated mechanisms are poorly understood. Using field investigation, wind tunnel experiments, and particle size and element analyses, we discuss the variation in the nutrient elements of surface soils that forms in the presence of aeolian processes of four vegetation species (Caragana microphylla Lam, Artemisia frigida Willd. Sp. Pl., Leymus chinensis (Trin.) Tzvel. and Stipa grandis P. Smirn) growing in the Otindag Desert, China. These four vegetation communities correspond to increasing degrees of degradation. A total of 40 macro elements, trace elements, and oxides were measured in the surface soil and in wind-transported samples. The results showed that under the different degradation stages, the compositions and concentrations of nutrients in surface soils differed for the four vegetation species. Aeolian processes may cause higher heterogeneity and higher loss of soil nutrient elements for the communities of Artemisia frigida Willd. Sp. Pl., Leymus chinensis (Trin.) Tzvel, and Stipa grandis P. Smirn than for the Caragana microphylla Lam community. There was remarkable variation in the loss of nutrients under different aeolian transportation processes. Over the past several decades, the highest loss of soil elements occurred in the 1970s, whereas the loss from 2011 to the present was generally 4.0% of that in the 1970s. These results indicate that the evident decrease in nutrient loss has played an important role in the rehabilitation that has occurred in the region recently.

Stressor-Response Models Relating Nutrient Enrichment to Algal Communities in Pacific Northwest Streams and Rivers

Science.gov (United States)

Sobota, D. J.; Hubler, S.; Paul, M. J.; Labiosa, R.

2015-12-01

Excessive algal growth in streams and rivers from nutrient enrichment can cause costly human health and environmental problems. As part of the US Environmental Protection Agency's Nutrient Scientific Technical Exchange Partnership and Support (N-STEPS) program, we have been developing stressor-response (S-R) models relating nutrients to attached algal (periphyton) communities to help prioritize monitoring for water quality impairments in Oregon (Pacific Northwest, USA) streams and rivers. Existing data from the state and neighboring states were compiled and standardized from the Oregon Department of Environmental Quality, US Environmental Protection Agency, and the US Geological Survey. To develop S-R models, algal community and biomass metrics were compared with nitrogen (N) and phosphorus (P) concentration data, including total, dissolved, and inorganic forms of these nutrients. In total, 928 paired algal-nutrient samples were compiled from the 8 Level-III Ecoregions occurring in Oregon. Relationships between algal biomass metrics and nutrient concentrations were weak, with only ash-free dry mass and standing stock of chlorophyll a showing slight positive relationships across gradients of total N and soluble reactive P concentrations, respectively. In contrast, metrics describing algal community composition, including percent diatoms and abundance of nutrient-sensitive species, showed very strong nonlinear relationships with total N or P concentrations. This suggests that data describing algal community composition can help identify specific nutrient stressors across environmentally-diverse streams and rivers in the Pacific Northwest. Future analyses will examine if nutrient-algal S-R models vary across different hydrological, physiographical, and ecological settings in the region.

Trees and Streets as Drivers of Urban Stormwater Nutrient Pollution.

Science.gov (United States)

Janke, Benjamin D; Finlay, Jacques C; Hobbie, Sarah E

2017-09-05

Expansion of tree cover is a major management goal in cities because of the substantial benefits provided to people, and potentially to water quality through reduction of stormwater volume by interception. However, few studies have addressed the full range of potential impacts of trees on urban runoff, which includes deposition of nutrient-rich leaf litter onto streets connected to storm drains. We analyzed the influence of trees on stormwater nitrogen and phosphorus export across 19 urban watersheds in Minneapolis-St. Paul, MN, U.S.A., and at the scale of individual streets within one residential watershed. Stormwater nutrient concentrations were highly variable across watersheds and strongly related to tree canopy over streets, especially for phosphorus. Stormwater nutrient loads were primarily related to road density, the dominant control over runoff volume. Street canopy exerted opposing effects on loading, where elevated nutrient concentrations from trees near roads outweighed the weak influence of trees on runoff reduction. These results demonstrate that vegetation near streets contributes substantially to stormwater nutrient pollution, and therefore to eutrophication of urban surface waters. Urban landscape design and management that account for trees as nutrient pollution sources could improve water quality outcomes, while allowing cities to enjoy the myriad benefits of urban forests.

The role of aquatic fungi in transformations of organic matter mediated by nutrients

Science.gov (United States)

Cynthia J. Tant; Amy D. Rosemond; Andrew S. Mehring; Kevin A. Kuehn; John M. Davis

2015-01-01

1. We assessed the key role of aquatic fungi in modifying coarse particulate organic matter (CPOM) by affecting its breakdown rate, nutrient concentration and conversion to fine particulate organic matter (FPOM). Overall, we hypothesised that fungal-mediated conditioning and breakdown of CPOM would be accelerated when nutrient concentrations are increased and tested...

Effects of atrazine, metolachlor, carbaryl and chlorothalonil on benthic microbes and their nutrient dynamics.

Directory of Open Access Journals (Sweden)

Daniel Elias

Full Text Available Atrazine, metolachlor, carbaryl, and chlorothalonil are detected in streams throughout the U.S. at concentrations that may have adverse effects on benthic microbes. Sediment samples were exposed to these pesticides to quantify responses of ammonium, nitrate, and phosphate uptake by the benthic microbial community. Control uptake rates of sediments had net remineralization of nitrate (-1.58 NO3 µg gdm⁻¹ h⁻¹, and net assimilation of phosphate (1.34 PO4 µg gdm⁻¹ h⁻¹ and ammonium (0.03 NH4 µg gdm⁻¹ h⁻¹. Metolachlor decreased ammonium and phosphate uptake. Chlorothalonil decreased nitrate remineralization and phosphate uptake. Nitrate, ammonium, and phosphate uptake rates are more pronounced in the presence of these pesticides due to microbial adaptations to toxicants. Our interpretation of pesticide availability based on their water/solid affinities supports no effects for atrazine and carbaryl, decreasing nitrate remineralization, and phosphate assimilation in response to chlorothalonil. Further, decreased ammonium and phosphate uptake in response to metolachlor is likely due to affinity. Because atrazine target autotrophs, and carbaryl synaptic activity, effects on benthic microbes were not hypothesized, consistent with results. Metolachlor and chlorothalonil (non-specific modes of action had significant effects on sediment microbial nutrient dynamics. Thus, pesticides with a higher affinity to sediments and/or broad modes of action are likely to affect sediment microbes' nutrient dynamics than pesticides dissolved in water or specific modes of action. Predicted nutrient uptake rates were calculated at mean and peak concentrations of metolachlor and chlorothalonil in freshwaters using polynomial equations generated in this experiment. We concluded that in natural ecosystems, peak chlorothalonil and metolachlor concentrations could affect phosphate and ammonium by decreasing net assimilation, and nitrate uptake rates by

Nutrient Budgets Calculated in Floodwaters Using a Whole-Ecosystem Experimental Manipulation

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Talbot, C. J.; Paterson, M. J.; Xenopoulos, M. A.

2017-12-01

Flooding provides pathways for nutrients to move into surface waters and alter nutrient concentrations, therefore influencing downstream ecosystems and increasing events of eutrophication. Nutrient enrichment will likely affect water quality, primary production, and overall ecosystem function. Quantifying nutrient movement post-flood will help evaluate the risks or advantages that flooding will have on ecosystem processes. Here we constructed nutrient budgets using data collected as part of the Flooded Upland Dynamics Experiment (FLUDEX) at the Experimental Lakes Area (ELA) in northwestern Ontario. Three experimental reservoirs with varying amounts of stored carbon were created by flooding forested land from May through September annually from 1999 to 2003. Organic matter became a significant source of nutrients under flooded conditions and elevated reservoir total nitrogen (TN) and total phosphorus (TP) concentrations within one week of flooding. The highest TN (2.6 mg L-1) and TP (579 µg L-1) concentrations throughout the entire flooding experiment occurred in the medium carbon reservoir within the first two weeks of flooding in 1999. TN and TP fluxes were positive in all years of flooding. TP fluxes decreased after each flooding season therefore, TP production may be less problematic in floodplains subject to frequent repeated flooding. However, TN fluxes remained large even after repeated flooding. Therefore, flooding, whether naturally occurring or from anthropogenic flow alteration, may be responsible for producing significant amounts of nitrogen and phosphorus in aquatic ecosystems.

Differential Concentrations of some Nutrient Element in Forage of Corn (Zea mays L. as Affected by Organic Fertilizers and Soil Compaction

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N. Najafi

2016-01-01

Full Text Available Soil compaction is one of the most important limiting factor for normal crop growth, because it reduces absorption by the plant. Application of organic fertilizers in agricultural soils can reduce the detrimental effects of soil compaction on plant growth and also supply some nutrients to plant. Thus, a factorial experiment was carried out in a randomized complete block design with three replications and 14 treatments to evaluate the effects of organic fertilizers in mitigating soil compaction. The first factor in this study was the source and amount of organic fertilizer at seven levels (control, farmyard manure, sewage sludge compost and municipal solid waste compost and each of organic fertilizers at two levels of 15 and 30 g/kg of soil. The second factor was soil compaction at two levels (bulk density of 1.2 and 1.7 g/cm3. To perform this experiment, 10 kg of dry soil was poured into special PVC pots and then seeds of single cross 704 corn were planted. At the end of the growth period, the corn shoot was harvested and concentrations of phosphorus (P, potassium (K, sodium (Na, iron (Fe, zinc (Zn, manganese (Mn, cadmium (Cd and lead (Pb were determined by dry ashing method. The results showed that concentrations of Cd and Pb in the shoot, related to the different treatments, were negligible. Concentrations of P, K, Fe, Mn and Zn in the corn shoot were increased significantly by application of farmyard manure, sewage sludge compost and municipal solid waste compost at both levels of soil compaction. However, Na concentration of shoot did not change significantly. Soil compaction significantly reduced P, Fe, Mn and Zn concentrations of corn shoot, but it affected concentrations of Na and K significantly. Application of organic fertilizers and increasing their levels reduced the negative effects of soil compaction on nutrients uptake by corn plant. This study showed that to improve forage corn nutrition, application of 15 or 30 g of farmyard

Effect of Plant Growth Promoting Rhizobacteria on the Concentration and Uptake of Macro Nutrients by Corn in a Cd-contaminated Calcareous Soil under Drought Stress

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shahrzad karami

2017-02-01

Full Text Available Introduction: Heavy metals such as cadmium (Cd are found naturally in soils, but their amount can be changed by human activities. The study of the uptake and accumulation of heavy metals by plants is done in order to prevent their threats on human and animal’s health.Cadmium is a toxic element for living organisms. Cadmium competes with many of nutrients to be absorbed by the plant and interferes with their biological roles. Water stress affects the cell structure and the food is diverted from its normal metabolic pathway. It also reduces the availability and uptake of nutrients by the plant. One reason for the reduction of plant growth under drought stress is the accumulation of ethylene in plants. There are ways to mitigate the negative effects of drought stress that one of which is the use of Plant Growth Promoting Rhizobacteria(PGPRs to increasing the availability of nutrients. Soil beneficial bacteria play an important role in the biological cycles and have been used to increase plant health and soil fertility over the past few decades.The aim of this study was to investigate theeffect of PGPRson the concentration and uptake of macro nutrients by corn in a Cd-contaminated calcareous soil under drought stress. Materials and Methods: A greenhouse factorial experiment was conducted in a completely randomized design with three replications. The treatments were two levels of bacteria (with and without bacteria, four levels of Cd (5, 10, 20, and 40 mg kg-1, and three levels of drought stress (without stress, 80, and 65% of field capacity. The pots were filled with 3 kg of treated soil. Cd was treated as its sulfate salt in amounts of 5, 10, 20, and 40 mg kg-1. The soil was mixed uniformly with 150 mg N kg-1 as urea, 20 mg P kg-1 as Ca (H2PO42, 5 mg Fe kg-1 as Fe-EDDHA and 10, 10 and 2.5 mg Zn, Mn and Cu kg-1, respectively as their sulfate salt in order to meet plant needs for these nutrients. Six seeds of Zea mays (var. HIDO were planted at

Potential of thin stillage as a low-cost nutrient source for direct cellulose fermentation by Clostridium thermocellum

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Rumana Islam

2015-11-01

Full Text Available Utilization of thin stillage (TS, derived from grain-based ethanol production, was investigated as an alternative source for microbial growth nutrients during direct conversion of cellulose by Clostridium thermocellum DSM 1237. Fermentation end-products synthesized by C. thermocellum grown on media prepared with various concentrations (50-400 g/L of TS were compared to those synthesized by C. thermocellum grown on reagent grade chemical (reference medium. Cell-growth in TS media, monitored with the aid of quantitative polymerase chain reactions (qPCR technique, showed prolonged growth with increasing TS concentration. Final fermentation end-product concentrations from TS media were comparable with those from the reference medium despite lower growth-rates. The volumetric H2 production generated by C. thermocellum grown with medium containing a low concentration (50 g/L of TS matched the volumetric H2 production by C. thermocellum grown in the reference medium, while higher concentrations (200 g/L of TS resulted in greater synthesis of ethanol. Supplementation of TS-media with Mg++ enhanced ethanol production, while hydrogen production remained unchanged. These results suggest that TS, an attractive source of low-cost nutrients, is capable of supporting the growth of C. thermocellum and that high concentrations of TS favor synthesis of ethanol over hydrogen from cellulose.

Pathogen and nutrient pulsing and attenuation in "accidental" urban wetland networks along the Salt River in Phoenix, AZ

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Palta, M. M.; Grimm, N. B.

2013-12-01

Increases in available nutrients and bacteria in urban streams are at the forefront of research concerns within the ecological and medical communities, and both pollutants are expected to become more problematic under projected changes in climate. Season, discharge, instream conditions (oxygen, water velocity), and weather conditions (antecedent moisture) all may influence loading rates to and the retention capabilities of wetlands fed by urban runoff and storm flow. The aim of this research was to examine the effect of these variables on nutrient (nitrogen, phosphorus) and Escherichia coli (E. coli) loading and attenuation along flow paths in urban wetland networks along the Salt River in Phoenix, AZ. Samples were collected for one year along flowpaths through wetlands that formed below six perennially flowing outfalls. Collection took place monthly during baseflow (dry season) conditions, and before and immediately following storm events, in the summer monsoon and winter rainy seasons. Water quality was assessed at the following points: immediately downstream of the outfall, mid-wetland, and downstream of the wetland. For determination of E. coli counts, samples were plated on coliform-selective media (Chromocult) and incubated for 24 hours. Plates were then used to enumerate E. coli. For determination of nutrient concentrations, samples were filtered and frozen until they could be analyzed by ion chromatography and automated wet chemistry. During both summer and winter, total discharge into the wetlands increased during storm events. Concentrations of PO43+, NH4+, and E. coli were significantly higher following storm events than during baseflow conditions, and post-storm peaks in concentration ('pulses') were higher during the summer monsoon than in winter storms. Pulses of pollutants during storms were highest when preceded by hot, dry conditions. NO3- was high in both base and stormflow. E. coli counts and nutrient concentrations dropped along flowpaths

Consumption of grapefruit is associated with higher nutrient intakes and diet quality among adults, and more favorable anthropometrics in women, NHANES 2003–2008

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Mary M. Murphy

2014-05-01

Full Text Available Background: Dietary guidance recommends consumption of a nutrient-dense diet containing a variety of fruits. The purpose of this study was to estimate usual nutrient intakes and adequacy of nutrient intakes among adult grapefruit consumers and non-consumers, and to examine associations between grapefruit consumption and select health parameters. Methods: The analysis was conducted with data collected in the National Health and Nutrition Examination Survey (NHANES 2003–2008. Respondents reporting consumption of any amount of grapefruit or 100% grapefruit juice at least once during the 2 days of dietary recall were classified as grapefruit consumers. Results: Among adults aged 19+ years with 2 days of dietary recall (n=12,789, 2.5% of males and 2.7% of females reported consumption of 100% grapefruit juice or fresh, canned, or frozen grapefruit during the recalls. Grapefruit consumers were less likely to have usual intakes of vitamin C (males: 0% vs. 47%; females: 0% vs. 43%; P<0.001 and magnesium (P<0.05 below the estimated average requirement (EAR compared to non-consumers, and they were more likely to meet adequate intake levels for dietary fiber (P<0.05. Potassium and β-carotene intakes were significantly higher among grapefruit consumers (P<0.001. Diet quality as assessed by the Healthy Eating Index-2005 (HEI-2005 was higher in grapefruit consumers (males: 66.2 [95% CI: 61.0–71.5] vs. 55.4 [95% CI: 54.4–56.4]; females: 71.4 [95% CI: 65.1–77.6] vs. 61.2 [95% CI: 59.8–62.6]. Among women, grapefruit consumption was associated with lower body weight, waist circumference, body mass index (BMI, triglycerides, C-reactive protein (CRP, and higher high-density lipoprotein (HDL cholesterol (P<0.05, However, risk of being overweight/obese was not associated with grapefruit consumption. Conclusion: Consumption of grapefruit was associated with higher intakes of vitamin C, magnesium, potassium, dietary fiber, and improved diet quality

Ambient and elevated carbon dioxide on growth, physiological and nutrient uptake parameters of perennial leguminous cover crops under low light intensities

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Adaptability and optimum growth of cover crops in plantation crops is affected by the inherent nature of the cover crop species and the light intensity at canopy levels. Globally concentrations of atmospheric CO2 are increasing and this creates higher photosynthesis and nutrient demand by crops as l...

Growth, allocation and tissue chemistry of Picea abies seedlings affected by nutrient supply during the second growing season.

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Kaakinen, Seija; Jolkkonen, Annika; Iivonen, Sari; Vapaavuori, Elina

2004-06-01

One-year-old Norway spruce (Picea abies (L.) Karst.) seedlings were grown hydroponically in a growth chamber to investigate the effects of low and high nutrient availability (LN; 0.25 mM N and HN; 2.50 mM N) on growth, biomass allocation and chemical composition of needles, stem and roots during the second growing season. Climatic conditions in the growth chamber simulated the mean growing season from May to early October in Flakaliden, northern Sweden. In the latter half of the growing season, biomass allocation changed in response to nutrient availability: increased root growth and decreased shoot growth led to higher root/shoot ratios in LN seedlings than in HN seedlings. At high nutrient availability, total biomass, especially stem biomass, increased, as did total nonstructural carbohydrate and nitrogen contents per seedling. Responses of stem chemistry to nutrient addition differed from those of adult trees of the same provenance. In HN seedlings, concentrations of alpha-cellulose, hemicellulose and lignin decreased in the secondary xylem. Our results illustrate the significance of retranslocation of stored nutrients to support new growth early in the season when root growth and nutrient uptake are still low. We conclude that nutrient availability alters allocation patterns, thereby influencing the success of 2-year-old Norway spruce seedlings at forest planting sites.

Relation of watershed setting and stream nutrient yields at selected sites in central and eastern North Carolina, 1997-2008

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Harden, Stephen L.; Cuffney, Thomas F.; Terziotti, Silvia; Kolb, Katharine R.

2013-01-01

Data collected between 1997 and 2008 at 48 stream sites were used to characterize relations between watershed settings and stream nutrient yields throughout central and eastern North Carolina. The focus of the investigation was to identify environmental variables in watersheds that influence nutrient export for supporting the development and prioritization of management strategies for restoring nutrient-impaired streams. Nutrient concentration data and streamflow data compiled for the 1997 to 2008 study period were used to compute stream yields of nitrate, total nitrogen (N), and total phosphorus (P) for each study site. Compiled environmental data (including variables for land cover, hydrologic soil groups, base-flow index, streams, wastewater treatment facilities, and concentrated animal feeding operations) were used to characterize the watershed settings for the study sites. Data for the environmental variables were analyzed in combination with the stream nutrient yields to explore relations based on watershed characteristics and to evaluate whether particular variables were useful indicators of watersheds having relatively higher or lower potential for exporting nutrients. Data evaluations included an examination of median annual nutrient yields based on a watershed land-use classification scheme developed as part of the study. An initial examination of the data indicated that the highest median annual nutrient yields occurred at both agricultural and urban sites, especially for urban sites having large percentages of point-source flow contributions to the streams. The results of statistical testing identified significant differences in annual nutrient yields when sites were analyzed on the basis of watershed land-use category. When statistical differences in median annual yields were noted, the results for nitrate, total N, and total P were similar in that highly urbanized watersheds (greater than 30 percent developed land use) and (or) watersheds with greater

Composition of methane-oxidizing bacterial communities as a function of nutrient loading in the Florida everglades.

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Chauhan, Ashvini; Pathak, Ashish; Ogram, Andrew

2012-10-01

Agricultural runoff of phosphorus (P) in the northern Florida Everglades has resulted in several ecosystem level changes, including shifts in the microbial ecology of carbon cycling, with significantly higher methane being produced in the nutrient-enriched soils. Little is, however, known of the structure and activities of methane-oxidizing bacteria (MOB) in these environments. To address this, 0 to 10 cm plant-associated soil cores were collected from nutrient-impacted (F1), transition (F4), and unimpacted (U3) areas, sectioned in 2-cm increments, and methane oxidation rates were measured. F1 soils consumed approximately two-fold higher methane than U3 soils; additionally, most probable numbers of methanotrophs were 4-log higher in F1 than U3 soils. Metabolically active MOB containing pmoA sequences were characterized by stable-isotope probing using 10 % (v/v) (13)CH(4). pmoA sequences, encoding the alpha subunit of methane monooxygenase and related to type I methanotrophs, were identified from both impacted and unimpacted soils. Additionally, impacted soils also harbored type II methanotrophs, which have been shown to exhibit preferences for high methane concentrations. Additionally, across all soils, novel pmoA-type sequences were also detected, indicating presence of MOB specific to the Everglades. Multivariate statistical analyses confirmed that eutrophic soils consisted of metabolically distinct MOB community that is likely driven by nutrient enrichment. This study enhances our understanding on the biological fate of methane being produced in productive wetland soils of the Florida Everglades and how nutrient-enrichment affects the composition of methanotroph bacterial communities.

Nutrient concentrations, loads, and yields in the Eucha-Spavinaw Basin, Arkansas and Oklahoma, 2002-09

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Esralew, Rachel A.; Tortorelli, Robert L.

2010-01-01

The city of Tulsa, Oklahoma, uses Lake Eucha and Spavinaw Lake in the Eucha-Spavinaw Basin in northwestern Arkansas and northeastern Oklahoma for public water supply. The city has spent millions of dollars over the last decade to eliminate taste and odor problems in the drinking water from the Eucha-Spavinaw system, which may be attributable to blue-green algae. Increases in the algal biomass in the lakes may be attributable to increases in nutrient concentrations in the lakes and in the waters feeding the lakes. The U.S. Geological Survey, in cooperation with the City of Tulsa, investigated and summarized total nitrogen and total phosphorus concentrations in water samples and provided estimates of nitrogen and phosphorus loads, yields, and flow-weighted concentrations during base flow and runoff for two streams discharging to Lake Eucha for the period January 2002 through December 2009. This report updates a previous report that used data from water-quality samples collected from January 2002 through December 2006. Based on the results from the Mann-Whitney statistical test, unfiltered total nitrogen concentrations were significantly greater in runoff water samples than in base-flow water samples collected from Spavinaw Creek near Maysville and near Cherokee City, Arkansas; Spavinaw Creek near Colcord, Oklahoma, and Beaty Creek near Jay, Oklahoma. Nitrogen concentrations in runoff water samples collected from all stations generally increased with increasing streamflow. Nitrogen concentrations in base-flow and runoff water samples collected in Spavinaw Creek significantly increased from the station furthest upstream (near Maysville) to the Sycamore station and then significantly decreased from the Sycamore station to the station furthest downstream (near Colcord). Nitrogen concentrations in base-flow and runoff water samples collected from Beaty Creek were significantly less than base-flow and runoff water samples collected from Spavinaw Creek. Based on the results

Evaluating Riparian and Agricultural Systems as Sinks for Surface Water Nutrients in the Upper Rio Grande

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Oelsner, G. P.; Brooks, P. D.; Hogan, J. F.; Phillips, F. M.; Villinski, J. E.

2005-12-01

We have performed five years of biannual synoptic sampling along a 1200km reach of the Rio Grande to develop relationships between discharge, land use, and major water quality parameters. Both total dissolved nitrogen (TDN) and dissolved organic carbon (DOC) concentrations gradually increase with distance downstream, however for TDN and phosphate this trend is punctuated by large, localized inputs primarily from urban wastewater. Somewhat surprisingly, surface water draining from areas of intensive, irrigated agriculture during the growing season often had lower nutrient and DOC concentrations than the river. To better quantify the effects of urban and agricultural systems on water quality we conducted three years of higher spatial resolution sampling of a 250km reach (between Cochiti Dam and Elephant Butte Reservoir) that contains both major agricultural and urban water users. During the higher flow years of 2001 and 2005 TDN concentrations in the river were higher (x = 1.19mg/L, SD = 0.21) than in the drier years 2002-2004 (x = 0.52mg/L, SD = 0.42). TDN concentrations decreased from 1.97mg/L to 0.78 mg/L in a 5km reach below the Albuquerque wastewater treatment plant during the low discharge year of 2004, but there was little to no decrease in TDN concentrations over the 180km below the wastewater treatment plant in years with higher river discharge. In contrast, water diverted to agricultural fields and returned to the river in drains experienced a 60% reduction in TDN concentrations in dry years and a 30% reduction in wet years compared to initial river water. During the dry years, water in the conveyance channel appears to be a mixture of river and drain water whereas in wetter years the conveyance channel has a lower average TDN concentration than either the river or the drains. These data suggest that the river-riparian-hyporheic system of the Rio Grande can serve at best as a weak N sink, while the combination of agricultural fields and drains serve as a

{delta}{sup 15}N of seagrass leaves for monitoring anthropogenic nutrient increases in coral reef ecosystems

Energy Technology Data Exchange (ETDEWEB)

Yamamuro, M.; Kayanne, H.; Yamano, H

2003-04-01

In a coral reef environment, a slight increase in dissolved inorganic nitrogen (DIN;{>=}1.0 {mu}M) can alter the ecosystem via macroalgal blooms. We collected seagrass leaves from the tropical and subtropical Pacific Ocean in five countries and examined the interactions between nutrient concentrations (C, N, P), molar ratios of nutrients, and {delta}{sup 15}N to find a possible indicator of the DIN conditions. Within most sites, the concentrations of nutrients and their molar ratios showed large variations owing to species-specific values. On the other hand, almost identical {delta}{sup 15}N values were found in seagrass leaves of several species at each site. The correlations between {delta}{sup 15}N and nutrient concentrations and between {delta}{sup 15}N and molar ratios of nutrients suggested that nutrient availability did not affect the {delta}{sup 15}N value of seagrass leaves by altering the physiological condition of the plants. Increases in {delta}{sup 15}N of seagrass leaves mostly matched increases in DIN concentrations in the bottom water. We suggest that {delta}{sup 15}N in seagrass leaves can be a good tool to monitor time-integrated decrease/increase of DIN concentrations at a site, both in the water column and the interstitial water.

Food and Nutrient Intake and Nutritional Status of Finnish Vegans and Non-Vegetarians.

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Elorinne, Anna-Liisa; Alfthan, Georg; Erlund, Iris; Kivimäki, Hanna; Paju, Annukka; Salminen, Irma; Turpeinen, Ursula; Voutilainen, Sari; Laakso, Juha

2016-01-01

Vegetarian and vegan diets have become more popular among adolescents and young adults. However, few studies have investigated the nutritional status of vegans, who may be at risk of nutritional deficiencies. To compare dietary intake and nutritional status of Finnish long-term vegans and non-vegetarians. Dietary intake and supplement use were estimated using three-day dietary records. Nutritional status was assessed by measuring biomarkers in plasma, serum, and urine samples. Vegans' (n = 22) data was compared with those of sex- and age-matched non-vegetarians (n = 19). All vegans adhered strictly to their diet; however, individual variability was marked in food consumption and supplementation habits. Dietary intakes of key nutrients, vitamins B12 and D, were lower (P vegans than in non-vegetarians. Nutritional biomarker measurements showed lower concentrations of serum 25-hydroxyvitamin D3 (25(OH)D3), iodine and selenium (corrected for multiple comparisons, P Vegans showed more favorable fatty acid profiles (P vegans were higher than expected. The median concentration of iodine in urine was below the recommended levels in both groups. Long-term consumption of a vegan diet was associated with some favorable laboratory measures but also with lowered concentrations of key nutrients compared to reference values. This study highlights the need for nutritional guidance to vegans.

Evaluation of a combined macrophyte–epiphyte bioassay for assessing nutrient enrichment in the Portneuf River, Idaho, USA

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Ray, Andrew M.; Mebane, Christopher A.; Raben, Flint; Irvine, Kathryn M.; Marcarelli, Amy M.

2014-01-01

We describe and evaluate a laboratory bioassay that uses Lemna minor L. and attached epiphytes to characterize the status of ambient and nutrient-enriched water from the Portneuf River, Idaho. Specifically, we measured morphological (number of fronds, longest surface axis, and root length) and population-level (number of plants and dry mass) responses of L. minor and community-level (ash-free dry mass [AFDM] and chlorophyll a [Chl a]) responses of epiphytes to nutrient enrichment. Overall, measures of macrophyte biomass and abundance increased with increasing concentrations of dissolved phosphorus (P) and responded more predictably to nutrient enrichment than morphological measures. Epiphyte AFDM and Chl a were also greatest in P-enriched water; enrichments of N alone produced no measurable epiphytic response. The epiphyte biomass response did not directly mirror macrophyte biomass responses, illustrating the value of a combined macrophyte–epiphyte assay to more fully evaluate nutrient management strategies. Finally, the most P-enriched waters not only supported greater standing stocks of macrophyte and epiphytes but also had significantly higher water column dissolved oxygen and dissolved organic carbon concentrations and a lower pH. Advantages of this macrophyte–epiphyte bioassay over more traditional single-species assays include the use of a more realistic level of biological organization, a relatively short assay schedule (~10 days), and the inclusion of multiple biological response and water-quality measures.

Leaf mineral nutrient remobilization during leaf senescence and modulation by nutrient deficiency.

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Anne eMaillard

2015-05-01

Full Text Available Higher plants have to cope with fluctuating mineral resource availability. However strategies such as stimulation of root growth, increased transporter activities, and nutrient storage and remobilization have been mostly studied for only a few macronutrients. Leaves of cultivated crops (Zea mays, Brassica napus, Pisum sativum, Triticum aestivum, Hordeum vulgare and tree species (Quercus robur, Populus nigra, Alnus glutinosa grown under field conditions were harvested regularly during their life span and analysed to evaluate the net mobilization of 13 nutrients during leaf senescence. While N was remobilized in all plant species with different efficiencies ranging from 40% (maize to 90% (wheat, other macronutrients (K-P-S-Mg were mobilized in most species. Ca and Mn, usually considered as having low phloem mobility were remobilized from leaves in wheat and barley. Leaf content of Cu-Mo-Ni-B-Fe-Zn decreased in some species, as a result of remobilization. Overall, wheat, barley and oak appeared to be the most efficient at remobilization while poplar and maize were the least efficient. Further experiments were performed with rapeseed plants subjected to individual nutrient deficiencies. Compared to field conditions, remobilization from leaves was similar (N-S-Cu or increased by nutrient deficiency (K-P-Mg while nutrient deficiency had no effect on Mo-Zn-B-Ca-Mn, which seemed to be non-mobile during leaf senescence under field conditions. However, Ca and Mn were largely mobilized from roots (-97 and -86% of their initial root contents, respectively to shoots. Differences in remobilization between species and between nutrients are then discussed in relation to a range of putative mechanisms.

Soil-plant nutrient interactions in two mangrove areas at Southern Brazil

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Ana Paula Lang Martins Madi

2016-01-01

The results exposed that the nutritional state of the mangrove species is different and independent form the soil attributes in which they grow. Few correlations were found among leaf nutrient concentrations and soil attributes, suggesting differential selective nutrient uptake among species.

Effect of feeding guar meal on nutrient utilization and growth performance in Mahbubnagar local kids

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Razia Sultana Janampet

2016-10-01

Full Text Available Aim: This study was conducted to evaluate the growth performance and nutrient digestibility of guar meal, an unconventional protein-rich feed ingredient in kids in comparison to conventional groundnut cake. Materials and Methods: A total of 18 kids were randomly allotted to three groups, and T1 group was fed on basal diet, T2 and T3 groups were offered diet replacing groundnut cake at 50% and 100% with guar meal, respectively, for a period of 120-day. At the end of the growth trial, a digestibility trial was conducted to evaluate the nutrient utilization. Results: There was no significant difference in dry matter intake among three groups. Nutrient digestibilities were significantly higher (p<0.05 in kids fed T2 ration with 50% replacement of groundnut cake with guar meal. Conclusion: It can be concluded that guar meal can be incorporated at 50% level in the concentrate mixture of goats replacing groundnut cake without any adverse effects.

Tree root systems and nutrient mobilization

DEFF Research Database (Denmark)

Boyle, Jim; Rob, Harrison; Raulund-Rasmussen, Karsten

sometimes stored at depth. Other recent studies on potential release of nutrients due to chemical weathering indicate the importance of root access to deep soil layers. Release profi les clearly indicate depletion in the top layers and a much higher potential in B and C horizons. Review of evaluations......Roots mobilize nutrients via deep penetration and rhizosphere processes inducing weathering of primary minerals. These contribute to C transfer to soils and to tree nutrition. Assessments of these characteristics and processes of root systems are important for understanding long-term supplies...... of nutrient elements essential for forest growth and resilience. Research and techniques have signifi cantly advanced since Olof Tamm’s 1934 base mineral index for Swedish forest soils, and basic nutrient budget estimates for whole-tree harvesting systems of the 1970s. Recent research in areas that include...

FOLIAR NUTRIENT CONTENTS AND FRUIT YIELD IN CUSTARD APPLE PROGENIES

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Paulo Sérgio Lima e Silva

2009-01-01

Full Text Available Foliar nutrient contents are evaluated in several fruit trees with many objectives. Leaf analysis constitutes a way of evaluating the nutritional requirements of crops. Due to the positive impact that fertilizers have on crop yields, researchers frequently try to evaluate the correlations between yield and foliar nutrient contents. This work's objective was to present fruit yields from the 4th to the 6th cropping seasons, evaluate foliar nutrient contents (on the 5th cropping season, and estimate the correlations between these two groups of traits for 20 half-sibling custard apple tree progenies. The progenies were evaluated in a random block design with five replicates and four plants per plot. One hundred leaves were collected from the middle third of the canopy (in height of each of four plants in each plot. The leaves were collected haphazardly, i.e., in a random manner, but without using a drawing mechanism. In the analysis of variance, the nutrient concentrations in the leaves from plants of each plot were represented by the average of four plants in the plot. Fruit yield in the various progenies did not depend on cropping season; progeny A4 was the most productive. No Spearman correlation was found between leaf nutrient concentrations and fruit yield. Increased nutrient concentrations in the leaves were progeny-dependent, i.e., with regard to Na (progenies FE5 and JG1, Ca (progeny A4, Mg (progeny SM7, N (progeny A3, P (progeny M, and K contents (progeny JG3. Spearman's correlation was negative between Na-Mg, Na-Ca, and Mg-P contents, and positive between Mg-Ca and N-K contents.

Recovery of Nutrients from Biogas Digestate with Biochar and Clinoptilolite

DEFF Research Database (Denmark)

Kocatürk, Nazli Pelin

in recovery of nutrients whose natural reserves are being depleted such as phosphorus and potassium. In this thesis I propose the use of sorbents i.e. biochar and clinoptilolite to concentrate nutrients and subsequently the application of digestate-enriched biochar and clinoptilolite as fertiliser. Therefore...... the overall objective of this thesis is to investigate the use of clinoptilolite and biochar to recover plant nutrients from the liquid fraction of digestate resulting from anaerobic digestion of animal manure and investigate the plant-availability of the recovered form of nutrients. In Chapter 1 (General...... of nutrients on sorbent) but decreasing efficiencies of clinoptilolite to remove nutrients from the liquid fraction of digestate. In Chapter 3, I studied the chemical activation of biochar by treating the biochar with deionised water, hydrogen peroxide, sulfuric acid and sodium hydroxide solutions...

Phytoremediation to remove nutrients and improve eutrophic stormwaters using water lettuce (Pistia stratiotes L.).

Science.gov (United States)

Lu, Qin; He, Zhenli L; Graetz, Donald A; Stoffella, Peter J; Yang, Xiaoe

2010-01-01

Water quality impairment by nutrient enrichment from agricultural activities has been a concern worldwide. Phytoremediation technology using aquatic plants in constructed wetlands and stormwater detention ponds is increasingly applied to remediate eutrophic waters. The objectives of this study were to evaluate the effectiveness and potential of water lettuce (Pistia stratiotes L.) in removing nutrients including nitrogen (N) and phosphorus (P) from stormwater in the constructed water detention systems before it is discharged into the St. Lucie Estuary, an important surface water system in Florida, using phytoremediation technologies. In this study, water lettuce (P. stratiotes) was planted in the treatment plots of two stormwater detention ponds (East and West Ponds) in 2005-2007 and water samples from both treatment and control plots were weekly collected and analyzed for water quality properties including pH, electrical conductivity, turbidity, suspended solids, and nutrients (N and P). Optimum plant density was maintained and plant samples were collected monthly and analyzed for nutrient contents. Water quality in both ponds was improved, as evidenced by decreases in water turbidity, suspended solids, and nutrient concentrations. Water turbidity was decreased by more than 60%. Inorganic N (NH(4) (+) and NO(3) (-)) concentrations in treatment plots were more than 50% lower than those in control plots (without plant). Reductions in both PO(4) (3-) and total P were approximately 14-31%, as compared to the control plots. Water lettuce contained average N and P concentrations of 17 and 3.0 g kg(-1), respectively, and removed 190-329 kg N ha(-1) and 25-34 kg P ha(-1) annually. Many aquatic plants have been used to remove nutrients from eutrophic waters but water lettuce proved superior to most other plants in nutrient removal efficiency, owing to its rapid growth and high biomass yield potential. However, the growth and nutrient removal potential are affected by many

Interannual heavy element and nutrient concentration trends in the top sediments of Venice Lagoon (Italy).

Science.gov (United States)

Masiol, Mauro; Facca, Chiara; Visin, Flavia; Sfriso, Adriano; Pavoni, Bruno

2014-12-15

The elemental composition of surficial sediments of Venice Lagoon (Italy) in 1987, 1993, 1998 and 2003 were investigated. Zn and Cr concentrations resulted in higher than background levels, but only Cd and Hg were higher than legal quality standards (Italian Decree 2010/260 and Water Framework Directive 2000/60/EC). Contaminants with similar spatial distribution are sorted into three groups by means of correlation analysis: (i) As, Co, Cd, Cu, Fe, Pb, Zn; (ii) Ni, Cr; (iii) Hg. Interannual concentrations are compared by applying a factor analysis to the matrix of differences between subsequent samplings. A general decrease of heavy metal levels is observed from 1987 to 1993, whereas particularly high concentrations of Ni and Cr are recorded in 1998 as a consequence of intense clam fishing, subsequently mitigated by better prevention of illegal harvesting. Due to the major role played by anthropogenic sediment resuspension, bathymetric variations are also considered. Copyright © 2014 Elsevier Ltd. All rights reserved.

Nutrient status and plant growth effects of forest soils in the Basin of Mexico

Energy Technology Data Exchange (ETDEWEB)

Fenn, M.E. [USDA Forest Service, Pacific Southwest Research Station, Forest Fire Laboratory, 4955 Canyon Crest Dr., Riverside, CA 92507 (United States)]. E-mail: mfenn@fs.fed.us; Perea-Estrada, V.M. [Instituto de Recursos Naturales, Colegio de Postgraduados, CP 56230 Montecillo (Mexico); Bauer, L.I. de [Instituto de Recursos Naturales, Colegio de Postgraduados, CP 56230 Montecillo (Mexico)]. E-mail: libauer@colpos.mx; Perez-Suarez, M. [Instituto de Recursos Naturales, Colegio de Postgraduados, CP 56230 Montecillo (Mexico); Parker, D.R. [Department of Environmental Sciences, University of California, Riverside, CA 92521 (United States)]. E-mail: david.parker@ucr.edu; Cetina-Alcala, V.M. [Instituto de Recursos Naturales, Colegio de Postgraduados, CP 56230 Montecillo (Mexico)

2006-03-15

The nutrient status of forest soils in the Mexico City Air Basin was evaluated by observing plant growth responses to fertilization with N, P or both nutrients combined. P deficiency was the most frequent condition for soil from two high pollution sites and N deficiency was greatest at a low N deposition site. Concentrations of Pb and Ni, and to a lesser extent Zn and Co, were higher at the high pollution sites. However, positive plant growth responses to P and sometimes to N, and results of wheat root elongation bioassays, suggest that heavy metal concentrations were not directly phytotoxic. Further studies are needed to determine if heavy metal toxicity to mycorrhizal symbionts of eucalyptus (Eucalyptus camaldulensis Dehnh.) from high pollution sites may explain the P deficiency and stunted growth. P deficiency is expected to limit the capacity for biotic N retention in N saturated forested watersheds in the Basin of Mexico dominated by Andisols. - Plant response to N deposition may be limited by P limitation in forests growing on Andisol soils in the Basin of Mexico.

Nutrient status and plant growth effects of forest soils in the Basin of Mexico

International Nuclear Information System (INIS)

Fenn, M.E.; Perea-Estrada, V.M.; Bauer, L.I. de; Perez-Suarez, M.; Parker, D.R.; Cetina-Alcala, V.M.

2006-01-01

The nutrient status of forest soils in the Mexico City Air Basin was evaluated by observing plant growth responses to fertilization with N, P or both nutrients combined. P deficiency was the most frequent condition for soil from two high pollution sites and N deficiency was greatest at a low N deposition site. Concentrations of Pb and Ni, and to a lesser extent Zn and Co, were higher at the high pollution sites. However, positive plant growth responses to P and sometimes to N, and results of wheat root elongation bioassays, suggest that heavy metal concentrations were not directly phytotoxic. Further studies are needed to determine if heavy metal toxicity to mycorrhizal symbionts of eucalyptus (Eucalyptus camaldulensis Dehnh.) from high pollution sites may explain the P deficiency and stunted growth. P deficiency is expected to limit the capacity for biotic N retention in N saturated forested watersheds in the Basin of Mexico dominated by Andisols. - Plant response to N deposition may be limited by P limitation in forests growing on Andisol soils in the Basin of Mexico

Reeds as indicators of nutrient enrichment in a small temporarily ...

African Journals Online (AJOL)

Nutrient (NH4 and SRP) concentrations decreased from the bank towards the main estuary channel, suggesting that nutrients introduced into the estuary in groundwater and surface runoff were taken up by the fringe of reeds. The roots, rhizomes, stems and leaves of Phragmites at the site with the greatest Phragmites ...

Metal and nutrient dynamics on an aged intensive green roof.

Science.gov (United States)

Speak, A F; Rothwell, J J; Lindley, S J; Smith, C L

2014-01-01

Runoff and rainfall quality was compared between an aged intensive green roof and an adjacent conventional roof surface. Nutrient concentrations in the runoff were generally below Environmental Quality Standard (EQS) values and the green roof exhibited NO3(-) retention. Cu, Pb and Zn concentrations were in excess of EQS values for the protection of surface water. Green roof runoff was also significantly higher in Fe and Pb than on the bare roof and in rainfall. Input-output fluxes revealed the green roof to be a potential source of Pb. High concentrations of Pb within the green roof soil and bare roof dusts provide a potential source of Pb in runoff. The origin of the Pb is likely from historic urban atmospheric deposition. Aged green roofs may therefore act as a source of legacy metal pollution. This needs to be considered when constructing green roofs with the aim of improving pollution remediation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Two tales of legacy effects on stream nutrient behaviour

Science.gov (United States)

Bieroza, M.; Heathwaite, A. L.

2017-12-01

Intensive agriculture has led to large-scale land use conversion, shortening of flow pathways and increased loads of nutrients in streams. This legacy results in gradual build-up of nutrients in agricultural catchments: in soil for phosphorus (biogeochemical legacy) and in the unsaturated zone for nitrate (hydrologic legacy), controlling the water quality in the long-term. Here we investigate these effects on phosphorus and nitrate stream concentrations using high-frequency (10-5 - 100 Hz) sampling with in situ wet-chemistry analysers and optical sensors. Based on our 5 year study, we observe that storm flow responses differ for both nutrients: phosphorus shows rapid increases (up to 3 orders of magnitude) in concentrations with stream flow, whereas nitrate shows both dilution and concentration effects with increasing flow. However, the range of nitrate concentrations change is narrow (up to 2 times the mean) and reflects chemostatic behaviour. We link these nutrient responses with their dominant sources and flow pathways in the catchment. Nitrate from agriculture (with the peak loading in 1983) is stored in the unsaturated zone of the Penrith Sandstone, which can reach up to 70 m depth. Thus nitrate legacy is related to a hydrologic time lag with long travel times in the unsaturated zone. Phosphorus is mainly sorbed to soil particles, therefore it is mobilised rapidly during rainfall events (biogeochemical legacy). The phosphorus stream response will however depend on how well connected is the stream to the catchment sources (driven by soil moisture distribution) and biogeochemical activity (driven by temperature), leading to both chemostatic and non-chemostatic responses, alternating on a storm-to-storm and seasonal basis. Our results also show that transient within-channel storage is playing an important role in delivery of phosphorus, providing an additional time lag component. These results show, that consistent agricultural legacy in the catchment (high

Seasonal variations and effects of nutrient applications on N and P and microbial biomass under two temperate heathland plants

DEFF Research Database (Denmark)

Nielsen, Pia Lund; Andresen, Louise Christoffersen; Michelsen, Anders

2009-01-01

. The microbial biomass on the other hand was positively related to soil water content in fertilized plots indicating that this was due to an indirect effect of enhanced nutrient availability. Microbial N and P pools were respectively 1000 and 100 times higher than the pool of inorganic N and P, and microbes...... this process. In this study the soil properties under two dominant heathland plants, the dwarf shrub Calluna vulgaris and the grass Deschampsia flexuosa, were investigated, with focus on nutrient content in the organic top soil and soil microbes during the main growing season and effects of nutrient amendments...... therefore may play an important role in regulating plant nutrient supply. Judged from responses of inorganic and microbial N and P concentrations to added N and P, N seemed to limit C. vulgaris and soil microbes below while P seemed to limit D. flexuosa and soil microbes below this species. There were lower...

Mycorrhiza formation and nutrient concentration in leeks (¤Allium porrum¤) in relation to previous crop and cover crop management on high P soils

DEFF Research Database (Denmark)

Sørensen, J.N.; Larsen, J.; Jakobsen, I.

2005-01-01

An improved integration of mycorrhizas may increase the sustainability in plant production. Two strategies for increasing the soil inoculum potential of mycorrhizal fungi were investigated in field experiments with leeks: Pre-cropping with mycorrhizal main crops and pre-establishment of mycorrhizal......, increased the colonization of leek roots by mycorrhizal fungi. During early growth stages, this increase was 45-95% relative to no cover crop. However, cover cropping did not significantly increase nutrient concentration or growth. These variables were not influenced by the time of cover crop incorporation...... or tillage treatments. Differences in colonization, nutrient uptake and plant growth diminished during the growing period and at the final harvest date, the effects on plant production disappeared. High soil P level or high soil inoculum level was most likely responsible for the limited response of increased...

Phytoplankton and nutrient dynamics in Winyah Bay, SC.

Science.gov (United States)

Boneillo, G. E.; Brooks, S. S.; Brown, S. L.; Woodford, K. M.; Wright, C. R.

2016-02-01

Winyah Bay is a coastal plain estuary located in South Carolina that has been classified for a moderate risk of Eutrophication by NOAA. Winyah Bay receives freshwater input from four rivers, the Waccamaw, Sampit, Black, and Pee Dee Rivers. The Waccamaw, Sampit and Black River are blackwater systems that discharge elevated amounts of colored dissolved organic matter. During the summer and fall of 2015, bioassay experiments were performed to simultaneously examine both light and nutrient (nitrogen & phosphate) limitation throughout Winyah Bay. Sampling stations near the mouth of the Waccamaw and Sampit Rivers showed that phytoplankton were light limited in the late summer instead of nutrient limited. These stations were located in the industrialized area of the bay and typically had the highest nutrient concentrations and highest turbidity, with Secchi depths typically less than 0.5 meters. Results indicated that phytoplankton may be nitrogen limited near the mouth of Winyah Bay, where nutrient concentrations and turbidity were observed to be lower than locations further upstream. There was also an observed dissolved oxygen and pH gradient during the summer of 2015. Dissolved oxygen levels less than 4.0 mg/L were routinely observed near the industrialized head of the estuary and corresponded with lower pH values.

The competing impacts of climate change and nutrient reductions on dissolved oxygen in Chesapeake Bay

Science.gov (United States)

Irby, Isaac D.; Friedrichs, Marjorie A. M.; Da, Fei; Hinson, Kyle E.

2018-05-01

The Chesapeake Bay region is projected to experience changes in temperature, sea level, and precipitation as a result of climate change. This research uses an estuarine-watershed hydrodynamic-biogeochemical modeling system along with projected mid-21st-century changes in temperature, freshwater flow, and sea level rise to explore the impact climate change may have on future Chesapeake Bay dissolved-oxygen (DO) concentrations and the potential success of nutrient reductions in attaining mandated estuarine water quality improvements. Results indicate that warming bay waters will decrease oxygen solubility year-round, while also increasing oxygen utilization via respiration and remineralization, primarily impacting bottom oxygen in the spring. Rising sea level will increase estuarine circulation, reducing residence time in bottom waters and increasing stratification. As a result, oxygen concentrations in bottom waters are projected to increase, while oxygen concentrations at mid-depths (3 < DO < 5 mg L-1) will typically decrease. Changes in precipitation are projected to deliver higher winter and spring freshwater flow and nutrient loads, fueling increased primary production. Together, these multiple climate impacts will lower DO throughout the Chesapeake Bay and negatively impact progress towards meeting water quality standards associated with the Chesapeake Bay Total Maximum Daily Load. However, this research also shows that the potential impacts of climate change will be significantly smaller than improvements in DO expected in response to the required nutrient reductions, especially at the anoxic and hypoxic levels. Overall, increased temperature exhibits the strongest control on the change in future DO concentrations, primarily due to decreased solubility, while sea level rise is expected to exert a small positive impact and increased winter river flow is anticipated to exert a small negative impact.

Nutrients in the Western Wadden Sea: Freshwater Input Versus Internal Recycling

NARCIS (Netherlands)

Leote, C.; Mulder, L.; Philippart, C.J.; Epping, E.

2016-01-01

At present, phosphorus (P) is seen as the main limiting nutrient for phytoplankton growth in the western Wadden Sea. Six cruises were performed for water sampling at selected stations covering a full tidal cycle for later determination of dissolved and particulate nutrient concentrations. The major

Morphology-dependent water budgets and nutrient fluxes in arctic thaw ponds

Science.gov (United States)

Koch, Joshua C.; Gurney, Kirsty; Wipfli, Mark S.

2014-01-01

Thaw ponds on the Arctic Coastal Plain of Alaska are productive ecosystems, providing habitat and food resources for many fish and bird species. Permafrost in this region creates unique pond morphologies: deep troughs, shallow low-centred polygons (LCPs) and larger coalescent ponds. By monitoring seasonal trends in pond volume and chemistry, we evaluated whether pond morphology and size affect water temperature and desiccation, and nitrogen (N) and phosphorus (P) fluxes. Evaporation was the largest early-summer water flux in all pond types. LCPs dried quickly and displayed high early-summer nutrient concentrations and losses. Troughs consistently received solute-rich subsurface inflows, which accounted for 12 to 42 per cent of their volume and may explain higher P in the troughs. N to P ratios increased and ammonium concentrations decreased with pond volume, suggesting that P and inorganic N availability may limit ecosystem productivity in older, larger ponds. Arctic summer temperatures will likely increase in the future, which may accelerate mid-summer desiccation. Given their morphology, troughs may remain wet, become warmer and derive greater nutrient loads from their thawing banks. Overall, seasonal- to decadal-scale warming may increase ecosystem productivity in troughs relative to other Arctic Coastal Plain ponds. 

Utilization of Bioslurry on Maize Hydroponic Fodder as a Corn Silage Supplement on Nutrient Digestibility and Milk Production of Dairy Cows

Directory of Open Access Journals (Sweden)

H. D. Nugroho

2015-04-01

Full Text Available The research was conducted to study the effect of addition of 7% DM maize hydroponic fodder (MHF in corn silage on digestibility and milk production of dairy cows. The experiment used a completely randomized block design with two treatments, and four replications. The treatments were dairy cows fed with grass (Pennisetum purpureum, corn silage, and concentrate (R0, and dairy cows fed with grass (P. purpureum, corn silage, concentrate, and MHF (R1. This research used eight dairy cows with initial average milk production of 13.01±2.96 L/d. MHF was produced in a hydroponic system using bioslurry as a fertilizer enriched with mineral fertilizer. Variables observed were chemical composition of bioslurry, nutrient content of ration, daily dry matter intake, nutrient digestibility, Total Digestible Nutrient (TDN, and Digestible Energy (DE. Data were analyzed with ANOVA, except for milk production using ANCOVA. Supplementation of MHF resulted a higher total dry matter intake on R1 than R0 (P<0.05, 12.99±0.063 kg/head/d, and 11.98±0.295 kg/head/d, respectively. The digestibility of nutrients were not affected by the addition of MHF. Energy consumption in R1 was also higher than R0 (P<0.05, 49.95±0.36 Mkal/kg, and 46.11±0.54 Mkal/kg, respectively. Supplementation of MHF also increased nitrogen consumption, R1 was higher than R0 (P<0.05, 318.3±2.3 g/head/d, and 295.9±3.5 g/head/d, respectively, and could maintain the persistency of milk production at the end of lactation. It can be concluded that supplementation of MHF in corn silage can increase dry matter intake, energy consumption, and nitrogen consumption, also can maintain nutrient digestibility and maintain persistency of milk production during late lactation of dairy cows.

Developmental Strategy For Effective Sampling To Detect Possible Nutrient Fluxes In Oligotrophic Coastal Reef Waters In The Caribbean

Science.gov (United States)

Mendoza, W. G.; Corredor, J. E.; Ko, D.; Zika, R. G.; Mooers, C. N.

2008-05-01

The increasing effort to develop the coastal ocean observing system (COOS) in various institutions has gained momentum due to its high value to climate, environmental, economic, and health issues. The stress contributed by nutrients to the coral reef ecosystem is among many problems that are targeted to be resolved using this system. Traditional nutrient sampling has been inadequate to resolve issues on episodic nutrient fluxes in reef regions due to temporal and spatial variability. This paper illustrates sampling strategy using the COOS information to identify areas that need critical investigation. The area investigated is within the Puerto Rico subdomain (60-70oW, 15-20oN), and Caribbean Time Series (CaTS), World Ocean Circulation Experiment (WOCE), Intra-America Sea (IAS) ocean nowcast/forecast system (IASNFS), and other COOS-related online datasets are utilized. Nutrient profile results indicate nitrate is undetectable in the upper 50 m apparently due to high biological consumption. Nutrients are delivered in Puerto Rico particularly in the CaTS station either via a meridional jet formed from opposing cyclonic and anticyclonic eddies or wind-driven upwelling. The strong vertical fluctuation in the upper 50 m demonstrates a high anomaly in temperature and salinity and a strong cross correlation signal. High chlorophyll a concentration corresponding to seasonal high nutrient influx coincides with higher precipitation accumulation rates and apparent riverine input from the Amazon and Orinoco Rivers during summer (August) than during winter (February) seasons. Non-detectability of nutrients in the upper 50 m is a reflection of poor sampling frequency or the absence of a highly sensitive nutrient analysis method to capture episodic events. Thus, this paper was able to determine the range of depths and concentrations that need to be critically investigated to determine nutrient fluxes, nutrient sources, and climatological factors that can affect nutrient delivery

Effects of different fertilizers on growth and nutrient uptake of Lolium multiflorum grown in Cd-contaminated soils.

Science.gov (United States)

Liu, Mohan; Li, Yang; Che, Yeye; Deng, Shaojun; Xiao, Yan

2017-10-01

This study aimed to explore the effects of different fertilizers and their combinations on growth and nutrient and Cd uptake of Lolium multiflorum. Compared with control treatment, chemical fertilizer, organic manure, and their conjunctions with biofertilizer increased shoot biomass. Biofertilizers were found to cause significant reductions in shoot biomass of plants grown in organic manure-treated and control soil. Decreased soil-available N and P and shoot N and K concentrations in biofertilizer amendment treatments indicated that plant growth and nutrient absorption might be negatively affected under nutrient deficiency conditions. Elevated shoot biomasses contributed to the highest shoot Cd contents in chemical fertilizer and chemical fertilizer + biofertilizer treatments among all treatments. But the maximum translocation efficiency occurred in biofertilizer + chemical fertilizer + organic manure treatment, followed by organic manure and chemical fertilizer + organic manure treatments. Based on the results, we can conclude that the application of only the biofertilizer Bacillus subtilis should be avoided in nutrient-limited soils. Chemical fertilizer application could benefit the amount of Cd in shoots, and organic manure application and its combinations could result in the higher translocation efficiency.

Mass loss and nutrient concentrations of buried wood as a function of organic matter removal, soil compaction, and vegetation control in a regenerating oak-pine forest

Science.gov (United States)

Felix Ponder; John M. Kabrick; Mary Beth Adams; Deborah S. Page-Dumroese; Marty F. Jurgensen

2017-01-01

Mass loss and nutrient concentrations of northern red oak (Quercus rubra) and white oak (Q. alba) wood stakes were measured 30 months after their burial in the upper 10 cm of soil in a regenerating forest after harvesting and soil disturbance. Disturbance treatments were two levels of organic matter (OM) removal (only...

Erythroneura lawsoni abundance and feeding injury levels are influenced by foliar nutrient status in intensively managed American sycamore.

Energy Technology Data Exchange (ETDEWEB)

Coyle, David, Robert: Aubrey, Doug, Patric; Bentz, Jo-Ann

2010-01-01

Abstract 1 Abundance and feeding injury of the leafhopper Erythroneura lawsoni Robinson was measured in an intensively-managed American sycamore Platanus occidentalis L. plantation. Trees were planted in spring 2000 in a randomized complete block design, and received one of three annual treatments: (i) fertilization (120 kg N/ha/year); (ii) irrigation (3.0 cm/week); (iii) fertilization + irrigation; or (iv) control (no treatment). 2 Foliar nutrient concentrations were significantly influenced by the treatments because only sulphur and manganese levels were not statistically greater in trees receiving fertilization. 3 Over 116 000 E. lawsoni were captured on sticky traps during the study. Leafhopper abundance was highest on nonfertilized trees for the majority of the season, and was positively correlated with foliar nutrient concentrations. Significant temporal variation in E. lawsoni abundance occurred, suggesting five discrete generations in South Carolina. 4 Significant temporal variation occurred in E. lawsoni foliar injury levels, with the highest injury ratings occurring in late June and August. Foliar injury was negatively correlated with foliar nutrient content, and higher levels of injury occurred more frequently on nonfertilized trees. 5 The results obtained in the present study indicated that increased E. lawsoni abundance occurred on trees that did not receive fertilization. Nonfertilized trees experienced greater foliar injury, suggesting that lower foliar nutrient status may have led to increased levels of compensatory feeding.

Mycorrhizal fungi enhance plant nutrient acquisition and modulate nitrogen loss with variable water regimes.

Science.gov (United States)

Bowles, Timothy M; Jackson, Louise E; Cavagnaro, Timothy R

2018-01-01

Climate change will alter both the amount and pattern of precipitation and soil water availability, which will directly affect plant growth and nutrient acquisition, and potentially, ecosystem functions like nutrient cycling and losses as well. Given their role in facilitating plant nutrient acquisition and water stress resistance, arbuscular mycorrhizal (AM) fungi may modulate the effects of changing water availability on plants and ecosystem functions. The well-characterized mycorrhizal tomato (Solanum lycopersicum L.) genotype 76R (referred to as MYC+) and the mutant mycorrhiza-defective tomato genotype rmc were grown in microcosms in a glasshouse experiment manipulating both the pattern and amount of water supply in unsterilized field soil. Following 4 weeks of differing water regimes, we tested how AM fungi affected plant productivity and nutrient acquisition, short-term interception of a 15NH4+ pulse, and inorganic nitrogen (N) leaching from microcosms. AM fungi enhanced plant nutrient acquisition with both lower and more variable water availability, for instance increasing plant P uptake more with a pulsed water supply compared to a regular supply and increasing shoot N concentration more when lower water amounts were applied. Although uptake of the short-term 15NH4+ pulse was higher in rmc plants, possibly due to higher N demand, AM fungi subtly modulated NO3- leaching, decreasing losses by 54% at low and high water levels in the regular water regime, with small absolute amounts of NO3- leached (<1 kg N/ha). Since this study shows that AM fungi will likely be an important moderator of plant and ecosystem responses to adverse effects of more variable precipitation, management strategies that bolster AM fungal communities may in turn create systems that are more resilient to these changes. © 2017 John Wiley & Sons Ltd.

Nutrient balances in the forest energy cycle

International Nuclear Information System (INIS)

Olsson, Bengt

2006-02-01

In Sweden, recycling of stabilised wood-ashes to forests is considered to compensate for nutrient removals from whole-tree harvesting (i.e. use of harvest residues - slash - for energy purposes). This study has analysed nutrient fluxes through the complete forest energy cycle and estimated mass balances of nutrients in harvested biomass with those in ashes, to investigate the realism in large-scale nutrient compensation with wood-ash. Expected nutrient fluxes from forests through energy plants were calculated based on nutrient and biomass data of forest stands in the Nordic countries, and from data on nutrient fluxes through CFB-plants. The expected stoichiometric composition of wood-ashes was compared with the composition of CFB-fly ashes from various Swedish energy plants. Nutrient contents for different tree fractions were calculated to express the average nutrient concentrations in slash and stems with bark, respectively. A nutrient budget synthesis of the effects of whole-tree harvesting on base cation turnover in the following stand was presented for two experimental sites. Major conclusions from the study are: In the CFB-scenario, where the bottom ash is deposited and only the fly ash can be applied to forests, the fly ash from the slash do not meet the demands for nutrient compensation for slash harvesting. Stem material (50% wood, 50% bark) must be added at equivalent amounts, as the slash to produce the amounts of fly ash needed for compensation of slash harvesting. In the scenario where more stem material was added (75% of total fuel load), the amounts of fly ashes produced hardly compensated for nutrient removals with both stem and slash harvesting. The level of nutrient compensation was lowest for potassium. The stoichiometric nutrient composition of CFB-fly ashes from Swedish energy plants is not similar with the nutrient composition of tree biomass. The higher Ca/P ratio in ashes is only partly explained by the mixture of fuels (e.g. increasing bark

Nutrient imbalance in Norway spruce

International Nuclear Information System (INIS)

Thelin, Gunnar

2000-11-01

The studies presented in my thesis indicate that growing Norway spruce in monoculture does not constitute sustainable forest management in a high N and S deposition environment, such as in southern Sweden. The combination of N-induced high growth rates and leaching due to soil acidification causes soil reserves of nutrients to decrease. This will increase the risk of nutrient imbalance within the trees when nutrient demands are not met. The development of nutrient imbalance in Scania, southern Sweden, was shown as negative trends in needle and soil nutrient status from the mid-80s to the present in Norway spruce and Scots pine stands. This imbalance appears to be connected to high levels of N and S deposition. Clear negative effects on tree vitality were found when using a new branch development method. Today, growth and vitality seems to be limited by K, rather than N, in spruce stands older than 40 years. However, younger stands appear to be able to absorb the deposited N without negative effects on growth and vitality. When investigating effects of nutrient stress on tree vitality, indicators such as branch length and shoot multiplication rate, which include effects accumulated over several years, are suitable. Countermeasures are needed in order to maintain the forest production at a high level. Positive effects on tree nutrient status after vitality fertilization (N-free fertilization) was shown in two micronutrient deficient stands in south-central Sweden. In addition, tree vitality was positively affected after the application of a site-adapted fertilizer to the canopy. Site-adaption of fertilizers will most likely improve the possibilities of a positive response on tree growth and vitality in declining stands. In a survey of Norway spruce in mixtures with beech, birch, or oak compared to monocultures it was shown that spruce nutrient status was higher in mixtures with deciduous species than in monocultures. By using mixed-species stands the need for

Nutrient imbalance in Norway spruce

Energy Technology Data Exchange (ETDEWEB)

Thelin, Gunnar

2000-11-01

The studies presented in my thesis indicate that growing Norway spruce in monoculture does not constitute sustainable forest management in a high N and S deposition environment, such as in southern Sweden. The combination of N-induced high growth rates and leaching due to soil acidification causes soil reserves of nutrients to decrease. This will increase the risk of nutrient imbalance within the trees when nutrient demands are not met. The development of nutrient imbalance in Scania, southern Sweden, was shown as negative trends in needle and soil nutrient status from the mid-80s to the present in Norway spruce and Scots pine stands. This imbalance appears to be connected to high levels of N and S deposition. Clear negative effects on tree vitality were found when using a new branch development method. Today, growth and vitality seems to be limited by K, rather than N, in spruce stands older than 40 years. However, younger stands appear to be able to absorb the deposited N without negative effects on growth and vitality. When investigating effects of nutrient stress on tree vitality, indicators such as branch length and shoot multiplication rate, which include effects accumulated over several years, are suitable. Countermeasures are needed in order to maintain the forest production at a high level. Positive effects on tree nutrient status after vitality fertilization (N-free fertilization) was shown in two micronutrient deficient stands in south-central Sweden. In addition, tree vitality was positively affected after the application of a site-adapted fertilizer to the canopy. Site-adaption of fertilizers will most likely improve the possibilities of a positive response on tree growth and vitality in declining stands. In a survey of Norway spruce in mixtures with beech, birch, or oak compared to monocultures it was shown that spruce nutrient status was higher in mixtures with deciduous species than in monocultures. By using mixed-species stands the need for

Response of algal metrics to nutrients and physical factors and identification of nutrient thresholds in agricultural streams

Science.gov (United States)

Black, R.W.; Moran, P.W.; Frankforter, J.D.

2011-01-01

Many streams within the United States are impaired due to nutrient enrichment, particularly in agricultural settings. The present study examines the response of benthic algal communities in agricultural and minimally disturbed sites from across the western United States to a suite of environmental factors, including nutrients, collected at multiple scales. The first objective was to identify the relative importance of nutrients, habitat and watershed features, and macroinvertebrate trophic structure to explain algal metrics derived from deposition and erosion habitats. The second objective was to determine if thresholds in total nitrogen (TN) and total phosphorus (TP) related to algal metrics could be identified and how these thresholds varied across metrics and habitats. Nutrient concentrations within the agricultural areas were elevated and greater than published threshold values. All algal metrics examined responded to nutrients as hypothesized. Although nutrients typically were the most important variables in explaining the variation in each of the algal metrics, environmental factors operating at multiple scales also were important. Calculated thresholds for TN or TP based on the algal metrics generated from samples collected from erosion and deposition habitats were not significantly different. Little variability in threshold values for each metric for TN and TP was observed. The consistency of the threshold values measured across multiple metrics and habitats suggest that the thresholds identified in this study are ecologically relevant. Additional work to characterize the relationship between algal metrics, physical and chemical features, and nuisance algal growth would be of benefit to the development of nutrient thresholds and criteria. ?? 2010 The Author(s).

Nutrient content of biomass components of Hamlin sweet orange trees

Directory of Open Access Journals (Sweden)

Mattos Jr. Dirceu

2003-01-01

Full Text Available The knowledge of the nutrient distribution in trees is important to establish sound nutrient management programs for citrus production. Six-year-old Hamlin orange trees [Citrus sinensis (L. Osb.] on Swingle citrumelo [Poncirus trifoliata (L. Raf. x Citrus paradisi Macfad.] rootstock, grown on a sandy Entisol in Florida were harvested to investigate the macro and micronutrient distributions of biomass components. The biomass of aboveground components of the tree represented the largest proportion of the total. The distribution of the total tree dry weight was: fruit = 30.3%, leaf = 9.7%, twig = 26.1%, trunk = 6.3%, and root = 27.8%. Nutrient concentrations of recent mature leaves were in the adequate to optimal range as suggested by interpretation of leaf analysis in Florida. Concentrations of Ca in older leaves and woody tissues were much greater than those in the other parts of the tree. Concentrations of micronutrients were markedly greater in fibrous root as compared to woody roots. Calcium made up the greatest amount of nutrient in the citrus tree (273.8 g per tree, followed by N and K (234.7 and 181.5 g per tree, respectively. Other macronutrients comprised about 11% of the total nutrient content of trees. The contents of various nutrients in fruits were: N = 1.20, K = 1.54, P = 0.18, Ca = 0.57, Mg = 0.12, S = 0.09, B = 1.63 x 10-3, Cu = 0.39 x 10-3, Fe = 2.1 x 10-3, Mn = 0.38 10-3, and Zn = 0.40 10-3 (kg ton-1. Total contents of N, K, and P in the orchard corresponded to 66.5, 52.0, and 8.3 kg ha-1, respectively, which were equivalent to the amounts applied annually by fertilization.

Effects of traditional Chinese medicine formula on ruminal fermentation, enzyme activities and nutrient digestibility of beef cattle.

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Zhu, Zhi; Song, Zhen-Hui; Cao, Li-Ting; Wang, Yong; Zhou, Wen-Zhang; Zhou, Pei; Zuo, Fu-Yuan

2018-04-01

This study was conducted to evaluate effects of traditional Chinese medicine formula (TCMF) combined with several herbs on ruminal fermentation, enzyme activities and nutrient digestibility. Twenty finishing bulls were assigned to control or different TCMFs (Yufeisan-1, -2, -3; 2.5% dry matter (DM) in concentrate). Results showed that DM intake was higher (P < 0.05) in the Yufeisan-3 group than others. Compared to control, apparent digestibility of crude protein and neutral detergent fiber were increased (P < 0.05) by Yufeisan-3. No changes were observed in ruminal pH, concentrations of ammonia-N, microbial crude protein and total volatile fatty acid, whereas ratio of acetate to propionate was lower (P < 0.05) and propionate proportion tended to be higher (P < 0.1) in three TCMFs than control. Ruminal xylanase (P = 0.061) and carboxymethylcellulase (P < 0.05) activities were higher in Yufeisan-3 than control. No changes were observed in abundance of total bacteria, fungi and protozoa, whereas Fibrobacter succinogenes (P = 0.062) and Ruminococcus flavefaciens (P < 0.05) were increased and total methanogens was reduced (P = 0.069) by Yufeisan-3 compared to control. Yufeisan-3 improved nutrient digestibility and ruminal enzyme activity, and modified fermentation and microbial community, maybe due to the presence of Herba agastaches, Cortex phellodendri and Gypsum fibrosum. © 2018 Japanese Society of Animal Science.

Interannual heavy element and nutrient concentration trends in the top sediments of Venice Lagoon (Italy)

International Nuclear Information System (INIS)

Masiol, Mauro; Facca, Chiara; Visin, Flavia; Sfriso, Adriano; Pavoni, Bruno

2014-01-01

Highlights: • Heavy element concentrations in sediments of a transitional system were studied. • Element contamination in the recent years has generally declined. • Mercury and cadmium contamination still remain above the limits in hot spots. • The role of sediment resuspension due to anthropogenic activity is discussed. • A basic knowledge to assess the impact of the MOSE construction is provided. - Abstract: The elemental composition of surficial sediments of Venice Lagoon (Italy) in 1987, 1993, 1998 and 2003 were investigated. Zn and Cr concentrations resulted in higher than background levels, but only Cd and Hg were higher than legal quality standards (Italian Decree 2010/260 and Water Framework Directive 2000/60/EC). Contaminants with similar spatial distribution are sorted into three groups by means of correlation analysis: (i) As, Co, Cd, Cu, Fe, Pb, Zn; (ii) Ni, Cr; (iii) Hg. Interannual concentrations are compared by applying a factor analysis to the matrix of differences between subsequent samplings. A general decrease of heavy metal levels is observed from 1987 to 1993, whereas particularly high concentrations of Ni and Cr are recorded in 1998 as a consequence of intense clam fishing, subsequently mitigated by better prevention of illegal harvesting. Due to the major role played by anthropogenic sediment resuspension, bathymetric variations are also considered

Early warning indicators for river nutrient and sediment loads in tropical seagrass beds: a benchmark from a near-pristine archipelago in Indonesia.

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van Katwijk, M M; van der Welle, M E W; Lucassen, E C H E T; Vonk, J A; Christianen, M J A; Kiswara, W; al Hakim, I Inayat; Arifin, A; Bouma, T J; Roelofs, J G M; Lamers, L P M

2011-07-01

In remote, tropical areas human influences increase, potentially threatening pristine seagrass systems. We aim (i) to provide a bench-mark for a near-pristine seagrass system in an archipelago in East Kalimantan, by quantifying a large spectrum of abiotic and biotic properties in seagrass meadows and (ii) to identify early warning indicators for river sediment and nutrient loading, by comparing the seagrass meadow properties over a gradient with varying river influence. Abiotic properties of water column, pore water and sediment were less suitable indicators for increased sediment and nutrient loading than seagrass properties. Seagrass meadows strongly responded to higher sediment and nutrient loads and proximity to the coast by decreasing seagrass cover, standing stock, number of seagrass species, changing species composition and shifts in tissue contents. Our study confirms that nutrient loads are more important than water nutrient concentrations. We identify seagrass system variables that are suitable indicators for sediment and nutrient loading, also in rapid survey scenarios with once-only measurements. Copyright © 2011 Elsevier Ltd. All rights reserved.

A comparison of nutrient density scores for 100% fruit juices.

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Rampersaud, G C

2007-05-01

The 2005 Dietary Guidelines for Americans recommend that consumers choose a variety of nutrient-dense foods. Nutrient density is usually defined as the quantity of nutrients per calorie. Food and nutrition professionals should be aware of the concept of nutrient density, how it might be quantified, and its potential application in food labeling and dietary guidance. This article presents the concept of a nutrient density score and compares nutrient density scores for various 100% fruit juices. One hundred percent fruit juices are popular beverages in the United States, and although they can provide concentrated sources of a variety of nutrients, they can differ considerably in their nutrient profiles. Six methodologies were used to quantify nutrient density and 7 100% fruit juices were included in the analysis: apple, grape, pink grapefruit, white grapefruit, orange, pineapple, and prune. Food composition data were obtained from the USDA National Nutrient Database for Standard Reference, Release 18. Application of the methods resulted in nutrient density scores with a range of values and magnitudes. The relative scores indicated that citrus juices, particularly pink grapefruit and orange juice, were more nutrient dense compared to the other nonfortified 100% juices included in the analysis. Although the methods differed, the relative ranking of the juices based on nutrient density score was similar for each method. Issues to be addressed regarding the development and application of a nutrient density score include those related to food fortification, nutrient bioavailability, and consumer education and behavior.

[Aboveground biomass and nutrient distribution patterns of larch plantation in a montane region of eastern Liaoning Province, China].

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Yan, Tao; Zhu, Jiao-Jun; Yang, Kai; Yu, Li-Zhong

2014-10-01

Larch is the main timber species of forest plantations in North China. Imbalance in nutrient cycling in soil emerged due to single species composition and mono system structure of plantation. Thus it is necessary to grasp its biomass and nutrients allocation for scientific management and nutrient cycling studies of larch plantation. We measured aboveground biomass (stem, branch, bark and leaf) and nutrient concentrations (C, N, P, K, Ca, Mg, Fe, Mn, Cu and Zn), and analyzed the patterns of accumulation and distribution of 19-year-old larch plantation with diameter at breast height of 12. 8 cm, tree height of 15. 3 m, and density of 2308 trees · hm(-2), in a montane region of eastern Liaoning Province, China. The results showed that aboveground biomass values were 70.26 kg and 162.16 t · hm(-2) for the individual tree of larch and the stand, respectively. There was a significant difference between biomass of the organs, and decreased in the order of stem > branch > bark > leaf. Nutrient accumulation was 749.94 g and 1730.86 kg · hm(-2) for the individual tree of larch and the stand, respectively. Nutrient accumulation of stem was significantly higher than that of branch, bark and leaf, whether it was macro-nutrient or micro-nutrient. Averagely, 749.94 g nutrient elements would be removed from the system when a 19-year-old larch tree was harvested. If only the stem part was removed from the system, the removal of nutrient elements could be reduced by 40.7%.

Bioremediation of oil on shorelines with organic and inorganic nutrients

International Nuclear Information System (INIS)

Sveum, P.; Ramstad, S.

1995-01-01

Two experiments to study the mechanisms associated with nutrient-enhanced biodegradation of oil (Statfjord crude oil)-contaminated shorelines were done in continuous-flow seawater exchange basins with simulated tides. The fertilizers included fish and meal pellets, stick water pellets, and two concentrations of Max Bac: standard and five times higher. Both one-time and repeated additions of fish meal were studied. The number of oil-degrading bacteria in the sediment increased by three to four orders of magnitude after adding oil and fertilizer, and repeated fertilization had little effect. Oil degradation was found to be extensive with all treatments in both experiments, which lasted 35 or 98 days. Polycyclic aromatic hydrocarbon degradation seems to be most extensive in the sediments with repeated application of fish meal. The relation between accumulated total soluble nitrogen in interstitial water and nC 17 /pristane differs between the sediments treated with Max Bac and the organic additives, and indicates that this concentration cannot be used as a sole indication of the oil degradation rate if organic nutrients are used. The relation between accumulated CO 2 production and nC 17 /pristane ratio indicates a diauxic use of the two different sources of carbon present, without being absolute. Repeated fertilization with organic additives is neither beneficial nor detrimental to the oil degradation activity

Trophic categorization in the Rías Baixas (NW Spain: nutrients in water and in macroalgae

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Rubén Villares

2006-03-01

Full Text Available Marine eutrophication caused by an excess supply of nutrients is a serious problem in many coastal areas throughout the world. In the present study we used the capacity of macroalgae (Ulva and Enteromorpha to integrate the nutrient regime of a water body in order to examine the trophic categorization in the embayments studied. We found that the trophic categorization established based on nutrient levels in macroalgae differed from that established based on concentrations in the water. The waters of the innermost areas of the inlets were the most nutrient enriched; the algae appeared to be more affected by specific local conditions and did not display the gradient of decreasing nutrient concentrations from inner to outer areas that was observed in the water samples. The lack of correspondence between nutrients in the water and in the algae in the present study may have been due to the heterogeneous nutrient conditions found in coastal areas, so that the intertidal algae did not adequately reflect the nutrient levels of the inner zones of the embayments under study.

Ethnic disparities among food sources of energy and nutrients of public health concern and nutrients to limit in adults in the United States: NHANES 2003-2006.

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O'Neil, Carol E; Nicklas, Theresa A; Keast, Debra R; Fulgoni, Victor L

2014-01-01

Identification of current food sources of energy and nutrients among US non-Hispanic whites (NHW), non-Hispanic blacks (NHB), and Mexican American (MA) adults is needed to help with public health efforts in implementing culturally sensitive and feasible dietary recommendations. The objective of this study was to determine the food sources of energy and nutrients to limit [saturated fatty acids (SFA), added sugars, and sodium] and nutrients of public health concern (dietary fiber, vitamin D, calcium, and potassium) by NHW, NHB, and MA adults. This was a cross-sectional analysis of a nationally representative sample of NWH (n=4,811), NHB (2,062), and MA (n=1,950) adults 19+ years. The 2003-2006 NHANES 24-h recall (Day 1) dietary intake data were analyzed. An updated USDA Dietary Source Nutrient Database was developed using current food composition databases. Food grouping included ingredients from disaggregated mixtures. Mean energy and nutrient intakes from food sources were sample-weighted. Percentages of total dietary intake contributed from food sources were ranked. Multiple differences in intake among ethnic groups were seen for energy and all nutrients examined. For example, energy intake was higher in MA as compared to NHB; SFA, added sugars, and sodium intakes were higher in NHW than NHB; dietary fiber was highest in MA and lowest in NHB; vitamin D was highest in NHW; calcium was lowest in NHB; and potassium was higher in NHW as compared to NHB. Food sources of these nutrients also varied. Identification of intake of nutrients to limit and of public health concern can help health professionals implement appropriate dietary recommendations and plan interventions that are ethnically appropriate.

Recent land cover history and nutrient retention in riparian wetlands

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Hogan, D.M.; Walbridge, M.R.

2009-01-01

Wetland ecosystems are profoundly affected by altered nutrient and sediment loads received from anthropogenic activity in their surrounding watersheds. Our objective was to compare a gradient of agricultural and urban land cover history during the period from 1949 to 1997, with plant and soil nutrient concentrations in, and sediment deposition to, riparian wetlands in a rapidly urbanizing landscape. We observed that recent agricultural land cover was associated with increases in Nitrogen (N) and Phosphorus (P) concentrations in a native wetland plant species. Conversely, recent urban land cover appeared to alter receiving wetland environmental conditions by increasing the relative availability of P versus N, as reflected in an invasive, but not a native, plant species. In addition, increases in surface soil Fe content suggests recent inputs of terrestrial sediments associated specifically with increasing urban land cover. The observed correlation between urban land cover and riparian wetland plant tissue and surface soil nutrient concentrations and sediment deposition, suggest that urbanization specifically enhances the suitability of riparian wetland habitats for the invasive species Japanese stiltgrass [Microstegium vimenium (Trinius) A. Camus]. ?? 2009 Springer Science+Business Media, LLC.

POSSIBLE RAMIFICATIONS OF HIGHER MERCURY CONCENTRATIONS IN FILLET TISSUE OF SKINNIER FISH

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Mercury concentrations were found to be statistically higher in the fillet tissue of the skinnier individuals of a fish species (striped bass) that was experiencing starvation when collected from Lake Mead, which is located on the Arizona-Nevada border. This is considered a conse...

Nutrient and chlorophyll relations in selected streams of the New England Coastal Basins in Massachusetts and New Hampshire, June-September 2001

Science.gov (United States)

Riskin, Melissa L.; Deacon, J.R.; Liebman, M.L.; Robinson, K.W.

2003-01-01

The U.S. Environmental Protection Agency is developing guidance to assist states with defining nutrient criteria for rivers and streams and to better describe nutrient-algal relations. As part of this effort, 13 wadeable stream sites were selected, primarily in eastern Massachusetts, for a nutrient-assessment study during the summer of 2001. The sites represent a range of water-quality impairment conditions (reference, moderately impaired, impaired) based on state regulatory agency assessments and previously assessed nitrogen, phosphorus, and dissolved-oxygen data. In addition, a combination of open- and closed-canopy locations were sampled at six of the sites to investigate the effect of sunlight on algal growth. Samples for nutrients and for chlorophyll I from phytoplankton and periphyton were collected at all stream sites. Total nitrogen (dissolved nitrite + nitrate + total ammonia + organic nitrogen) and total phosphorus (phosphorus in an unfiltered water sample) concentrations were lowest at reference sites and highest at impaired sites. There were statistically significant differences (p phytoplankton were not significantly different among site impairment designations. Concentrations of chlorophyll a from periphyton were highest at nutrient-impaired open-canopy sites. Chlorophyll a concentrations from periphyton samples were positively correlated with total nitrogen and total phosphorus at the open- and closed-canopy sites. Correlations were higher at open-canopy sites (p periphyton samples were observed between the open- and closed-canopy sites (p relations between total nitrogen and total phosphorus to periphyton chlorophyll a in wadeable streams from this study were quantified to present potential techniques for determining nutrient concentrations. Linear regression was used to estimate the total nitrogen and total phosphorus concentrations that corresponded to various chlorophyll a concentrations. On the basis of this relation, a median concentration for

Socioeconomic Indicators Are Independently Associated with Nutrient Intake in French Adults: A DEDIPAC Study

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Wendy Si Hassen

2016-03-01

Full Text Available Studies have suggested differential associations of specific indicators of socioeconomic position (SEP with nutrient intake and a cumulative effect of these indicators on diet. We investigated the independent association of SEP indicators (education, income, occupation with nutrient intake and their effect modification. This cross-sectional analysis included 91,900 French adults from the NutriNet-Santé cohort. Nutrient intake was estimated using three 24-h records. We investigated associations between the three SEP factors and nutrient intake using sex-stratified analysis of covariance, adjusted for age and energy intake, and associations between income and nutrient intake stratified by education and occupation. Low educated participants had higher protein and cholesterol intakes and lower fibre, vitamin C and beta-carotene intakes. Low income individuals had higher complex carbohydrate intakes, and lower magnesium, potassium, folate and vitamin C intakes. Intakes of vitamin D and alcohol were lower in low occupation individuals. Higher income was associated with higher intakes of fibre, protein, magnesium, potassium, beta-carotene, and folate among low educated persons only, highlighting effect modification. Lower SEP, particularly low education, was associated with lower intakes of nutrients required for a healthy diet. Each SEP indicator was associated with specific differences in nutrient intake suggesting that they underpin different social processes.

Nutrient and Light Limitations on Grass Productivity in a Southern African Savanna

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Ries, L. P.; Shugart, H. H.; Caylor, K. K.; Okin, G. S.; Kgope, B.

2006-12-01

Despite the ubiquity of sub-tropical savannas throughout the earth, limitations of savanna productivity are understudied relative to other terrestrial systems. In particular, there has been little attention on the role of phosphorus (P) in savanna productivity and structure. This study examined the role of increased nitrogen (N) and P in grass productivity in a woodland savanna in Botswana. We added aqueous forms of N and P individually and together to selected grasses. During the following growing season we measured foliar nutrient concentrations, aboveground biomass productivity and photosynthetic response at various levels of incident photosynthetically active radiation to estimate the productivity response. As expected, we observed an increase in foliar P concentrations in P and N+P treatments. However, there was no increase in foliar N for any treatments. We also observed a significant increase in net carbon assimilation and Amax for all treatments relative to the control grasses. Despite a higher rate of leaf level carbon assimilation in the N treatment, the aboveground biomass production was smaller than that of the N+P treatment. These results suggest that the aboveground productivity of these woodland savanna grasses is limited by both N and P. Additionally, under constant CO2 availability, photosynthesis appears to be limited by nutrients for light levels greater than 500 μmol m-2s-1. This research will help broaden our understanding of the biogeochemical processes that govern savanna productivity. Ultimately, these data can be used to model canopy productivity and ecological succession of savannas under scenarios in which bush encroachment and desertification may alter light and nutrients availability.

Recovery of agricultural nutrients from biorefineries.

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Carey, Daniel E; Yang, Yu; McNamara, Patrick J; Mayer, Brooke K

2016-09-01

This review lays the foundation for why nutrient recovery must be a key consideration in design and operation of biorefineries and comprehensively reviews technologies that can be used to recover an array of nitrogen, phosphorus, and/or potassium-rich products of relevance to agricultural applications. Recovery of these products using combinations of physical, chemical, and biological operations will promote sustainability at biorefineries by converting low-value biomass (particularly waste material) into a portfolio of higher-value products. These products can include a natural partnering of traditional biorefinery outputs such as biofuels and chemicals together with nutrient-rich fertilizers. Nutrient recovery not only adds an additional marketable biorefinery product, but also avoids the negative consequences of eutrophication, and helps to close anthropogenic nutrient cycles, thereby providing an alternative to current unsustainable approaches to fertilizer production, which are energy-intensive and reliant on nonrenewable natural resource extraction. Copyright © 2016 Elsevier Ltd. All rights reserved.

Differences in egg nutrient availability, development, and nutrient metabolism of broiler and layer embryos.

Science.gov (United States)

Nangsuay, A; Molenaar, R; Meijerhof, R; van den Anker, I; Heetkamp, M J W; Kemp, B; van den Brand, H

2015-03-01

Selection for production traits of broilers and layers leads to physiological differences, which may already be present during incubation. This study aimed to investigate the influence of strain (broiler vs layer) on egg nutrient availability, embryonic development and nutrient metabolism. A total of 480 eggs with an egg weight range of 62.0 to 64.0 g from Lohmann Brown Lite and Ross 308 breeder flocks of 41 or 42 weeks of age were selected in two batches of 120 eggs per batch per strain. For each batch, 30 eggs per strain were used to determine egg composition, including nutrient and energy content, and 90 eggs per strain were separately incubated in one of two climate respiration chambers at an eggshell temperature of 37.8°C. The results showed that broiler eggs had a higher ratio of yolk: albumen with 2.41 g more yolk and 1.48 g less albumen than layers. The yolk energy content of broiler eggs was 46.32 kJ higher than that of layer eggs, whereas total energy content of broiler eggs was 47.85 kJ higher compared to layer eggs. Yolk-free body mass at incubation day 16 and chick weight and length at hatch were higher in broilers compared to layers. Respiration quotient of broiler embryos was higher than layer embryos during incubation day 8 to incubation day 10. A 0.24 g lower residual yolk at the hatch of broiler embryos than for the layer embryos indicated that broiler embryos used more yolk and had a higher energy utilization and energy deposition in yolk-free body mass. Heat production of broiler embryos was higher than that of layer embryos from incubation day 12 to incubation day 18, but efficiency of converting egg energy used by embryos to form yolk-free body mass was similar. In conclusion, broiler and layer embryos have different embryonic development patterns, which affect energy utilization and embryonic heat production. However, the embryos are equal in efficiency of converting the energy used to yolk-free body mass. © 2015 Poultry Science

Higher aluminum concentration in Alzheimer's disease after Box-Cox data transformation.

Science.gov (United States)

Rusina, Robert; Matěj, Radoslav; Kašparová, Lucie; Kukal, Jaromír; Urban, Pavel

2011-11-01

Evidence regarding the role of mercury and aluminum in the pathogenesis of Alzheimer's disease (AD) remains controversial. The aims of our project were to investigate the content of the selected metals in brain tissue samples and the use of a specific mathematical transform to eliminate the disadvantage of a strong positive skew in the original data distribution. In this study, we used atomic absorption spectrophotometry to determine mercury and aluminum concentrations in the hippocampus and associative visual cortex of 29 neuropathologically confirmed AD and 27 age-matched controls. The Box-Cox data transformation was used for statistical evaluation. AD brains had higher mean aluminum concentrations in the hippocampus than controls (0.357 vs. 0.090 μg/g; P = 0.039) after data transformation. Results for mercury were not significant. Original data regarding microelement concentrations are heavily skewed and do not pass the normality test in general. A Box-Cox transformation can eliminate this disadvantage and allow parametric testing.

Effect of increasing concentrations of lead, cadmium, chromium, nickel, or zinc on lettuce grown in nutrient solution

Energy Technology Data Exchange (ETDEWEB)

Foroughi, M.; Hoffmann, G.; Teicher, K.; Venter, F.

1975-01-01

Experiments were performed to examine concentrations at which excess symptoms could be expected, which kind of damage symptoms appear and in which amount the heavy metals are enriched in roots and leaves. The following results were revealed. Lettuce (Lactuca sativa L. var. capitata L.) can tolerate amounts of Cd below 1 ppm, of Ni below 2 ppm and of Pb below 20 ppm in the nutrient solution without any symptoms of excess. The growth of lettuce was mostly influenced by Cd, least of all by Pb. Only Ni caused specific poisoning symptoms. Heavy metals were enriched in different amounts in roots and leaves. The contents of Cd and Ni were more than twice as high as those of Pb. The heavy metals influenced the uptake and distribution of macro-elements more (nitrogen) or less (potassium) vigorously.

Combined Influence of Landscape Composition and Nutrient Inputs on Lake Trophic Structure

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The concentration of chlorophyll a is a measure of the biological productivity of a lake and is largely (but not exclusively) determined by available nutrients. As nutrient inputs increase, productivity increases and lakes transition from low trophic state (e.g. oligotrophic) to...

The Inflammatory Radicular Cysts Have Higher Concentration of TNF-α in Comparison to Odontogenic Keratocysts (Odontogenic Tumour

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Vladimir Jurisic

2007-01-01

Full Text Available TNF-α is a pleiotropic cytokine that is considered as a primary modifier of inflammatory and immune reaction in response to various inflammatory diseases and tumour. We investigated levels of TNF-α in 43 radicular cysts and 15 odontogenic keratocysts, obtained from patients undergoing surgery, under local anaesthesia, and after aspiration of cystic fluid from non-ruptured cysts. TNF-α is elevated in both cysts’ fluid, but higher values were found in radicular cysts in comparison to keratocysts. The significantly higher concentration of TNF-α was associated with smaller radicular cysts, higher protein concentration, higher presence of inflammatory cells in peri cystic tissues, and the degree of vascularisation and cysts wall thickness (Mann-Whitney U-test, p<0.05. No correlation was found based on these parameters in odontogenic keratocyst, but all cysts have detectable concentrations of TNF-α. We here for the first time present that a difference in the concentration of TNF-α exists between these two cystic types.

Effect of Gamma Irradiation and Foliar Application of Some Micro nutrients on Growth and Yield Quality of Common Bean (Phaseolus vulgaris L.)

International Nuclear Information System (INIS)

Fath El-Bab, T. Sh.; Abo Elkhier, OH.M.M.

2013-01-01

The experiments were carried out on common bean (Phaseoulus vulgaris L.) cv Bronco under sandy-loam soil conditions in the farm of the Research Station of the Atomic Energy Authority at Inshas, Kalubia Governorate on October 15 th in the two successive growing seasons of 2009-2010 and 2010-2011. The aim of the experiments was to investigate the effect of gamma irradiated seeds at the doses of 0, 40 and 80 Gy and foliar spray with Zn, Mn and Fe micro nutrients at the concentrations of 0, 25 and 50 ppm on vegetative growth, yield and chemical responses of common bean plants at age of 21 days. Three levels of application namely 0.0 (control), 25 and 50 ppm were sprayed twice during the growing seasons after two and four weeks of planting. Data analysis showed that all sprayed concentrations improved plant growth i.e plant height, number of branches and helped in earliness of flowering. Pod yield as well as pod quality parameters were also improved with the increase of concentration of sprayed materials. The improvement in plant growth and production were positively correlated with the doses and concentrations. The highest response recorded with the concentration 50 ppm with irradiated dose of 40 Gy after which the response started to decline but still significantly higher than control treatment. Pod yield was positively correlated with the applied concentration of the two substances with the highest effect recorded with 50 ppm of micro nutrients. The treatments resulted in higher total chlorophyll in leave content compared to control. Also treatments significantly improved chemical compositions of pod quality particularly total nitrogen and total sugar contents which responded more positively to all applied treatments. Mineral contents of Zn, Mn and Fe in un cracked seeds also showed similar trend to the applied concentrations. While the best results were in treated plants at 40 Gy and 50 ppm micro nutrient.

Nutrient depletion from rhizosphere solution by maize grown in soil with long-term compost amendment

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Improved understanding of rhizosphere chemistry will enhance our ability to model nutrient dynamics and on a broader scale, to develop effective management strategies for applied plant nutrients. With a controlled-climate study, we evaluated in situ changes in macro-nutrient concentrations in the rh...

Higher milk fat content is associated with higher 25-hydroxyvitamin D concentration in early childhood.

Science.gov (United States)

Vanderhout, Shelley M; Birken, Catherine S; Parkin, Patricia C; Lebovic, Gerald; Chen, Yang; O'Connor, Deborah L; Maguire, Jonathon L

2016-05-01

Current guidelines for cow's milk consumption in children older than age 2 years suggest 1% or 2% milk to reduce the risk of obesity. Given that milk is the main dietary source of vitamin D for North American children and that vitamin D is fat soluble, we hypothesized 25-hydroxyvitamin D (25(OH)D) concentration to be positively associated with the fat content of milk. The objective was to determine the relationship between the fat content of milk consumed and the serum 25(OH)D concentration; our secondary objective was to explore the role that the volume of milk consumed played in this relationship. We completed a cross-sectional study of children aged 12-72 months in the TARGetKids! research network. Multivariable linear regression was used to test the association between milk fat content and child 25(OH)D, adjusted for clinically relevant covariates. The interaction between volume of milk and fat content was examined. Two thousand eight hundred fifty-seven children were included in the analysis. The fat content of milk was positively associated with 25(OH)D (p = 0.03), and the interaction between the volume of milk consumed and the milk fat content was statistically significant (p = 0.005). Children who drank 1% milk needed 2.46 cups (95% confidence interval (CI) 2.38-2.54) of milk to have a 25(OH)D concentration similar to that of children who drank 1 cup of homogenized milk (3.25% fat). Children who consumed 1% milk had 2.05 (95% CI 1.73-2.42) times higher odds of having a 25(OH)D concentration <50 nmol/L compared with children who consumed homogenized milk. In conclusion, recommendations for children to drink lower-fat milk (1% or 2%) may compromise serum 25(OH)D levels and may require study to ensure optimal childhood health.

Effects of Urban Stormwater Infrastructure and Spatial Scale on Nutrient Export and Runoff from Semi-Arid Urban Catchments

Science.gov (United States)

Hale, R. L.; Turnbull, L.; Earl, S.; Grimm, N. B.

2011-12-01

-drained sites and therefore stormwater has higher concentrations of nutrients, although total loads are significantly lower. Nonlinearities in cross-storm rainfall-nutrient loading relationships for the wash and retention basin watersheds suggest that these systems may become supply limited during large rain events. Results show that characteristics of the hydrologic network such as hydrologic connectivity mediate terrestrial-aquatic linkages. Specifically, we see that increased hydrologic connectivity, as in the piped watershed, actually decreases the predictive power of storm size with regard to nutrient export, whereas nutrient loads from poorly connected watersheds are strongly predicted by storm size.

Effect of boron nutrition on American ginseng in field and in nutrient cultures

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John T.A. Proctor

2014-01-01

Full Text Available Field and nutrient cultures of American ginseng (Panax quinquefolius L. were used to establish foliar symptoms related to boron (B concentration in leaves and soils, and to evaluate radish as a time-saving model system for B nutrition. Application of excess B, 8 kg/ha versus the recommended 1.5 kg/ha, to field plantings of 2-, 3-, and 4-yr-old American ginseng plants just prior to crop emergence caused, within 4 wk after crop emergence, leaf symptoms of chlorosis followed by necrosis starting at the tips and progressing along the margins. The B concentration in leaves of 2–4-yr-old plants receiving 1.5 kg/ha B was 30 μg/g dry mass compared to 460 μg/g dry mass where 8 kg/ha B was applied. Similarly, B concentration in soils receiving the lower B concentration was 1.8 μg/g dry mass and 2.2–2.8 μg/g dry mass where the higher B concentration was applied. Application of 8 kg/ha B reduced the dry yield of 3rd-yr roots by 20% from 2745 kg/ha to 2196 kg/ha and 4th-yr roots by 26% from 4130 kg/ha to 3071 kg/ha. Ginseng seedlings and radish were grown under greenhouse conditions in nutrient culture with four B concentrations ranging from 0 mg/L to 10 mg/L. At 5 mg/L and 10 mg/L ginseng and radish developed typical leaf B toxicity symptoms similar to those described above for field-grown plants. Increasing B in the nutrient solution from 0.5 mg/L to 10 mg/L decreased, in a linear fashion, the root and leaf dry mass of ginseng, but not radish. Given the many similarities of ginseng and radish to B utilization, radish might be used as a time-saving model system for the study of B, and other micronutrients, in the slow-growing perennial ginseng.