Factors Affecting Nitrate Concentrations in Stream Base Flow

2020 ◽  
Author(s):  
Susan A. Wherry ◽  
Anthony J. Tesoriero ◽  
Silvia Terziotti
Keyword(s):  
Base Flow ◽  
Factors Affecting ◽  
Nitrate Concentrations

FACTORS AFFECTING THE REGENERATION OF PEPPER (CAPSICUM ANNUUM L.)

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1120G-1120
Author(s):  
J. L. Jacobs ◽  
C. T. Stephens
Keyword(s):  
Growth Hormone ◽  
Silver Nitrate ◽  
Callus Formation ◽  
Leaf Explants ◽  
Regeneration System ◽  
Factors Affecting ◽  
Nitrate Concentrations ◽  
Leaf Differentiation ◽  
Whole Plants

Several growth hormone combinations and silver nitrate concentrations were examined for their effect on regeneration of different pepper genotypes. Primary leaf explants from in vitro seedlings were cultured on a revised Murashige and Skoog medium supplemented with auxin, cytokinin and 1.6% glucose. Combinations of different concentrations of indole-3-acetic acid (IAA), 0-5 mg/l, and 6-benzylaminopurine (BAP), 0-5 mg/l, were tested to determine the most effective medium for shoot primordium formation. Experiments with IAA and BAP did not result in a specific growth hormone combination appropriate for regeneration of all genotypes tested. Of the silver nitrate concentrations tested, 10 mg/l resulted in the best shoot and leaf differentiation and reduced callus formation. Differences in organogenic response of individual genotypes were evaluated on a single regeneration medium. Whole plants were regenerated from 11 of 63 genotypes examined. Based on these experiments, a reproducible regeneration system for pepper was developed with a total of 500 plants regenerated to date.

scholarly journals Effect on nitrate concentration in stream water of agricultural practices in small catchments in Brittany: II. Temporal variations and mixing processes

2002 ◽  
Vol 6 (3) ◽  
pp. 507-514 ◽  
Author(s):  
L. Ruiz ◽  
S. Abiven ◽  
C. Martin ◽  
P. Durand ◽  
V. Beaujouan ◽  
...  
Keyword(s):  
Land Use ◽  
Nitrate Concentration ◽  
Stream Water ◽  
Agricultural Practices ◽  
Temporal Variations ◽  
Base Flow ◽  
Seasonal Patterns ◽  
Annual Variations ◽  
Nitrogen Inputs ◽  
Nitrate Concentrations

Abstract. In catchments with impervious bedrock, the nitrate concentrations in streamwater often show marked seasonal and small inter-annual variations. The inter-annual trends are usually attributed to changes in nitrogen inputs, due to changes in land use or in nitrogen deposition whereas seasonal patterns are explained in terms of availability of soil nitrate for leaching and of seasonality of nitrogen biotransformations. The companion paper showed that inter-annual variations of nitrogen in streamwater are not directly related to the variations of land use. The aim of this study is to describe nitrate concentration variations in a set of very small adjacent catchments, and to discuss the origin of the inter-annual and seasonal trends. Data from four catchments at the Kerbernez site (South Western Brittany, France) were used in this study. Nitrate concentrations in streamwater were monitored for eight years (1992 to 1999) at the outlet of the catchments. They exhibit contrasting inter-annual and seasonal patterns. An extensive survey of agricultural practices during this period allowed assessment of the amount of nitrogen available for leaching. The discharges measured since 1997 show similar specific fluxes but very different seasonal dynamics between the catchments. A simple, lumped linear store model is proposed as an initial explanation of the differences in discharge and nitrate concentration patterns between the catchments. The base flow at the outlet of each catchment is considered as a mixture of water from two linear reservoirs with different time constants. Each reservoir comprises two water stores, one mobile contributing to discharge, the other, immobile, where nitrate moves only by diffusion. The storm flow, which accounts for less than 10% of the annual flux, is not considered here. Six parameters were adjusted for each catchment to fit the observed data: the proportion of deep losses of water, the proportion of the two reservoirs and the size and initial concentration of the two immobile stores. The model simulates the discharge and nitrate concentration dynamics well. It suggests that the groundwater store plays a very important role in the control of nitrate concentration in streamwater, and that the pattern of the seasonal variation of nitrate concentration may result from the long term evolution of nitrogen losses by leaching. Keywords: nitrate, diffuse pollution, groundwater, seasonal variations, agricultural catchment, simulation model

scholarly journals FACTORS AFFECTING THE REGENERATION OF PEPPER (CAPSICUM ANNUUM L.)

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1120g-1120 ◽  
Author(s):  
J. L. Jacobs ◽  
C. T. Stephens
Keyword(s):  
Growth Hormone ◽  
Silver Nitrate ◽  
Callus Formation ◽  
Leaf Explants ◽  
Regeneration System ◽  
Factors Affecting ◽  
Nitrate Concentrations ◽  
Leaf Differentiation ◽  
Whole Plants

Several growth hormone combinations and silver nitrate concentrations were examined for their effect on regeneration of different pepper genotypes. Primary leaf explants from in vitro seedlings were cultured on a revised Murashige and Skoog medium supplemented with auxin, cytokinin and 1.6% glucose. Combinations of different concentrations of indole-3-acetic acid (IAA), 0-5 mg/l, and 6-benzylaminopurine (BAP), 0-5 mg/l, were tested to determine the most effective medium for shoot primordium formation. Experiments with IAA and BAP did not result in a specific growth hormone combination appropriate for regeneration of all genotypes tested. Of the silver nitrate concentrations tested, 10 mg/l resulted in the best shoot and leaf differentiation and reduced callus formation. Differences in organogenic response of individual genotypes were evaluated on a single regeneration medium. Whole plants were regenerated from 11 of 63 genotypes examined. Based on these experiments, a reproducible regeneration system for pepper was developed with a total of 500 plants regenerated to date.

A coupled watershed-biogeochemical model to simulate dissolved and particulate 137Cs discharge from a forested catchment affected by the Fukushima accident

2020 ◽  
Author(s):  
Kazuyuki Sakuma ◽  
Kazuya Yoshimura ◽  
Hiroshi Kurikami ◽  
Alex Malins ◽  
Hironori Funaki
Keyword(s):  
River Water ◽  
Seasonal Variability ◽  
Compartment Model ◽  
Forest Litter ◽  
General Purpose ◽  
Base Flow ◽  
Biogeochemical Model ◽  
Forested Catchments ◽  
Fukushima Accident ◽  
Factors Affecting

<p>Dissolved <sup>137</sup>Cs discharge represents approximately 30% of the total <sup>137</sup>Cs discharge from the forested upstream catchment of the Ohta River in Fukushima, Japan [1]. It is thought that a major source of the dissolved <sup>137</sup>Cs entering the river water may be leaching from forest litter [1]. A watershed simulation based on the distribution coefficient (K<sub>d</sub>) that modelled water, sediment, and particulate and dissolved <sup>137</sup>Cs transport could not reproduce the seasonal variability of the base flow dissolved <sup>137</sup>Cs concentrations, nor the peaks in concentration that occurred during storms [2].</p><p>We developed a combined watershed-biogeochemistry model for simulating dissolved and particulate <sup>137</sup>Cs discharge from forest catchments to describe the two phenomenon as mentioned above. A compartment model for the forest ecosystem was appended to the General-purpose Terrestrial fluid-Flow Simulator (GETFLOWS) watershed code. The compartment model included compartments for undecomposed and decomposed litter, with transfer from the former into the latter depending on temperature. A pathway for dissolved <sup>137</sup>Cs input to forest streams was linked from the decomposed litter compartment.</p><p>The results from a simulation with the new simulation model reproduced the seasonal variability of dissolved <sup>137</sup>Cs concentrations and the peaks occurring during storms. Therefore the new modelling results add weight to the theory that leaching from decomposed litter can input dissolved <sup>137</sup>Cs concentrations in river water in Fukushima Prefecture. The developed model is expected to be useful for further explorations into factors affecting dissolved <sup>137</sup>Cs input to river water in forested catchments.</p><p> </p><p>[1]Tsuji et al., 2016. J. Geophys. Res. Biogeosci. 121, 2588-2599.</p><p>[2]Sakuma et al., 2018. J. Environ. Radioact. 184-185, 53-62.</p>

scholarly journals Nitrate Removal and Woodchip Properties across a Paired Denitrifying Bioreactor Treating Centralized Agricultural Ditch Flows

Water ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 56
Author(s):  
Bryan Maxwell ◽  
Laura Christianson ◽  
Richard A. C. Cooke ◽  
Mary Foltz ◽  
Niranga Wickramarathne ◽  
...  
Keyword(s):  
Stream Water ◽  
Nitrate Removal ◽  
Chemical Properties ◽  
Base Flow ◽  
Agricultural Watershed ◽  
Drainage Ditches ◽  
Denitrification Potential ◽  
Passive Flow ◽  
Nitrate Concentrations ◽  
And Chemical Properties

Treatment of nitrate loads by denitrifying bioreactors in centralized drainage ditches that receive subsurface tile drainage may offer a more effective alternative to end-of-pipe bioreactors. A paired denitrifying bioreactor design, consisting of an in-ditch bioreactor (18.3 × 2.1 × 0.2 m) treating ditch base flow and a diversion bioreactor (4.6 × 9.1 × 0.9 m) designed to treat high-flow events, was designed and constructed in an agricultural watershed (3.2 km2 drainage area) in Illinois, USA. Flow and water chemistry were monitored for three years and the woodchip and bioreactor-associated soil were analyzed for denitrification potential and chemical properties after 25 months. The in-ditch bioreactor did not significantly reduce nitrate concentrations in the ditch, likely due to low hydraulic connectivity with stream water and sedimentation. The diversion bioreactor significantly reduced nitrate concentrations (58% average reduction) but treated only ~2% of annual ditch flow. Denitrification potential was significantly higher in the in-ditch bioreactor woodchips versus the diversion bioreactor after 25 months (2950 ± 580 vs. 620 ± 310 ng N g−1 dry media h−1). The passive flow design was simple to construct and did not restrict flow in the drainage ditch but resulted in low hydraulic exchange, limiting nitrate removal.

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