Biochar impacts on nutrient dynamics in a subtropical grassland soil: 1. Nitrogen and phosphorus leaching

Abstract. Recent studies on the impacts of ocean acidification on pelagic communities have identified changes in carbon to nutrient dynamics with related shifts in elemental stoichiometry. In principle, mesocosm experiments provide the opportunity of determining the temporal dynamics of all relevant carbon and nutrient pools and, thus, calculating elemental budgets. In practice, attempts to budget mesocosm enclosures are often hampered by uncertainties in some of the measured pools and fluxes, in particular due to uncertainties in constraining air/sea gas exchange, particle sinking, and wall growth. In an Arctic mesocosm study on ocean acidification using KOSMOS (Kiel Off-Shore Mesocosms for future Ocean Simulation) all relevant element pools and fluxes of carbon, nitrogen and phosphorus were measured, using an improved experimental design intended to narrow down some of the mentioned uncertainties. Water column concentrations of particulate and dissolved organic and inorganic constituents were determined daily. New approaches for quantitative estimates of material sinking to the bottom of the mesocosms and gas exchange in 48 h temporal resolution, as well as estimates of wall growth were developed to close the gaps in element budgets. Future elevated pCO2 was found to enhance net autotrophic community carbon uptake in 2 of the 3 experimental phases but did not significantly affect particle elemental composition. Enhanced carbon consumption appears to result in accumulation of dissolved organic compounds under nutrient recycling summer conditions. This carbon over-consumption effect becomes evident from budget calculations, but was too small to be resolved by direct measurements of dissolved organics. The out-competing of large diatoms by comparatively small algae in nutrient uptake caused reduced production rates under future ocean CO2 conditions in the end of the experiment. This CO2 induced shift away from diatoms towards smaller phytoplankton and enhanced cycling of dissolved organics was pushing the system towards a retention type food chain with overall negative effects on export potential.

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Nutrient dynamics along the Moskva River under heavy pollution and limited self-purification capacity

E3S Web of Conferences ◽

10.1051/e3sconf/202016305014 ◽

2020 ◽

Vol 163 ◽

pp. 05014

Author(s):

Maria Tereshina ◽

Oxana Erina ◽

Dmitriy Sokolov ◽

Lyudmila Efimova ◽

Nikolay Kasimov

Keyword(s):

Nutrient Dynamics ◽

Inorganic Nitrogen ◽

Water Quality Management ◽

Urban Pollution ◽

Extensive Study ◽

Low Flow ◽

Urban Region ◽

Anthropogenic Pressure ◽

Nitrogen And Phosphorus ◽

Moskva River

An extensive study conducted during the dry summer of 2019 provided a detailed picture of the nutrient content dynamics along the Moskva River. Water sampling at 38 locations on the main river and at 17 of its tributaries revealed a manifold increase in phosphorus and nitrogen concentrations as the river crosses the Moscow metropolitan area, which can be attributed to both direct discharge of poorly treated sewage and nonpoint urban pollution. Even at the Moskva River lower reaches, where the anthropogenic pressure on the river and its tributaries is less pronounced, the inorganic nitrogen and phosphorus content remains consistently high and exceeds the environmental guidelines by up to almost 10 times. This indicates increased vulnerability of the Moskva River ecosystem during periods of low flow, which can be a major factor of eutrophication in the entire Moskva-Oka-Volga system. Comparison of our data with some archive records shows no significant improve in the nutrient pollution of the river since the 1990s, which raises further concern about the effectiveness of water quality management in Moscow urban region.

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Nitrogen and Phosphorus Budget for a Deep Tropical Reservoir of the Brazilian Savannah

Water ◽

10.3390/w11061205 ◽

2019 ◽

Vol 11 (6) ◽

pp. 1205 ◽

Cited By ~ 1

Author(s):

Jackeline do S. B. Barbosa ◽

Valéria R. Bellotto ◽

Damiana B. da Silva ◽

Thiago B. Lima

Keyword(s):

Wastewater Treatment ◽

Nutrient Dynamics ◽

Wastewater Treatment Plants ◽

Organic Phosphorus ◽

Inorganic Nitrogen ◽

Nutrient Input ◽

Nitrogen And Phosphorus ◽

Tropical Reservoir ◽

Artificial Lake ◽

Total Organic Nitrogen

This research investigated the source and fate of different chemical species of N and P on a deep tropical urban reservoir, the artificial Lake Paranoá, located in the city of Brasilia (Brazil). To determine an N and P budget, nutrient input from the external load (four main tributaries and two wastewater treatment plants), internal load (from sediment) and nutrient output (from a downstream dam) were estimated empirically. Nutrient storage was evaluated in two compartments: water column and sediment. Nutrient input from the tributaries varied by season presenting higher loads in the wet season, especially N. Nutrient budgets in our study indicated that Lake Paranoá retained dissolved inorganic nitrogen (DIN), PO43−-P, total organic phosphorus (TOP) and exported total organic nitrogen (TON), both on a seasonal and annual scale. Surface sediment is the major storage compartment for both N and P. These results show the pressing need for action to reduce the P outcome charges, mainly, from the wastewater treatment plants. The data here presented contributes to the recognition of this situation and to a better comprehension of these nutrient dynamics, as well as an understanding of the behavior of tropical deep-water reservoirs. This can help to promote more effective management, providing a reference for other similar systems.

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Impacts of soil erosion on organic carbon and nutrient dynamics in an alpine grassland soil

Soil Science & Plant Nutrition ◽

10.1080/00380768.2013.795475 ◽

2013 ◽

Vol 59 (4) ◽

pp. 660-668 ◽

Cited By ~ 15

Author(s):

X.J. Nie ◽

T.Q. Zhao ◽

X.N. Qiao

Keyword(s):

Soil Erosion ◽

Organic Carbon ◽

Nutrient Dynamics ◽

Alpine Grassland ◽

Grassland Soil

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Preferential phosphorus leaching from an irrigated grassland soil

European Journal of Soil Science ◽

10.1111/j.1365-2389.2004.00656.x ◽

2005 ◽

Vol 56 (2) ◽

pp. 155-168 ◽

Cited By ~ 51

Author(s):

G. S. Toor ◽

L. M. Condron ◽

B. J. Cade-Menun ◽

H. J. Di ◽

K. C. Cameron

Keyword(s):

Phosphorus Leaching ◽

Grassland Soil

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Biochar impacts on nutrient dynamics in a subtropical grassland soil: 2. Greenhouse gas emissions

Journal of Environmental Quality ◽

10.1002/jeq2.20141 ◽

2020 ◽

Vol 49 (5) ◽

pp. 1421-1434

Author(s):

Yanyan Lu ◽

Maria Lucia Silveira ◽

Michel Cavigelli ◽

George A. O'Connor ◽

Joao M. B. Vendramini ◽

...

Keyword(s):

Greenhouse Gas Emissions ◽

Greenhouse Gas ◽

Nutrient Dynamics ◽

Grassland Soil ◽

Gas Emissions

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Nitrogen and phosphorus leaching losses from paddy fields with different water and nitrogen managements

Paddy and Water Environment ◽

10.1007/s10333-010-0246-y ◽

2011 ◽

Vol 9 (3) ◽

pp. 333-342 ◽

Cited By ~ 88

Author(s):

Shi-Zhang Peng ◽

Shi-Hong Yang ◽

Jun-Zeng Xu ◽

Yu-Feng Luo ◽

Hui-Jing Hou

Keyword(s):

Paddy Fields ◽

Phosphorus Leaching ◽

Nitrogen And Phosphorus ◽

Leaching Losses

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Nutrients in Australian tropical rivers: changes with agricultural development and implications for receiving environments

Marine and Freshwater Research ◽

10.1071/mf04081 ◽

2005 ◽

Vol 56 (3) ◽

pp. 279 ◽

Cited By ~ 98

Author(s):

Jon E. Brodie ◽

Alan W. Mitchell

Keyword(s):

Agricultural Development ◽

Nutrient Dynamics ◽

Inorganic Nitrogen ◽

Nutrient Concentrations ◽

Tropical Rivers ◽

Nutrient Inputs ◽

Material Transport ◽

Nitrogen And Phosphorus ◽

North East ◽

The North

In tropical Australia, intensive studies of river suspended sediment (SS) and nutrient dynamics have been restricted to streams on the north-east coast between the Fitzroy and Normanby Rivers (Queensland), Magela Creek/East Alligator River (Northern Territory) and the Ord River (Western Australia). Historical conditions in these rivers were probably characterised by low–moderate SS concentrations and low concentrations of dissolved inorganic nitrogen and phosphorus in flow events. Introduction of agriculture has transformed SS and nutrient dynamics. Grazing has led to soil erosion and increased SS and particulate nutrient concentrations and fluxes in event flows. Fertilised cropping has increased nutrient inputs to catchments, where it forms a substantial proportion of the catchment area. Consequently, both particulate and dissolved inorganic nutrient concentrations and fluxes have increased. Australian tropical rivers have episodic flows, with most material transport occurring during large flow events. The restricted period of these highly energetic flows means little trapping of materials in waterways occurs. Loads are transported efficiently downstream and processes such as denitrification and in-channel sedimentation may be of limited importance. Owing to excessive nutrient inputs associated with agriculture, a number of northern freshwater, estuarine and coastal ecosystems are now eutrophic. Continued development, especially fertilised cropping, without adequate management of nutrient losses is likely to exacerbate these problems.

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