نتایج جستجو برای: phosphorus loss

تعداد نتایج: 485722  

2014
Jing Qian Li-Ping Zhang Wen-Yan Wang Qiao Liu

In order to evaluate the effects of different slope lengths (1, 2, 3, 4, and 5 m) and different vegetation coverage ratios (20%, 45%, 60%, and 90%) on the mechanisms of nutrient loss and runoff producing processes, we have conducted 14 simulated rainfall experiments. The results show that N and P loss are decided by the concentration and the runoff volume, but when the amounts of N and P in top...

Journal: :Ecology letters 2014
Daniel B Metcalfe Gregory P Asner Roberta E Martin Javier E Silva Espejo Walter Huaraca Huasco Felix F Farfán Amézquita Loreli Carranza-Jimenez Darcy F Galiano Cabrera Liliana Durand Baca Felipe Sinca Lidia P Huaraca Quispe Ivonne Alzamora Taype Luzmila Eguiluz Mora Angela Rozas Dávila Marlene Mamani Solórzano Beisit L Puma Vilca Judith M Laupa Román Patricia C Guerra Bustios Norma Salinas Revilla Raul Tupayachi Cécile A J Girardin Christopher E Doughty Yadvinder Malhi

The functional role of herbivores in tropical rainforests remains poorly understood. We quantified the magnitude of, and underlying controls on, carbon, nitrogen and phosphorus cycled by invertebrate herbivory along a 2800 m elevational gradient in the tropical Andes spanning 12°C mean annual temperature. We find, firstly, that leaf area loss is greater at warmer sites with lower foliar phospho...

2006
E. J. Dunne K. R. Reddy M. W. Clark

Hydrological restoration of historically isolated wetlands may mitigate phosphorus (P) loss. The objectives of this study were to quantify P in soil, determine effect of (1) soil characteristics on P release, and (2) antecedent soil hydrological conditions on P dynamics. Humic/fulvic acid bound P and residual P accounted for majority of P (>78%) in surface soils. Soils with highest nutrient sta...

Journal: :Clinical journal of the American Society of Nephrology : CJASN 2011
Marcelo S Sampaio Miklos Z Molnar Csaba P Kovesdy Rajnish Mehrotra Istvan Mucsi John J Sim Mahesh Krishnan Allen R Nissenson Kamyar Kalantar-Zadeh

BACKGROUND AND OBJECTIVES Serum phosphorus levels are associated with mortality, cardiovascular disease, and renal function loss in individuals with and without chronic kidney disease. The association of pretransplant serum phosphorus levels with transplant outcomes is not clear. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Data of the Scientific Registry of Transplant Recipients (SRTR) up t...

2017
Daniel S. Andersen Matthew J. Helmers Robert T. Burns

Accumulation of phosphorus in soil is a major factor limiting the operational life of land application waste disposal systems. Moreover, for nutrient management purposes and evaluation of potential environmental problems it is necessary to understand the impact of manure application on soil phosphorus sorption characteristics. In this study laboratory experiments were conducted to investigate t...

2015
Piotr Rozentryt Jacek T Niedziela Bartosz Hudzik Andrzej Lekston Wolfram Doehner Ewa A Jankowska Jolanta Nowak Stephan von Haehling Robert Partyka Tomasz Rywik Stefan D Anker Piotr Ponikowski Lech Poloński

BACKGROUND A higher serum phosphate level is associated with worse outcome. Energy-demanding intracellular transport of phosphate is needed to secure anion bioavailability. In heart failure (HF), energy starvation may modify intracellular and serum levels of phosphate. We analysed determinants of serum phosphates in HF and assessed if catabolic/anabolic balance (CAB) was associated with elevati...

2009
K. H. Reckhow R. D. Harmel

Multilevel or hierarchical models have been applied for a number of years in the social sciences but only relatively recently in the environmental sciences. These models can be developed in either a frequentist or Bayesian context and have similarities to other methods such as empirical Bayes analysis and random coefficients regression. In essence, multilevel models take advantage of the hierar...

2011
Yongping Yuan Ronald L. Bingner Martin A. Locke Jim Stafford Fred D. Theurer

High phosphorus (P) loss from agricultural fields has been an environmental concern because of potential water quality problems in streams and lakes. To better understand the process of P loss and evaluate the effects of different phosphorus fertilization rates on phosphorus losses, the USDA Annualized AGricultural Non-Point Source (AnnAGNPS) pollutant loading model was applied to the Ohio Uppe...

Journal: :Journal of environmental quality 2008
Andrew N Sharpley Peter J A Kleinman A Louise Heathwaite William J Gburek Jennifer L Weld Gordon J Folmar

Most states in the USA have adopted P Indexing to guide P-based management of agricultural fields by identifying the relative risk of P loss at farm and watershed scales. To a large extent, this risk is based on hydrologic principles that frequently occurring storms can initiate surface runoff from fields. Once initiated, this hydrological pathway has a high potential to transport P to the stre...

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