scholarly journals A route to decreasing N pollution from livestock: Use of Festulolium hybrids improves efficiency of N flows in rumen simulation fermenters

2020 ◽  
Vol 9 (3) ◽  
Author(s):  
Stephen Kamau ◽  
Alejandro Belanche ◽  
Teri Davies ◽  
Pauline Rees Stevens ◽  
Mike Humphreys ◽  
...  
Keyword(s):  
N Pollution

scholarly journals Integrated modelling to assess N pollution swapping in slurry amended soils

2020 ◽  
Vol 713 ◽  
pp. 136596 ◽  
Author(s):  
Maria do Rosário Cameira ◽  
Rick Li ◽  
David Fangueiro
Keyword(s):  
Integrated Modelling ◽  
Amended Soils ◽  
N Pollution

Leaching behaviour of rare earth elements from low-grade weathered crust elution-deposited rare earth ore using magnesium sulfate

Clay Minerals ◽  
2018 ◽  
Vol 53 (3) ◽  
pp. 505-514
Author(s):  
Kaihua Chen ◽  
Jiannan Pei ◽  
Shaohua Yin ◽  
Shiwei Li ◽  
Jinhui Peng ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Magnesium Sulfate ◽  
Low Grade ◽  
Second Stage ◽  
Leaching Solution ◽  
Weathered Crust ◽  
Leaching Behaviour ◽  
N Pollution ◽  
Leaching Efficiency

ABSTRACTThe present study investigates the use of magnesium sulfate (MgSO4) instead of (NH4)2SO4 as a lixiviant in the recovery of rare earth elements (REEs) from clays. Experiments were carried out to investigate the influence of leaching conditions such as leaching time, lixiviant concentration and liquid:solid ratio on the leaching efficiency. The optimum leaching conditions, leading to 75.48% of total REE leaching efficiency, required a stirring speed of 500 rpm, a leaching time of 30 min, a lixiviant concentration of 3 wt.% and a liquid:solid ratio of 3:1. After extension of the leaching process by a second stage, the leaching efficiency may reach up to 96.19%, which is slightly higher than that obtained by (NH4)2SO4. Leaching varies from element to element, with Ce presenting the lowest leaching efficiency, and the partition in leaching solution is in agreement with that in raw ore other than for Ce. Based on these findings, MgSO4 lixiviant is an excellent alternative leaching agent for a sustainable REE industry because it reduces or eliminates NH4+–N pollution.

Ammonia emission from dairy cow manure stored in a lagoon over summer

2008 ◽  
Vol 88 (4) ◽  
pp. 611-615 ◽  
Author(s):  
S M McGinn ◽  
T. Coates ◽  
T K Flesch ◽  
B. Crenna
Keyword(s):  
Dairy Cow ◽  
Dispersion Model ◽  
Sonic Anemometer ◽  
Stochastic Approach ◽  
Dairy Manure ◽  
Ammonia Emission ◽  
Ammonia Emissions ◽  
N Pollution ◽  
Significant Pathway ◽  
Dairy Cow Manure

It is recognized that volatilized ammonia (NH3) from intensive livestock production can be a significant pathway for nitrogen (N) pollution to land and water, and can contribute to poor air quality. The objectives of our study were to document NH3 emissions from a dairy lagoon and to assess the influence of meteorology on NH3 emissions. Ammonia emissions were determined using a backward Lagrangian Stochastic approach using WindTrax software, an open-path NH3 laser and a sonic anemometer. Results indicate that an average 5.1 ± 1.6 g NH3 m-2 d-1 was released over the summer; however, the emission varied typically over 24 h between 3.6 and 8.6 g NH3 m-2 d-1. Wind speed and surface temperature of the lagoon had similar influences on the magnitude of the release, where their direct impact on NH3 emission accounted for 28 and 31% of the variability, respectively. The main implication of this study is that NH3 losses are significant from dairy lagoons, contributing to the issue of N pollution. As well, NH3 emissions are a loss of valuable N for manure used as fertilizer, which in our study amounted to approximately 13% of the total ammoniacal N content of the manure in the lagoon. Key words: Ammonia, dairy, manure, cattle, dispersion model

Retraction Statement: Comparison of nitrogen inputs and accumulation in 210 Pb‐dated peat cores: Evidence for biological N 2 ‐fixation in Central European peatlands despite decades of atmospheric N pollution

2018 ◽  
Vol 25 (4) ◽  
pp. 1547-1547
Author(s):  
Martin Novak ◽  
Melanie A. Vile ◽  
Jan Curik ◽  
Bohuslava Cejkova ◽  
Jiri Barta ◽  
...  
Keyword(s):  
Central European ◽  
Nitrogen Inputs ◽  
N Pollution

ROLE OF SOIL AND GRASS STRIPS IN REDUCING NITRATE-N POLLUTION IN SUBSURFACE DRAINED FARMLANDS: LYSIMETER RESULTS

1997 ◽  
Vol 22 (3) ◽  
pp. 351-361 ◽  
Author(s):  
Abdolmajid Liaghat ◽  
Shiv O. Prasher
Keyword(s):  
Nitrate N ◽  
N Pollution

Application of a dynamic nitrogen model to reduce nutrient pollution by dairy cows

2002 ◽  
Vol 2002 ◽  
pp. 106-106
Author(s):  
E. Kebreab ◽  
J.A.N. Mills ◽  
L.A. Crompton ◽  
J. France
Keyword(s):  
Mathematical Models ◽  
Environmental Pollution ◽  
Dairy Cows ◽  
Dairy Herds ◽  
Nutrient Pollution ◽  
Dairy Production ◽  
Biological Processes ◽  
Annual Output ◽  
N Utilization ◽  
N Pollution

Agriculture is one of the major sources of nitrogen (N) pollution. Dairy production causes losses of N in faeces and urine that contribute to environmental pollution with an estimated annual output of 320 kt N and 80 kt ammonia in the U.K. alone. Therefore, improving N utilization in dairy cows and especially reducing N output in excreta is desirable to reduce environmental N pollution, particularly as ammonia. Mathematical models have been used to predict potential N excretion from dairy cows. However, these models generally are empirical in nature, hence not process based and therefore there is a need to develop a model that can describe biological processes in the animal. The objective of the present study was to develop a dynamic N model to predict the amount and form of N excreted by dairy herds and seek to make appropriate recommendations that will reduce N excretion from dairy cows.

Invasion of Onondaga Lake, New York, by the zebra mussel (Dreissena polymorpha) following reductions in N pollution

2002 ◽  
Vol 21 (4) ◽  
pp. 634-650 ◽  
Author(s):  
Michael E. Spada ◽  
Neil H. Ringler ◽  
Steven W. Effler ◽  
David A. Matthews
Keyword(s):  
New York ◽  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Onondaga Lake ◽  
N Pollution

The Fate of 15N Tracer in Waterlogged Peat Cores from Two Central European Bogs with Different N Pollution History

2018 ◽  
Vol 229 (3) ◽  
Author(s):  
Martin Novak ◽  
Marketa Stepanova ◽  
Frantisek Buzek ◽  
Ivana Jackova ◽  
Jan Curik ◽  
...  
Keyword(s):  
15N Tracer ◽  
Pollution History ◽  
Central European ◽  
N Pollution

The distribution of urine deposited on a pasture from grazing animals

2006 ◽  
Vol 145 (1) ◽  
pp. 81-86 ◽  
Author(s):  
A. B. PLEASANTS ◽  
P. R. SHORTEN ◽  
G. C. WAKE
Keyword(s):  
Water Quality ◽  
Ground Water ◽  
Agricultural Production ◽  
Probability Distributions ◽  
Management Regimes ◽  
N Pollution ◽  
Production Practices ◽  
Grass Growth ◽  
Short Time ◽  
Stocking Rates

Intensive agricultural production practices are known to cause far-reaching effects on water quality. The current paper addresses and quantifies these effects caused by high stocking rates.A set of stochastic difference equations describing the development of the proportion of a grazed field either unaffected by urine deposition, or affected by multiple (1, 2, …) urine depositions is described. A solution to this set of equations is found for the expected value of multiple (0, 1, 2, …) urine depositions, and the variances of these depositions. It is assumed that an animal voids urine with a Poisson probability distribution, and that each urine deposition covers a random area with a Gaussian probability density. Given these reasonable assumptions, the probability distributions for each multiplicity of patch distribution can be found numerically.The utility of the results obtained is illustrated for a problem in assessing the nitrogen (N) pollution of ground water from different grazing strategies. It is demonstrated quantitatively that mob stocking (typical of winter management regimes in New Zealand) is often caused by rotational grazing. The latter is often used to optimize grass growth and intake, especially in winter. This increases (more than linearly) the level of N pollution in ground water. This is because of the increased frequency of multiple urine depositions, i.e. more than one urine deposition on the same patch of land in a short time.

N pollution sources and denitrification in waterbodies in Taihu Lake region

2001 ◽  
Vol 44 (3) ◽  
pp. 304-314 ◽  
Author(s):  
Guangxi Xing ◽  
Yacheng Cao ◽  
Shulian Shi ◽  
Guoqing Sun ◽  
Lijuan Du ◽  
...  
Keyword(s):  
Taihu Lake ◽  
Pollution Sources ◽  
Lake Region ◽  
N Pollution
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