scholarly journals Processes controlling the flux of legacy phosphorus to surface waters at the farm scale

2021 ◽  
Author(s):  
Victoria Barcala ◽  
Joachim Rozemeijer ◽  
Leonard Osté ◽  
Bas Van Der Grift ◽  
Laurens Gerner ◽  
...  
2020 ◽  
Vol 16 (1) ◽  
pp. 015003
Author(s):  
Victoria Barcala ◽  
Joachim Rozemeijer ◽  
Leonard Osté ◽  
Bas Van der Grift ◽  
Laurens Gerner ◽  
...  

Geoderma ◽  
2021 ◽  
Vol 403 ◽  
pp. 115257
Author(s):  
Cäcilia von Arb ◽  
Sebastian Stoll ◽  
Emmanuel Frossard ◽  
Christian Stamm ◽  
Volker Prasuhn

1992 ◽  
Vol 21 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Adel El Titi

European agriculture operates in challenging times as it faces uncertainties arising from economic, political, environmental and other pressures. In the arable sector, there are serious problems associated with overproduction and declining farm incomes as well as concerns about species decline and the pollution of ground and surface waters by agrochemicals. Such issues are forcing a fundamental re-orientation in agriculture. An Integrated Farming System (IFS) is identified as a most promising approach. It integrates natural regulatory components into farming activities with the aim of replacing purchased off-farm inputs, whilst maintaining farm income. Farm-scale trials across Europe indicate positive benefits of IFS. Yield potential does not deteriorate, agrochemical inputs are reduced and several agroecosystem components are enhanced without losses in financial returns. This paper discusses developments in IFS, together with possible technology transfer systems, in the context of the new, environmentally-orientated CEC-agropolicy to achieve sustainable agriculture in Europe.


1985 ◽  
Vol 6 (2) ◽  
pp. 52-58 ◽  
Author(s):  
Susan T. Bagley

AbstractThe genus Klebsiella is seemingly ubiquitous in terms of its habitat associations. Klebsiella is a common opportunistic pathogen for humans and other animals, as well as being resident or transient flora (particularly in the gastrointestinal tract). Other habitats include sewage, drinking water, soils, surface waters, industrial effluents, and vegetation. Until recently, almost all these Klebsiella have been identified as one species, ie, K. pneumoniae. However, phenotypic and genotypic studies have shown that “K. pneumoniae” actually consists of at least four species, all with distinct characteristics and habitats. General habitat associations of Klebsiella species are as follows: K. pneumoniae—humans, animals, sewage, and polluted waters and soils; K. oxytoca—frequent association with most habitats; K. terrigena— unpolluted surface waters and soils, drinking water, and vegetation; K. planticola—sewage, polluted surface waters, soils, and vegetation; and K. ozaenae/K. rhinoscleromatis—infrequently detected (primarily with humans).


Author(s):  
James S. Webber

INTRODUCTION“Acid rain” and “acid deposition” are terms no longer confined to the lexicon of atmospheric scientists and 1imnologists. Public awareness of and concern over this phenomenon, particularly as it affects acid-sensitive regions of North America, have increased dramatically in the last five years. Temperate ecosystems are suffering from decreased pH caused by acid deposition. Human health may be directly affected by respirable sulfates and by the increased solubility of toxic trace metals in acidified waters. Even man's monuments are deteriorating as airborne acids etch metal and stone features.Sulfates account for about two thirds of airborne acids with wet and dry deposition contributing equally to acids reaching surface waters or ground. The industrial Midwest is widely assumed to be the source of most sulfates reaching the acid-sensitive Northeast since S02 emitted as a byproduct of coal combustion in the Midwest dwarfs S02 emitted from all sources in the Northeast.


2015 ◽  
Vol 77 ◽  
pp. 29-34 ◽  
Author(s):  
P.C. Beukes ◽  
S. Mccarthy ◽  
C.M. Wims ◽  
A.J. Romera

Paddock selection is an important component of grazing management and is based on either some estimate of pasture mass (cover) or the interval since last grazing for each paddock. Obtaining estimates of cover to guide grazing management can be a time consuming task. A value proposition could assist farmers in deciding whether to invest resources in obtaining such information. A farm-scale simulation exercise was designed to estimate the effect of three levels of knowledge of individual paddock cover on profitability: 1) "perfect knowledge", where cover per paddock is known with perfect accuracy, 2) "imperfect knowledge", where cover per paddock is estimated with an average error of 15%, 3) "low knowledge", where cover is not known, and paddocks are selected based on longest time since last grazing. Grazing management based on imperfect knowledge increased farm operating profit by approximately $385/ha compared with low knowledge, while perfect knowledge added a further $140/ha. The main driver of these results is the level of accuracy in daily feed allocation, which increases with improving knowledge of pasture availability. This allows feed supply and demand to be better matched, resulting in less incidence of under- and over-feeding, higher milk production, and more optimal post-grazing residuals to maximise pasture regrowth. Keywords: modelling, paddock selection, pasture cover


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