Table Of ContentAgric., Hydrol. - 00 Prelims 9/9/02 9:29 AM Page vii
Contributors
S. Anthony, ADAS Research and Development, Woodthorne, Wergs Road,
Wolverhampton WV16 8TQ, UK
D.S. Baldwin, Cooperative Research Centre for Freshwater Ecology and Murray–Darling
Freshwater Research Centre, PO Box 921, Albury, NSW 2640, Australia
D.B. Beegle, Department of Crop and Soil Sciences, The Pennsylvania State University,
116 ASI Building, University Park, PA 16802, USA
K. Beven, Institute of Environmental and Natural Sciences, Lancaster University,
Lancaster LA1 4YQ, UK
M.S.A. Blackwell, Royal Holloway Institute for Environmental Research, Department of
Geography, Royal Holloway University of London, Surrey GU25 4LN, UK
J.J.B. Bronswijk, National Institute of Public Health and Environment (RIVM), PO Box 1,
3720 BA, Bilthoven, The Netherlands
K.C. Cameron, Centre for Soil and Environmental Quality, PO Box 84, Lincoln University,
Canterbury, New Zealand
G. Campbell, Department of Plant and Soil Science, University of Aberdeen, Aberdeen
AB24 3UU, UK
D.R. Chadwick, Institute of Grassland and Environmental Research, North Wyke
Research Station, Okehampton, Devon EX20 2SB, UK
P.A. Chambers, National Water Research Institute, 867 Lakeshore Boulevard, PO Box
5050, Burlington, Ontario L7R 4S6, Canada
S. Chen, Centre for Land and Water Stewardship, University of Guelph, Guelph, Ontario
N1G 2W1, Canada
F.J. Coale, Department of Natural Resource Sciences and Landscape Architecture,
University of Maryland, College Park, MD 20742, USA
L.M. Condron, Centre for Soil and Environmental Quality, PO Box 84, Lincoln University,
Canterbury, New Zealand
J. Cox, CSIRO Land and Water, PMB 2, Glen Osmond, SA 5064, Australia
H.J. Di, Centre for Soil and Environmental Quality, PO Box 84, Lincoln University,
Canterbury, New Zealand
A.C. Edwards, Macaulay Land Use Research Institute, Craigiebuckler, Aberdeen AB15
8QH, UK
G. Fishburn, New South Wales Department of Land and Water Conservation, PO Box 10,
Wagga Wagga, NSW 2650, Australia
vii
Agric., Hydrol. - 00 Prelims 9/9/02 9:29 AM Page viii
viii Contributors
R.H. Foy, Agricultural and Environmental Science Division, Department of Agriculture
and Rural Development, Newforge Lane, Belfast BT9 5PX, UK
A.I. Fraser, National Soil Resources Institute, North Wyke Research Station,
Okehampton, Devon EX20 2SB, UK
W.J. Gburek, United States Department of Agriculture – Agricultural Research Service,
Pasture Systems and Watershed Management Research Unit, Curtin Road, University
Park, PA 16802-3702, USA
B. Gevao, Institute of Environmental and Natural Sciences, Lancaster University,
Lancaster LA1 4YQ, UK
K.E. Giller, Department of Soil Science and Agricultural Engineering, University of
Zimbabwe, PO Box MP167, Mount Pleasant, Harare, Zimbabwe
K. Goulding, Soil Science Department, Institute of Arable Crop Research, Rothamsted,
Harpenden, Hertfordshire AL5 2JQ, UK
R. Grant, National Environmental Research Institute, Department of Streams and
Riparian Areas, Vejlsøvej 25, DK-8600, Silkeborg, Denmark
D. Halliwell, Agriculture Victoria Ellinbank, RMB 2460, Ellinbank, VIC 3821, Australia
G. Harris, CSIRO Land and Water, Canberra, Australian Capital Territory, Australia
T.R. Harrod, National Soil Resources Institute, North Wyke Research Station,
Okehampton, Devon EX20 2SB, UK
D. Hatch, Institute of Grassland and Environmental Research, North Wyke Research
Station, Okehampton, Devon EX20 2SB, UK
T.J. Hatton, CSIRO Land and Water GPO Box 1666, Canberra, ACT 2601, Australia
P.M. Haygarth, Institute of Grassland and Environmental Research, North Wyke Research
Station, Devon, UK
D.V. Hogan, Royal Holloway Institute for Environmental Research, Department of
Geography, Royal Holloway University of London, Surrey GU25 4LN, UK
S.C. Jarvis, Institute of Grassland and Environmental Research, North Wyke Research
Station, Devon, UK
D.L. Jones, School of Agricultural and Forest Sciences, University of Wales, Bangor,
Gwynedd LL57 2UW, UK
K.C. Jones, Institute of Environmental and Natural Sciences, Lancaster University,
Lancaster LA1 4YQ, UK
C.W. Kaspar, Department of Food Microbiology and Toxicology, Food Research Institute,
University of Wisconsin, Madison, WI 53706-1187, USA
P.J.A. Kleinman, United States Department of Agriculture – Agricultural Research
Service, Pasture Systems and Watershed Management Research Unit, Curtin Road,
University Park, PA 16802-3702, USA
B. Kronvang, National Environmental Research Institute, Department of Streams and
Riparian Areas, Vejlsøvej 25, DK-8600, Silkeborg, Denmark
L.E. Lanyon, Department of Crop and Soil Sciences, The Pennsylvania State University,
116 ADI Building, University Park, PA 16802, USA
A.R. Laubel, National Environmental Research Institute, Department of Streams and
Riparian Areas, Vejlsøvej 25, DK-8600, Silkeborg, Denmark
T. van Leeuwen, Agricultural Economic Research Institute (LEI), PO Box 29703, 2502 LS,
The Hague, The Netherlands
P. Leinweber, Institute of Soil Science, University of Rostock, Justus-von-Liebig-Weg 6,
D-18059 Rostock, Germany
E. Maltby, Royal Holloway Institute for Environmental Research, Department of
Geography, Royal Holloway University of London, Surrey GU25 4LN, UK
E. Mangwayana, Department of Soil Science and Agricultural Engineering, University of
Zimbabwe, PO Box MP167, Mount Pleasant, Harare, Zimbabwe
R.W. McDowell, United States Department of Agriculture – Agricultural Research Service,
Agric., Hydrol. - 00 Prelims 10/9/02 12:40 PM Page ix
Contributors ix
Pasture Systems and Watershed Management Research Unit, Curtin Road, University
Park, PA 16802-3702 USA. Present address: AgResearch Invermay, Private Bag 50034,
Mosgiel, New Zealand
R. Meissner, UFZ Centre for Environmental Research, Leipzig-Halle, Lysimeter Station,
D-39615 Falkenberg, Germany
A.M. Mitchell, Cooperative Research Centre for Freshwater Ecology and Murray–Darling
Freshwater Research Centre, PO Box 921, Albury, NSW 2640, Australia
K.E. Motsi, Department of Soil Science and Agricultural Engineering, University of
Zimbabwe, PO Box MP167, Mount Pleasant, Harare, Zimbabwe
D. Murphy, Centre for Land Rehabilitation, Soil Science and Plant Nutrition, The
University of Western Australia, Nedlands 6009, Western Australia
D. Nash, Agriculture Victoria Ellinbank, RMB 2460, Ellinbank, VIC 3821, Australia
W.C.K. O’Connor, Agricultural and Environmental Science Division, Department of
Agriculture and Rural Development, Newforge Lane, Belfast BT9 5PX, UK
J.M. Olley, CSIRO Land and Water, PO Box 1666, Canberra, ACT 2601, Australia
M.L. Pedersen, National Environmental Research Institute, Department of Streams and
Riparian Areas, Vejlsøvej 25, DK-8600, Silkeborg, Denmark
S. Pengelly, New South Wales Department of Land and Water Conservation, PO Box 365,
Queanbeyan, NSW 2620, Australia
P.F. Quinn, Water Resources Systems Research Laboratory, Newcastle University,
Newcastle-upon-Tyne, UK
P.F.A.M. Römkens, Alterra Green World Research, POBox 44, 6700 AA, Wageningen, The
Netherlands
A.N. Sharpley, United States Department of Agriculture – Agricultural Research Service, Pasture
Systems and Watershed Management Research Unit, Curtin Road, University Park, PA
16802-3702, USA
J.T. Sims, Department of Plant and Soil Science, 163 Townsend Hall, University of
Delaware, Newark, DE 19717-1303, USA
F.D. Theurer, National Water and Climate Center, Natural Resources Conservation
Service, United States Department of Agriculture, 7413 Cinnabar Terrace,
Gaithersburg, MD 20879-4575, USA
P.A. Troch, Department of Water Management, Wageningen Agricultural University,
Wageningen, The Netherlands
B.L. Turner, United States Department of Agriculture – Agricultural Research Service,
Northwest Irrigation and Soils Research Laboratory, 3793 N. 3600 E. Kimberly, ID
83341, USA
Y.J.P. Van Herpe, Laboratory of Hydrology and Water Management, Ghent University,
Ghent, Belgium
W. de Vries, Alterra Green World Research, PO Box 44, 6700 AA, Wageningen, The
Netherlands
G.R. Walker, CSIRO Land and Water, GPO Box 1666, Canberra, ACT 2601, Australia
J. Williams, CSIRO Land and Water, GPO Box 1666, Canberra, ACT 2601, Australia
Agric., Hydrol. - 00 Prelims 9/9/02 9:29 AM Page x
Acknowledgements
Special thanks are due to Trisha Butler for extensive editorial assistance and support, also
to Anne Roker, Linda Jewell, Jo Chisholm and Adrian Joynes all at the Institute of
Grassland and Environmental Research. Thanks also to Louise Heathwaite at Sheffield
University, Leo Condron and Neil Smith at Lincoln University, Ben Turner at USDA Idaho
and Anne Haygarth for help, discussions and inspiration in producing this volume.
x
Agric., Hydrol. - 00 Prelims 9/9/02 9:29 AM Page xi
Note on Terminology and Abbreviations
Terminology lights the need for caution and clarity
when interpreting issues of scale.
At the start of the editorial process, we 4. Terms such as ‘dissolved’ and ‘particu-
referred authors to three aspects of our late’ need careful interpretation as some
published work, which were intended be researchers use different filter sizes to
used for guidance on use of terminology define the thresholds.
(Haygarth and Jarvis, 1999; Haygarth et 5. The use of ‘phosphate’ is unacceptable
al., 2000; Haygarth and Sharpley, 2000). if describing forms determined by Mo-reac-
Despite these efforts, there remain five tion chemistry, because the reaction does
key areas of terminology that were vul- not exclusively determine free phosphate.
nerable to ambiguity and therefore wor- Reactive P is operationally defined and
thy of special note: thus more correct.
1. ‘Runoff’ is a term to be avoided as it is
not pathway specific and is ambiguous.
Instead, we encouraged use of specific Abbreviations
pathway terms such as overland flow and
subsurface lateral flow. Our policy was that Below is a list of selected ‘common’ abbre-
runoff is only acceptable in a general con- viations used throughout the book. The
text and where this is made clear. abbreviated form is always used, except at
2. ‘Leaching’ was often incorrectly referred the start of sentences or in headings. Any
to as a pathway, while it is actually a abbreviation not listed here is defined at
mechanism that describes the elluviation the first time of using in the specific chap-
of solutes through soil, and is not pathway ter; thereafter it follows the style of com-
specific. Preferred alternative terms for mon abbreviations.
pathways are preferential flow, saturated
flow, macropore flow, etc. Al aluminium
3. Hydrological scale is often difficult to BMP(s) best management practice(s)
conceptualize. Haygarth et al. (2000) BOD biological oxygen demand
attempted a definition of ‘soil profile’, C carbon
‘slope/field’ and ‘catchment’ scale, but it is Ca calcium
clear that contributors have individual Cd cadmium
views about these boundaries. This high- Co cobalt
xi
Agric., Hydrol. - 00 Prelims 9/9/02 9:29 AM Page xii
xii Terminology and Abbreviations
CO carbon dioxide LU livestock units
2
COD chemical oxygen demand Mn manganese
CSA critical source area Mo molybdenum
Cu copper MRP molybdate reactive phosphorus
DDD 1,1-dichloro-2,2-bis N nitrogen
(p-chlorophenyl)ethane NH ammonia
3
DDE 1,1-bis-(p-chlorophenyl)-2,2- NH+ ammonium
4
dichloroethane Ni nickel
DDT 1,1,1-trichloro-2,2-bis NO(cid:2) nitrate
3
(p-chlorophenyl)ethane O oxygen
2
DO dissolved oxygen OM organic matter
DOC dissolved organic carbon P phosphorus
DOM dissolved organic matter Pb lead
DON dissolved organic nitrogen PCP pentachlorophenol
DRP dissolved reactive phosphorus PO3(cid:2) phosphate
4
DW dry weight PP particulate phosphorus
Fe iron RP reactive phosphorus
GIS geographical information systems SO2(cid:2) sulphate
4
H hydrogen SRP soluble reactive phosphorus
ha hectare SS suspended solids
HCB hexachlorobenzene TP total phosphorus
Hg mercury UP unreactive phosphorus
K potassium Zn zinc
References
Haygarth, P.M. and Jarvis, S.C. (1999) Transfer of phosphorus from agricultural soils. Advances in
Agronomy66, 195–249.
Haygarth, P.M. and Sharpley, A.N. (2000) Terminology for phosphorus transfer. Journal of
Environmental Quality29, 10–15.
Haygarth, P.M., Heathwaite, A.L., Jarvis, S.C. and Harrod, T.R. (2000) Hydrological factors for phos-
phorus transfer from agricultural soils. Advances in Agronomy69, 153–178.
Agric., Hydrol. - 00 Prelims 9/9/02 9:29 AM Page 1
Introduction: an Interdisciplinary Approach for
Agriculture, Hydrology and Water Quality
In the short time since we started the pro- transport; and (iii) impacts and case stud-
duction of Agriculture, Hydrology and ies from around the world.
Water Quality, interest in the subject has During the editorial process we were
already increased. In the USA, Congress able to identify some emerging areas of
has been called to strengthen the Clean interest and importance:
Water Act, with polluted runoff being
1. The increasing interest in soil biology
described as the ‘most pervasive problem
and organic forms of particularly N and P
in the coastal marine environment’
in soil and water; traditional thinking has
(Schlein and Yum, 1999). Most recently,
been dominated by inorganic chemistry
the European Commission and the
(Chapters 1 and 2).
European Parliament have confirmed the
2. The terrible cost of salinization in
Water Framework Directive, which aims to
Australia (Chapter 21).
achieve ‘good water status’ in all European
3. Discrete soil erosion problems con-
countries by 2010.
tributing to long-term sediment transfers
This volume is aimed at undergradu-
and river sedimentation, presenting dual
ates, postgraduates, researchers and policy
problems of: (i) impaired freshwater ecol-
makers in all related areas: the science is
ogy; and (ii) ‘carrying’ other contaminants
complex and, by its nature, interdiscipli-
such as pathogens, persistent organic pol-
nary. Herewith was the challenge, with the
lutants and P (Chapters 2, 4, 6 and 7).
aim of drawing in researchers from differ-
4. Problems of manure production, storage
ent fields and different spheres of under-
and land application, confounded by con-
standing. Agronomists, aquatic ecologists,
flicts of N versus P management priorities
chemists, hydrologists and soil scientists
(Chapters 3 and 8).
all have perspectives that are different, but
5. The rise in farm soil P levels in some
of equal value. The aim of this book has
intensive agricultural regions, representing
been to bring these disciplines together, to
a potential reservoir that may contribute to
work towards an improved understanding
water problems in the future (Chapter 19).
of the processes involved and impacts of
agriculture on water. Our first priority was Uncertainty will always be a factor in
to establish a logical way of developing a the complexity of the various features of
structure. The result is a separation into the system. We are students of a ‘real
the three sections: (i) agriculture as a world’ where climates, rainfall and soils,
potential source; (ii) hydrology as the among others, are varied; controlled and
1
Agric., Hydrol. - 00 Prelims 9/9/02 9:29 AM Page 2
2 Introduction
replicated experimental catchments do not case (see, for example, Chapters 1, 9, 16, 17
exist. Because of these difficulties, the sub- in relation to N effects and Chapters 2, 9,
ject is especially vulnerable to the prolifer- 16, 17, 19 in relation to P effects). In the
ation of ‘anecdotal’ at the expense of practical sense, it is easy to understand
‘scientific’ evidence, which can become why reducing fertilizer inputs is thought to
self-perpetuating and lead to misunder- be a more effective mitigation strategy
standings. Take, for example, the problems than, for example, controlling irrigation
of P transfer from land to water: the impact water flow on to and over the soil.
may be universal (i.e. eutrophication and However, while this may be appropriate for
the associated problems in waters) but it some issues (N for example) a concern is
would be a mistake to assume there was a that in other instances, such ‘source con-
single global solution. Indeed, the science trol’ wisdom may exist because it is conve-
may vary depending on location, from nient, rather than because of any objective
physical detachment of soil (and attached scientific evaluation. A large source may
P) (e.g. extensively farmed catchments of not necessarily equate to a high impact,
south-east Australia) to the leaching of P especially if issues of scale and connectiv-
following a history of high fertilizer inputs ity are taken into consideration (Haygarth
(e.g. intensively farmed pastures of et al., 2000).
Northern Ireland). In these cases the avail- For these reasons, there is a pressing
able mitigation options are completely dif- need to rationalize the scientific basis of
ferent; thus a solution in one part of the land management and its impacts down-
world cannot be transposed to another stream, through a holistic perspective
region. We need to become more aware of (Haygarth and Jarvis, 1999). We hope that
such differences and establish scientific the assembly of these 22 chapters in
principles that transcend regional and Agriculture, Hydrology and Water Quality
causal differences. has made a contribution to this process.
Therefore, without an interdisciplinary
approach, these issues become overlaid Philip Haygarth and Steve Jarvis
and muddled. The popular wisdom has Institute of Grassland and
been that reducing the inputs to a farm will Environmental Research, North Wyke
reduce water problems: indeed there are Research Station, Devon
some powerful examples where this is the July 2001
References
Haygarth, P.M., Heathwaite, A.L., Jarvis, S.C. and Harrod, T.R. (2000) Hydrological factors for phos-
phorus transfer from agricultural soils. Advances in Agronomy69, 153–178.
Haygarth, P.M. and Jarvis, S.C. (1999) Transfer of phosphorus from agricultural soils. Advances in
Agronomy66, 195–249.
Schlein, S. and Yum, S. (1999) Polluted runoff called ‘Most Pervasive problem in Coastal Marine
Environment’. Press release (http://www.cmc-ocean.org), Centre for Marine Conservation,
Washington DC.
Agric., Hydrol - Chap .01 9/9/02 9:29 AM Page 3
Section 1
Agriculture:
Potential Sources of Water Pollution
Agric., Hydrol - Chap .01 9/9/02 9:29 AM Page 4
Introduction: Agriculture as a Potential Source
of Water Pollution
Andrew N. Sharpley
USDA–ARS, Pasture Systems and Watershed Management Research Unit, Curtin Road,
University Park, PA 16802-3702, USA
The production of grain and protein has 1999). The result has been greater use of
increased so dramatically since the indus- fertilizers (N and P) and pesticides, and a
trialization of agricultural systems in the greater potential for erosion and runoff
1950s, that supply now exceeds demand in with current land cultivation methods.
most developed countries. This has drawn Studies have shown that modern agricul-
public, political and ultimately research tural systems accumulate nutrients (espe-
attention from issues of food supply to cially from animal feed in manure),
those of maintaining or improving environ- increasing their potential for loss to surface
mental quality (National Research Council, and groundwaters (Haygarth et al., 1998).
2000). With the advent of point source pol- The controlling factors influencing loss
lutant controls in most European and include physical location, chemical specia-
North American countries in the 1970s, tion, fate and environmental availability.
came some improvement in water quality, These must be combined with hydrologic
most notably in the Baltic and North Seas, processes transporting chemicals from a field
Rhine River (Germany), as well as the (where they are perceived as a resource) to
Chesapeake Bay and Great Lakes (USA) point of impact (where they are perceived as
(Sharpley, 2000). Even so, many water a pollutant) (Gburek et al., 2000). Overlaying
quality problems still exist, such as these are the complex interactions of land
eutrophication, elevated groundwater NO(cid:2), management, topography and climate; these
3
siltation of navigational waterways, and act in combination with market forces that
contamination of waters with pesticides, can dictate on-farm management decisions.
heavy metals and pathogens. Thus, the rel- Even so, an awareness of agricultural or
ative importance and role of agriculture, environmental problems and potential solu-
along with urban development, as contrib- tions does not necessarily cause people to
utors to water quality degradation are now change their behaviour to correct such prob-
being questioned (Carpenter et al., 1998). lems. Solutions have to be adapted in practi-
In developed countries, agricultural sys- cal ways to individual circumstances, as
tems have been developed to produce recognized in Australia, where action agen-
cheaper grain and protein on a smaller land cies are investigating the capacity of rural
area. Most agricultural produce (>80%) communities to implement changes to help
from these countries now comes from a few protect soil and water resources (National
farms (<10% of farms) (Withers et al., Land and Water Resources Audit, 1998).
© CAB International2002. Agriculture, Hydrology and Water Quality
4 (eds P.M. Haygarth and S.C. Jarvis)
