CPB Nitrate Vulnerable Zone research
Submitting Institution
Harper Adams UniversityUnit of Assessment
Agriculture, Veterinary and Food ScienceSummary Impact Type
EnvironmentalResearch Subject Area(s)
Environmental Sciences: Soil Sciences
Biological Sciences: Plant Biology
Engineering: Environmental Engineering
Summary of the impact
This research discovered that the time of application of animal manure to
the land, for disposal
and as a fertilizer nutrient source, has an important influence on the
risk of water pollution.
Leaching of nitrate from the manure into the soil and thence into
groundwater and surface
water courses (and ultimately into drinking water) was found to be greater
from autumn
compared with spring applications. These findings were used by the
Department for
Environment, Food and Rural Affairs (Defra) when writing the Nitrate
Vulnerable Zones (NVZ)
Regulations. Implementation of these regulations has led to reductions in
the nitrate
concentration of water in the UK.
Underpinning research
- The key research insight was to show that more nitrate leached from
autumn compared
with spring applications of manure. Before this research, there was no
experimental
evidence for the effect of manure timing on nitrate leaching in the UK.
- The research involved field experiments on both arable crops and on
grassland applying
manure at different times of year. Nitrate leaching into the soil was
measured to quantify
the pollution risk from manure application at different times of year.
- The research was conducted from 1994-1997
- The research component at Harper Adams University was led by Dr Paul
Beckwith,
Senior Lecturer in Soil Science (now retired) and involved Paul Lewis
(current HAU staff)
as a Research Assistant. The overall project was led by Dr Ken Smith
(ADAS).
- The context for the research was the need to respond to the EU
Nitrates Directive to
avoid exceeding the EU limit for nitrate concentration, because of the
possible risk to
human health. The Ministry of Agriculture, Fisheries and Food (MAFF, now
Defra)
needed to establish the effects of time of manure application on nitrate
leaching in order
to contribute to a wider body of knowledge on nitrate leaching from
farmland so that the
NVZ Regulations could be devised to ensure compliance with the EU
Nitrates Directive.
The immediate aim of the Regulations was to reduce the nitrate
concentration in surface
and ground waters, and thereby ultimately to influence the concentration
in drinking
water.
References to the research
a. Beckwith CP, Cooper J, Smith KA, Shepherd MA (1998) Nitrate leaching
loss following
application of organic manures to sandy soils in arable cropping. I.
Effects of application
time, manure type, overwinter crop cover and nitrification inhibition. Soil
Use and
Management 14 (3):123-130. DOI: 10.1111/j.1475-2743.1998.tb00135.x
b. Beckwith CP, Lewis PJ, Chalmers AG, Froment MA, Smith KA (2000)
Successive annual
application of organic manures for cut grass: short-term observations on
utilization of
manure nitrogen. Grass and Forage Science 57 (3): 191-202. DOI:
10.1046/j.1365-2494.2002.00317.x
c. Smith KA, Beckwith CP, Chalmers AG, Jackson DR (2002) Nitrate leaching
following
autumn and winter application of animal manures to grassland. Soil Use
and
Management 18 (4): 428-434. DOI: 10.1111/j.1475-2743.2002.tb00262.
Indicators of quality of the research
i. Grant awarded to Dr C.P. Beckwith
Grant title: Nitrate leaching risk from livestock manures (NT1410)
Sponsor: MAFF
Period of Grant: 1994-1997 (36 months)
Value of Grant: £172,137
ii. The above papers have received 80, 11 and 30 total citations in
Google Scholar
respectively (20 November 2013).
Details of the impact
This research was part of the evidence used to formulate Defra policy in
relation to Nitrate
Vulnerable Zones (NVZ). The NVZ Regulations impose legal requirements on
farmers within
NVZs to aid the reduction of nitrate pollution of UK groundwater and
surface waters fed by
groundwater. The NVZs cover about two-thirds of UK farmland. The main
impact has been
to reduce the nitrate concentration in surface and ground waters, since
the NVZ Regulations
were introduced. The research led to the component of the regulations on
timing of manure
application to land, restricting the time when manure could be applied to
avoid autumn
application when nitrate was found in the research to be at greatest risk
of leaching from
manure. The impact of the research and the resulting Regulations has been
demonstrated
in a report by ADAS for Defra based on assessments of nitrate pollution in
2009 and 2010.
Sources to corroborate the impact
a. ADAS (2007) Diffuse nitrate pollution from agriculture — strategies
for reducing nitrate
leaching, ADAS Report to Defra. Available at:
http://archive.defra.gov.uk/environment/quality/water/waterquality/diffuse/nitrate/documents/consultation-supportdocs/d3-inventory-measures.pdf
b. ADAS (2011) Nitrates Directive Consultation Document: Environmental
Impact of the
2009-13 Nitrates Action Programme & of potential further measures.
Available at:
http://www.defra.gov.uk/consult/files/20111220nitrates-directive-consult-evid2.pdf
c. Defra (2008) Environmental Impact of Livestock Production. London:
Defra. Available at:
http://archive.defra.gov.uk/foodfarm/farmanimal/documents/envimpacts-livestock.pdf
d. Chambers BJ, Smith KA, Pain BF (2000) Strategies to encourage better
use of nitrogen
in animal manures. Soil Use and Management 16 (): 157-161. DOI:
10.1111/j.1475-2743.2000.tb00220.x
e. The Nitrate Pollution Prevention Regulations (2008) Statutory
Instrument No. 2349:
pages 9 &12. Available at: http://www.legislation.gov.uk/uksi/2008/2349/contents/made
f. Smith KA, Chambers BJ, Williams JR (2008) Towards sustainable
recycling of farm
manures; in search of practical solutions to technical problems. In T.
Matsunaka and T.
Sawamoto (Eds.) Animal Manure — Pollutant or Resource? Pp. 13-39.
Available upon
request.