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Integrating slurry management strategies to minimise nitrogen losses - application rates and method (Slurry-NR) - ES0114

Description
The overall objective of the project is to evaluate the effects of slurry application rate and method (broadcasting and bandspreading/shallow injection) on nitrogen emissions (ammonia, nitrous oxide and nitrate) to the air and water environments. Twenty experiments will be carried out using cattle and pig slurries at 4 sites with contrasting soil and climatic conditions. Experiments will compare ammonia emissions (measured using windtunnels) following slurry broadcasting, bandspreading (arable and grassland) and shallow injection (grassland only) at target rates of 20, 35, 50, 65 and 80 m3/ha. We anticipate that ammonia emissions (as a percentage of the ammonium N applied) will decrease with increased slurry application rate following broadcasting, however, in the case of bandspreading/shallow injection there will be a ‘threshold’ rate above which ammonia emissions will increase rapidly. The project will also quantify any nitrogen ‘pollution swapping’ effects that reducing ammonia emissions through the use of bandspreading/shallow injection may have on nitrous oxide emissions (all sites) and nitrate leaching losses (sandy soils only). The fertiliser N replacement value of the slurry applications will also be measured to quantify effects of the contrasting slurry management practices on crop N recovery.

The results from this project will be used to develop application rate and method guidelines to minimise nitrogen emissions following the broadcasting and bandspreading/shallow injection of slurry, and to quantify the effects of ammonia abatement practices on other N loss routes (i.e. N ‘pollution swapping’ issues) to the air and water environments. The information will assist DEFRA in implementation of the EU Directive on Integrated Pollution Prevention and Control, the EU National Ceilings Directive arising from the EU Acidification Strategy, N protocol of the UNECE Convention on Long-Range Transboundary Air Pollutants, EC Nitrates Directive and the Kyoto Protocol for reducing greenhouse gas emissions. The work also supports DEFRAs policy objectives of quantifying and limiting nitrogen losses from agricultural land, and improving the utilisation of nitrogen from farm manures as part of sustainable farming systems.
Objective

The overall objective of the project is to evaluate the effects of slurry application rate and method (broadcasting and bandspreading/shallow injection) on total and the balance of nitrogen emissions (ammonia, nitrous oxide and nitrate) to the air and water environments, and slurry fertiliser nitrogen (N) replacement values. The project will measure ammonia emissions following the application of cattle and pig slurries to arable land and grassland, at four sites with contrasting soil and climatic conditions. Nitrous oxide emissions will be quantified on each experiment and nitrate leaching measurements will be made following autumn applications to sandy soils. In more detail, the study objectives are:

1. To determine optimum slurry application rates to minimise ammonia emissions following the broadcasting and bandspreading/shallow injection of farm slurries.
2. To quantify ammonia loss reductions achieved by the bandspreading and shallow injection techniques at a range of application rates compared with conventional surface broadcast application.
3. To quantify the effect of broadcasting and bandspreading/shallow injection of farm slurries on nitrous oxide emissions across a range of soil types
4. To quantify the effect of broadcasting and bandspreading/shallow injection of farm slurries on nitrate leaching losses from sandy soils
5. To quantify the effect of broadcasting and bandspreading/shallow injection on the fertiliser N replacement value of farm slurries.
6. To construct N balances for the surface broadcast and bandspread/shallow injected slurry applications
7. To provide application rate and method guidelines for minimising N losses following the broadcasting and bandspreading/shallow injection of farm slurries.

Project Documents
• FRP - Final Report : ES0114 SID5   (812k)
Time-Scale and Cost
From: 2002

To: 2007

Cost: £1,128,045
Contractor / Funded Organisations
ADAS UK Ltd.
Keywords
Air Pollution              
Ammonia              
Environmental Protection              
Nitrate              
Pollution              
Water Pollution