Defra - Department for Environment, Food and Rural Affairs.

Science Search

Science and Research Projects

Return to Science Search homepage   Return to Project List

Detection and quantitification of nitrite in drainage waters from grassland - NT1911

Description
Intensively managed grassland systems may provide opportunities for release of unacceptably high levels of nitrite (NO2-) to surface waters, resulting in detrimental effects on aquatic ecosystems. This study will aim to quantify the extent of NO2- leaving typical pasture soils in south west England. The study will be composed of 4 specific objectives outlined as follows, together with ways in which they might be achieved: 1. Development of sampling and analytical protocols appropriate to the analysis of NO2- in waters. An analytical methodology based on existing described protocols and using flow injection procedures will be developed. A sampling and storage protocol will also be determined in order to avoid problems of transformation in the sample vial during storage; 2. Perform routine measurements of NO2- concentrations in water draining from a number of experimental grassland systems encompassing a range of different N managements. Measurements will be based on the Rowden Drainage experiments with hydrologically isolated plots and will be conducted on a soil type with a hydrological classification which is representative of a large proportion of the soils used for grassland production in lowland Britain. A range of different grassland management systems will be investigated; 3. Provide an estimation of the annual losses of NO2- from these grassland soils during a winter's drainage season. Measurements of NO2- will be made weekly and the cumulative quantities of N leached in this state calculated for the complete drainage system for each of the N management treatments; and 4. Provide periodic measurements of NO2- in a transect of the River Taw and from sectors of the local rivers. Fortnightly samples of local river waters will be taken for analysis of NO2-; these will include a range of sites on the River Taw (from upland through agricultural landscapes) and from selected sites on a number of other local rivers. Results of the study will provide MAFF with baseline information on release of NO2- from UK grassland systems, so that any necessary remedial measures can be developed in accordance with EU standards for water quality.
Time-Scale and Cost
From: 1996

To: 1997

Cost: £19,698
Contractor / Funded Organisations
Institute of Grassland and Environment Research (IGER)
Keywords
              
Fields of Study
Fertilisers and Nitrate Pollution