Defra - Department for Environment, Food and Rural Affairs.

Science Search

Science and Research Projects

Return to Science Search homepage   Return to Project List

Re-examination of existing data on N mineralisation and the construction of a database to analyse existing and new data - NT1503

It has proved difficult to predict satisfactorily the rates of mineralization and immobilization of N for specific field situations; this is a serious drawback in providing more precise and field-specific advice to farmers on the fertilizer N requirements of crops, and limits the further development and use of models for C and N cycling. Substantial data exists on fertilizer response trials, in which mineral crop N uptake is measured in both zero N and fertilized treatments; data from such experiments shows how much N has been taken up by a crop, but provides no information on the quantity of N that has been mineralized and subsequently lost. This study will aim to enhance the value of available fertilizer response data, and will be composed of 3 specific objectives outlined as follows: 1. Construction of a database to analyse existing and new data. An interface between the user and a decision support system to evaluate data quality will be developed and incorporated into a database containing categorized data on mineralization and immobilization. Procedures for comparing different types of data on mineralization and immobilization within the decision support system will be developed. A process-based N model (the SUNDIAL model) will be linked to the database and decision support system to allow improved calculation of rates of mineralization and immobilization; 2. Collation of existing data on mineralization and immobilization. A preliminary literature search will be conducted, which will provide the basis for requirements of the decision support system. All available data will be collated and evaluated using the decision support system. Collated data will be stored in the linked database; and 3. Analysis of existing data on mineralization and immobilization. Data from fertilizer response trials where detailed measurements of net or gross mineralization have been made at the same site will be compared within the decision support system. Improved calculations of rates of mineralization and immobilization will be made using the collated experimental data in the SUNDIAL model linked to the decision support system.
Time-Scale and Cost
From: 1995

To: 1997

Cost: £81,137
Contractor / Funded Organisations
Rothamsted Research (BBSRC)
Fields of Study
Fertilisers and Nitrate Pollution