End of Project ReportCurrently, advice on nitrogen (N) use for tillage crops employs an index
system based on crop management. However, there has not been a
systematic evaluation of several of its components or of the relevance of
soil tests, alone or in conjunction. The objective of the current study,
therefore, was to evaluate relevant soil management data, various
biological and chemical soil tests, and measurements of Nmin (NH4 +
NO3) in the root profile, for prediction of fertiliser N requirements. The
data used in the study were derived from a data bank of results of field
and laboratory experiments for sugar beet.
The following topics were addressed: selection of regression models based
on soil management criteria; sustainability of contribution of soil N
reserves; limitations of soil tests for N; long-term trends in Nmin and
biomass C; relationship of mineral-N flush with biomass C; relevance of
Nmin with growing-season rainfall; implications of winter rainfall for
residual effects and their justification within the current soil N index.European Union
Structural Funding (EAGGF
