Spatial and temporal trends in yield map data

As part of the research programme to develop precision farming management guidelines, started in 1995/96 on four sites in England, yield map data were recorded from 1995 onwards. Their trends were used as an input to assist in the development of management strategies, namely applying nitrogen based upon long term (historic) yield data (Welsh et al., 2001a and 2001b). This section gives the simplest analysis of this data showing the variation in yield both i) within the field (spatial), and ii) between years (temporal).