Fig. 2. Proportion of P applied to fields in the catchment for 2010–2011, showing regulated dates of closed periods for spreading organic fertilizers in grey. The proportion of P applied to fields during the closed (C) and open (O) periods for spreading organic fertilizers in October and January Fosbretabulin indicated.Figure optionsDownload full-size imageDownload as PowerPoint slide
The total P load applied to soils across the whole catchment area (excluding deposition by grazing animals) was estimated, assuming similar P management practices on grassland and arable areas flora were not captured in the NMRs as those that were, and assuming no P application to non-agricultural areas. Loads applied were markedly higher in 2010 at 28,768 kg P, or 38.0 kg P ha−1, compared to 2011 at 19,820 kg P, or 26.1 kg P ha−1. It was noted that P is also deposited directly by animals at pasture; however, the focus of the NAP is on field management of fertilizer P. In any event loads applied are likely to be correlated with P deposited.