Grassland: Selecting indicators of success for grassland enhancement (TIN050)

Soil phosphate index

This is a mandatory indicator. Sites need to be selected very carefully for HK7 to ensure the best chance of botanical enhancement (for further information see note Sward enhancement: selection of suitable sites). There is most chance of successful habitat restoration with a P index of 0-1. Thus this option would normally be used on sites with a P index of 0-1. In a few exceptional circumstances the starting point might be an index of 2. In any event the P index should be known and this will dictate what is set as an indicator of success.

The P index at the interim and end points of the agreement should not rise, whatever it is at the start. Thus if the starting point is a P index of 1 the indicator should be set as 1 or below. For the minority of sites that start with a higher P index the aim would usually be to reduce it to 1 or less during the lifetime of the agreement. Whether this would be achievable would depend on factors such as soil type (less likely on clay soils, more likely on well-drained sandy soils) and on management (more likely to be reduced with hay cutting regime, though soil type would have a greater influence).

If it is not likely that the P index can be reduced to 1 or below within the agreement period it might be that HK7 is not really an appropriate option as the chance of achieving species-rich grassland is low.

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