Unimproved grassland comprises areas that have never been cultivated, fertilised or subjected to pesticides and herbicides. In the Chilswell Valley there is an area of calcareous grassland with over 130 species of wild flowers present including bee, common spotted and pyramidal orchid and the local wild liquorice astragalus glycyphyllos. There are also 21 species of butterfly recorded in the valley. Lowland calcareous grassland is well draining and often shallow and infertile. It generally occurs in warmer, drier areas and is one of the UK’s rarest and most threatened habitats.

As indicated on the plan there are also two areas of unimproved neutral grassland located below Harcourt Wood along the nature trail from the golf club. These areas are dominated by grasses but are relatively herb rich. Grasses present include meadow foxtail alopecurus pratensis, false oat grass arrhenatherum elatius, crested dogstail cynosurus cristatus, cocksfoot dactylis glomerata, meadow fescue festuca pratensis and tufted hair grass deschampsia cespitosa. Parts of the area are overgrazed and thistles cirsium sp and docks rumex sp become the dominant herbs amongst the short sward (CRC,1995).

Semi improved grassland has been previously cultivated and managed but has now been recolonised by native plant species. This may have resulted from the land being of marginal value due to its low fertility where the increasing need for additives reduced the profit made by intensive farming methods. Increasing areas of land throughout the UK are now being included into this category with the reduced demands for agricultural land arising from the Common Agricultural Policy (CAP) of the EU. Examples of such land in the parish comprise those fields alongside the southwest side of the A34 as indicated below.

Towards Harcourt Wood the area consists of semi improved neutral grassland with grasses dominating and less herbs than the adjoining unimproved areas referred to above. Grasses present include false oat grass, perennial rye grass lolium perenne, cocksfoot, meadow fescue and Yorkshire fog holcus lanatus. In the wetter areas rushes juncos sp and particularly hard rush juncos inflexus are present. Other fields closer to the golf course access road were used as arable land but this was converted to set aside for the last ten years and has now acquired an interesting selection of grasses including tufted hair grass deschampsia caespitosa. Parts of the area are dominated by thistles cirsium arvense and cirsium vulgare and docks rumex sp with other herbs typical of ex arable land apparent, such as prickly lettuce lactuca serriola, ragwort senecio jacobaea, mugwort artemisia vulgaris, cow parsley anthriscus sylvestris and hogweed heracleum spondylium (CRC,1995) .

Improved grassland is that land subjected to herbicides and pesticides, fertilizer, drainage or irrigation and grazed, ploughed or otherwise changed from the original unimproved state. The golf course area which was formerly arable land was developed in the early 1990’s is a typical improved grassland area. Subject to constant mowing and cutting and the application of herbicides especially on the tees and greens the main fairways are of limited attraction to wildlife. There are however many areas of “rough’ (long grass) alongside the fairway which in some cases extend to areas of semi improved ground that offer more opportunities for wildlife and native plants to survive. The presence of breeding skylark and meadow pipit are good indicators of wildlife suitability in this area.

Other improved grassland comprises many large fields of pastureland located on the lower flood plain closer to the Hinksey Stream. These are often flooded with overspill water from the River Thames during the winter but are used to grow grass for hay making or grazing of cattle during the summer.