In the picture below, that field shows only a little more yellow than the surrounding fields which entertain mainly buttercup. It’s slightly above and to the left of centre.
However, cross the Bletch Brook and climb through one field and this is what confronts you......
I can’t find much about it but this hay meadow is not thick with wild flowers by accident. It is the result of careful management by local farmers. There is plenty of yellow rattle in there which is parasitic to grass.