The agri-environmental schemes to improve biodiversity in Dutch agricultural landscapes are not effective. A profound study which compares fields with management agreements with common managed fields, finds no positive effects on plant and bird species diversity. Meadow birds like the Lapwing, Oystercatcher, Common Redshank and Black-tailed Godwit - four main target species of management agreements - are even less common in grassland with agri-environmental schemes. Hover flies and bees show modest increases in these fields. These are the main results of a field study conducted by Dr. David Kleijn and Professor Frank Berendse of the Nature Management and Plant Ecology Group of Wageningen University, which will be published in Nature of October 18th. The results indicate there is pressing need for a scientifically sound evaluation of agri-environmental schemes.