Do multi species swards grow more dry matter than ryegrass based leys? Are multi species leys more productive than ryegrass based swards under organic and low input systems? These are two of the questions that William and a group of farmers have been trying to answer over the last few years. Whilst many questions remain and challenges will need to be addresses it does seem that multi species herbal leys have an important role to play in both the short term forage output and as a way in the longer term of building soil organic matter. During this workshop we will discuss the importance of quality as well as quantity, and how longer grazing rotations can be used to ensure an extended grazing season and less reliance on conserved forages. We will look at what factors need to be considered in designing a diverse ley mixture. Managing these swards on a mob grazing basis does seem to have enabled soil organic matter to be built up faster than one is normally led to believe.