Cover crops contribute to soil quality improvement principally through their decomposition by soil microbes. The products of decomposition, while generally adding to the soil organic matter (SOM) reservoir, benefit the soil in two specific ways, i.e., through soil physical conditioning and through fertility building. The degree of enrichment depends on the quantity and quality of cover-crop biomass. Cellulose-rich plants or plant parts degrade far more rapidly than if they were ligneous – as is the nature of mature grasses (Edwards and Burney, 2005).