Fig. 2. Retention percentages for an 8-wk incubation of wheat straw and crimson clover, with retention defined as material not passing through a YM1 1000 MWCO ultrafiltration membrane. Values presented are mean values for two replicates; error bars represent one standard deviation. Circles = retention percentage for water-extractable carbon (C_ws) extracted from wheat straw (filled circles) and crimson clover (empty circles). Triangles = retention percentage for Folin–Ciocalteau reactive soluble phenolic compounds (FSP) content of water-extractable C extracts from wheat straw (filled triangles) and crimson clover (empty triangles).