Seasonal Fluctuations of Blue Grama Roots and Chemical Characteristics

Abstract

Root collections of blue grama (B. gracilis (H.B.K.) Lag.) were made at intervals near Manyberries, Alberta [Canada], over 3 yr. Root samples, after being weighed, were analyzed for C, N, ethanol/benzene-extractable C, methoxyl groups, lignin, soluble and structural carbohydrates, and calorific value. Significant fluctuations occurred over the seasons for all characteristics. Over 50% of the root mass was lost in Oct.-May. This occurred regardless of soil moisture levels. The relationship of (C:N) (percent lignin)/(percent carbohydrate-0.5) showed significant differences between the roots collected in the fall and those collected in spring and early summer. The chemical composition of the roots in the fall may have to be considered in explaining root mass losses in Oct.-May.