Yield and Carbohydrate Content of Blue Grama Grass as Affected by Clipping

This experiment was designed to determine the influence of different intensities of clipping on the yield of herbage and carbohydrate content of roots and crowns of newly seeded stands of blue grama (Bouteloua gracilis).

Abstract

During recent years revegetation of marginal lands in the Great Plains has received considerable emphasis. Research has been done as to several of the factors affecting establishment, but the effects of varying intensities of grazing on new stands have not been thoroughly studied. Any system of grazing that permits frequent removal of herbage and thus retards manufacture and storage of carbohydrates may result in depletion or destruction of the grass (McCarty 1938). This is particularly true of recently seeded ranges. It is imperative that grasses store sufficient food during the growing season to carry them through the winter and to produce initial growth in the spring (McCarty and Price 1942). This experiment was designed to determine the influence of different intensities of clipping on the yield of herbage and carbohydrate content of roots and crowns of newly seeded stands of blue grama (Bouteloua gracilis). Related Studies Hanson and Stoddart (1940), in their studies with bunch wheat grass (Agropyron inerme), found that heavily-grazed plants had 14.3 per cent total carbohydrates while protected plants had 17.7 per cent. Heavy grazing also reduced root systems, seed production, and size and number of plants. Kinsinger (1953), working in west-central Kansas, found a considerable decrease in carbohydrates during the second year of close clipping of native grasses. Sampson and McCarty (1930), working with needle grass (Stipa pulchra), found an inverse correlation between the annual march of the carbohydrates and the growth rate. Accumulation of food was related to low or declining growth velocity and was most active near the close of the annual growth cycle. Grazing or clipping once or twice early in the growth cycle had little if any influence on the total forage yield and did not prevent the accumulation of maximum amounts of carbohydrates in the late part of the growth