Journal of Range Management, Volume 51, Number 5 (September 1998)http://hdl.handle.net/10150/6354822024-03-28T11:39:43Z2024-03-28T11:39:43ZJournal of Range Management, Volume 51, Number 5 (September 1998)http://hdl.handle.net/10150/6505712020-12-23T01:26:41Z1998-09-01T00:00:00ZJournal of Range Management, Volume 51, Number 5 (September 1998)
Complete digitized issue.
1998-09-01T00:00:00ZVariations in nutritional quality and biomass production of semiarid grasslandsCorona, M. E. P.de Aldana, B. R. V.Criado, B. G.Ciudad, A. G.http://hdl.handle.net/10150/6440382020-09-24T01:06:07Z1998-09-01T00:00:00ZVariations in nutritional quality and biomass production of semiarid grasslands
Corona, M. E. P.; de Aldana, B. R. V.; Criado, B. G.; Ciudad, A. G.
The effect of the growing season and topographic zone on biomass production, protein content, cell content (CC), lignin, cellulose, hemicellulose, digestibility (DMD), and mineral element concentrations (P, K, Ca, Mg, Na, Mn, Fe, Cu, Zn) were studied in herbage samples collected from semiarid grasslands in Central Western Spain. Protein and mineral contents decreased as the growing season progressed whereas fibre properties tended to increase. Topographic gradient significantly affected peak biomass production, fibre properties, protein and mineral contents. Stepwise multiple regression showed that the prediction of biomass production on these areas was related to cellulose, Na, Fe, and Mg contents in the grassland community whereas fibre properties were mainly predicted by Ca, Na, and Cu. Principal component analysis indicated that the temporal evolution (component II) of the organic variables determined pasture quality whereas most of the variation in mineral content was related to the topographical gradient (component I). Some organic and inorganic parameters may cause deficiencies in cattle grazing en the upper and middle zones, mostly at the end of the growing season. The data suggest that information about the temporal and spatial variations of the production and nutritional quality of semiarid grassland is necessary for making correct management.
1998-09-01T00:00:00ZTechnical Note: Rainfall simulator runoff hydrograph analysisFrasier, G. W.Weltz, M.Weltz, L.http://hdl.handle.net/10150/6440322020-09-24T01:05:13Z1998-09-01T00:00:00ZTechnical Note: Rainfall simulator runoff hydrograph analysis
Frasier, G. W.; Weltz, M.; Weltz, L.
Rainfall simulators have been used more than 50 years to evaluate hydrologic parameters. The generated runoff hydrograph is a continuous integration of all factors that affect runoff flow. The complexity and interaction of site factors on runoff and infiltration processes makes it difficult to identify a single component of the hydrograph that accurately characterizes the entire runoff event. A technique was developed to separate the runoff hydrograph into segments representative of different portions of the flow event. Each segment grouping is analyzed for treatment and/or site factor differences or influences on the runoff. Comparing the treatment or site impacts on each hydrograph component allows a more detailed interpretation of the runoff and infiltration processes. This approach to runoff hydrograph analysis makes it possible to quantitatively assess differences in rainfall simulator runoff results and provide insight into why hydrographs may be similar or different.
1998-09-01T00:00:00ZTechnical Note: A rotary seed processor for removing pubescence from seed of prairie grassesVogel, K. P.Masters, R. A.Callahan, P. J.Grams, K.http://hdl.handle.net/10150/6440302020-09-24T02:30:22Z1998-09-01T00:00:00ZTechnical Note: A rotary seed processor for removing pubescence from seed of prairie grasses
Vogel, K. P.; Masters, R. A.; Callahan, P. J.; Grams, K.
Many of the perennial prairie grasses that are used in restoration plantings in the central Great Plains have seed appendages such as awns and pubescence that make seed now through planters difficult. We have developed a rotary seed processor that efficiently processes small breeder or experimental lots of seed that can then be easily planted with small plot cone planters or conventional planters. The processor consists of a metal cylinder that is lined with corrugated rubber and a rotating center shaft with rubber paddles. Processing can be controlled by varying shaft rotation speed and processing time. A top-opening, full length trap door allows for easy loading and the cylinder can be inverted to dump out processed seed. The processor has been used successfully for several years on big bluestem [Andropogon gerardii Vitman], indiangrass [Sorghastrum nutans (L) Nash], little bluestem [Schizachyrium scoparium (Michaux) Nash], prairie sand reed [Calamovilfa longifolia (Rook.) Scribner] , and blue grama [Bouteloua gracilis (Willd. ex Kunth) Lagascaex Griffiths] seed. By removing seed appendages and pubescence, seed bulk is reduced and seed density and flow ability are improved. The processing operation is relatively gentle and seed germination per unit weight of seed is improved.
1998-09-01T00:00:00Z