The effects of phosphorus fertilization on the growth and survival of Liatris pycnostachya, Physostegia virginiana, and Sporobolus heterolepis seedlings were examined in a prairie restoration project. Treatment included fertilizing once at the time of planting. Plant responses were measured on two soil types, Bono (very high phosphorus levels, lower and flatter) and Morley (very low phosphorus levels, on a slight hill with some slope). P fertilization did not increase the growth of any species on either soil type, although results may have been limited by the effects of surrounding plant competition. Only one significant difference in plant growth was observed between fertilized and unfertilized plots; control Liatris pycnostachya and Physostegia virginiana in the Bono soils produced more shoots than fertilized plants of the same species. P- fertilized Liatris pycnostachya in Morley soil had significantly higher survivorship than unfertilized plants. In contrast, P-fertilized Physostegia virginiana in the Bono soil had the significantly lower survivorship than unfertilized plants. For the other species on either soil type, the survivorship was not significantly different. Because P-fertilization produced very limited benefit, and even adverse plant responses in some cases, the recommendation of this study is that P-fertilization should not be applied at the time of planting of prairie restoration projects. / Department of Biology

The objective of this study was the evaluation of grass silage made from P. maximum cv. Gatton (P. maximum) and Digitaria eriantha spp. eriantha (Smutsfinger) grass. The study was conducted in two phases. In phase one the influence of sugar (molasses) addition, wilting, growth stage and plant species, on the quality of the silages obtained, were investigated. Three growth stages were incorporated, an early (physiologically young), medium (boot) and late (full bloom) stage. Four different treatments were applied during ensiling, namely direct cut, direct cut + sugar, wilted and wilted + sugar. The second phase comprised of a partial digestibility study to evaluate the differences between plant species and growth stage, within a specific treatment. The silages used were made from the medium and late growth stages, where prior wilting and sugar addition occurred. The addition of sugar during ensiling, even with prior wilting, had a positive effect on silage quality, leading to a lower pH, ammonia-nitrogen concentration and a higher lactic acid concentration in the silage. These effects were less pronounced with the plant material ensiled at a late growth stage. These silages tended to undergo secondary fermentation between day 21 and day 120, when sugar was added. When comparing the three growth stages, within the direct cut + sugar and wilted + sugar treatments, the following was observed. The silages made from early and medium growth stages tended to be of better quality compared to the silages made from the late growth stage. In most of the comparisons the silages made from the medium growth stage were of a better quality than that of the silages made from the younger plant material. In the comparison between P. maximum and D. eriantha silages, the silages made from P. maximum grass tended to be of a better quality than that made from D. eriantha grass. The difference between the two species was smaller than the differences observed between growth stages within a specie. In the partial digestibility study, there was a difference in OMI, with sheep receiving the late growth stage silages having higher intakes. When expressed as DOMI / W0.75 no significant differences were observed between the four diets. There were no significant differences in the total digestibility of OM across the four diets. There were differences in the rumen ammonia and VFA's concentrations across the diets. There was a significant difference in the intake of nitrogen across the four diets, resulting in differences in the disappearance of nitrogen, ammonia and non-ammonia-nitrogen across the four diets. There was no difference in the total true nitrogen digestibility across the four diets. / Dissertation (MSc Agric (Animal Nutrition))--University of Pretoria, 2006. / Animal and Wildlife Sciences / unrestricted

Study was conducted to evaluate in vitro digestibility of native warm-season grasses. Three grasses were used: big bluestem (Andropogon gerardii Vitman), little bluestem (Schizachyrium scoparium Nash), and indiangrass (Sorghastrum nutans Nash). There were no differences in NDF, ADF, FAT and OM of the three grass species. However, DM, hemicellulose and CP were slightly different in the three grass species. Also, the frequency nested in cutting effects was determined. In vitro dry matter disappearance of big bluestem, little bluestem and indiangrass was evaluated to determine rate of disappearance. The 100 % indiangrass revealed the greatest rate of disappearance for IVDMD and 100 % little bluestem grass the least, respectively. However, that of other proportion mixtures of treatments and 100 % big bluestem grass were in between. There were no differences in in vitro neutral detergent fiber disappearances among treatments.

Research was conducted in Sri Lanka to study the effects of growth stage, chopping length and additives on ensiling characteristics of Guinea-'A' (Panicum maximum - Ecotype-'A') and NB-21 (Pennisetum purpureum Schumac x Pennisetum americanum). The forages were harvested 1, 2 and 3 wk after growth, chopped and ensiled in small laboratory silos (3 liter cardboard cylinders double lined with polyethylene bags) alone or with additions of cassava tuber meal, coconut oil meal and formic acid. Cutting grass at 1 wk increased (P<.05) acetic and lactic acid of silage, compared to 3 wk. Addition of cassava tuber meal and coconut oil meal increased (P<.05) lactic acid and decreased (P<.05) pH and acetic acid of silage, compared with the control. The effects were greater for cassava tuber meal. In a second study 3-wk growth of Guinea-'A' grass was hand chopped to 1.5, 7.5 and 15 cm, and ensiled in small laboratory silos. Lactic and acetic acid of silage increased (P<.01), whereas dry matter loss and pH decreased (P<.05) with fineness of chop. In a third study, 2 and 3 wk growths of Guinea-'A' were harvested and ensiled in 210 liter metal drums, double lined with polyethylene bags, chopped or unchopped. Cutting grass at 2 wk decreased (P<.05) pH and increased (P<.01) lactic acid, compared to 3 wk. Chopping decreased (P<.05) the pH and increased (P<.05) lactic acid and acetic acid of silage. Experiments were also conducted to study the digestibility and palatability by sheep of Guinea-'A' silage prepared in the third study. Apparent digestibility of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) were higher (P<.01) for 2 wk compared to 3-wk growth. Chopping the grass before ensiling increased (P<.01) the apparent digestibility of DM, CP, NDF, ADF and hemicellulose. No significant differences were observed for DM intake by sheep due to the growth stage, but chopping increased (P<.01) DM intake by 17%. Lengthening the cutting interval of Guinea-'A' and NB-21 resulted in linear increases (P<.01) in DM yield. / Ph. D.

Call number: LD2668 .T4 1958 O65

Call number: LD2668 .T4 1979 M78 / Master of Science

For the successful reclamation of disturbed land, the reduction of initial erosion risk must be balanced with later vegetation establishment. A combination of erosion control and revegetation practices was researched using commercial (full-sized) equipment on a semi-desert grassland site in southern Arizona, USA. Two soils with different parent materials were used to add a 30 cm cap on sites at two elevations: 1646 and 1403 m asl. There were two surface roughness treatments: smooth and rough. Three straw mulch treatments were applied: no mulch, mulch incorporated into the surface soil, and mulch tackified onto the surface. Plots were planted with a 10 species native mix dominated by perennial grasses. After two growing seasons, the incorporated mulch treatment resulted in significantly more seeded grass aboveground biomass than the no mulch treatment while the no mulch treatment had more forb and volunteer biomass than the surface mulch treatment. There was significantly higher erosion on the rough surface treatment compared to the smooth surface. Increasing perennial grass biomass was correlated with reduced erosion while forb and volunteer biomass showed no relationship with erosion. The smooth surface with surface mulch best established perennial grasses, minimized weeds, and reduced erosion. This combination of practices both minimized erosion as well as maximized vegetation establishment. (C) 2016 The Authors. Published by Elsevier B.V.

Thesis (MSc)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: The microbial degradation of the lignin carbohydrate complex of plant material is only partially understood. Lignin carbohydrate complex was extracted from wheat straw and subsequently analysed. An adjustment to the standard protocol was required to increase the amount of lignin carbohydrate complex extracted from wheat straw. Characterization of the lignin carbohydrate complex after trifluoacetic acid hydrolysis was done by capillary electrophoresis. HPLC proved ineffective, as baseline separation could not be achieved. Characterization of the lignin carbohydrate complex revealed that a large portion (68 %) consisted of carbohydrate and lignin (20 %). Capillary electrophoresis of the trifluoroacetic acid hydrolysates of the lignin carbohydrate complex revealed that the carbohydrates consisted of mannose, xylose, arabinose, galactose, glucose and rhamnose. The major monosaccharide present in the lignin carbohydrate complex was mannose which made up 34 % of the total carbohydrate composition. Ferulic and p-coumaric acid were present in the lignin carbohydrate complex, but in concentrations less than 1 % of the lignin carbohydrate complex. The lignin carbohydrate complex of wheat straw probably had a heterogenous structure consisting of a variety of molecules, as molecular weight determination could not be accurately determined. An estimated molecular weight of 5.9 kOa was determined. Ten fungal strains (Aspergillus niger, Aureobasidium pul/u/ans, Bjerkandera adusta, Corio/us versicolor, Lenzitus betu/ina, Phanerochaete chrysosporium, Pycnoporus coccineus, Pycnoporus sanguineus 294, Pycnoporus sanguineus K5-2-3 and Trichoderma reeseï; were evaluated for growth on the lignin carbohydrate complex. All strains except B. adusta showed growth after 5 days with A. niger, A. pul/u/ans, C. versicolor, P. chrysosoporium and T. reesei showing the best growth on the lignin carbohydrate complex. The culture fluid revealed a number of proteins secreted by these organisms. The protein determination was confirmed by SOS-PAGE which revealed an array of proteins ranging from 8 kOa to 180 kOA. Prominent bands between 26 kOa and 80 kOa could be observed in the culture fluid of A. niger, A. pul/ulans and T. reesei, but not in C. versicolor. Activity studies on the culture fluid of these four strains revealed activity for xylanase, xylosidase, arabinofuranosidase, ferulic acid esterase and laccase, with vast differences between the activities of the various fungi. The enzymes of these fungal strains were also evaluated for their ability to degrade xylan and sugar cane bagasse using capillary electrophoresis. It appeared that all the organisms produced enzymes to degrade birchwood xylan. However, the electropherograms revealed that the degradation patterns of birchwood xylan differed among these organisms over the same time interval, as xylotetraose, xylotriose, xylobiose and xylose were released in various concentrations. The electropherograms obtained from the enzyme hydrolysates of sugar cane bagasse, pointed to the substrate being inaccessible. Electropherograms of the culture fluid of A. niger, A. pul/ulans, C. versicolor and T. reesei, when incubated on the lignin carbohydrate complex indicated similar peaks to those obtained and identified in the trifluoroacetic acid hydrolysates. However, the electropherograms of the culture fluid of these organisms revealed additional smaller peaks which could not be identified. The electropherograms of the culture fluid of the various organisms also indicated a complete release of some sugars, using the trifluoacetic acid hydrolysate of the lignin carbohydrate complex as a control for the amount of sugars present. HPLC analyses revealed that after 72 h, no apparent degradation of the lignin carbohydrate complex took place as peak height and areas appeared to be similar. These peaks could however not be identified due to a lack of standards as well as baseline separation which could not be achieved. / AFRIKAANSE OPSOMMING: Tans word die mikrobiese afbraak van die lignienkoolhidraatkompleks van plant materiaal slegs gedeeltelik verstaan. Lignienkoolhidraatkompleks was vanaf koringstrooi geïsoleer en gevolglik geanaliseer. Daar moes van die standaard prosedure vir die ekstraksie van lignienkoolhidraatkompleks afgewyk word ten einde beter lignienkoolhidraatkompleks opbrengs te lewer. Karakterisering van die lignienkoolhidraatkompleks na trifluoroasynsuurvertering was deur kapillêre elektroforese bepaal. Dit wou voorkom asof kapillêre elektroforese "n beter opsie vir die analise van die verteerde monster van lignienkoolhidraatkompleks is, vergeleke met hoëdruk vloeistof chromatografie. Daar was gevind dat die lignienkoolhidraatkompleks uit 68 % koolhidraat en 20 % lignien bestaan. Kapillêre elektroforese het die teenwoordigheid van die volgende suikers bevestig naamlik, mannose, xilose, arabinose, glukose, galaktose en ramnose. Mannose was die dominerende suiker in die lignienkoolhidraatkompleks wat 34 % van die totale koolhidraat opbrengs uitgemaak het. Ferulien- en p-kumaarsuur kon ook identifiseer word, maar die twee sure het minder as 1 % van die totale inhoud van die lignienkoolhidraatkompleks uitgemaak. Vanuit resultate bekom wil dit voorkom dat die lignienkoolhidraatkompleks "n heterogene molekuul is omdat die molekulêre gewig daarvan nie akkuraat bepaal kon word nie. 'n Geskatte molekulêre grootte van ongeveer 5.9 kDa was bepaal met verwysing na die hoogste piek wat in die chromatogram waargeneem was. Tien fungus kulture was in die studie gebruik om hul vermoë te toets om op die lignienkoolhidraatkompleks te groei, naamlik Aspergillus niger, Aureobasidium pullulans, Bjerkandera adusfa, Goriolus versicolor, Lenziius betuline. Phanerochaefe chrysosporium, Pycnoporus coccineus, Pycnoporus sanguineus 294, Pycnoporus sanguineus K5-2-3 en Trichoderma reesei. B. eauste het nie groei na 5 dae getoon nie, en dit wou voorkom asof A. niger, A. pul/ulans, G. versicolor, P. chrysosoporium en T. reesei die beste kon groei op die substraat na 5 dae. Die kultuurvloeistof van die vier kulture het getoon dat proteïene deur hierdie organisms uitgeskei was. Hierdie proteinbepaling was ook bevestig deur SOS-PAGE, wat bande tussen 8 kDa en 180 kDa gelewer het. Prominente bande tussen 26 kDa en 80 kDa kon waargeneem word in die kultuurvloeistof van A. niger, A. pul/ulans, en T. reesei, maar nie in die kultuurvloeistof van C. versicolor nie. Aktiwiteitstudies op die kultuur vloeistowwe het getoon dat daar aktiwiteit was vir die volgende ensieme, naamlik xilanase, xilosidase, arabinofuranosidase en feruliensuur esterase. Hierdie aktiwiteit het aansienlik verskil tussen die verskillende organismes. Die ensieme van die vier organismes was ook gebruik om hul vermoë te toets om xilaan en suikerriet af te breek. Daar was gevind dat xilaanafbraak verskillend was vir die organisms oor dieselfde tydperk. Xilotetraose, xilotriose, xilobiose en xilose was in verskillende konsentrasies gevind vir die verskillende organismes. Die elektroferogramme van die kultuurvloeistof op suikerriet van die verskillende organismes het getoon dat die substraat nie toeganklik vir die ensieme was nie. Die elektroferogramme van die kultuurvloeistof op lignienkoolhidraatkompleks van die verskillende organismes het dieselfde pieke getoon soos geïdentifiseer in die elektroferogramme van die trifluoroasynsuur vertering. Die elektroferogramme met die ensiem vertering het egter addisionele pieke getoon wat nie sigbaar op die elektroferogramme van die trifluoroasynsuur vertering was nie. Hierdie pieke het min of meer dieselfde tyd ge-elueer as die monosakkariede. Kapillêre elektroforese het ook getoon dat die ensiematiese afbraak van die lignienkoolhidraatkompleks gelei het tot algehele vrystelling van sommige suikers, wanneer die trifluoroasynsuur vertering as maatstaaf dien vir die hoeveelheid suikers teenwoordig in die lignienkoolhidraatkompleks. Hoëdruk vloeistof chromatografie het getoon dat geen sigbare afbraak na 72 h van inkubasie met die ensieme op die lignienkoolhidraatkompleks plaasgevind het nie aangesien die piek hoogtes konstant gebly het. Hierdie pieke kon egter nie geïdentifiseer word nie as gevolg van lae resolusie van die pieke asook standaarde wat nie beskikbaar was nie.

Despite the agronomic benefits of exotic grass plantings for pasture and rangeland forage, exotic grass invasions are capable of having dramatic and widespread impacts on native communities and ecosystems. Exotic Old World bluestem grasses (OWBG; Bothriochloa and Dichanthium spp.) have become increasingly invasive throughout the central and southern U.S. Little is known regarding the impacts of OWBG invasion on native grassland and savannah ecology and how to successfully control OWBG invasions in natural areas. Accordingly, this dissertation research had several objectives: 1) Evaluate the efficacy of herbicide and/or disking to control OWBG; 2) Assess the relative competitive ability of the OWBG, Kleberg bluestem (Dichanthium annulatum); 3) Evaluate herbicide application and native grass seeding to rehabilitate an OWBG invaded coastal prairie; 4) Examine whether ecosystem function differs between areas dominated by OWBG vs. native coastal prairie; and 5) Characterize the germinable soil seed bank of an OWBG invaded coastal prairie. Herbicide treatments of imazapyr, glyphosate, and imazapyr + glyphosate were found to provide effective, albeit temporary, OWBG control (often less than six months). A combination regimen of disking followed by herbicide treatments, regardless of herbicide active ingredient or application rate, controlled OWBG more effectively than herbicide alone or herbicide followed by disking. Herbicide treatments followed by native grass seeding did not markedly rehabilitate coastal prairie invaded by OWBG. OWBG appeared to reinvade from the seed and/or bud bank suggesting the restoration of OWBG invaded grasslands will likely require aggressive and repetitive control methods to completely extirpate OWBG at a given site before native plantings occur. A seed bank survey revealed the density of OWBG germinable seeds increases dramatically with increasing OWBG invasion (i.e., canopy cover) while the native grass seed bank is generally depauperate even when levels of OWBG invasion were low. Dominance of OWBG appears to have altered native coastal prairie ecosystem function; yet the directionality and extent of OWBG effects were strongly soil texture dependent. Here, ecosystem function parameters between areas dominated by OWBG compared to native prairie differed most often on sandy loam vs. clay soil. Moreover, DeWit replacement series experiments revealed the relative competitive ability of Dichanthium annulatum was significantly greater than the native grass, little bluestem (Schizachyrium scoparium). OWBG will likely persist throughout the central and southern Great Plains, USA, for years to come and intensive management efforts will be necessary to keep OWBG invasions under control in natural areas of high conservation value.

Biomass, cover, density, height and concentrations of N, P, C, Fe, Mn, Cu and Zn were evaluated in Sporobolus cryptandrus and Eragrostis lehmanniana at flowering and at seed ripening stage to determine whether these attributes are affected by the type of litter used or by litter treatment. Annual rye, California poppy and rye-poppy mixture were the sources of litter while litter treatments included removing organic residue, leaving organic residue standing or roto-tilling organic residue into the surface soil. The effect of litter type and litter treatment on the soil was evaluated. A parallel greenhouse experiment was carried out. Results indicate that California poppy contained a higher level of all nutrients studied compared to annual rye and contained about twice the concentrations of N, Mn, Zn and Fe. For both annuals and perennials, the nutrient content generally decreased between flowering and seed ripening with annuals indicating more decline than perennial grasses. The greatest decline was observed for N in California poppy. Field observation confirmed that the non-lignified California poppy shoots broke down faster than culms of annual rye. Biomass production in Sporobolus and Eragrostis was unaffected by litter type. However, for both species the highest biomass was obtained in the tilled treatment. Litter tilling produced more vigorous and healthier plants compared to other treatments. Except for P, nutrient concentrations were largely unaffected by litter type. The highest P concentrations were consistently obtained from perennial plants grown in annual rye plots. Fe and Cu concentrations were consistently higher in the tilled treatment. C and P appeared unaffected by litter treatment. N, Mn and Zn concentrations were more variable and more difficult to categorize. In soil samples, all nutrient concentrations were higher at the end of the study than at the beginning. Litter source appeared to have minimum effect on nutrient concentration while tilled treatment was superior to standing which was superior to the removed treatment.