The goal of this work was to quantify the effects of eucalypt woodland blocks on the productivity of native pastures. This research was conducted on the Southern Tablelands of New South Wales. Tree planting or retention is seen by many as an important tool in addressing the problems of soil degradation resulting from clearing and pasture improvement that threaten the sustainability of pasture systems. In particular these are dry land salinity and erosion, both of which affect large areas of agricultural lands in the south east of Australia. Whilst native tree cover remains over substantial portions of Australian pasture lands, mainly on steeper slopes and poorer soils, little has been done to measure the effects of trees on pasture productivity and soil fertility on the Southern Tablelands. Previous studies in other areas have shown a range of effects�from facilitation to inhibition�of pasture growth in the presence of trees. Soil fertility beneath trees has been shown by a number of workers to be elevated in comparison with situations in the open. Given that the range of effects may be highly site dependent, application of results from one area to another may not be valid. Thus it is necessary to measure tree effects on a regional scale if results are to be reliable. Pasture productivity was assessed over a two year period on four sites in the vicinity of Bungendore, New South Wales. A pair of plots was selected on each site, one plot in a block of eucalypt woodland, and the other nearby in an exposed, open situation. Plots were chosen to be as similar to each other as possible with the exception of tree cover. Treed plots had a tree basal area of between 10 and 20 m2 ha-1 and plots had an area of 900 m2. Two of the sites were on granitic soils and had a tree cover consisting predominantly of Eucalyptus pauciflora. The remaining two sites were on soil derived from sedimentary rocks with tree cover consisting mainly of E. mannifera, E. dives and E. melliodora. Perennial native pasture species present were similar across all sites, although their relative contributions to standing biomass varied between sites. As the plots were grazed during the period of measurement, productivity and offtake were measured seasonally using exclosure cages on each plot. Pasture standing biomass was assessed using the comparative yield technique. Microclimate was monitored in each plot by automatic weather stations. Soil moisture to a depth of 45 cm was measured by time domain reflectometry using permanent probes in each plot. Ten additional survey plots on each site, covering the range of tree basal area from 0 - 30 m2 ha-1, were assessed each season in the second year for standing biomass, soil fertility and pasture quality; expressed by nitrogen content and dry matter digestibility. Pasture floristics were measured using the dry-weight-rank method. These additional plots were chosen to be as representative of the paddocks as possible. Over the two years that productivity was measured, it was found to be higher under trees than in the open. This was predominantly due to higher winter and spring growth within treed plots. Grazing offtake was also found to be higher under trees, partly accounting for lower standing biomass found in the treed plots. Wind run, evapotranspiration and photosynthetically active radiation were all reduced by the presence of trees. Beneficial effects of shelter from winds may largely explain the higher productivity observed in the treed plots, and could outweigh negative effects of below ground competition and radiation interception by tree canopies at low to moderate tree densities. Soil moisture was not affected by the presence of trees. Soil fertility also did not differ between treed and open plots nor was there any difference in pasture nitrogen content or dry matter digestibility. On the sites where soils were derived from sedimentary rocks, pasture floristics were found to be related to tree basal area. Themeda ausfralis biomass was negatively related to tree basal area, and was partially replaced by large tussock species such as Poa sieberiana and Chionochloa pallida. A reduction of pasture quality resulted, particularly as the latter species is not grazed to any significant extent. Given the desirability of having deep rooted perennial components in grazing lands, the results of this study indicate that it may be possible to utilise trees to assist in preventing or reducing a range of adverse environmental consequences arising from agricultural activities, without unduly compromising pasture productivity. Additionally, the wide range of environmental conditions provided by a mix of treed and open pasture promotes a higher degree of heterogeneity of the herbaceous layer. This may assist in maintaining productivity over a greater range of climatic conditions than would be the case with a more homogeneous pasture.

Condensed tannins (CT) play an integral role in terrestrial nutrient cycling. Despite being the fourth most abundant terrestrial biochemical product, the regulatory processes of tannin production in plants and their subsequent ecological influences are not completely understood. The defining characteristic of CT’s is their affinity for proteins, though they willingly interact with minerals, carbohydrates, and other polyphenolic compounds. Previous tannin investigations in agriculture have centred on bioactivity related to ruminant digestive physiology and pathology. These studies have revealed that CT’s have the potential to increase liveweight gain, wool production, and sheep ovulation rates, prevent pasture bloat, reduce enteric and stockpiled manure greenhouse gas (GHG) emissions, and control gastrointestinal parasites. The present study has explored how tannin-containing resident plant material and applied manure derived from tannin-containing beef cattle diets influences tame forage biomass yield, proximate analysis, and tannin production, as well as residual fall soil nutrient status, in southern Manitoba. To test these hypotheses, we conducted an experiment over two growing seasons (2007-2008) where in the fall of 2007, both tannin-derived (sainfoin, Onobrychis viciifolia) and non-tannin (alfalfa, Medicago sativa) composted beef manures were applied at a rate of 44.8 t/ha in a randomized split plot fashion, including a manure-free control, on a four repetition randomized complete block design which included both tannin-containing and non-tannin containing forage monocultures and mixtures. Plant samples were harvested in two cuts, and soil measurements were taken in the fall of both years. It was found that across all sainfoin treatments, manure origin did not have a significant effect on plant CT concentration, which was extremely variable within treatments and cuts. Over four harvest dates, sainfoin CT concentrations ranged from 14.1 g/kg to 91.9 g/kg in monoculture plots, and 16.6 g/kg to 123 g/kg when grown in a mixture with meadow brome. In most cases, the presence of either manure type did not significantly affect soil nutrient status or forage yield, though results were similarly variable. Using a stepwise regression which included all soil and plant measurements across all cuts and treatments, it was found that NDF (R2 = 0.548) and plant phosphorus (R2 = 0.126) were the only significant model contributors to tannin concentration in sainfoin at P < 0.15. These findings suggest that nutrient effects of beef cattle manure are not realized in either plant or soil in the year following application, and consequently, that tannin agronomy requires longer-term analysis.

No description available.

Condensed tannins (CT) play an integral role in terrestrial nutrient cycling. Despite being the fourth most abundant terrestrial biochemical product, the regulatory processes of tannin production in plants and their subsequent ecological influences are not completely understood. The defining characteristic of CT’s is their affinity for proteins, though they willingly interact with minerals, carbohydrates, and other polyphenolic compounds. Previous tannin investigations in agriculture have centred on bioactivity related to ruminant digestive physiology and pathology. These studies have revealed that CT’s have the potential to increase liveweight gain, wool production, and sheep ovulation rates, prevent pasture bloat, reduce enteric and stockpiled manure greenhouse gas (GHG) emissions, and control gastrointestinal parasites. The present study has explored how tannin-containing resident plant material and applied manure derived from tannin-containing beef cattle diets influences tame forage biomass yield, proximate analysis, and tannin production, as well as residual fall soil nutrient status, in southern Manitoba. To test these hypotheses, we conducted an experiment over two growing seasons (2007-2008) where in the fall of 2007, both tannin-derived (sainfoin, Onobrychis viciifolia) and non-tannin (alfalfa, Medicago sativa) composted beef manures were applied at a rate of 44.8 t/ha in a randomized split plot fashion, including a manure-free control, on a four repetition randomized complete block design which included both tannin-containing and non-tannin containing forage monocultures and mixtures. Plant samples were harvested in two cuts, and soil measurements were taken in the fall of both years. It was found that across all sainfoin treatments, manure origin did not have a significant effect on plant CT concentration, which was extremely variable within treatments and cuts. Over four harvest dates, sainfoin CT concentrations ranged from 14.1 g/kg to 91.9 g/kg in monoculture plots, and 16.6 g/kg to 123 g/kg when grown in a mixture with meadow brome. In most cases, the presence of either manure type did not significantly affect soil nutrient status or forage yield, though results were similarly variable. Using a stepwise regression which included all soil and plant measurements across all cuts and treatments, it was found that NDF (R2 = 0.548) and plant phosphorus (R2 = 0.126) were the only significant model contributors to tannin concentration in sainfoin at P < 0.15. These findings suggest that nutrient effects of beef cattle manure are not realized in either plant or soil in the year following application, and consequently, that tannin agronomy requires longer-term analysis.

152 leaves : ill., photos., tables ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Botany, 1979

Thesis (Ph. D.)--University of Adelaide, Dept. of Soil Science, 1996. / Copy of author's previously published work inserted. Includes bibliographical references (leaves 261-306).

Thesis (M. Ag. Sci.)--University of Adelaide, 1956. / Typewritten copy. Includes bibliographical references.

Thesis (Ph. D.)--Auburn University. / Abstract. Vita. Includes bibliographical references (p. 97-104).

Target of this thesis is the evaluation of the level of reproduction indicators of selected sheep breed Suffolk - raised primarily for meat. Evaluation of indicators has been made on Ing. Jan Houška & his son Jan Houška ml. farm in village Pístina. Evaluation of input data took place in years 2009 - 2012. Needed data has been provided from personal breeding archive of Ing. Jan Houška. Afterwards this data have been confronted with entries from performance recording of Sheep & Goats Breeders Union in Czech Republic in years 2009 - 2012. On the basis of results from performance control in this thesis are compared four indicators: fertilization rate, fertility rate, intensity rate and breeding rate. Next part of the thesis is focused on sheep breeding in ecological farming with emphasis mostly on the form of stabling, nutrition, pasture system and measuring of pasture workload. The thesis is also focused on cultivation of pasture herbage in area of CHKO Třeboňsko. The SWOT analysis is applied on the current state of the homestead in the last part of the thesis.

Made available in DSpace on 2014-06-11T19:23:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-11-22Bitstream added on 2014-06-13T18:50:27Z : No. of bitstreams: 1 navarrovasquez_l_me_jabo.pdf: 340342 bytes, checksum: 91345316793b99279a087fe813dda533 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Os sistemas de manejo alteram a qualidade dos solos, devido à influência da quantidade e da qualidade da matéria orgânica do solo, as quais podem afetar a agregação do solo. O objetivo do presente trabalho foi avaliar a influência de usos do solo no teor de carbono total, substâncias húmicas e na estabilidade de agregados do solo. Os sistemas de uso do solo foram: pastagem, sistema convencional de preparo do solo (PC) e dois sistemas em semeadura direta (SSD), um com sucessão milho/milho (SDMM) e outro com a sucessão soja/milho (SDSM), utilizando como referência de qualidade do solo uma mata nativa (MN). A área de estudo localizou-se em Jaboticabal, SP, em um Latossolo Vermelho eutroférrico. Amostras de solo foram coletadas na camada de 0-0,1 m, as quais foram analisadas quando ao diâmetro médio ponderado (DMP) e ao índice de estabilidade (IEA) dos agregados, teores de C orgânico total (COT), ácidos fúlvicos (AF), ácidos húmicos (AH) e humina (HUM) do solo. O solo sob pastagem apresentou teores de COT e C-AH semelhantes àqueles do solo sob MN. O solo sob pastagem apresentou maiores teores de C-HUM do que o solo sob MN, porém, observou-se resultado contrário nos teores de C-AF. O solo sob pastagem apresentou maiores teores de COT, C-HUM, C-AH e C-AF em relação aos sistemas de uso com SSD e PC. O solo sob pastagem apresentou agregados com tamanhos semelhantes àqueles observados no solo sob MN; porém superiores aos solos sob SDMM e SDSM. O solo sob PC apresentou os menores valores de DMP e IEA e teores de COT e C nas substâncias húmicas. Correlações significativas e positivas foram obtidas entre COT e os índices de agregação (IEA e DMP) em todos os manejos avaliados. Portanto, nesse estudo, a agregação do solo foi governada principalmente pelo COT do solo / The soil management systems change the soil quality, due to the amounts and quality of soil organic matter, which may affect the soil aggregation. The aim of this study was to assess the influence of soil use on organic C content in total soil and in humic substances and the soil aggregation stability. The soil uses assessed were a pasture, conventional soil tillage (CT) and two systems under no-tillage (NT), one with maize/maize succession (NTMM) and other with soybean/maize succession (NTSM). A native forest (natural ecosystem) was used as reference of soil quality. The sites were located at Jaboticabal, Sao Paulo, Brazil, within the same soil, an Eutroferric Red Latosol (Oxisol). The soil samples were collected at 0-0.1 m depth layer and analyzed for aggregates mean-weight diameter (MWD), aggregates stability index (ASI), total organic C (TOC), fulvic acid (C-FA), humic acid (C-HA) and humin (C-HUM). The soil under pasture showed similar TOC and C-HA contents when compared with those from the soil under native forest. The C-HUM content of the soil under pasture was higher than that from the soil under native forest, however, an opposite result was observed in C-FA. The soil under pasture showed higher TOC, C-HUM, C-HA and C-FA when compared with the soils under NT and CT. The soils under pasture and MN were similar within the aggregate sizes (MWD), however, higher than the soils under NTMM and NTSM. The soil under CT showed the lowest MWD and ASI values and organic C contents in TOC and in humic substances. Positive correlations were observed between the COT contents and ASI and MWD values in all sites. Therefore, in this study, the soil aggregation was governed by TOC