Swine slurry is a source of nutrients to grasslands. However, accumulation of N or P can lead to their movement to groundwater. This thesis’ research was conducted using a tame pasture fertilized over six years with swine slurry at N-requirement rates, on a gravelly soil in south-eastern Manitoba. Objectives were to determine N and P soil surplus and accumulation over time, soil profile P fractions and soil surface P saturation, and nitrate and dissolved-P in shallow groundwater for treatment combinations of forage utilization (Hay and Grazed), slurry application in spring (Single), split in fall and spring (Split) and no slurry (Control), and Grassed areas of grazed paddocks and Bare areas where cattle congregated around water troughs. There were less surplus and accumulation of extractable-P in the soil surface for the Split compared to the Single treatment because of less P in fall- than in spring-applied manure. With Grazing, there were greater surpluses of N and P than with Haying, and surface accumulation of extractable-P over time was linear being 16.5 and 11.9 mg P kg-1 year-1at 0-5 cm for Grazed and Hay treatments, respectively. Labile inorganic-P fractions (water- and bicarbonate-extractable) increased in the Bare and in the Single Grassed treatments. In the Bare treatment, P-sorption capacity at 0-5 cm decreased compared to the Grassed treatment. The surface soil of the Bare areas had large concentrations of water-soluble-P up to 165 mg P kg-1 associated with an increase in P-saturation to 88 % of the sorption capacity, and nitrate was elevated in the soil profile. Concentrations of nitrate-N and dissolved-P in groundwater were below the environmental thresholds of 10 mg nitrate-N L-1 and 0.025 mg P L-1, respectively, in both the Hay and the Grazed Grassed treatments. In contrast, the Control and Single Bare treatments had nitrate concentrations always above the threshold, and the Bare areas in the Single paddocks had P concentrations of environmental concern in 2009, averaging 0.7 mg total dissolved P L-1. Nitrogen-based slurry applications did not cause leaching of N or P, but Bare areas in grazed pastures are at risk of N and P leaching.

Sequestering atmospheric carbon in soil is an attractive option for mitigation of rising atmospheric carbon dioxide concentrations through agriculture. Perennial crops are more likely to gain carbon while annual crops are more likely to lose carbon. A pair of eddy covariance towers were set up near Winnipeg Manitoba, Canada to measure carbon flux over adjacent fertilized long-term perennial grass hay fields with high soil organic carbon. In 2009 the forage stand of one field (Treatment) was sprayed with herbicide, cut and bailed; following which cattle manure was applied and the land was tilled. The forage stand in the other field (Control) continued to be cut and bailed. Differences between net ecosystem productivity of the fields were mainly due to gross primary productivity; ecosystem respiration was similar for both fields. When biomass removals and manure applications are included in the carbon balance, the Treatment conversion lost 149 g C m^(-2) and whereas the Control sequestered 96 g C m^(-2), for a net loss of 245 g C m^(-2) over the June to December period (210 days). This suggests that perennial grass converted for annual cropping can lose more carbon than perennial grasses can sequester in a season.

Swine slurry is a source of nutrients to grasslands. However, accumulation of N or P can lead to their movement to groundwater. This thesis’ research was conducted using a tame pasture fertilized over six years with swine slurry at N-requirement rates, on a gravelly soil in south-eastern Manitoba. Objectives were to determine N and P soil surplus and accumulation over time, soil profile P fractions and soil surface P saturation, and nitrate and dissolved-P in shallow groundwater for treatment combinations of forage utilization (Hay and Grazed), slurry application in spring (Single), split in fall and spring (Split) and no slurry (Control), and Grassed areas of grazed paddocks and Bare areas where cattle congregated around water troughs. There were less surplus and accumulation of extractable-P in the soil surface for the Split compared to the Single treatment because of less P in fall- than in spring-applied manure. With Grazing, there were greater surpluses of N and P than with Haying, and surface accumulation of extractable-P over time was linear being 16.5 and 11.9 mg P kg-1 year-1at 0-5 cm for Grazed and Hay treatments, respectively. Labile inorganic-P fractions (water- and bicarbonate-extractable) increased in the Bare and in the Single Grassed treatments. In the Bare treatment, P-sorption capacity at 0-5 cm decreased compared to the Grassed treatment. The surface soil of the Bare areas had large concentrations of water-soluble-P up to 165 mg P kg-1 associated with an increase in P-saturation to 88 % of the sorption capacity, and nitrate was elevated in the soil profile. Concentrations of nitrate-N and dissolved-P in groundwater were below the environmental thresholds of 10 mg nitrate-N L-1 and 0.025 mg P L-1, respectively, in both the Hay and the Grazed Grassed treatments. In contrast, the Control and Single Bare treatments had nitrate concentrations always above the threshold, and the Bare areas in the Single paddocks had P concentrations of environmental concern in 2009, averaging 0.7 mg total dissolved P L-1. Nitrogen-based slurry applications did not cause leaching of N or P, but Bare areas in grazed pastures are at risk of N and P leaching.

Understanding the nutrient dynamics of pastures is essential to their profitable and sustainable management.  Tall fescue [Schendonorus phoenix (Scop.) Holub.] is the predominant forage species in Virginia pasturelands.  Although tall fescue pasture is common, little research has attempted to document how soil and herbage nutrient concentrations change through time.  This thesis summarizes two studies conducted within the context of a larger grazing systems project near Steele's Tavern, VA.  The objectives were to: (1) examine temporal changes in plant available soil nutrient concentrations in four grazing systems, (2) determine how hay feeding and use of improved forages affected soil and herbage nutrient concentrations (3) examine the relationship between and variability within soil and herbage nutrient concentrations, (4) analyze the seasonal variation in herbage mineral concentration with regard to beef cattle requirements, and (5) create a statistical model to predict variation in herbage mineral concentration across the growing season.  Analysis of plant and soil nutrients through 5 years of grazing produced several important findings.  Soil pH, P, and Ca, Mg, and B declined through five years of grazing.  Higher concentrations of herbage N and K and soil P, K, Fe, Zn, and Cu were measured in hay feeding paddocks.  Herbage nutrient concentrations showed less variability in P and K than did soil test results.  Fertility testing in pastures is important to monitor changing nutrient concentrations, and this study showed that herbage analysis may provide a more stable and accurate assessment of pasture fertility than soil testing.  Pasture herbage, grown without fertilization, contained sufficient concentrations of macronutrients to meet the requirements of dry beef cows through the growing season and to meet the requirements of lactating beef cows in April.  A model was developed using soil moisture and relative humidity that predicted (R2 = 0.75) variation in herbage mineral concentration throughout the growing season.  As described in this thesis, use of modeling to predict nutrient dynamics in pasture could allow for more efficient mineral supplementation strategies that lead to improved profitability, nutrient retention, and livestock health. / Master of Science

Nutrient exports, in particular phosphorus, are a major problem for Gippsland and many other regions of the world. This thesis investigates the export of phosphorus in overland flow from pasture-based grazing systems in south-eastern Australia. Initially, field-scale monitoring is used to investigate the forms of phosphorus in overland flow with a view to identifying the primary mobilisation process. It is shown that from a well-managed pasture, phosphorus was primarily mobilised as a result of dissolution rather than physical detachment (erosion) processes. Phosphorus in the overland flow is shown to be predominantly in the dissolved reactive form (DRP). It follows that remedial strategies that rely on physically trapping phosphorus entrained in overland flow (i.e. buffer strips and riparian zones) are unlikely to be effective. The field-scale monitoring data are then used to investigate the structure of phosphorus exports. It is shown that the data conforms to a base-plus-increments model. It is proposed that phosphorus exports can be divided into a base or systematic component that results from a particular land use management system, and an incremental or incidental (preventable) component that is the result of particular management decisions, activities or incidents. (For complete abstract open document)

Biserrula pelecinus L. has been introduced to Australia from the Mediterranean region, in the last decade due to many attractive agronomic features. This deep rooted, hard seeded, acid tolerant and insect resistant legume species provides high quality food for cattle and sheep, and grows well under the harsh edaphic and environmental conditions of Australia. In 1994, B. pelecinus was introduced to a site in Northam, Western Australia where there were no native rhizobia capable of nodulating this legume. The introduced plants were inoculated with a single inoculant strain of Mesorhizobium sp., WSM1271. This study investigated whether a diversity of rhizobia emerged over time. A second objective was to investigate the possible mechanisms involved in the diversification of rhizobia able to nodulate B. pelecinus. Eighty eight isolates of rhizobia were obtained from nodules on B. pelecinus growing at the Northam site in August 2000, six years after introduction. These plants were self-regenerating offspring from the original seeds sown. Molecular fingerprinting PCR with RPO1 and ERIC primers revealed that seven strains (novel isolates) had banding patterns distinct from WSM1271 while 81 strains had similar banding patterns to WSM1271. A 1400 bp internal fragment of the 16S rRNA gene was amplified and sequenced for four of the novel isolates (N17, N18, N45 and N87) and WSM1271. The phylogenetic tree developed using these sequences clustered the novel isolates in Mesorhizobium. There were >6 nucleotide mismatches between three of the novel isolates (N17, N18, N87) and WSM1271 while there were 23 nucleotide mismatches between N45 and WSM1271. When B. pelecinus cv. Casbah was inoculated with the novel isolates, five (N17, N18, N39, N46 and N87) yielded <40% of the shoot dry weight of the plants inoculated with the original inoculant (WSM1271). Novel isolates N15 and N45 were completely ineffective on B. pelecinus cv. Casbah. Physiological experiments to test the ability of the novel isolates and WSM1271 to grow on 14 different carbon sources (N acetyl glucosamine, arabinose, arbutine, dulcitol, β-gentiobiose, lactose, maltose, melibiose, D-raffinose, saccharose, L-sorbose, D-tagatose, trehalose and D-turanose) as the sole source of carbon, intrinsic resistance to eight different antibiotics (ampicillin, chloramphenicol, gentamicin, kanamycin, nalidixic acid, spectinomycin, streptomycin and tetracycline) and pH tolerance (pH 4.5, 5.0, 7.0, 9.0) revealed that the novel isolates had significantly different carbon source utilization patterns to WSM1271. However, pH tolerance and intrinsic resistance to antibiotics were similar between the novel isolates and WSM1271 except for streptomycin (100 μg/ml). Novel isolates N17, N18, N46 and N87 were susceptible for this antibiotic while the other novel isolates and WSM1271 were resistant. Host range experiments were performed for the novel isolates N17, N18, N45, N87, WSM1271 and two other root nodule bacteria (RNB) previously isolated from B. pelecinus growing in the Mediterranean region (WSM1284 and WSM1497) for twenty one legumes (Amorpha fruticosa, Astragalus adsurgens, Astragalus membranaceus, Astragalus sinicus, Biserrula pelecinus cv Casbah, Dorycnium hirsutum, Dorycnium rectum, Glycyrrhiza uralensis, Hedysarum spinosissimum, Leucaena leucocephala, Lotus corniculatus, Lotus edulis, Lotus glaber, Lotus maroccanus, Lotus ornithopodioides, Lotus parviflorus, Lotus pedunculatus, Lotus peregrinus, Lotus subbiflorus, Macroptilium atropurpureum, and Ornithopus sativus). Only isolate N17 have the same host range as WSM1271 in that they both nodulated B. pelecinus and A. membranaceus, while the other three novel isolates, WSM1284 and WSM1497 had a broader host range than WSM1271. Three isolates N18, N45 and N87 formed small white nodules on M. atropurpureum, in addition to nodulating the above hosts. Isolates N18 and N45 also nodulated A. adsurgens while N45 was the only isolate to nodulate L. edulis. Isolate N87 was the only isolate to nodulate A. fruticosa. WSM1497 nodulated A. adsurgens, A. membranaceus, B. pelecinus and L. corniculatus while WSM1284 was a promiscuous strain that nodulated 16 host species out of the 21 tested. A 710 bp internal region of nifH, a 567 bp internal region of nodA and a 1044 bp internal region of intS were sequenced for N17, N18, N45, N87 and WSM1271. The sequence comparison showed that the sequences of the above three genes of the four novel isolates were identical to that of WSM1271. Eckhardt gel electrophoresis revealed that WSM1271, three other RNB isolates from B. pelecinus from the Mediterranean region and isolate N18 each have a plasmid of approximately 500 kb while N17, N45 and N87 are plasmid free. Probing of the plasmid DNA from the Eckhardt gel with nifH and nodA probes indicated that these two genes were not located on the plasmid. Furthermore, the results of this study demonstrated that 92% of the nodules on B. pelecinus growing in the Northam site six years after the introduction of this plant were occupied by the inoculant strain and the N2 fixation efficiency of the progeny strains of WSM1271 remain similar to the mother culture. This study also showed that the carbon source utilization pattern, intrinsic antibiotic resistance and pH range of the progeny strains of WSM1271 remain relatively similar, except for few variations in carbon source utilization patterns. This thesis clearly demonstrated that phenotypicaly, genetically and phylogenetically diverse strains capable nodulating B. pelecinus evolved through symbiotic gene transfer from the inoculant strain to other soil bacteria within six years. The presence of intS, and the evidence of gene transfer between these Mesorhizobium strains indicates that transfer of symbiotic genes may have occurred via a symbiosis island present in WSM1271.

Thesis (Ph. D.)--University of Adelaide, Waite Agricultural Research Institute, 1955. / Typewritten copy. Includes bibliographical references.

The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on Feb. 11, 2010). Thesis advisor: Dr. Robert L. Kallenbach. Vita. Includes bibliographical references.

The aim of this thesis was to obtain and evaluate information from behavioural monitoring of beef cattle herd (cows, bull, calves) reared in the suckler system in the year-round grazing. The beef herd situated in the Pilsen region near Přeštice and is owned by private breeder was chosen for observation. Basic herd consisted of 20 cows with calves and one Charolais sire. There were three ethological observations, two observations in 2014 and one observation in 2015, duration of observations was 24 hours. The course of each category of behaviour was recorded by interval group method with interval length of 5 minutes. Activities as feed intake, rest, standing and movement. It was also reported comfort, sexual and maternal behaviour within the herd. The longest period of cows feed intake was recorded at the end of the grazing season (30.56% of the day, i.e. 7.33 hours). In contrast, feed intake took cattle in the winter months only 28.31% of the day (6.8 hours). Values in the standing category were not substantially different during the year. The longest standing time in the spring and autumn (5.97 hours respectively. 5.95 hours), standing time in the winter was shortened to 5.56 hours. Locomotion activity of animals in the spring reached 7.78%, i.e. 1.87 hour and due to the fact that cattle was still fed hay, but also first low vegetation started to grow in some areas and animals on its wintering actively sought it. In contrast, in the autumn the value was only 2.43%, i.e. 0.58 hours of the day due to sufficient suitable pasture. In the winter due to bad weather conditions, the value also decreased to 7.8%, i.e. 1.88 hours of the day. The longest representation of rest category in form of laying was recorded in the herd in autumn at level of 10.13 hours of the day (i.e. 40.22% of the day). In the spring rest category took 9.00 hours (i.e. 37.48%). The form of animal husbandry at the farm was in correspondence with the natural biorhythms of the animals and allowed them to freely demonstrate natural instincts and behaviour. Based on the findings it is possible to judge that the system of suckler beef herds is useful in terms of ensuring animal welfare and Charolais breed is exercisable under those conditions.

The main goal of this master?s thesis is to assess heifer fattening conducted in two grazing cycles in the mountain region of Southern Bohemia. The observation was carried out in two cycles in the years 2008/2009 and 2010/2011. A total of 99 heifers was observed, all of them crossbreeds of Aberdeen Angus or Simmental cattle. In the first grazing cycle, the heifers were raised on pasture together with the mothers and stabled for the winter season. The heifers were slaughtered after the end of the second grazing cycle in the next year. Live weight of the heifers was recorded at the end of the first grazing cycle, at the end of the winter season and again at the end of the second grazing cycle. The weight of the dressed carcass and results of the SEUROP carcass classification were further recorded. The average daily gain was calculated for each period from the live weight. The data set was sorted by the month of birth and by the SEUROP class score. Data analysis was conducted using Microsoft Excel. In order to evaluate the results, basic statistical parameters were calculated for each of the selected variables and the cogency of the differences between the groups was tested with the two-tailed t-test at the corresponding level of significance. The average weight of the heifers at the end of the first grazing cycle was 281,2 kg, average weight at the end of the winter season was 366,1 kg and the average weight at the end of the second grazing cycle was 511,6. The average age of the heifers at the end of the first grazing cycle was 221,5 days and they were slaughtered at the average age of 568,9 days. The average daily gain was 1,16 kg during the first grazing cycle, 0,53 kg during the winter season and 0,81 kg during the second grazing cycle. The lifetime average daily gain was 0.85 kg. Net gain averaged 0,45 kg per heifer. The average weight of the dressed carcass was 253,8 kg. 2,1 % of the heifers gained SEUROP class ?U?; 54,5 % class ?R? and 43,4 % class ?O?. The heifers showed considerable variability, especially in the weight at the end of the second grazing cycle (sx = 42,4 kg). Data analysis revealed correlations of r2=0,62 between weaning weight and slaughter weight and r2=0,69 between weaning weight and JUT weight.