The prevalence of Salmonella within poultry environments and on poultry products has been well documented. However, there has not been a study documenting the effect of utilizing used litter in newly constructed commercial broiler houses on Salmonella status or on the rate and source of Salmonella contamination within new houses. Objectives of this study are to 1) determine environmental source and rate of Salmonella spp. colonization in two newly constructed broiler houses 2) to evaluate the effect of mixing used broiler litter with clean litter in a new broiler house. Results of this study suggest that Salmonella contamination of the poultry house environment occurred within the first 2-4 weeks of bird placement and that the source of contamination may have been the chicks themselves. Litter inoculation may be beneficial in reducing Salmonella levels within the first flock if it is known that the chicks are already contaminated with Salmonella spp.

Litter is a possible source of Campylobacter colonization for broilers as well as contamination of crops when used as fertilizer. A survey of Arkansas broiler litter indicated that Campylobacter recovery rates were higher in pine shavings and rice hulls than sand. Two experiments utilized three types of litter, which were artificially contaminated with Campylobacter. After 24 hours no Campylobacter could be recovered from any sample. Campylobacter growth was also examined for used pine shaving litter in varying conditions: aerobic atmosphere, micro aerobic atmosphere (6% O2), and moisture content. Campylobacter was recovered for all treatments at the initial sampling, and by the 12 hour sampling time, only the added moisture and micro aerobic atmosphere yielded recoverable Campylobacter. This research suggests that without birds present in the house to shed fresh Campylobacter cells onto the litter, that the litter itself is incapable of harboring the bacteria long enough to colonize sequential flocks.

Litter is a possible source of Campylobacter colonization for broilers as well as contamination of crops when used as fertilizer. A survey of Arkansas broiler litter indicated that Campylobacter recovery rates were higher in pine shavings and rice hulls than sand. Two experiments utilized three types of litter, which were artificially contaminated with Campylobacter. After 24 hours no Campylobacter could be recovered from any sample. Campylobacter growth was also examined for used pine shaving litter in varying conditions: aerobic atmosphere, micro aerobic atmosphere (6% O2), and moisture content. Campylobacter was recovered for all treatments at the initial sampling, and by the 12 hour sampling time, only the added moisture and micro aerobic atmosphere yielded recoverable Campylobacter. This research suggests that without birds present in the house to shed fresh Campylobacter cells onto the litter, that the litter itself is incapable of harboring the bacteria long enough to colonize sequential flocks.

Little is known about the effect of biochar created from poultry litter on soil properties and plant growth. Five studies were conducted using biochar made by the fast pyrolysis of poultry litter. Two were greenhouse studies and three were field studies. The greenhouse studies were conducted with a sandy loam soil and a silt loam soil. First, lettuce (Lactuca sativa L) seeds were germinated in the greenhouse across biochar incorporation rates from 0 to 100%, and secondly a trial was conducted in which green peppers (capsicum annum L) were grown in soils with up to 5% biochar by weight. Elemental analysis was completed on the biochar and the soils were analyzed for bulk density (BD), water holding capacity (WHC), pH, cation exchange capacity (CEC), soluble salts (SS) and extractable nutrients. The field studies all used the rates of 0, 4.5, and 9 Mg ha-1 biochar and the rates were applied in the early spring of 2009 and 2010. Biochar was surface applied on a tall fescue pasture [Lolium arundinaceum (Schreb.) Darbysh. (=Festuca arundinacea Schreb. subsp. arundinacea)] and tilled in on two green pepper field sites. The soils were analyzed for carbon (C) content, pH, CEC, Mehlich 1 P, and SS. No significant difference was found in yields at any of the three sites, but differences in forage quality were found. Biochar made from poultry litter showed several benefits as a soil amendment in all the studies, but application rates would be limited by soil test P and pH. / Master of Science

Manure from turkey poults on five diets were extracted both fresh (wet) and after drying. Soils amended with wet manure were also extracted. Phosphorus, Cu, and Zn were extracted with 0.01 M CaCl₂ and acidic Mehlich III extractant (Zn in soil extracts was not evaluated). Dietary treatments were (1) normal phytic acid (NPA) corn and 0.135% inorganic P (NPA diet); (2) NPA corn, 600 units phytase enzyme, and 0.135% inorganic P (NPA+Phyt diet); (3) High available phosphorus (HAP) corn and 0.135% inorganic P (HAP diet); (4) HAP corn, 600 units phytase, and 0.135% inorganic P (HAP+Phyt diet); (5) NPA corn and 0.345% inorganic P (NPA+P diet). The NPA+P diet was similar to conventional diets being fed commercially. The NPA+Phyt diet was similar to alternative, phytase-amended diets being fed commercially. Feeding the alternative NPA+Phyt, HAP, and HAP+Phyt diets instead of the NPA+P diet reduced total P in manures by 40%, but increased the percentage of total manure P extracted with 0.01 M CaCl₂ from fresh excreta (P < 0.05). Soils amended with wet NPA+Phyt, HAP, and HAP+Phyt manures released 29 to 49% more water-soluble P than soils amended with NPA+P manure on an equal-P basis (P < 0.05). Feeding the NPA+Phyt diet instead of the NPA+P diet did not affect the percentage of total P manure extracted by Mehlich III from wet excreta, while feeding the HAP and HAP+Phyt diets increased the percentage of total manure P soluble in Mehlich III (P < 0.05). Soils amended with wet NPA+Phyt manure did not release more Mehlich III-extractable P than soils amended with NPA+P manure on an equal-P basis. Soils amended with wet HAP and HAP+Phyt manures released more Mehlich III-extractable P than soils amended with NPA+P manure on an equal-P basis (P < 0.05). Treatment-induced differences in extractability of manure and soil P appeared to be caused by a higher proportion of P in calcium phosphate form in the NPA+P manure. Drying manures prior to extraction generally heightened differences in solubility of P between the NPA+P and other manures. Feeding the alternative NPA+Phyt, HAP, and HAP+Phyt diets instead of the NPA+P diet did not affect total Cu levels in manure or the percentage of total Cu extracted from manure with 0.01 M CaCl₂. After soils were treated with manure on an equal-Cu and equal-N basis, soils amended with NPA+Phyt, HAP, and HAP+Phyt manures released more water-soluble Cu than NPA+P-amended soils (P < 0.05). Under P-based manure management, soils amended with the three alternative manures released 92 to 108% more water-soluble Cu than NPA+P-treated soils (P < 0.05). Extractable Cu increased so dramatically because conversion to the alternative diets boosted total manure loadings by 67%. Mehlich III extraction of soils amended with manure on an equal-N and -Cu basis indicated no effect of manure type on Cu availability. Feeding the NPA+Phyt, HAP, and HAP+Phyt diets instead of the NPA+P diet did not affect total Zn levels in excreta, but caused at least a five-fold increase in the percentage of total manure Zn extracted by 0.01 M CaCl₂ from fresh excreta (P < 0.05). Feeding the NPA+Phyt, HAP, and HAP+Phyt diets did not alter the percentage of total manure Zn extracted by Mehlich III from wet excreta. / Master of Science

Previous research has shown that treatment of poultry litter with alum is an effective management strategy to reduce phosphorus (P) solubility in litter thereby reducing potential P losses to surface runoff after surface applications. However, limited data are available evaluating alum-treated poultry litter (ATPL) environmental impact in cultivated systems and how its application will affect crop production. In addition little is known as to how its application affects various P fractions or exchangeable Aluminum (Al) content in treated soils. Two, 3-yr field trials with corn (Zea mays L.) were used to show that, when applied at rates based on current litter management strategies, ATPL resulted in yields similar to those achieved through applications of non-treated poultry litter (NPL). These trials also showed that ATPL applications resulted in lower soil P status and decreased P losses in surface water runoff compared to application of NPL. A 4-yr field trial with fescue (Festuca arudinacea) also showed no significant differences in productivity when comparing ATPL and NPL. This trial was utilized to evaluate the distribution of P in soils receiving ATPL. Soil analysis data showed that ATPL applications result in decreased water-extractable P (H2O-P) and that this decrease was associated with an elevation in NaOH extractable organic soil P. A laboratory incubation was utilized to evaluate the short and long-term impact of ATPL application on soil pH, exchangeable soil Al and H2O-P. Data from this incubation confirmed that the relationship between soil pH and exchangeable Al is not adversely affected by ATPL applications. Also, variations in the H2O-P content of soils treated with two different ATPL sources could not be associated with differences in Al:P ratio or soluble P content of the two litters, providing evidence that additional characteristics also control P availability after incorporation in soil. / Ph. D.

This research evaluates the decomposition of leaf litter while in litter traps. More specifically this study asks, ‘Does sugar maple (Acer saccharum Marsh.), American basswood (Tilia Americana L.) and American beech (Fagus grandifolia Ehrh.) leaf litter collected bi-weekly from litter traps undergo a loss of dry mass and nutrient content (C, N, P, K, Ca and Mg) in comparison to freshly abscised leaf litter?’The objective of the initial experiment was to determine if sugar maple, basswood and beech leaf litter collecting in litter traps, while exposed to in-situ conditions, experienced decomposition. Results indicated that sugar maple, basswood and beech leaf litter experienced early stages of decomposition and identified precipitation, freezing temperatures and microbial activity as possible mechanisms for the observed decomposition. It was found that the dry weight of sugar maple and basswood differed significantly (p < 0.05 and p < 0.10, respectively) post- 14-day experiment period as compared to the initial dry weight. Consequently, three experiments were completed to examine the aforementioned variables. Conclusions were based on measured changes in the mass and nutrient (C, N, P, K, Ca and Mg) content of freshly abscised sugar maple, basswood and beech leaf litter under ex-situ conditions. It was found that the dry weight sugar maple and basswood leaf litter exposed to 30 mm, 60 mm and 100 mm of precipitation differed significantly (p < 0.05) as compared to freshly abscised leaf litter. In general, this research affirmed that precipitation and freezing temperature contribute to a change in mass and nutrient content of leaf litter collecting in litter traps. Furthermore, through measurable production of CO2 and Community Level Physiological Profiling it was determined that microbes are present and active on the leaf surface and contribute to the decomposition of leaf litter in litter traps.

This research evaluates the decomposition of leaf litter while in litter traps. More specifically this study asks, ‘Does sugar maple (Acer saccharum Marsh.), American basswood (Tilia Americana L.) and American beech (Fagus grandifolia Ehrh.) leaf litter collected bi-weekly from litter traps undergo a loss of dry mass and nutrient content (C, N, P, K, Ca and Mg) in comparison to freshly abscised leaf litter?’The objective of the initial experiment was to determine if sugar maple, basswood and beech leaf litter collecting in litter traps, while exposed to in-situ conditions, experienced decomposition. Results indicated that sugar maple, basswood and beech leaf litter experienced early stages of decomposition and identified precipitation, freezing temperatures and microbial activity as possible mechanisms for the observed decomposition. It was found that the dry weight of sugar maple and basswood differed significantly (p < 0.05 and p < 0.10, respectively) post- 14-day experiment period as compared to the initial dry weight. Consequently, three experiments were completed to examine the aforementioned variables. Conclusions were based on measured changes in the mass and nutrient (C, N, P, K, Ca and Mg) content of freshly abscised sugar maple, basswood and beech leaf litter under ex-situ conditions. It was found that the dry weight sugar maple and basswood leaf litter exposed to 30 mm, 60 mm and 100 mm of precipitation differed significantly (p < 0.05) as compared to freshly abscised leaf litter. In general, this research affirmed that precipitation and freezing temperature contribute to a change in mass and nutrient content of leaf litter collecting in litter traps. Furthermore, through measurable production of CO2 and Community Level Physiological Profiling it was determined that microbes are present and active on the leaf surface and contribute to the decomposition of leaf litter in litter traps.

Thesis (M.S.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 99-104). Also available on the World Wide Web.

Thesis (M.S.)--Oregon State University, 1999. / Typescript (photocopy). Includes bibliographical references (leaves 96-102). Also available on the World Wide Web.