Agroecosystem and cycling loops are open when considering the reutilization of inputs in farming areas. Non-renewable resources have been transformed or relocated from the air, water and land into the system and are flowing out as wastes rather than reusable, recyclable resources. Therefore, current trends in agriculture have moved towards more sustainable cultivation systems with higher efficiency of input use, since mineral nutrient losses due to runoff, leaching, erosion and gas emissions are leading to environmental degradation. A huge variety of materials can serve as a crop nutrient supply and they can be derived from different resources. The integrated plant nutrition system (IPNS) thrives tailoring plant nutrition and soil fertility management, taking advantage of the conjunctive and harmonious use of inorganic, organic and biological resources. We hypothesize that the synergetic effects of the combination of humic acid HA + biofertilizer will improve plant agronomic outcomes when comparing the application of each product alone. We initiated this project conducting a greenhouse study and field experiments evaluating the effects of an IPNS on corn. Posteriorly, the positive results in terms of corn biomass increasing, led to another greenhouse study addressing cannabis (Cannabis sativa L.) due its valuable biomass as an end/selling product. The greenhouse studies evaluated the effects of commercial synthetic fertilizer, HA, compost/manure teas and bioinoculant as inorganic, organic and biological resources, respectively, and their synergy on corn and cannabis early development under a period of water deficit stress. Generally, for both studies, when compared to the control values, the use of HA, biofertilizers and the integration of both substances generated significantly greater early season plant height, chlorophyll content and photosynthetic efficiency. The three-year field trial investigated the effects of nitrogen (N) fertilizer, HA, compost/manure teas and bioinoculant as inorganic, organic and biological resources, respectively and their synergy on corn growth. The individual and integrated application of HA and biofertilizer generally influenced corn development, to varying degrees. In 2017, corn height, NDVI, greenness and vigor were sensitive to the application of these biostimulants in different magnitudes and growth stages, however grain yield and nutrient content were not affected. In combined studies from 2018 and 2019 corn height was not impacted by biostimulant application but NDVI, photosynthetic efficiency, greenness and vigor were affected at different doses and corn growth stages. Only one treatment integrating HA + biofertilizer led to increased grain yield. In sum, these studies provided evidence that the individual and combined application of HA and biofertilizer can positively influence corn and cannabis growth most likely due to their plant biostimulant effects. However, the current study cannot conclusively affirm that the integrated use of HA and biofertilizers following the IPNS is a superior practice than the application of each compound individually and further studies should be conducted to validate these findings. / Doctor of Philosophy / The status of the corn (Zea mays L.) demand in Virginia and the Mid-Atlantic region is currently in deficit regarding the production in this area. This demand is exceeding supply by approximately 150%, then increasing feed grain yield and consequently production in the region can be simultaneously beneficial to crop farmers, end-users and the entire food supply chain. Furthermore, the consumer market is becoming more aware about sustainable practices for food production, which encourages producers to adopt agricultural practices that can minimize negative environmental impacts. This scenario enforces the scientific community's responsibility to test and develop environmental-friendly methods able to increase fertilization efficiency, decreasing the use in synthetic inputs but maintaining yield. The integrated plant nutrition system (IPNS) implements the combined and harmonious use of inorganic, organic and biological resources to take advantage of the potential synergetic effects. We conducted greenhouse studies and field experiments evaluating the effects of an IPNS on corn, and posteriorly based on the preliminary results obtained with corn, a greenhouse study addressing cannabis (Cannabis sativa L.) was also carried out. The greenhouse studies evaluated the effects of commercial synthetic fertilizer, humic acid (HA), compost/manure teas and bioinoculant as inorganic, organic and biological resources, respectively, and their synergy on corn and cannabis growth under a period of drought. Generally, for both studies, when comparing to the control values, the use of HA, biofertilizers and the integration of both compounds generated significantly greater early season plant height and photosynthesis measurements. The three-year field trial investigated the effects of nitrogen (N) fertilizer, HA, compost/manure teas and bioinoculant as inorganic, organic and biological resources, respectively and their synergy on corn growth. The individual and combined application of HA and biofertilizer generally influenced corn development, to varying degrees. In 2017, corn height, vegetation index, greenness and vigor were sensitive to the application of these biostimulants in different magnitudes and growth stages, however grain yield and nutrient content were not affected. In combined studies from 2018 and 2019 corn height was not impacted by biostimulant application but vegetation index, photosynthetic efficiency, greenness and vigor were affected at different doses and corn growth stages. Only one treatment combining HA + biofertilizer led to increased grain yield. In sum, these studies provided evidence that the individual and combined application of HA and biofertilizer can positively influence corn and cannabis growth most likely due their plant biostimulant effects. Even though, the current study cannot affirm that the combined use of HA and biofertilizers following the IPNS is a better practice than the application of each compound individually, this practice can be a more sustainable alternative to fit in the conventional farming scene.

京都大学 / 新制・課程博士 / 博士(生命科学) / 甲第25513号 / 生博第529号 / 新制||生||70(附属図書館) / 京都大学大学院生命科学研究科統合生命科学専攻 / (主査)教授 中野 雄司, 教授 河内 孝之, 教授 荒木 崇 / 学位規則第4条第1項該当 / Doctor of Philosophy in Life Sciences / Kyoto University / DFAM

The feeding or 200 to 500 parts per million or molybdenum to rats resulted in a greater percentage of the total liver copper being found in the nuclei and debris and mitochondrial fractions at the expense of the supernatant fraction, while the molybdenum was found to be concentrated in the supernatant fraction. Dietary inorganic sulfate while lowering liver levels of copper and molybdenum appeared to have little or no effect upon their distribution. Dietary molybdenum also caused the relative amount of copper in the supernatant fraction and erythrocytes of blood to decrease, while the increase occurred in the albumin fraction. As with liver, the blood fraction which contained the most molybdenum was the supernatant. Statistical analysis indicated that a quantity whIch was relatively well correlated with molybdenum toxicity as measured by weight gain was a combination of liver molybdenum and copper concentrations divided by body weight. It appeared that the only beneficial effect of sulfate was to lower this quantity. Sulfate excretion or the manner in which rats handled a toxic amount of phenol was found to be unaffected by molybdenum feeding. Earlier reports that dietary molybdenum caused a decrease in cytochrome-c oxidase activity and an increase in erythrocyte fragility could not be substantiated. An injected dose of radioactive molybdenum was found not to be equilibrated with the already present dietary molybdenum in sixteen hours. / Ph. D.

Creeping Bentgrass (Agrostis stolonifera var. palustris (Huds.) Farw.) is the most widely used cool-season turf grass used for putting greens in North America. Frequently it becomes invaded with a persistent weed, annual bluegrass (Poa annua L.). Studies were conducted on a predominately annual bluegrass area managed as a putting green to attempt to quantify the impacts of plant growth regulator, seeding rate" and season on the success of introducing creeping bentgrass. Also, the impact of plant growth regulating substances on creeping bentgrass overall quality and seasonal rootmass production was evaluated. It was observed that creeping bentgrass does not become well established when overseeded into annual bluegrass regardless of plant growth regulator applications or season. Additionally 1I plant growth regulator application, following seedling emergence reduced creeping bentgrass seedling populations. Competition from established annual bluegrass and close frequent cutting were deemed reasons for lack of creeping bentgrass establishment success. Creeping bentgrass turf was maintained at a high level of quality with plant growth regulating substances. The use of the plant growth regulator trinexapac-ethyI reduced clipping production and was not detrimental to root production. Propiconizole application increased clippings and controlled Sclerotinia dollarspot. The application of a proprietary biostimulator material (3D) enhanced creeping bentgrass green color and generally increased rootmass over untreated turf. / Master of Science

Sustainability practices are leading to the development and use of alternative products in the floriculture and wastewater industries, such as the use of biodegradable containers instead of plastic containers. The objective of this research was to evaluate the efficacy of using digested biosolids from a regional wastewater treatment plant as an ingredient in creating a biodegradable transplant biocontainer. The biosolids were tested for metals limits as specified by the U.S. EPA Part 503 Rule, and met the requirements for Class B. Multiple mixes of biosolids, fibers, starch, polymer, and natural glue were developed to provide overall pot stability and structural strength. Engineering tests, such as tensile strength, pH, and saturated paste tests, were conducted on the different mixes to determine the optimum strength that could be produced. The top-performing biosolids mixes were used to make 10.2 cm (four-inch) pots that were compared in various ways to the market leaders, Peat Pots and standard plastic pots. A two-part mold was created on a 3D printer, which would allow for positive pressure to be used in forming the BioPots. Mixes were transferred to the lower half of the mold, the upper part was then plunged and fastened into the lower half, and then the mold with its mix was placed in an oven to dry. Laboratory germination bioassays were performed to test for the presence of phytotoxic compounds. Construction of BioPots for the lab-scale studies was tedious. Different methods (e.g., negative pressure systems) need to be investigated for use in producing the BioPots commercially. Most of the BioPots survived the resiliency study. Leachate quality from the biocontainers was no worse than from the plastic containers. Some discoloration was observed on the biocontainers, but it was not due to algal/fungal growth. Growth of soybeans, marigolds, and romaine in the biocontainers was significantly better (e.g., increased height, leaf sizes, and weight) than in the plastic containers. / Master of Science / The Western Virginia Water Authority serves the City of Roanoke, and Counties of Roanoke, Franklin and Botetourt. Approximately 141 million liters per day (37 million gallons per day) of wastewater from the service area is treated at the Roanoke Regional Water Pollution Control Plant (RRWPCP). Solids are anaerobically digested and lagooned prior to agricultural land application; biogas is stored and used to generate electricity. After about nine months in the lagoon, 9.07 million dry kilograms (10,000 dry tons) of biosolids are land applied locally each year. Solids management costs are a significant part of the RRWPCP’s operating budget. In an effort to decrease costs and increase sustainability, there has been growing interest in resource recovery by producing a high-quality nutrient product that can be beneficially used. In January 2014, research to develop a high-quality biosolids product for beneficial use was initiated by Virginia Tech, in collaboration with the RRWPCP. The drivers, research goals, methodology, and results from that research will be presented. The general public is familiar with several commercially available biocontainer products, such as Peat Pots and CowPots^TM. They are used in nurseries, greenhouses, and households, and minimize plastic waste while also contributing organic material for healthy plant growth. The WPCP was intrigued with developing a biosolids product that could be marketed and used like the Peat Pots. The objective of this research was to evaluate the efficacy of using digested biosolids from Roanoke WPCP as an ingredient in creating a biodegradable transplant pot. The biosolids were tested for and met the metals and contaminants limits as required by the U.S. EPA Part 503 Biosolids Rule. In addition to the biosolids, other fibrous materials, such as used cardboard or cellulose, were used to stabilize and add structural strength. Multiple blends, or mixes, were developed, each varying in biosolids and fiber content on a dry weight basis, as well as different additives such as starch, polymer, or a natural glue. Tensile and puncture tests were conducted on the different mixes to determine the optimum strength that could be produced. The top performing mixes were used to create four-inch pots, for comparison to market leader, Peat Pots, and standard plastic pots. Greenhouse studies were conducted in two phases: • Phase 1 – analysis of leachate and assessment of pot stability through watering cycles. • Phase 2 - growth studies for soybeans, marigolds, and romaine. These plants were selected based on growth ability and/or sensitivity. The RRWPCP does not currently produce Class A biosolids, but by producing biodegradable transplant pots, they hope to produce a high-value, sustainable product that meets Class A requirements and diversifies their current biosolids management program.

Recycled glass cullet is a potential alternative to fill substrate in salt marsh restoration projects, given its similarity to natural silica sands. However, the ability for common salt marsh plants to grow in glass cullet has not yet been tested. An outdoor mesocosm experiment assessed the ability of the dominant mid-marsh plant Juncus roemerianus and the upland marsh plant Spartina patens to grow in various mixtures of glass cullet versus fill soil. Results showed that J. roemerianus can survive in glass cullet, but growth declined as the proportion of cullet increased. However, S. patens grew comparably, if not better, in treatments up to 75% glass cullet. In the face of increased coastal land loss and a global sediment deficit, the use of glass cullet in upland salt marsh restoration projects can simultaneously divert glass from landfills and promote more sustainable coastal restoration strategies along the northern Gulf of Mexico.

Inoculation with diazotrophic bacteria is well documented as a means to enhance growth and increase yields of various crops, especially when used as an alternative or a supplement to the use of nitrogenous fertilizers and agrochemicals for sustainable agriculture. Nitrogen is the most limiting nutrient for increasing crop productivity, and the use of chemical sources of N fertilizers is expensive, and may contribute to environmental pollution. Therefore, there is a need to identify diazotrophic inoculants as an alternative or supplement to N-fertilizers for sustainable agriculture. The search for effective diazotrophic bacterial strains for formulation as biofertilizers has been going on for over 40 years and a number of inoculant biofertilizers have been developed and are commercially available. In the current study, 195 free-living diazotrophic bacteria were isolated from soils collected from the rhizosphere and leaves of different crops in different areas within the KwaZulu-Natal Province, Republic of South Africa. Ninety five of the isolates were selected for further screening because they were able to grow on N-free media using different carbon sources. Isolates that were very slow to grow on N-free media were discarded. Of these, 95 isolates were screened in vitro for growth promotion traits tests including tests for ammonia production and acetylene reduction. The best 20 isolates that were also able to reduce acetylene into ethylene were selected for growth-promotion trials on maize under greenhouse conditions. Of the 20 isolates, ten isolates enhanced (P = 0.001) growth of maize above the Un-inoculated Control. Molecular tests were conducted to identify the ten most promising isolates selected in the in vitro study. In the greenhouse study, these diazotrophic isolates were screened for their ability to enhance various growth parameters of maize (Zea mays L.), following various inoculation techniques (drenching, seed treatment, foliar spray and combination of these). Inoculations with the five best diazotrophic isolates by various methods of application increased dry weight and leaf chlorophyll content (P < 0.001, P = 0.001), respectively, compared to the Untreated Control. Although, all methods of application of diazotrophic inoculants used in this study resulted in increased dry weight and leaf chlorophyll content, combined methods of application (seed treatment + drenching) and sole application (seed treatment) were significantly more (P < 0.05) efficient. The best five most promising isolates were identified for growth promotion of maize under greenhouse conditions. They were also assessed for their effects on germination of wheat in vitro and were further tested in combination with various levels of nitrogenous fertilizer for growth-promotion of wheat (Triticum aestivum L.). These five isolates were also investigated for their potential to enhance growth and yields of maize and wheat crops in field trials, when combined with a low dose of nitrogenous fertilizer. These isolates were further studied for their contribution for enhancing plant growth through nitrogen fixation by predicting N content in leaves using a chlorophyll content meter (CCM-200) and correlated to extractable chlorophyll level at R2 = 0.96. In this study, relative to the Un-inoculated Control, the best five isolates enhanced growth of maize and wheat when combined with a 33% N-fertilizer levels for a number of growth parameters: increased chlorophyll levels and heights of maize, shoot dry weight of maize and wheat; and enhanced root and shoot development of these crops in both greenhouse and field conditions. The best contributions of diazotrophic bacteria was achieved by Isolate LB5 + 0% NPK (41%), V9 + 65% NPK (28.9%), Isolate L1 + 50% NPK (25%), Isolate L1 + 25%NPK (22%) and LB5 + 75% NPK (15%) undergreenhouse conditions. At 30 or 60 DAP, isolates with 33%N-fertilizer caused relatively higher dry weight than the 100%NPK. Inoculation of Isolate StB5 without 33N% fertilizer cuased significant (P<0.005) increases in stover dry weight. In field studies, inoculation of diazotrophic bacteria alone or with 33%N-fertilizer resulted in relatively greater increases of dry weight, stover dry weight, number of spikes and yield at different growth stages higher than the Un-inoculated or Unfertilized Control. However, the increases were not statistically significant. The use of microbial inoculants in combination with low doses of nitrogenous fertilizers can enhance crop production without compromising yields. The isolates obtained in this study can effectively fix nitrogen and enhance plant growth. The use of microbial inoculants can contribute to the integrated production of cereal crops with reduced nitrogenous fertilizer inputs, as a key component of sustainable agriculture. / Ph.D. University of KwaZulu-Natal, Pietermaritzburg 2013.

Expanding global populations, unequal food distribution and disease pressure suggest food poverty is increasing. Consequently, much attention is focussed on alternative natural methods in which to increase agricultural yield. Previously, it was observed that Trichoderma hamatum strain GD12 and its respective N-acetyl-β-D-Glucosamine mutant ∆Thnag:hph promoted plant biomass and fitness that, as a result, may provide a credible natural alternative to synthetic fertilisers. However, on a molecular level, the manner in which this is achieved has not been fully elucidated. In this thesis, I report the biofertiliser effect of GD12 and mutant ∆Thnag::hph once applied to autoclaved peat microcosms as sole applications. Furthermore, I demonstrate the biocontrol ability of GD12 when co-inoculated with Sclerotinia sclerotiorum or Rhizoctonia solani and reveal, that once mycelium co-inoculation has occurred, GD12 increase plant biomass and provide protection; whilst ∆Thnag::hph does not. Consequently, I challenged the biocontrol effects of Trichoderma metabolite extract where I validate that both Trichoderma wild type GD12 and mutant ∆Thnag::hph are incapable of suppressing pathogen growth. Subsequently, I characterised the up-regulated signatures associated with GD12 and ∆Thnag::hph using LC-MS techniques where unique compounds were discovered from each strain of Trichoderma. In conclusion, I provide evidence that N-acetyl-β-D-Glucosamine mutation bring about metabolomic changes that affect the fungal secretome which, in turn, alters plant phenotype, fitness and germination. Furthermore, I have shown that these effects are species specific and depend upon pathogen, plant and fungal properties. However, further investigations are needed to fully elucidate the compound(s) responsible for biocontrol and biofertilisation; especially plant-specific effects that take place as a consequence of fungal activity.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Call number: LD2668 .T4 1985 E27 / Master of Science