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1
Muskolus, Andreas. "Anthropogenic plant nutrients as fertiliser". Doctoral thesis, Humboldt-Universität zu Berlin, Landwirtschaftlich-Gärtnerische Fakultät, 2008. http://dx.doi.org/10.18452/15774.
Testo completoAbstract (sommario):
Nachhaltige Landbewirtschaftung impliziert ausgeglichene Pflanzennährstoffflüsse ohne die Abhängigkeit von Düngern aus nicht erneuerbaren Quellen. Stickstoff, Phosphor und Kalium aus der menschlichen Nahrung werden in Mitteleuropa im Allgemeinen in Schwemmkanalisationen gesammelt und dabei mit Schadstoffen vermengt. Neuartige stoffstromtrennende Sanitärsysteme ermöglichen die Bereitstellung von Humanurin und Fäkalien zur Verwendung als Düngemittel. In der vorliegenden Arbeit wurden praxisrelevante Aspekte der Verwendung von Düngemitteln anthropogener Herkunft untersucht. Die in Gefäß- und Feldversuchen in Berlin Dahlem ermittelte Ertragswirkung zeigte, dass Urin in dieser Hinsicht äquivalenten Mineraldüngern grundsätzlich gleichwertig ist. Bei sehr hohen Konzentrationen kam es abhängig von der Pflanzenart zu Depressionseffekten, welche vermutlich auf den Salz- und Ammoniumgehalt von Urin zurückzuführen sind. Unter Freilandbedingungen traten diese Effekte nicht auf. Bodenbiologische Auswirkungen von Düngerapplikationen sind entscheidend für die Abschätzung ihrer langfristigen Bodenfruchtbarkeitserhaltung. Sowohl in Labor-versuchen als auch im Freiland zeigten sich Regenwürmer durch menschlichen Urin aus Trenntoiletten deutlich beeinträchtigt. Die Ursache der Schädigung konnte nicht geklärt werden. Von einer langfristigen bodenfruchtbarkeitsreduzierenden Beein-trächtigung wird jedoch nicht ausgegangen. Mikrobielle Enzymaktivitäten im Boden wurden im Freiland durch Urinapplikation nicht beeinflusst. Für die Praxis wird empfohlen Urin während der Ausbringung einzuarbeiten, da die Tiere dann weniger mit der Flüssigkeit in Kontakt kommen. Da es ein umweltpolitisches Ziel ist, die Ammoniakemissionen der Landwirtschaft zu minimieren, wurden diese nach der Urinausbringung im Freiland gemessen. Auf Grund der sehr geringen Trockensubstanzgehalte von Humanurin emittierte deutlich weniger NH3 als üblicherweise nach Ausbringung von Schweine- oder Rindergülle. Verbraucherumfragen bestätigten eine hohe Bereitschaft pflanzliche Nahrung, welche mit Urin als Dünger erzeugt wurde, zu kaufen und zu verzehren. Praktizierende Landwirte reagierten dagegen deutlich reservierter. Die Ausbringung von Urin aus Trenntoiletten kann im Sinne einer nachhaltigen Landwirtschaft grundsätzlich empfohlen werden. Es besteht aber weiterer Forschungsbedarf.Sustainable agriculture implies balanced nutrient flows and independence from fertiliser made from non renewable resources. In Europe, plant nutrients excreted by humans are commonly collected in water borne sewage systems and thus mixed with potentially harmful substances. Novel segregating sanitation techniques can collect separated urine and faeces in a form which enables their use as fertiliser. In the presented thesis selected aspects concerning the use of anthropogenic plant nutrients relevant to farming were investigated. Pot and field experiments indicated that equal yields can be gained if urine instead of mineral fertiliser is applied. Very high concentrations of urine led to reduced growth, presumably caused by the presence of ammonium or salt. However, this was not found under field conditions. Soil biological effects caused by the application of a fertiliser must be considered when assessing its long term contribution to soil fertility. Laboratory experiments as well as field investigations showed that human urine application severely affects earthworms, however, the harmful components were not identified. The results suggest that the effect is of short term only. Soil microbial enzyme activities were not influenced by urine fertiliser. For farming practice it is recommended to inject or incorporate urine to prevent earthworms from coming into direct contact with the infiltrating fertiliser. Gaseous ammonia loss was measured after urine application on fields as reducing harmful emissions from agriculture is a goal of European environmental policy. Because of the very low Dry Matter contents of urine, far less ammonia was emitted to the atmosphere than usually occurs after application of cattle or pig slurry. A consumer acceptance study showed a general high public willingness to accept urine as fertiliser even if used on crops for food production. The reaction of farmers was mainly reserved as a result of the present legal regulations in Germany. Within the context of sustainable agriculture the use of human urine as fertiliser can be recommended. Further research is necessary, especially concerning any effects resulting from residues of pharmaceutical substances contained in human excreta.
2
Schlapp, Julia Emily, e julia schlapp@rmit edu au. "Modelling Fertiliser Use in the Glenelg Hopkins Catchment". RMIT University. Mathematics and Geospatial Science, 2009. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20090602.144534.
Testo completoAbstract (sommario):
The improvement of water quality in the streams of the Glenelg Hopkins catchment is a priority of the Glenelg Hopkins regional strategy. A major source of water pollution in the region is linked to agricultural activities as high nutrient levels from runoff have the potential to increase the incidence of blue-green algae in the waterways. Land use change, reduced rainfall, more frequent extreme rainfall events and higher temperatures associated with climate change are likely to exacerbate this trend. Water testing data of the Total Phosphorus (TP) levels in the Hopkins River and at other sites within the Hopkins Catchment indicate increasing incidence of TP above the Environment Protection Authority's target levels for extended periods of each year. Earlier research indicated that phosphorus in runoff increases when pasture fertility increases and that fertiliser management practices should be considered as an element of preventative action for reducing nutrient pollution. During our research, a survey was undertaken in the Hopkins River catchment, to determine the current management of phosphorus (P) fertilisers on grazing and mixed enterprise farms, the attitude of farmers to natural resource management and their understanding of nutrient pollution. The survey also gathered information on the way farmers made fertiliser management decisions. If cooperation relating to phosphorus fertiliser application could be facilitated between groups of farmers, it may be possible to reduce nutrient runoff into the Hopkins waterways. Cooperative game theory has successfully been used worldwide in the resolution of environmental problems where there is an economic impact to the decision making process. In this project, the amount of phosphorus applied per hectare was used in a cooperative game theory model assessing the potential for cooperative action on phosphorus management by groups of farmers, based on the trade off between the economic cost of pollution to the region waterways and the economic production benefits to the individual. The outcome of this work was individual optimal strategies for fertiliser application, allowing individual farmers to reduce their impact of agricultural production on the health of the catchment. Involving the farmer groups, while undertaking the project, raised awareness amongst the farming population of the regional nutrient pollution caused by runoff from agricultural land, and enlisted their assistance towards adopting a cooperative approach to the problem. In addition, the results have been mapped using a Geographical Information System (GIS) for visual presentation and to demonstrate the use of this process in natural resource management with the farmer groups.
3
Kirkpatrick, T. "Fertiliser formulations to maximise nitrogen efficiency on grassland". Thesis, Queen's University Belfast, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.398096.
Testo completo
4
O'Connell, Kathleen Ann. "Environmentally sustainable fertiliser nitrogen management practices for pasture production". Thesis, Queen's University Belfast, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.426720.
Testo completo
5
Sweet, Nina. "Temperature, grass growth and the timing of fertiliser application". Thesis, University of Nottingham, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316992.
Testo completo
6
Jamieson, Nicola. "Competition between roots and soil micro-organisms for fertiliser N". Thesis, University of Aberdeen, 1992. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU548165.
Testo completoAbstract (sommario):
Low fertiliser recoveries are often found for temperate coniferous forests and appear to be associated with the 'locking-up' of residual fertiliser N in stable organic forms. This phenomenon may well be caused by strong microbial immobilisation, out competing uptake by tree roots. This thesis investigates root/microbe competition for fertiliser-derived N (FDN) in microcosms of coniferous forest soil (supporting Sitka spruce seedlings) as well as in re-seeded blanket peat (supporting a mixed grass pasture). Combinations of selective microbial inhibitors, both with and without either 15N-labelled urea or NH4NO3, were applied to microcosms to selectively inhibit target microbial groups which may be competing with roots for FDN and determine the role of microbial immobilisation as a mechanism controlling N flow to seedlings/herbage. The dynamics of FDN novement into microcosm N pools was also studied in microcosms to which 15N-labelled urea was applied alone. At harvest, plant and soil N pools were analysed for 15N and total N (15 N &'43 14N). The impact of biocide and fertiliser N treatments on concentrations of target and non-target soil organisms were also determined. Biocidal (benlate and to a lesser extent streptomycin) inhibition of soil micro-organisms (particularly fungi) increased the uptake of both urea-derived N and NH4O3 N by Sitka spruce seedlings. Increases were associated with reduced percentages of FDA active hyphae and concentrations of FDN immobilised in the microbial biomass of LFH layer and peaty mineral soil. The results suggest that roots were competing with soil microbes for both fertiliser N forms. In conclusion this study has demonstrated the role of microbial biomass, particularly the dominant fungal component as a major competitive sink for fertiliser N and a major factor contributing to the low efficiency of fertiliser N in temperate coniferous forests. The study also has identified selective biocidal manipulation as a powerful technique for characterising competition between roots and microbes for nutrients in soil.
7
Lodge, Timothy Andrew. "The construction, irrigation and fertiliser nutrition of UK golf greens". Thesis, University of Leeds, 1994. http://etheses.whiterose.ac.uk/553/.
Testo completoAbstract (sommario):
A field trial was established of a mixed grass sward grown on three types of golf green construction. These consisted of a topsoil, a sand, peat and soil mixture, and a pure sand. Experimental treatments applied were three levels of irrigation, five of nitrogen fertiliser and two of phosphate. The trial was maintained as a golf green, and artificial wear was applied. Soil moisture deficit predictions by the Meteorological Office conformed with measurements from the soil construction, but the sand-based construction types showed higher deficits. The overall rate of evapotranspiration was around 65 % of predicted values. Pore structure of the sand-based rootzones changed slowly over time, but water infiltration rates fell markedly. The soil constructions showed a reduction in the proportion of larger pore spaces in the top of the profile, and infiltration rates were consistently low. Plant death was associated with both high and low rates of nitrogen fertiliser, low rates of irrigation, and was especially apparent on the sand constructions not receiving phosphate fertiliser. Ingress of the weed species Poa annua (L.) occurred mainly on the soil constructions and its rate of ingress was enhanced by increased nitrogen input. Golf ball roll and various aspects of their behaviour after impact onto the turf with simulated 5-iron flight characteristics were measured. Roll length declined with increasing fertiliser rate. Hard greens produced long, high bounces and shallow pitch marks. High rates of both irrigation and nitrogen produced deeper pitchmarks and were associated with the tendency of balls to "screw back". A multivariate method of classifying the quality of golf greens on the basis of a small number of objective measurements was developed. The classes of greens derived were described in terms of their average visual merit, green "speed", bail behaviour after impact, and the treatment factors which they had received.
8
Rose, Terry. "Deep-placed phosphate fertiliser improves phosphorus uptake and seed yield of canola (Brassica napus L.) in a Mediterranean-type climate". University of Western Australia. Dept. of Soil Science and Plant Nutrition, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0237.
Testo completoAbstract (sommario):
In Mediterranean-type climates, topsoil frequently dries out during spring. Problems associated with reduced nutrient (P, K) availability in dry topsoil may be overcome by placing fertilisers deeper in the soil, where the soil is more likely to remain moist for longer periods as opposed to conventional fertiliser placement. Deep-P placement has resulted in significant yield improvements for lupin crops in Mediterranean environments because lupin crops generally require soil P supply during spring (throughout the flowering stage); in contrast, wheat yields have seldom improved with deep P placement, presumably because plants have accumulated sufficient P prior to spring (grain filling stage) for maximum grain yields. The P and K accumulation patterns of canola had not been investigated, and therefore any potential yield benefits of deep placed fertilisers were unknown. This study aimed to define the P and K demands of canola throughout the growing season, and assess the viability of deep placement of fertiliser in matching soil P and K supply to crop demand. The study further investigated the impact of deep placement of P fertiliser on root growth and distribution throughout the soil profile. Initial glasshouse studies compared the P and K accumulation patterns of several canola cultivars with wheat, and found that the P and K demand of canola continued until later into the season than wheat, but there was little difference in the P and K accumulation patterns of the various canola cultivars. Further experiments in sand culture determined that regardless of the level of K supply, canola plants had accumulated sufficient K for maximum seed yields by early flowering. Under high P supply, canola plants had accumulated enough P for maximum seed yields by early flowering, but when P supply during vegetative growth was just adequate, plants required a continual P supply until mid silique-filling to attain maximum yields. Because plants had accumulated sufficient K for maximum seed yields by early flowering (therefore topsoil drying in spring was unlikely to affect yields), further field experiments examined only deep placement of P fertiliser to improve P uptake and yields.
9
Smaill, Joshua Ballantyne. "Geochemical variations in glauconitic minerals : application as a potassium fertiliser resource". Thesis, University of Canterbury. Geological Sciences, 2015. http://hdl.handle.net/10092/10407.
Testo completoAbstract (sommario):
Nutrients for plant growth are often limited in soil systems and additions are required in the form of fertiliser. Potassium is an essential macro-nutrient for plants and demands for K are expected to increase in the future. Glaucony is an abundant marine mineral which may provide an alternative K-rich fertiliser resource. The South Island of New Zealand contains deposits of glaucony-rich rocks which were deposited in the Early- to Mid-Cenozoic during periods of low sedimentation to the seafloor. Here, the geochemistry of glaucony from the Waitaki Basin (Otago), the Waipara Greensand (North Canterbury) and the Stoney Creek Limestone (Karamea) was examined using spatially resolved geochemical analysis and dissolution experiments. Grain-by-grain analysis using Laser Ablation Induction Coupled Plasma Mass Spectrscopy (LA-ICP-MS) and Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM + EDS) revealed that glaucony from all deposits were of the mature type and were enriched in K. Glaucony derived from growth inside faecal pellets was found to contain elevated K and Fe concentrations compared to bioclast hosted glaucony. These variations can be explained by the physical properties of host grains and sea-floor redox conditions at the time of precipitation, both of which increased ionic mobility into the zone of glauconitisation. Solubility analysis showed that K^{+}
was released from glaucony more rapidly than any other element. Additionally, decreasing the pH and introducing an oxidising agent (i.e, birnessite which is ubiquitous in soil environments) accelerated K^{+}
release 13-fold. Trace metals including Cr, Zn, Cu and Ni were present in the solid phase analysis, however further investigation revealed that these elements were released into solution in low concentrations and may present a source of micro-nutrients, not a soil contaminant. These results suggest that glaucony may offer a source of slow releasing K fertiliser, and the South Island of New Zealand is ideally situated as a place to consider using glaucony as a locally sourced, environmentally sustainable K resource for agriculture.
10
Moursy, Hossam El-Din Mohamed Nayer. "Reaction kinetics and granulation studies in the production of nitrophosphate fertiliser". Thesis, Queen's University Belfast, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287365.
Testo completo
11
Young, Sarah Louise. "Effect of nitrogen fertiliser on bacterial community dynamics in arable soils". Thesis, University of Essex, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.423712.
Testo completo
12
Böhme, Michael Henry. "Use of bio-waste as fertiliser for the protected vegetable cultivation". Technische Universität Dresden, 2018. https://tud.qucosa.de/id/qucosa%3A33317.
Testo completoAbstract (sommario):
The number of biogas plants in Germany is increasing from 3,711 in 2007 to 8,075 in 2016. In these biogas plants, it occurred more than 50 Mt digestate. Therefore, several investigations are started to use digestate as organic fertiliser mostly for field crop cultivation. Experiment with tomatoes was carried out were digestate was used as a supplement to the growing media in an amount of 5%, 15%, and 25%, compared with a treatment of mineral fertiliser and lupine wholemeal. The tomato yield was highest in the treatment with mineral fertilisation, the yield with 25% digestate was only a little lower. More experiments are necessary for particular regarding the amount and frequency of fertilization with digestate from biogas plants. In Germany and in Vietnam the number of sheep flocks is increasing, high amounts of uncleaned sheep wool are available. Because of the high amount of nutrients - especially nitrogen -, sheep wool pellets could be used as multi-functional fertiliser in vegetable cultivations. Four types of sheep wool pellets have been tested in protected cultivation. Tomatoes were cultivated in a greenhouse using substrate culture with perlite, bark compost, sheep wool slabs, respectively, and sheep wool pellets as fertiliser. Best growth and highest yield for tomatoes were obtained using pine bark and perlite as a substrate, both fertilised with sheep wool pellets. Based on the results of the yield and the analyses of the nutrient content in plants it seems that sheep wool pellets can be used, for the cultivation of vegetables in greenhouses.Số lượng các nhà máy biogas tại CHLB Đức tăng từ 3.711 năm 2017 lên 8.075 năm 2016. Các nhà máy biogas sản sinh ra hơn 50 triệu tấn chất thải. Vì vậy đã có nhiều nghiên cứu liên quan đến sử dụng nguồn chất thải này làm phân bón hữu cơ cho canh tác nông nghiệp. Thí nghiệm với cà chua sử dụng chất thải biogas làm chất bổ sung dinh dưỡng cho giá thể trồng cây theo các tỷ lệ 5%, 15% và 25% đối chứng với công thức sử dụng phân hóa học và bột nguyên vỏ họ đậu. Năng suất cà chua thu được từ các công thức bổ sung chất thải biogas đều cao hơn đối chứng, chỉ có công thức bổ sung 25% có năng suất thấp hơn. Tuy nhiên vẫn cần có những nghiên cứu tiêp theo về lượng và tần xuất sử dụng bón phân với chất thải từ nhà máy biogas. Ở Đức và ở Việt Nam số lượng đàn cừu đang tăng lên, một lượng lớn lông cừu phế phẩm phát sinh. Với hàm lượng dinh dưỡng cao, đặc biệt là nitơ, viên nén từ lông cừu phế phẩm có thể sử dụng làm phân bón đa chức năng cho trồng trọt. Nghiên cứu đã sử dụng 4 loại viên nén lông cừu làm phân bón trong điều kiện trồng có kiểm soát. Cà chua được trồng trong nhà kính với 3 loại giá thể là perlite, vỏ cây thông đã ủ hoai, thảm lông cừu với phân bón là viên nén từ lông cừu phế phẩm. Năng suất cao nhất và đem lại sinh trưởng tốt nhất cho cây cà chua là công thức sử dụng vỏ cây thông và perlite. Dựa trên kết quả về năng suất và phân tích dinh dưỡng trong cây và sản phẩm, nghiên cứu cho thấy sự phù hợp của viên nén từ lông cừu phế phẩm làm phân bón cho canh tác rau trong nhà kính.
13
Jinadasa, N., of Western Sydney Hawkesbury University, of Science Technology and Agriculture Faculty e School of Horticulture. "Cadmium effects on vegetables : production, physiology and biochemistry". THESIS_FSTA_HOR_Jinadasa_K.xml, 1998. http://handle.uws.edu.au:8081/1959.7/456.
Testo completoAbstract (sommario):
Cadmium (Cd) is absorbed through the lungs and the digestive tract; however, for most human non-smokers, the major route of Cd entry into the body is by ingestion. Perhaps 5% of ingested Cd is absorbed and once absorbed, Cd accumulates mostly in the liver and kidneys, where it can cause a variety of health problems. This applies equally to grazing stock. The major entry point of Cd into the food chain is therefore uptakes of traces of Cd by crop plants. This thesis focuses on Cd in vegetables. The study was conducted in an Australian context, where geogenic Cd contributions to soils are typically low. Most of the Cd in soils on Australian vegetable farms originates from materials added to boost crop production. Phosphate fertilisers were and remain the dominant Cd source. Most Australian soils are P-deficient and high rates of P fertiliser are essential for successful vegetable cropping. The P fertilisers used throughout Australia were formerly made from guano deposits mined on Pacific Islands. These contained high percentages of Cd. Current rock sources contain lower Cd concentrations. Studies showed that all the vegetable samples which contained excessive Cd concentrations were leafy vegetables, including cabbage, lettuce, silverbeet, parsley and bok choy. Cadmium impaired photosynthesis; reduced dry weight of the whole plant; slowed leaf elongation rate; decreased the length of fully expanded leaves; slowed the rate at which new leaves appeared; and altered foliar concentrations of Zn, Mn, Cu, Ca and S. These profound changes affected all parts of the plant; consequently, Cd did not affect the proportion of dry weight partitioned to the roots, stems and leaves.Doctor of Philosophy (PhD)
14
Kihanda, Francis Muchoki. "The role of farmyard manure in improving maize production in the sub-humid highlands of Central Kenya". Thesis, University of Reading, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360728.
Testo completo
15
Chapman, Ross. "The effect of slurry in the maintenance of the clover component in mixed grass/clover swards". Thesis, University of Aberdeen, 1988. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU022515.
Testo completoAbstract (sommario):
Low input grassland systems depend on cheap fertiliser sources, such as clover or animal manures, to maintain sward productivity. Clover is a poor competitor for phosphate (P2O5) and potash (K2O), a mixed sward will therefore require adequate inputs of these nutrients. Nitrogen (N) leads to the suppression of clover. Recycling of cattle slurry would be followed by small N and P2O5 but large K2O effects. The K2O and P2O5 would be expected to have a beneficial effect on the clover while the N would be detrimental. Two investigations into the balance between these aspects of cattle slurry on clover in a mixed sward were performed. Slurry N led to clover suppression, this effect was strongest following spring applications. K2O had a beneficial effect on the clover, the P2O5 supplied had a small positive effect but was insufficient to fully meet the clover's requirements. There was a suggestion that these beneficial effects were strongest following summer applications. In addition to these fertiliser effects, non nutritional secondary effects often followed slurry with a deleterious action on the clover. These effects were most common following higher rates of slurry and summer applications. A further investigation was performed to establish the effect of varying clover variety and companion grass species on the clover's susceptibility to cattle slurry N and secondary effects and the nature of these effects following pig slurry applications. This revealed that clover's susceptibility to slurry N was inversely related to leaf size. No difference in secondary effects susceptibility arose with different clover varieties or companion grass species. Pig slurry was not accompanied by secondary effects. Slurry applications to mixed swards may therefore have positive and negative nutritional effects on the clover component but non nutritional secondary effects may also act with a deleterious effect on the clover.
16
Seasman, Melanie. "Impacts of long-term fertiliser regimes on microbial communities in grassland soils". Thesis, University of Newcastle Upon Tyne, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.408464.
Testo completo
17
Batsmanova, L. M., L. M. Gonchar, N. Yu Taran e A. A. Okanenko. "Using a Colloidal Solution of Metal Nanoparticles as Micronutrient Fertiliser for Cereals". Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35441.
Testo completoAbstract (sommario):
We have developed the technology of using the colloidal solution of metal nanoparticles as fertilizers, which characterized by easiness to use, environmental safety and absence of corrosive properties. Colloidal solutions of biogenic metals, water-based, such as Fe, Mn, Zn, Mo, Co, Cu, and Ag, produced by a patented method of bittern natural colloidal solutions of the above metals were used. Seed treatment with colloidal solution of metal nanoparticles stored genetic purity grade, increased plant immune status via regulation of oxidative metabolism, photosynthetic activity, resistance to pathogens, and optimization of water regime of various winter wheat ecotypes during ontogenesis. Results of industrial tests proved that it is environ-mentally safe and economically feasible, since the cost of one liter of colloidal solutions of nanoparticles of metals ranges from 50-70 USD providing 500% level profitability. So, for the first time managed to opti-mize the function of biogenic metals through the use of physical and chemical characteristics of colloidal nanoparticle solutions to realize the productive potential of plants.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35441
18
Mlambo, Patricia Zanele. "Exploring the fertiliser potential of biosolids from algae integrated wastewater treatment systems". Thesis, Rhodes University, 2014. http://hdl.handle.net/10962/d1013342.
Testo completoAbstract (sommario):
High rate algae oxidation ponds (HRAOP) for domestic wastewater treatment generate biosolids that are predominantly microalgae. Consequently, HRAOP biosolids are enriched with minerals, amino acids, nutrients and possibly contain plant growth regulator (PGR)-like substances, which makes HRAOP biosolids attractive as fertiliser or PGR. This study investigated HRAOP biosolids as a starting material for a natural, cost-effective and readily-available eco-friendly organic fertiliser and/or PGRs. Various HRAOP extract formulations were prepared and their effect on plant growth and development was evaluated using selected bioassays. Initial screening included assessing the effect on change in specific leaf area, radish cotyledon expansion as an indicator of PGR-like activity, and seed germination index (GI). More detailed studies on fertiliser efficacy and PGR-like activity utilised bean (Phaseolus vulgaris) and tomato (Solanum lycopersicum) plants. Combined effects of sonicated (S) and 40% v/v methanol (M) extract (5:1 SM) had impressive plant responses, comparable to Hoagland solution (HS). Other potentially fertiliser formulations included 0.5% M, 1% M, 2.5% S and 5% S formulations. The 5:1 SM and 5% S showed greater PGR-like activity, promoting cotyledon expansion by 459 ± 0.02% and 362 ± 0.01%, respectively. GI data showed that none of the formulations negatively impacted germination. Further investigation showed that the 5% S formulation increased leaf length, width and area by 6.69 ± 0.24, 6.21 ± 0.2 mm and 41.55 ± 0.2 mm². All formulated fertiliser extracts had no adverse effect on chlorophyll content and plant nutrient balance as indicated by C:N (8-10:1) ratio. In addition, plants appeared to actively mobilise nutrients to regions where needed as evidenced by a shift in shoot: root ratio depending on C, N and water availability. Furthermore, 5% S caused a 75% increase in tomato productivity and had no effect on bean productivity. Whereas, 5:1 SM and 1% M formulation improved bean pod production by 33.3% and 11%, respectively but did not affect tomato production. Harvest index (HI) however indicated a 3% reduction in tomato productivity with 5:1 SM and little or no enhancement in bean productivity with both 5:1 SM and 5% S treatments. Bean plants treated with 5:1 SM and 5% S produced larger fruits, which could be an indication of the presence of a PGR effect. Overall, HRAOP biosolids extracts prepared and investigated in this study demonstrated both fertiliser characteristics and PGR-like activity with performances comparable and in some cases exceeding that of commercial products. However additional research is needed to confirm presence of PGR-like activities and fertiliser efficacy.
19
Maddern, Rowan John. "Low water-soluble superphosphate fertiliser for pasture production in south-western Australia". Thesis, Curtin University, 2016. http://hdl.handle.net/20.500.11937/2242.
Testo completoAbstract (sommario):
Single superphosphate is derived from chemically treating rock phosphate into relative proportions of monobasic, dibasic and tribasic calcium phosphate to produce a commonly used source of phosphorus fertiliser for pasture systems. The leaching of phosphorus on susceptible soil types contributes to eutrophication and environmental damage. By modifying the chemistry of single superphosphate to match a soils phosphorus binding index and rainfall conditions, pasture dry matter yield can be maintained and leaching of phosphorus significantly reduced.
20
Utami, Issa Dyah. "An approach to the assessment of resilience in Indonesian fertiliser industry supply networks". Thesis, University of Leeds, 2016. http://etheses.whiterose.ac.uk/13823/.
Testo completoAbstract (sommario):
The fertiliser industry is a significant contributor to the Indonesian economy. Given the need to distribute its products to customers on the 17,000 islands making up the Indonesian archipelago, capacity and availability of ports is a major factor in managing fertiliser product lifecycles and the supply networks. Fluctuations in the availability of infrastructure influence levels of risk in the supply networks. Supply network resilience is important to maintain the performance of the Indonesian fertiliser industry. Currently, decision makers in the Indonesian fertiliser industry use risk assessment reports to assess resilience. Discussions with Indonesian fertiliser industry managers highlighted a second, port management, report that is used to evaluate the availability of infrastructure. An opportunity was identified to use both reports in assessing resilience. This thesis is based on the premise that the risk assessment report can be used as an information resource for resilience assessment. A theoretical framework, based on a synthesis of literature and interviews with industry practitioners, is proposed. Results from interviews concluded that the supply network is a system consisting of social and technical factors. Thus, the approach needed to include both factors. Secondary data collected from risk assessment reports and primary data from brainstorming with key people in the industry were used to validate the approach. The theoretical framework was used to inform the construction of a conceptual model that was populated with data from a real-world case study. A simulation model was then built to translate the conceptual model into a practical application. The simulation model was used to investigate the results of the resilience assessment in different scenarios and predict levels of risk. Early feedback from Indonesian fertiliser industry practitioners indicated that the model could be valuable in the assessment of resilience. This research provides a new approach for managers to predict the level of risk in supply networks. Since the Indonesian fertiliser industry is owned and governed by the Indonesian state, the approach could be used by policy makers as a prototype to assess the current condition of the supply network in Indonesian industries and the output could be used to underpin the planning of supply networks in the future. For academia, the approach provides a new theoretical framework for research on supply network resilience and presents a real example of how agent-based modelling might be used as a tool to support the assessment of resilience.
21
Binoka, Danfung Teresa. "Effect of Phosphorus Fertiliser on Soil Organic Matter Composition of Hill Country Pasture". The University of Waikato, 2008. http://hdl.handle.net/10289/2225.
Testo completoAbstract (sommario):
Soil organic matter is important as storage for carbon and nutrients, supporting soil structure, and as a filter for pollutants entering the soil ecosystem. The recovery of soil organic matter in depleted soils can take decades, or even hundreds of years. It has been assumed that in non-eroding pasture, soil carbon levels either increase or not change over time. However, some recent studies have suggested that fertiliser addition to pasture soils may contribute to decreases in soil carbon content. My hypotheses were: 1. As P fertiliser loadings increase the soil carbon content and C:N ratio will decrease. 2. Changes in C pools will be greater in the more active pool (readily available carbon, and microbial biomass carbon) within the soil total carbon The study was undertaken at a long term fertiliser trial, established in 1980, at the Whatawhata Hill Country Research Station west of Hamilton, New Zealand. The fertiliser trial has P fertiliser application rates maintained since 1984. Olsen P, total C, total N, labile carbon, respirable carbon, specific respiration rate, microbial biomass C, microbial quotient, mineralised N, microbial biomass N, microbial N quotient, and mineralised N per microbial biomass nitrogen, C:N ratio, and soil pH were measured on soil samples collected from 12 paddocks with six P fertiliser loading (0, 10, 20, 30, 50, 100 kg P ha-1 yr-1). As expected, the available P (Olsen P) increased significantly (P less than 0.001) with increasing P fertiliser application rate. Total carbon, labile carbon, and total nitrogen all decreased significantly (P less than 0.05) with increasing P fertiliser application. No significant relationships were found between P fertiliser and respirable carbon, microbial carbon, microbial (C) quotient, microbial specific respiration, microbial nitrogen, microbial (N) quotient, mineralised N, or C:N ratio. The first hypothesis was rejected as the C:N ratio did not change with increased P fertiliser application. However, both C and N decreased with increased P fertiliser application. The second hypothesis was, therefore, accepted in part because there was a decrease in labile carbon (readily available carbon) and total carbon, with P fertiliser application, but no relationship was evident for the respirable carbon and microbial biomass.
22
Pask, Alistair. "Optimising nitrogen storage in wheat canopies for genetic reduction in fertiliser nitrogen inputs". Thesis, University of Nottingham, 2009. http://eprints.nottingham.ac.uk/12567/.
Testo completoAbstract (sommario):
Firstly, increasing true stem RN capacity as means to increase the maximum rate of N uptake (kg N per day) during stem elongation may be feasible through optimisation of traits such as stem length and wall thickness. Secondly, modifying true stem RN unloading by increasing storage N in relation to accumulation N may offer a realistic mechanism for improving crop BPE and thus UTE. Such an increase in true stem NRE might be achieved through manipulation of key N assimilation enzymes. Thirdly, it may be possible to select for ‘stay-green’ traits associated with lower leaf lamina NRE and lower grain N% to boost UTE. However, in each case further phenotyping studies are required to characterise genetic variability, identify the most appropriate germplasm resources for genetic studies, and to identify appropriate genetic sources of variation for breeding.
23
Javid, Shahid. "Residual effect of phosphate fertiliser measured using the Olsen method in Pakistani soils". Thesis, University of Reading, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342535.
Testo completo
24
Nicholsby, J. A. "The fate of fertiliser nitrogen when applied to winter wheat under field conditions". Thesis, University of Reading, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356236.
Testo completo
25
Lambrechts, Rhynhardt. "A performance and energy evaluation of a fertiliser-drawn forward osmosis (FDFO) system". Thesis, Cape Peninsula University of Technology, 2018. http://hdl.handle.net/20.500.11838/2747.
Testo completoAbstract (sommario):
Thesis (Master of Engineering in Chemical Engineering)--Cape Peninsula University of Technology, 2018.Globally, water is considered an essential resource as it sustains human, animal and plant life. Water is not only essential for all forms of life but imperative for economic growth. The world’s population is increasing at a disquieting rate, which will result in an increased demand for fresh water and food security. The agricultural industry is the main consumer of global freshwater and utilises fertilisers in order to meet food demands. The demand for water in South Africa (SA) has increased considerably due to the rapid expansion of the agricultural industry, and of the municipal and industrial sectors. Agricultural developments in SA are affected greatly as the country is facing a current drought crisis as a result of low rainfall and large water demands. With an abundance of saline water globally, desalinisation will be a major contributor to solving the global freshwater crisis. With limited fresh water resources accompanied by the agricultural industry as a major consumer, alternative measures are required to desalinate water specifically for agricultural use. Forward osmosis (FO) is a membrane technology that gained interest over the past decade because it has several advantages over pressure-driven membrane processes such as reverse osmosis (RO). FO technology is based on the natural osmotic process which is driven by a concentration gradient between two solutions separated by a semi-permeable membrane. Naturally, water will permeate through the membrane from a solution of low solute concentration or low osmotic pressure (OP) known as a feed solution (FS) to a solution of a higher concentration or higher OP also known as a draw solution (DS). Whilst various research studies have contributed to several advances in FO, several process limitations such as reverse solute flux (RSF), concentration polarisation (CP) and membrane fouling remain problematic, hindering FO for large-scale applications. Further investigation is therefore warranted and crucial in order to understand how to mitigate these limitations to develop/improve future processes. The aim of this study was to evaluate a fertiliser-drawn forward osmosis (FDFO) system by investigating the effects of membrane orientation, system flow rate, DS concentration, and membrane fouling on an FDFO systems performance and energy consumption. The FS used was synthetic brackish water with a sodium chloride (NaCl) content of 5 g/L whereas a potassium chloride (KCl) synthetic fertiliser was used as a DS. The membrane utilised was a cellulose triacetate (CTA) membrane and was tested in forward osmosis mode (FO mode) and pressure retarded osmosis mode (PRO mode) whilst the system flow rate was adjusted between 100, 200 and 400 mL/min. Additionally, the DS concentration was altered from 0.5, 1 and 2 M KCl, respectively. Experiments were performed using a bench scale FO setup which comprised of an i) FO membrane cell, ii) a double head variable peristaltic pump for transporting FS and DS’s respectively, iii) a digital scale to measure the mass of the DS, iv) a magnetic stirrer to agitate the FS, v) two reservoirs for the FS and DS, respectively, vi) a digital multiparameter meter to determine FS electrical conductivity (EC) and vii) a digital electrical multimeter to measure system energy consumption. Each experiment comprised of seven steps i) pre-FDFO membrane control, ii) membrane cleaning, iii) FDFO experiment, iv) post-FDFO membrane control, v) membrane cleaning, vi) membrane damage dye identification and vii) membrane cleaning. Pre- and post-FDFO membrane control experiments operated for 5 h whilst each membrane cleaning procedure operated for 30 min. The FDFO experiment operated for 24 h whilst the membrane damage dye identification operated until a minimum of 10 mL water was recovered. The process parameter which largely contributed to a beneficial system performance and specific energy consumption (SEC) was the increase in DS concentration. Water fluxes increased approximately threefold from a DS concentration increase from 0.5 to 1 M, followed by an additional 30 to 50 % rise in water flux at a DS concentration increase 1 to 2 M. SEC decreased by 58 and 53 % for FO and PRO modes, respectively, with a DS concentration increase from 0.5 to 1 M. An additional 35 and 37 % SEC reduction for FO and PRO modes was obtained for a DS concentration increase from 1 to 2 M. Altering the membrane from FO to PRO did not contribute to a beneficial system performance nor did it improve SEC. However, at a DS concentration of 0,5 M, the PRO mode obtained a 5.3 % greater water recovery compared to the FO mode. Conversely, at a DS concentration of 1 and 2 M, the FO mode achieved 5.4 and 7.0 % greater water recoveries compared to the PRO mode. The increase in flow rate also did not increase system performance significantly, however, a fluctuation in system SEC was observed. Throughout the study, no membrane fouling was observed, however, possible minute traces of membrane fouling could be observed from the membrane surface electron microscope (SEM) images. Additionally, minor changes in post- FDFO membrane control water recovery results were noticed which support the possible occurrence of membrane fouling during the FDFO experiment.
26
Roche, Leanne M. "Fate and transport of fertiliser nitrogen under spring barley cultivation on contrasting soils". Thesis, University of Reading, 2017. http://centaur.reading.ac.uk/72465/.
Testo completoAbstract (sommario):
Mineral nitrogen (N) fertiliser inputs are essential for achieving high crop yields in agricultural production systems and can help to drive farm profitability. However, when N fertiliser is applied to soil it can be lost to the environment and have negative consequences. Such losses include nitrous oxide (N2O) emissions, ammonia (NH3) emissions and nitrate (NO3-) leaching to waterways. This loss of N fertiliser also represents a substantial economic loss of N from the farm. The dominant N fertiliser source used on arable farms in Ireland is calcium ammonium nitrate (CAN) which, in environmental terms, principally contributes to N2O emissions and NO3- leaching. Switching from CAN to urea has the potential to reduce these N loss pathways, but can result in substantially higher NH3 emissions. Nitrogen stabilisers are compounds that can be added to N fertilisers to reduce these N losses. There are two main types of N stabilisers currently available: urease inhibitors and nitrification inhibitors. Urease inhibitors are used to regulate urea fertiliser hydrolysis and to reduce NH3 emissions and nitrification inhibitors are used to regulate the soil NO3- pool and to reduce N2O emissions and NO3- leaching. The urease inhibitor used in this study was N-(n-butyl) thiophosphoric triamide (NBPT) and the nitrification inhibitor used was dicyandiamide (DCD). An additional N fertiliser formulation, urea + the maleic – itaconic co-polymer (MICO), was added in 2014. Two field sites cropped with spring barley were established in 2013 and the overall study was conducted for three years. Nitrous oxide emissions, NH3 emissions, NO3- leaching and grain yield and N uptake were measured. The N fertilisers evaluated were CAN, urea, urea + NBPT, urea + DCD and urea + NBPT + DCD and Urea + MICO in 2014. Results showed that N2O emissions were low (over 50% lower than the IPCC default emission factor of 1%) regardless of the N fertilisers used but using the N stabilisers NBPT and DCD reduced emissions by up to 62%. There was no significant effect (P>0.05) of fertiliser formulation on NO3- leaching but there was a significant effect (P < 0.05) on NH3 emissions with urea + NBPT reducing emissions compared to urea. There was no significant effect (P > 0.05) of fertiliser formulation on spring barley grain yield but there was significantly lower N uptake with urea compared to CAN. Using urea + NBPT had similar N uptake levels to CAN. Overall this study showed that switching N fertiliser source from CAN to urea stabilised with the urease inhibitor NBPT can reduce environmental N losses and increase fertiliser N use efficiency (fNUE). This provides farmers with options to increase the environmental and economic sustainability of their arable farming systems while maintaining crop yields and quality.
27
David, Jean Lynette. "Agrochemical abuse : reasons for pesticide and fertiliser overuse among arable farmers of Guyana". Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/agrochemical-abuse-reasons-for-pesticide-and-fertiliser-overuse-among-arable-farmers-of-guyana(47a7139f-2c35-42f4-9472-9aee206481e9).html.
Testo completoAbstract (sommario):
The overuse of agrochemicals by arable crop farmers in Guyana is of increasing concern. But the literature reveals a paucity of information concerning the reasons for farmers‟ persistence of this inappropriate practice. No previous study has been conducted using a structured format to reveal the scope or reasons for farmers‟ sustained overuse of these chemicals. This research adopted an original structured-type approach, suitable for unearthing and explaining the reasons for this phenomenon. The study was theoretically and analytically guided by the theory of practices and critical realist theory respectively, to identify the prevalence, intensity and significant factors of farmer‟s pesticide and fertiliser overuse, but more importantly to elucidate reasons for overuse and formulate relevant recommendations. This investigation utilised a mixed methods strategy of complementary quantitative and qualitative techniques; comprising analysis of data from 229 farm unit surveys and 38 farmer and 19 key informant interviews, respectively. Quantitative analysis, conducted via SPSS software using tables and regression, revealed widespread prevalence of both pesticide and fertiliser overuse among farmers. The overuse consisted of high frequencies and concentrations of the chemicals. The study notes the factors which were significantly associated with overuse including farmers‟ age, education level, area cultivated, land tenure status and the „source-type‟ of information they accessed. However, qualitative analysis, utilising a grounded-theory approach with the aid of NVivo software, demonstrated that unlike the suggestions by other studies, the reasons for farmers‟ overuse were not the single factors which showed statistical significance for overuse practices. On the contrary, this study revealed original findings, which indicated that the reasons for farmers‟ overuse practices were embedded within an intricate network of contingent, support and contextual factors. These explained both the instigation and continuance of agrochemical overuse by farmers. Overall the findings emphasise the need for policy redress, especially regarding the mandate and conduct of farmer-training regarding chemical use, and the regulatory enforcement of appropriate agrochemical use. Understanding the reasons for farmers‟ inappropriate practices revealed new insight into the interpretation of these practices; as consequences of policy deficiency instead of farmer delinquency. Thus, the implications provided to address this problem of farmers‟ agrochemical overuse presented a new orientation to the type of suggestions previously suggested in other studies. The proposals indicated by this study for a targeted resolution of overuse in arable farmers of Guyana are more policy-oriented than farmer-targeted, since this study revealed that farmers‟ overuse behaviour is largely a response to policy-influenced support and contextual factors.
28
Harty, Mary. "Evaluation of fertiliser formulations on grassland N use efficiency and nitrous oxide emissions". Thesis, Queen's University Belfast, 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.706688.
Testo completoAbstract (sommario):
Obligations to reduce greenhouse gas emissions (GHG) in agriculture (30% below 1990 levels by 2030) have seen renewed interest in switching from ammonium nitrate (AN) based to urea based fertilisers as a mitigation strategy for GHG emissions. The performance of a comprehensive range of urea based formulations was compared to Calcium AN in a two-year study over three sites across the island of Ireland. The performance criteria were nitrous oxide (N2O) emissions, ammonia (NH3) emissions, grassland yield and N uptake encompassing a range of soils and climatic conditions. The results of the main field experiments showed that all urea formulations reduced N2O emissions relative to CAN in all site-years with larger reductions under the heavier and wetter soil conditions. The inclusion of the urease inhibitor NBPT also reduced NH3 emissions relative to urea and maintained yield and N uptake relative to CAN in all six site-years. In contrast, the nitrification inhibitor dicyandiamide (DCD) showed inconsistent effects on NH3 emissions compared to urea and reduced yield and N uptake relative to CAN in three and four of six site-years respectively. The most climate favourable option was urea incorporating NBPT, however as it is more expensive than urea, a tax on urea or financial incentive to use NBPT will be required to ensure farmers select the stabilised urea incorporating NBPT over urea. In addition, the assessment of N2O emissions from the same fertilisers also contributes to a more detailed accurate national inventory of mineral fertiliser N2O emissions. The tier 1 reporting of emission factors (EF) under the Intergovernmental Panel on Climate Change (IPCC) requirements uses a default EF for N2O from soils of 1% of the N applied, irrespective of its form even though N2O emissions tend to be higher from nitrate-containing fertilisers compared to urea. This research generated tier 2 emission factors for mineral N fertiliser by formulation and soil type.
29
Roberts, Shawn Conrad. "Surface/groundwater interactions in the Lincolnshire limestone aquifer". Thesis, University College London (University of London), 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313820.
Testo completo
30
Street, N. J. "A novel fluorescence based method for the determination of nitrate in aqueous media". Thesis, Cranfield University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.323924.
Testo completo
31
Bird, Deborah Jane. "Experimental and modelling studies of nitrogen oxides of interest in the atmosphere". Thesis, University of York, 1995. http://etheses.whiterose.ac.uk/10856/.
Testo completo
32
Winker, Martina. "Pharmaceutical residues in urine and potential risks related to usage as fertiliser in agriculture". Hamburg [TuTech Innovation], 2009. http://d-nb.info/994334494/34.
Testo completo
33
Manson, Philip Steven. "The sub-lethal effects of ammonium nitrate fertiliser on the common frog 'Rana temporaria'". Thesis, De Montfort University, 2002. http://hdl.handle.net/2086/10673.
Testo completoAbstract (sommario):
Increased use of fertilisers and pesticides has raised levels of agricultural pollution in surface and ground waters. Organism using these water sources are at risk of exposure to ammonium nitrate fertiliser. The effects of ammonium nitrate on spawn, larva and adult common frogs was investigated using ammonium nitrate fertiliser in solution and granular form at various stages of frog development. The concentrations used, up to 100mgIL NO-3-N used reflect nitrate concentrations on agricultural land in the United Kingdom in water bodies located within and adjacent to agricultural land at times when common frogs are actively breeding or developing. Nitrate concentrations in frog breeding ponds were high (> 1OOmgIL NO-3-N) during the frog breeding season, especially when water entered from field drains, but significantly lower (<25 mglL) for the remainder of the year. Frogs did not show a selective preference for ponds with low nitrate concentrations. Frog spawn swelled when exposed to ammonium nitrate and its viability was reduced (87% survival in controls; 63% at 80 mgIL NH\NO-3). The 96 hour LCso for frog larvae was 781 mglL (95% confidence intervals of 587 to 942) and the 48 hour ECso was 399 mgIL (95% Cl = 234 to 546). Long term exposure to 100 mgIL NW4NO-3 in a flow through system reduced larval survival from 85% (controls) to 53% after 96 days, with most mortality occurring during the three weeks prior to metamorphosis. Larval growth was affected marginally but with some evidence of enhanced mass in the treated larvae, especially at the lowest nitrate concentration of 25 mWL NH\NO-3. Metamorphosis in this group was earlier than in the other groups; by day 80, 48% of the metamorphs had emerged, by comparison with 38, 34 and 24% for the controls and those exposed to 50 and 100 mgIL NW4NO'3 respectively. Furthermore, the mass of emergent metamorphs in the 25 mgIL treatment group was significantly higher than that of the controls.
34
Burns, Lisa C. "Cycling of fertiliser-derived N in a Sitka spruce ecosystem after 15N-urea application". Thesis, University of Aberdeen, 1992. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU545404.
Testo completoAbstract (sommario):
Low recovery rates of fertiliser N in tree biomass are frequently reported due to the inefficiency of N fertilisers in afforested ecosystems. At Culloden (North East Scotland), only 13&'37 of 15N-urea fertiliser applied to Sitka spruce could be recovered in the above-ground tree biomass two years after fertilisation. Fertiliser N not taken up by trees was largely 'locked-up' in stable organic forms of N within the LFH layers of the soil profile. 15N-labelled litter was used in both field and microcosm experiments, the release and fate of litter-derived-N (LDN) being traced over the course of two growing seasons. In both experiments, the microbial biomass acted as a major sink for LDN. Measurement of soil microbial biomass was calibrated for Culloden soil samples by determination of a kEN-factor. Tree uptake of LDN, in the field, occurred within one month of labelled-litter application, with the foliage being the largest sink for LDN. Approximately 30&'37 of the N within the labelled-litter layer was taken up by the trees over the course of two growing seasons and was equivalent to 5.4 kg LDN ha-1 y-1. There was considerable mixing of the LFH and peat layers in Sitka spruce microcosm soil profiles. This was probably due to elevated soil animal population densities. After 18 months, approximately 83&'37 of LDN had been redistributed to other N pools in the microcosm. Uptake of LDN by seedlings accounted for 15.7&'37 of LDN after 12 months, the largest sink being the foliage, equivalent to 6.16 kg LDN ha-1 y-1. Again, the microbial biomass was a major sink for LDN. Measurement of availability (NH4+) N in Culloden soil samples incubated at different matric potentials and temperatures, appeared not to reflect N mineralisation rates. There was a strong interaction between temperature and soil matric potential, seedling uptake of N being greatest at 15oC and -16.0 kPa. The rate of turnover of the microbial biomass pool was identified as the key determinant of the rate of processing of LDN in forest soils.
35
Baldwin, A. F. "Studies on the decomposition of the organic components of sewage sludge with reference to the retention and release of toxic elements". Thesis, University of Oxford, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370309.
Testo completo
36
Van, der Linde Marné. "Embedding an activity driven operational accounting framework in a fertiliser company / van der Linde, M". Thesis, North-West University, 2011. http://hdl.handle.net/10394/7589.
Testo completoAbstract (sommario):
Activity–based Costing is a management tool which both covers the shortcomings of traditional costing methods and provides better cost information. There is a lot of competition in the economic environment where only the “fittest will survive”. The overall picture of ABC will bring operational processes to financial figures more visibly and accurately. Operational processes have changed dramatically over the past centuries, therefore we need to change our old way of doing things. Processes get more automated, thus there are higher percentages of variable and indirect costs.
When costs are visible, ACME Fertilizer can compete with confidence because they will know when a transaction is not financially beneficial any more. The actual cost of the final product or output is of critical importance. Activities which are not adding value to the process must be identified and eliminated or else costs will be inflated unnecessarily. Competitors will get a higher market share and sales because they might be able to enter the market at a lower price. The end user is extremely price–sensitive, and will accept the lower monetary value offer if the quality is equivalent.
It is of critical importance that companies understand and be aware of the true costs of their products. ABC has the ability to assist companies to strive for cost–competitive excellence.
In this mini–dissertation, a comparison between ABC and the traditional costing method in a fertilizer company attempts to investigate the distortion of cost. The same scenario is used for the two different costing methodologies: ABC versus the traditional method. The results are discussed and a conclusion with recommendations is made. By analysing the results, the non–value adding processes can be eliminated and management can shift their focus to the relevant activities. This will assist ACME Fertilizer’s management towards better decision–making and better competitiveness.
ACME manufactures and blends different mixes of fertilizer. The manufacturing of a product consists of various processes and activities from where the raw material enters the factory premises to the manufacturing, bagging and distribution of the final product. The cost of the raw material can be affected by fluctuating commodity prices, exchange rates and other unforeseen circumstances, for example the recent instances of Somali Piracy and so forth. Overheads and indirect costs get allocated based on the activities required to manufacture the final product. Products will not absorb costs which do not have a direct impact on the manufacturing of the final product or intermediates. The first step of the implementation of an ABC system is to identify the output or the product of which costing needs to be done. The
4
process and activities must be identified as well as the costs applicable to these activities. Costs then get allocated to the cost pools based on the activity driver per cost pool. The final cost can be calculated and assigned, per cost driver, to the final product or output.
The main objective of this study was to determine the feasibility of implementing an ABC system within ACME Fertilizer. The results proved that with the traditional costing method, all the costs are not visible and may be distorted. Thus, the cost of a product will be understated – in other words all the actual costs occurred were higher than the budgeted costs and will not be recovered through the cost of sales. Instead it will take a bite out of the annual profit! On the other hand, should the cost of a final product be overstated, more costs are to be recovered and this becomes a snowball effect. Companies have to either contribute its margin to remain competitive or increase the price of the product and the risk of lost sales and market share increases.
ABC is a useful tool to use to control and have visibility of the costs, improved decision–making abilities and the possibility of closely shaven profits to ensure that the necessary volumes get manufactured. The right product, at the right quantity, at the right price!Thesis (M.Com. (Management Accountancy))--North-West University, Potchefstroom Campus, 2012.
37
Gash, Alan Frederick Jones. "The influence of nitrogen fertiliser applications on the cereal aphids Metopolophium dirhodum and Sitobion avenae". Thesis, University of Birmingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368789.
Testo completo
38
Winker, Martina [Verfasser]. "Pharmaceutical residues in urine and potential risks related to usage as fertiliser in agriculture / Martina Winker". Hamburg : [TuTech Innovation], 2009. http://d-nb.info/994334494/34.
Testo completo
39
Lekasi, John Kennedy. "Manure management in the Kenya Highlands : collection, storage and utilisation to enhance fertiliser quantity and quality". Thesis, Coventry University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.323520.
Testo completo
40
Baggie, Idriss. "Effect of organic residue and inorganic fertiliser phosphorus on phosphorus transformations and utilisation by upland rice". Thesis, University of Reading, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.502488.
Testo completoAbstract (sommario):
The aim of the study was to examine the effect of combined use of organic residue with inorganic fertiliser-P on organic residue decomposition, P transformations and utilisation by upland rice. Five agroforestry tree prunings (organic residues) were incubated without and with inorganic fertiliser-P for 56 days using soil as inoculum only. Decomposition and P release were in the same order i.e. Gliricidia sepium > Senna siamea > Leucaena leucocephela > Paraserienthus falcataria > Acacia mangium. The lignin, polyphenol and cellulose contents and their ratios to the P content of the residue influenced decomposition and hence P release. Added inorganic fertiUser-P had no effect on decomposition. A greater proportion of inorganic fertiliser-P was recovered when applied with low quality residue and less with high quality residue. Gliricidia sepium and Acacia mangium prunings were incubated without and with morganic fertiliser-P for 56 days in high and low P status soils. Gross mineralisation was estimated by isotopic dilution. Unlike Acacia, Gliricidia increased gross mineralisation in the low P status soil with weaker P sorbing capacity although net mineralisation was not attained. Inorganic fertiliser-P had no effect on gross mineralisation. Organic residue influenced both the inorganic and organic labile soil P fractions while inorganic fertiliser-P influenced only the labile inorganic P fractions. Upland rice (ROK 16) grown on the two soil types treated without and with Gliricidia and inorganic fertiliser-P indicated increased dry shoot weight and total P uptake in the low P soil and not the high P soil. With a double isotopic labelling technique, it was observed that in the low P status soil, Gliricidia P-accounted for over 50% of the total rice P uptake followed by organic-P (25%). Over 80% of the total P uptake in the high P status soil was soil-P. Organic residue increased the quantity of inorganic fertiliser-P utilised but not the native soil P.
41
Mansor, Shazali Abu. "Malaysia's 'strategic vision' and the international economy : a case study of the ASEAN Bintulu fertiliser industry". Thesis, University of Salford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.426872.
Testo completo
42
Hill, Sarah. "A predictive model of the effects of agricultural fertiliser on the common frog (Rana temporaria L.)". Thesis, University of Leicester, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243271.
Testo completo
43
Harms, Allan. "Fast pyrolysis and nitrogenolysis of biomass and biogenic residues : production of a sustainable slow release fertiliser". Thesis, Aston University, 2013. http://publications.aston.ac.uk/18728/.
Testo completoAbstract (sommario):
The production of agricultural and horticultural products requires the use of nitrogenous fertiliser that can cause pollution of surface and ground water and has a large carbon footprint as it is mainly produced from fossil fuels. The overall objective of this research project was to investigate fast pyrolysis and in-situ nitrogenolysis of biomass and biogenic residues as an alternative route to produce a sustainable solid slow release fertiliser mitigating the above stated problems. A variety of biomasses and biogenic residues were characterized by proximate analysis, ultimate analysis, thermogravimetric analysis (TGA) and Pyrolysis – Gas chromatography – Mass Spectroscopy (Py–GC–MS) for their potential use as feedstocks using beech wood as a reference material. Beech wood was virtually nitrogen free and therefore suitable as a reference material as added nitrogen can be identified as such while Dried Distillers Grains with Solubles (DDGS) and rape meal had a nitrogen content between 5.5wt.% and 6.1wt.% qualifying them as high nitrogen feedstocks. Fast pyrolysis and in-situ nitrogenolysis experiments were carried out in a continuously fed 1kg/h bubbling fluidized bed reactor at around 500°C quenching the pyrolysis vapours with isoparaffin. In-situ nitrogenolysis experiments were performed by adding ammonia gas to the fast pyrolysis reactor at nominal nitrogen addition rates between 5wt.%C and 20wt.%C based on the dry feedstock’s carbon content basis. Mass balances were established for the processing experiments. The fast pyrolysis and in-situ nitrogenolysis products were characterized by proximate analysis, ultimate analysis and GC– MS. High liquid yields and good mass balance closures of over 92% were obtained. The most suitable nitrogen addition rate for the in-situ nitrogenolysis experiments was determined to be 12wt.%C on dry feedstock carbon content basis. However, only a few nitrogen compounds that were formed during in-situ nitrogenolysis could be identified by GC–MS. A batch reactor process was developed to thermally solidify the fast pyrolysis and in-situ nitrogenolysis liquids of beech wood and Barley DDGS producing a brittle solid product. This was obtained at 150°C with an addition of 2.5wt% char (as catalyst) after a processing time of 1h. The batch reactor was also used for modifying and solidifying fast pyrolysis liquids derived from beech wood by adding urea or ammonium phosphate as post processing nitrogenolysis. The results showed that this type of combined approach was not suitable to produce a slow release fertiliser, because the solid product contained up to 65wt.% of highly water soluble nitrogen compounds that would be released instantly by rain. To complement the processing experiments a comparative study via Py–GC–MS with inert and reactive gas was performed with cellulose, hemicellulose, lignin and beech wood. This revealed that the presence of ammonia gas during analytical pyrolysis did not appear to have any direct impact on the decomposition products of the tested materials. The chromatograms obtained showed almost no differences between inert and ammonia gas experiments indicating that the reaction between ammonia and pyrolysis vapours does not occur instantly. A comparative study via Fourier Transformed Infrared Spectroscopy of solidified fast pyrolysis and in-situ nitrogenolysis products showed that there were some alterations in the spectra obtained. A shift in frequencies indicating C=O stretches typically related to the presence of carboxylic acids to C=O stretches related to amides was observed and no double or triple bonded nitrogen was detected. This indicates that organic acids reacted with ammonia and that no potentially harmful or non-biodegradable triple bonded nitrogen compounds were formed. The impact of solid slow release fertiliser (SRF) derived from pyrolysis and in-situ nitrogenolysis products from beech wood and Barley DDGS on microbial life in soils and plant growth was tested in cooperation with Rothamsted Research. The microbial incubation tests indicated that microbes can thrive on the SRFs produced, although some microbial species seem to have a reduced activity at very high concentrations of beech wood and Barley DDGS derived SRF. The plant tests (pot trials) showed that the application of SRF derived from beech wood and barley DDGS had no negative impact on germination or plant growth of rye grass. The fertilizing effect was proven by the dry matter yields in three harvests after 47 days, 89 days and 131 days. The findings of this research indicate that in general a slow release fertiliser can be produced from biomass and biogenic residues by in-situ nitrogenolysis. Nevertheless the findings also show that additional research is necessary to identify which compounds are formed during this process.
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Acton, Stuart David. "The effect of fertiliser application rate and soil pH on methane oxidation and nitrous oxide production". Thesis, University of Aberdeen, 2007. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU223405.
Testo completoAbstract (sommario):
This study investigated the effect of fertiliser application on methane oxidation and nitrous oxide emissions. During this study a combination of 13C-CH4 and 15N stable isotope techniques were applied to laboratory soil incubations and traditional gas flux methodologies were applied to culture incubations. It was found that fertiliser application rate and soil pH were major influences on both methane oxidation and nitrous oxide emissions from an arable soil. Profiles of the main nitrous oxide producing processes were obtained, and it was shown that nitrification was the predominant source of nitrous oxide from most aerobic soil incubations and that soil acidification greatly reduced nitrous oxide emissions from nitrification. Additionally denitrification was shown to not be restricted to anaerobic conditions. Similar profiles were obtained for 13C soil incubations and the effect of increasing fertiliser concentrations on methane oxidation was determined. Methane oxidation was inhibited by fertiliser concentrations up to 20 g N m-2. However, above 20g N m-2 inhibition declined and there was no apparent effect of increasing fertiliser concentration on methane oxidation. Culture incubations aimed to determine the contribution of methane oxidising bacteria to nitrous oxide emissions and ammonia oxidation. Ammonia oxidation was observed in all methylotrophic bacterial cultures. Nitrous oxide production was only observed in Methylomicrobium chloromethanicum and Methylocystis parvus and it was not possible to determine if this nitrous oxide was produced via ammonia oxidation, nitrate reduction or via the reduction of nitrite produced during ammonia oxidation, in a process similar to nitrifier denitrification that has been observed in autotrophic ammonia oxidising bacteria.
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Syakhroza, Akhmad. "Influence of politics on the budgeting process : a study of the fertiliser manufacturing industry in Indonesia". Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2001. https://ro.ecu.edu.au/theses/1043.
Testo completoAbstract (sommario):
This study investigates the influence of politics on the budgeting process within the fertiliser manufacturing industry in Indonesia. Prior budgeting studies have focused on one of the following three theoretical frameworks - economic, psychological, and social. This study expands the research corpus by assessing the effect of politics on the budgeting process. The objectives of this study arc: (a) to investigate the effect of politics in the relationship between managerial roles and budgeting process – budgetary participation, budgetary communication, and budgetary control including budgetary monitoring and budgetary evaluation, and (b) to assess the impact of structural and individual power on the budgeting process. The study uses a mixed research methodology survey method supplemented by interviews. The survey questionnaire is adapted from previous studies. The sample for this study consists of four fertiliser-manufacturing enterprises in the state owned sector of Indonesia. The respondents of the survey questionnaire were middle managers responsible for unit budgets in the sample companies. Respondents were asked to rate on a seven-point scale their agreement or disagreement with issues concerning the budgeting process, managerial roles and politics. Survey interviews, based on the questionnaire, were developed for a select group of respondents, consisting of middle and senior managers. The results of the study, both survey questionnaire and interviews, indicate that politics has significant influence on the budgeting process. Further, it showed that the influence appeared different, depending whether structural or individual power is involved. The major implications of this study centre on the strong moderating effect of politics on the relationship between the budgeting process and managerial roles: this seems to be a relevant construct and should be developed further. Hopefully, the study will advance the thinking of scholars in this area and create interest in replicating this method of analysis and validating the findings. The conceptual model should also be applied to the role of politics on the budgeting process in other industries to assess the external validity of the model.
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Ben, Mahmud Merfat, e s3037372@student rmit edu au. "The effect of Burkholderia as biofertiliser on cereal productivity". RMIT University. Applied Sciences, 2009. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20090304.124323.
Testo completoAbstract (sommario):
Biofertilisers are rhizosphere microorganisms inoculated to reduce the need for N or P fertiliser application and maximise plant growth and nutrition, resulting in greater grain yield and N or P content. This study aimed to evaluate the effectiveness of diazotrophic bacteria isolated from the rhizosphere of wheat in Victoria, Australia. This thesis shows that N2-fixing Burkholderia species have great potential as biofertilisers on wheat productivity. In Chapter 2, strains of bacteria were isolated from wheat-growing soils in main Victoria wheat belt at Horsham and Birchip in North West Victoria. Strains were identified as Burkholderia spp. by their closest matches in the 16S DNA and by morphology and physiology. In Chapter 3, one selected strain from each of Birchip and Horsham were used to inoculate wheat in a pot trial in a glasshouse during winter-spring. Soil was collected on site from wheat fields. Pots were inoculated with these strains to evaluate the effects of Burkholderia inoculum as biofertiliser on the plant growth and yield. Different nitrogen sources (urea 46% N and ammonium sulphate 21% N) were used as fertiliser at one of four levels (0, 50, 100 and 150 kg N/ ha). There was a greater effect in Birchip than in Horsham soil and with ammonium sulphate than with urea due to waterlogying in Horsham soil. In Chapter 4, field-grown wheat was inoculated with the same strains of Burkholderia. Three experiments were carried out in plots at two sites, dryland and irrigated fields at Horsham and a dryland field at Birchip, during the winter wheat season of 2006, to evaluate the effect of Burkholderia species inoculum and different types of nitrogen source at one of four levels of added N (0, 50, 100 and 150 kg N/ha) on wheat growth and yield. The effects of both bacterial inoculation and N fertiliser on growth promotion and grain yield. Since 2006 was a year of drought, dry land crops were unsuccessful. Grain %N as well as total N content in grain per area in the Horsham irrigated field increased with increasing N fertiliser levels up to 100 kg N/ha. In Chapter 5, acetylene reduction (ARA) activity was measured in the pots for both inoculated and uninoculated plants at various growth stages and populations of nitrogen-fixing bacteria associated with the wheat roots and bulk soil were measured in addition to biomass and N content of plants and grain. Molecular tracing using specific primers showed that the inoculum was present only in inoculated treatments. Up to 60% of the increased N content of the grain in inoculated plants was potentially derived from nitrogen fixed by the inoculum in the rhizosphere. It was concluded that the most significant result due to inoculation was the consistent maximal increase of N content in grain in inoculated treatments with ammonium sulphate fertiliser at 100 kg N/ha. Inoculation with Burkholderia consistently increased %N in wheat grain, with the potential benefit of decreasing the production cost and reducing use of chemical fertilisers.
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Dawar, Khadim M. "The impacts of urease inhibitor and method of application on the bioavailability of urea fertiliser in ryegrass (Lolium perenne L.)". Thesis, University of Canterbury. School of Biological Sciences, 2010. http://hdl.handle.net/10092/5193.
Testo completoAbstract (sommario):
The use of urea fertiliser has been associated with relatively poor nitrogen (N) use efficiency (NUE) due to heavy N losses such as gaseous emissions of ammonia (NH₃) and nitrous oxide (N₂O) and nitrate (NO₃⁻) leaching into surface and ground waters. Improving N use-efficiency of applied urea is therefore critical to maximise its uptake and to minimise its footprint on the environment. The study was conducted under laboratory-glasshouse conditions (Chapter 2-4)and lysimiter-field plot studies (Chapter 5). In chapter 2, Two glasshouse-based experimentswere conducted to investigate the potential of incorporating urea fertiliser with ureaseinhibitor, (N-(n-butyl) thiophosphoric triamide (nBTPT) or ‘Agrotain’) to enhance fertiliser N uptake efficiency. Urea, with or without Agrotain, was applied to Ryegrass (Lolium perenne
L.) grown in standard plant trays maintained at soil moisture contents of 75–80% field capacity, at rates equivalent to 25 or 50 kg Nha⁻¹. These treatments were compared with other common forms of N fertilisers (ammonium nitrate, ammonium sulphate and sodium nitrate). In a separate pot experiment, granular ¹⁵N urea (10 atom %) with or without Agrotain, was applied at 25 kg Nh⁻¹ to track N use-efficiency and the fate of ¹⁵N-labelled fertiliser. In both experiments, Agrotain-treated urea improved bioavailability (defined as the fraction of total
soil N that can interact with a biological target in the plant or that can be taken up by plant) of added N and resulted in significantly higher herbage DM yield and N uptake than urea alone or other forms of N fertilisers. Results from the ¹⁵N experiment support the suggestion that a delay in urea hydrolysis by Agrotain provided an opportunity for direct plant uptake of an increased proportion of the applied urea-N than in the case of urea alone.
In chapter 3, two more glasshouse-based experiments were conducted to investigate if urea applied in fine particle application (FPA), with or without Agrotain, had any effect on fertiliser-N uptake efficiency (defined as the difference in N uptake between the fertiliser treatment and the control as a percentage of the amount of N applied) under optimum soil moisture (75-80% field capacity) and temperature (25 °C) conditions, in comparison with other common forms of N fertilisers applied, either in FPA or in granular form. In a separate pot experiment, ¹⁵N urea (10 atom %), with or without Agrotain, was applied to either shoots or leaves only or to the soil surface (avoiding the shoots and leaves) to determine urea hydrolysis, herbage DM and ¹⁵N uptake. In both experiments, herbage DM yield and N
uptake were significantly greater in the FPA treatments than in those receiving granular application. Agrotain-treated urea FPA resulted in significantly higher N response efficiency (difference between the dry matter produced by the various fertiliser treatments and the
control, divided by the amount of N applied) than urea FPA alone or other forms of N fertilisers. Results from the ¹⁵N experiment support the idea that Agrotain treatment improves
the N response of urea applied in FPA form due to a delay in hydrolysis of urea, thus providing herbage an extended opportunity to absorb added urea directly through leaves,
cuticles and roots.
A further glasshouse-based study was conducted to investigate the effect of Agrotain and irrigation on urea hydrolysis and its movement in a Typic Haplustepts silt loam soil (Chapter 4). A total of 72 repacked soil cores (140 mm inner diameter and 100 mm deep) were used -
half (36) of these cores were adjusted to soil moisture contents of 80% field capacity (FC) and the remaining 36 cores to 50% FC. Granular urea, with or without Agrotain, was applied at a rate equivalent to 100 kg N ha⁻¹. Twelve pots were destructively sampled at each day after 1, 2, 3, 4, 7, and 10 days of treatment application to determine urea hydrolysis and its lateral and vertical movement in different soil layers. Agrotain-treated urea delayed urea
hydrolysis compared with urea alone during the first 7 days of its application. This delay in urea hydrolysis by Agrotain enabled added urea to disperse and move away from the surface soil layer to the sub-surface soil layer both vertically and laterally. In contrast, most urea in the absence of Agrotain hydrolysed within 2 days of its application. Irrigation after 1 day resulted in further urea movement from the surface soil layer (0-10 mm) to the sub-soil layer (30-50 mm) in Agrotain-treated urea. These results suggest that Agrotain delayed urea hydrolysis and allowed more time for rainfall or irrigation to move the added urea from the surface layer to sub-soil layers where it is likely to make good contact with plant roots. This
distribution of urea in the rooting zone (0-200 mm) has the potential to enhance N use efficiency and minimise N losses via ammonia (NH₃) volatilisation from surface-applied
urea.
Finally, a field study using lysimeters (300 mm inner diameter and 400 mm deep), and small field plots (1 m² in area) was established using a silt loam Typic Haplustepts soil (Soil Survey Staff 1998) to investigate the effect of FPA and granular applications of urea, with or without Agrotain, on N losses and N use efficiency (Chapter 5). The five treatments were: control (no N) and ¹⁵N-labelled urea (10 atom %), with or without Agrotain, applied to lysimeters or mini plots (un-labelled urea), either in granular form to the soil surface or in FPA form (through a
spray) at a rate equivalent to 100 kg N ha⁻¹. Gaseous emissions of NH₃ and N₂O, NO₃⁻ leaching, herbage production, N response efficiency, total N uptake and total recovery of applied ¹⁵N in the plant and soil were determined up to 63 days. Urea-alone and urea with Agrotain, applied in FPA form, was more effective than its granular form and reduced N2O emissions by 5-12% and NO3- leaching losses by 31-55%. Urea-alone applied in FPA form
had no significant effect in reducing NH₃ losses compared with granular form. However, urea with Agrotain applied in FPA form reduced NH₃ emissions by 69% compared with the
equivalent granular treatment. Urea-alone and with Agrotain applied in FPA form increased herbage dry matter production by 27% and 38%, and N response efficiency compared with
the equivalent granular urea application, respectively. Urea applied in FPA form resulted in significantly higher ¹⁵N recovery in the shoots compared with granular treatments – this was improved further when urea in FPA form was applied with Agrotain. Thus, treating urea with
Agrotain in FPA under field conditions has the potential to delay its hydrolysis, minimise N losses and improve N use efficiency and herbage production. The lower dry matter
production and N-response efficiency to urea applied in FPA form in Chapter 3 are probably because of additional factors such as lower application rates (25 kg N ha⁻¹ ) or lack of interception of urea by the leaves. Applying urea in FPA form is a good management strategy and I conclude that combining FPA urea with Agrotain has the potential to increase N use efficiency and herbage production further.
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Shepherd, Jessica Grace. "Ochre and biochar : technologies for phosphorus capture and re-use". Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/28907.
Testo completoAbstract (sommario):
Despite recent instability in the global supply of phosphate-rock derived fertiliser and the potential for this to continue into the future, the recovery of phosphorus (P) from wastewater treatment systems, where P is abundant and accessible, is well below maximum potential. Considerable resource is spent on removing P from wastewater in order to comply with environmental standards and to protect aquatic ecosystems from eutrophication, yet there is little emphasis on capturing the P in a way that is optimised for re-using it as agricultural fertiliser. To address this lack of innovation in the face of climate change and food insecurity, a concept for a material capable of capturing P from wastewater was developed, with an emphasis on the utilisation of otherwise waste materials and the use of carbon neutral or negative production technologies. Based on the demonstrated P capture properties of coal minewater treatment waste (ochre) and biochar made from anaerobically digested feedstocks, a range of biochars were designed and produced using different mixtures of ochre (“OC”), sourced from the UK Coal Authority Minto minewater treatment scheme in Fife, Scotland and anaerobically digested sewage sludge (“AD”), sourced from the Newbridge wastewater treatment plant in Edinburgh. A first generation of materials consisting of either AD or a 1:1 mixture (dry weight basis) of OC and AD were produced in a small-scale batch pyrolysis unit at two pyrolysis highest treatment temperatures (HTTs) (450 and 550°C) to give the biochars AD450, AD550, OCAD450 and OCAD550. These were tested for their P capture properties in repeated P-exposure experiments with pH buffering in comparison to unpyrolysed ochre, activated carbon and a natural zeolite. After 5 days of repeated exposure to a P solution at a wastewater-relevant concentration (20 mg P l-1) replenished every 24 h, relatively high masses of P were recovered by ochre (1.73 ± 8.93×10-3 mg P g-1) and the biochars OCAD550 (1.26 ± 4.66×10-3 mg P g-1), OCAD450 (1.24 ± 2.10×10-3 mg P g-1), AD450 (1.06 ± 3.84×10-3 mg P g-1), and AD550 (0.986 ± 9.31×10-3 mg P g-1). The biochar materials had higher removal rates than both activated carbon (0.884 ± 1.69×10-2 mg P g-1) and zeolite (0.130 ± 1.05×10-2 mg P g-1). To assess the extractability of recovered P and thus potential plant bioavailability, P exposure was followed by repeated extraction of the materials for 4 days with pH 7-buffered deionised water. The AD biochars retained 55% of the P recovered, OCAD biochars 78% and ochre 100%. Assessment of potentially toxic element (PTE) concentrations in the biochars against guideline values indicated low risk associated with their use in the environment. A second generation of materials were produced to examine the scalability of the concept. Mixtures of AD and OC were pelletised with a lignin binder (89.1:9.9:1.0 ratio, dry weight basis) and AD was pelletised with binder (99:1 ratio, dry weight basis). The pelletised feedstocks were pyrolysed in a bench-scale continuous flow pyrolysis kiln at the same two HTTs to give the pelletised biochars PAD450, PAD550, POCAD450 and POCAD550. Analysis of digested biochar samples compared to the previous generation of biochars showed general similarities between the two groups, apart from the substantially lower Fe content. Sub-samples of the pelletised biochars were exposed to a 20 mg l-1 P solution over 6 days, with the solution replaced every 24 h to give the P-exposed biochars EPAD450, EPAD550, EPOCAD450 and EPOCAD550. To probe the mechanisms of P capture by these materials and how feedstock preparation and pyrolysis conditions affected these, spectroscopic analysis using laser-ablation (LA) ICP-MS, X-ray diffraction, X-ray photo-electron spectroscopy (XPS) and scanning electron microscopy coupled with energy dispersive X-ray was performed. The results highlighted the general importance of Fe minerals in P capture and subsidiary roles for Al, Ca and Si. A 3-week barley (Hordeum vulgare) seedling growth experiment was conducted using the pelletised and P-exposed biochars, in comparison with other biochars produced using feedstock which contained high amounts of PTEs. The biochars were also extracted using a range of different methods used to assess the bioavailability of PTEs and nutrients in soils, and the results compared to digests of barley leaves to identify whether any of these could reliably predict plant bioavailability in biochar. The above ground biomass and its total P concentration of barley grown in a 5% mixture of EPOCAD550 in sand was significantly higher than the control (p < 0.05 and p < 0.01, respectively). A significant positive correlation between mean leaf P mass and dry weight leaf yield (R2 = 0.865, p < 0.001) was found, indicating that dry weight yield could be used as an indicator for the P fertilising capability of biochar for barley seedlings. Element concentrations in unbuffered and buffered and (pH 7) 0.01 M CaCl2 biochar extractions were significantly positively correlated with plant leaf concentration for 6 of the 18 elements investigated, more than any of the other extractions. A longer barley growth experiment was conducted, using rhizoboxes, to test the bioavailability of P in the biochars compared to conventional fertiliser. The pelletised and Pexposed biochars were applied to a sandy loam soil with P constraints. Biochar application rates were based on 2% formic acid extractable P, calculated for summer barley using Index 0 soil. Analysis of total leaf length at harvest (12 weeks), dry weight yield, leaf P concentration and leaf P mass showed no significant differences between the biochar treatments, NPK fertilised and NK fertilised controls. This shows that biochar, when applied at low total application rates based on extractable P, is as effective as conventional fertiliser. Now that AD biochar materials have been shown to have useful phosphorus recycling properties in laboratory experiments, additional work is required to optimise their use in wastewater and agricultural systems. The next stage of research should determine their performance in flow-through filtration systems with simulated and real wastewater effluent, as well as their performance in field trials with different crops of interest to demonstrate their potential as viable alternative fertilisers.
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Liyanage, Anuga. "The impact of using urban derived compost on nitrogen use efficiency, greenhouse gas emissions and productivity from tropical cropping systems". Thesis, Queensland University of Technology, 2019. https://eprints.qut.edu.au/134463/2/Anuga%20Liyanage%20Thesis.pdf.
Testo completoAbstract (sommario):
This thesis is a multiyear study in Sri Lanka to evaluate the impact of using urban derived compost in combination with synthetic N fertiliser on nitrogen use efficiency, greenhouse gas emissions, and productivity from tropical cropping systems. The study demonstrated the high potential for N losses in low CEC tropical soils. However, the high relative cost of OA compared to synthetic N fertilisers requires substantial additional benefits above the value of the nutrients alone to make their use economical.
50
Simpson, Jacquelyn. "The role of organic nitrogen in the nutrition of Eucalyptus". Thesis, The University of Sydney, 2015. http://hdl.handle.net/2123/14147.
Testo completoAbstract (sommario):
Nitrogen availability commonly limits plant growth. Addition of N fertiliser alleviates N limitation and increases productivity but can have significant environmental and economic costs, providing incentives to optimise fertiliser application with accurate predictive tests to diagnose N limitation. Traditionally N limitation has been ascertained under the premise that plants are only capable of taking up inorganic nitrogen. We now suspect that organic nitrogen could also play a role in plant nutrition, but additional research is required before organic N can be used as the basis for diagnostic tests of N limitation. The aim of this thesis is to increase our understanding of the role of organic N in nutrition of two plantation tree species, Eucalyptus nitens and Eucalyptus globulus, to determine a simple and robust method of indicating nitrogen limitation. Protease activity and total exchangeable amino acid concentration are strongly correlated with N-limitation in E. nitens forestry plantation soils. Although there is minimal seasonal variation in protease activity, we measured significant seasonal variation in the absolute and relative abundance of small (<250 Da) dissolved organic and extracted inorganic and organic nitrogen compounds of E. nitens plantations. Strong correlation between nitrogen limitation and the abundance of ammonium, nitrate and amino acids in soil extracts are consistent with a growing body of literature arguing plants can take up organic nitrogen compounds. Our results indicate depolymerisation (protease activity) is the rate limiting step of N availability. Organic nitrogen is abundant in soil, taken up by plants and strongly related to N-limitation. Protease activity is a strong indicator of N-limitation with great potential as a reliable and ubiquitous indicator of N-limitation in soils