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1
Fleming, Nigel Kevin. "Polyphosphates and microbial uptake of phosphorus : studies with soil and solution culture". Title page, contents and summary only, 1992. http://web4.library.adelaide.edu.au/theses/09A/09af598.pdf.
Testo completo
2
Smith, Leslie Owen 1960. "Effect of broadcast phosphorus on alfalfa yield and quality". Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/558068.
Testo completo
3
Zhang, Tiequan. "Chemical behavior of phosphorus over time in fertilized soils". Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=34486.
Testo completoAbstract (sommario):
Fertilizer P accumulates in soils, with potential for movement to waterways, causing eutrophication. Fertilizer P reactions in monoculture corn (Zea mays L.) production over time will determine environmentally sound soil management practices. Soil P changes over time were determined on a Chicot sandy clay loam (Grey Brown Luvisol) and a Ste. Rosalie clay (Humic Gleysol). Fertilizer P was added at 44 and 132 kg P ha$ sp{-1}$ and to the Chicot soil only, manure containing 60 kg P for the first five years. Mehlich-3 (M3) extraction, soil P fractionation, $ sp{31}$P NMR analysis, P in leaching water, and path analysis were measured. Added P increased M3 P more when manure was also added, and in clay soils. To increase M3 P by 1 kg ha$ sp{-1}$ required from 3.6 to 8.1 kg ha$ sp{-1}$ fertilizer P, and when "net" fertilizer additions were used, fertilizer required was from 1.8 to 5.3 kg P ha$ sp{-1}.$ Moderately labile organic P (Po) decreased at 0 added P. With P at the rate of plant removal, inorganic (Pi) and Po fractions were unchanged. Excess P increased labile P and resistant P through moderately labile Pi. More P remained in labile Pi fractions when manure P was added, or in the soil with the higher clay content. Soil organic P levels increased upon fertilization only in the sandy loam soil. Labile and moderately labile Po could be estimated using monoester phosphate values determined by $ sp{31}$P NMR. Inorganic P values in gravitational water increased above 0.05 mg P L$ sp{-1}$ when soil labile Pi increased above 108 mg kg$ sp{-1}$ in the sandy loam soil and 69 mg L$ sp{-1}$ in the clay soil. Thus soil P movement was related to inorganic P additions. Increased fertilizer P did not increase organic P leaching losses. Fertilizer P in corn production may result in groundwater eutrophication.
4
Mkpong, Offiong Etim. "The effects of variable moisture levels on extractable Bray-l P, Bray-l Al, Bray-l Fe, Bray-l Mn : fertilizer P recommendation based on quicktest technique /". The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487329662144707.
Testo completo
5
Norrish, Shane A., University of Western Sydney, of Science Technology and Environment College e School of Environment and Agriculture. "Soil and water interactions controlling wheat crop response to phosphorus fertiliser in north-western New South Wales". THESIS_CSTE_EAG_Norrish_S.xml, 2003. http://handle.uws.edu.au:8081/1959.7/613.
Testo completoAbstract (sommario):
This thesis examines the response to P fertiliser by wheat crops growing in the vertosol soils of the low rainfall areas of the northern grain zone of eastern Australia. Farmers in this region depend on water accumulated from rainfall over a fallow period and stored in the subsoil to increase wheat grain yield beyond that normally achievable from in-crop rainfall and to decrease the production risks due to rainfall variability. The large variability in stored water, seasonal rainfall and subsoil properties result in extremely varied yield and yield responses to P fertiliser between seasons and between sites. Finally, as a practical guide to predicting wheat response to P fertilizer: 1/. current sampling strategies of determining P only in the surface 10 cm appear to be adequate for soils with bicarbonate P concentrations greater than 15 mg/kg. 2/. For soils with lower concentrations in the surface, sampling of 80 cm is recommended. Crops with a mean concentration of bicarbonate P greater than 7 mg/kg between 10 - 80 cm are unlikely to respond to P fertiliser. 3/. No increase in profitable grain yield response was found for fertiliser applications greater than 10 kg P/ha.Doctor of Philosophy (PhD)
6
Melland, Alice Rowena. "Pathways and processes of phosphorus loss from pastures grazed by sheep /". Connect to thesis, 2003. http://eprints.unimelb.edu.au/archive/00002204.
Testo completoAbstract (sommario):
Thesis (Ph.D.)--University of Melbourne, School of Agriculture and Food Systems,Institute of Land and Food Resources, 2004.Typescript (photocopy). Includes bibliographical references (leaves 249-282).
7
Fu, Yong 1948. "Solid activity coefficients of phosphate adsorbed by soil". Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276722.
Testo completoAbstract (sommario):
The data of 14 soils were used to compute the ion activity product (IAP), the ratio of the ion activity product and to the solubility product (Ksp) of the pure minerals (IAP/Ksp) and to estimate the solid activity coefficients (SAC) of the soil components. The value of IAP and SAC of AlPO4 differs from soil to soil and increases with increasing P added to soil in acid soils and for calcium phosphate in basic soils. Magnesium apparently did not cause P adsorption or precipitation in the soils studied. The SAC of aluminum phosphate ranged from 10 to 10000 in acid soils. The mole fraction of the total phosphate in soil seemed to be a more satisfactory basis for calculating the concentration of the solid phase than was measurements of the available phosphate.
8
Guppy, Christopher Neil. "Phosphorus and organic matter interactions in highly weathered soils /". St. Lucia, Qld, 2003. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17420.pdf.
Testo completo
9
Nash, David. "Phosphorus transfer from land to water in pasture-based grazing systems /". Connect to thesis, 2002. http://eprints.unimelb.edu.au/archive/00000752.
Testo completo
10
Grenier, Aline M. "Influence of selected endomycorrhizal fungi and phosphorus fertilization on the growth and mineral nutrition of onion grown in newly reclaimed organic soil". Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=69533.
Testo completoAbstract (sommario):
Onions are highly responsive to endomycorrhizae and improved plant growth is among the benefits associated with this symbiosis, particularly in low phosphorus soils. Although this crop is grown extensively in organic soils, few studies have been conducted on these. Onion plants (Allium cepa L. cv. Norstar) were inoculated with Glomus aggregatum Schenck & Smith, Glomus clarum Nicolson & Schenck, Glomus fasciculatum Gerdemann & Trappe, Glomus intraradix Schenck & Smith and Glomus versiforme (Karst.) Berch and grown in the field and under controlled conditions to evaluate their efficiency in newly reclaimed organic soil of low P fertility. Three species were selected to evaluate the effects of introduced endomycorrhizal fungi effects and P fertilization (equivalent to 0, 24 and 48 kg P ha$ sp{-1}$) on the growth and mineral nutrition of onion plants.Introducing endomycorrhizal fungi in non-sterile soil did not affect the growth and mineral nutrition of onion. Crop maturity was advanced when plants were inoculated, however. Increasing levels of P fertilization did not depress root colonization and onion growth was increased significantly at the highest rate only. These results suggest that higher levels than recommended could be used in this soil. Inoculation in $ gamma$-irradiated (10 kGy, $ sp{60}$Co) soil alleviated excessive Mn absorption by onion plants. Adding P fertilizer depressed growth and root colonization when plants were inoculated with G. clarum and G. intraradix and was related to the low irradiance levels used in this study. G. versiforme appeared to be the most efficient of the introduced species.
11
Sprinkle, Amy Lyn. "Nutrient management on golf courses in Delaware". Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file 1.01Mb, 155 p, 2005. http://wwwlib.umi.com/dissertations/fullcit/1428197.
Testo completo
12
Kilgour, Douglas William. "Potential negative effects of adding phosphate-based fertilizers to lead in metal-contaminated soils". Auburn, Ala., 2007. http://repo.lib.auburn.edu/07M%20Theses/KILGOUR_DOUGLAS_2.pdf.
Testo completo
13
Ochwoh, Victor Akangah. "The dynamics of phosphorus extractability, adsorption, and desorption rates as influenced by phosphorus applications and incubation times". Thesis, University of Pretoria, 2002. http://hdl.handle.net/2263/28636.
Testo completoAbstract (sommario):
In a study to investigate the fate of the applied P in soils, a red-sandy clayey soil (Ferric Luvisols) from Rustenburg (high P fixing) and a red-sandy loam soil (Ferric Acrisols) from Loskop (low P fixing) were used. Sequential P fractionations were used to determine the content of the different P pools to show which pool the applied P was transformed to. The soils treatments consisted of different Prates (0, 25, 50, 100, 150, and 200 mg kg-1), and incubation periods (1, 60, 120, 180, and 240 days) under a laboratory conditions. The sequential P fractionation procedure consisted of extraction with hydrous ferric oxide in a dialysis membrane tube (DMT-HFO), 0.5M NaHC03, O.1M NaOH-P, 1.0M HCI, concentrated HCI, and concentrated H2S04 + H2O2. Approximately 30 to 60 % of the added P were transformed into less labile P pools within one day and 80-90 % after 60 days. This transformation was faster in the Rustenburg than in the Loskop soil showing a higher P fixation capacity. A major part of the P transformation was to the -OH-P1 pool with a recovery of about 30%. In the second experiment an attempt was made to determine P desorption rates by successive DMT-HFO extractions (1, 7, 14, 28, and 56 days) after the transformations of the applied P. This was followed by the sequential extractions to determine the changes and distribution of the added P into different P pools as well as which pools the P was des orbed from. The Rustenburg and Loskop soils were treated to different Prates (0, 25, 50, 100, and 200 mg P kg-1) and incubation periods (1, 120, and 240 days). The cumulative DMT -HFO extraction curves for 56 days showed that desorption could continue for a much longer period. This property is important in the economical management of fertilizer applications rates. Results showed the transformations and distribution of the applied P during incubation periods and proved that all the stable soil P pools contributed to the labile P pool by different proportions after prolonged successive DMT-HFO extractions. Although Rustenburg soil is considered a high P fixing soil, the P release rates under laboratory conditions were high enough to meet the requirements of cotton and tobacco crops. Root systems of these crops do not exploit 100 % soil volume as this laboratory method, which could explain why these crops experience P deficiencies. It is envisage that by using this method the P releasing properties of a soil could be used to develop a P desorption model to determine how much extractable P, with a specific extractant, in a particular soil, should be available at the beginning of a growing season to sustain a high enough P releasing rate to meet the requirements of a certain crop up to the end of the growing season. To do this, a model to describe root development that represents the percentage of the soil exploited P desorption rates that simulate P uptake by plant roots will be necessary.Thesis (DPhil (Plant Production: Horticulture))--University of Pretoria, 2006.
Plant Production and Soil Science
unrestricted
14
Mengesha, Abi Taddesse. "Characterizing phosphate desorption kinetics from soil: an approach to predicting plant available phosphorous". Pretoria : [s.n.], 2008. http://upetd.up.ac.za/thesis/available/etd-01212009-094137.
Testo completo
15
More, Ketseemang. "Response of cabbage (Brassica Oleracea Var Capitata) transplants to nitrogen, phosphorus and potassium nutrition". Diss., Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-09212007-133240.
Testo completo
16
Unuofin, Frank Oshioname. "Optimization of the vermidegradation of cow dung – waste paper mixtures". Thesis, University of Fort Hare, 2014. http://hdl.handle.net/10353/d1021276.
Testo completoAbstract (sommario):
Vermicomposting is an eco-friendly waste management strategy. Its successful performance necessitate that key functioning parameters like earthworm stocking density, nutrient enrichment be established for each target waste/waste mixture. One main target waste mixture in South Africa, and in the University of Fort Hare in particular is waste paper mixed with cow dung and rock phosphate (RP) for phosphorus (P) enrichment. This study was carried out to address the following specific objectives, to determine (i) the effect of Eisenia fetida stocking density on the bioconversion of cow dung waste paper mixtures enriched with rock phosphate, (ii) an optimum application rate of low grade South African Rock Phosphate and time required for efficient vermicomposting of cow dung-waste paper mixtures, and (iii) to determine if the phosphorus in RP is responsible for improved biodegradation during the vermicomposting of cow dung-waste paper mixtures. Results of this study revealed that bioconversion of cow dung waste paper mixtures enriched with RP was highly dependent on E. fetida stocking density and time. The stocking density of 12.5 g-worms kg-1 feedstock of the mixtures resulted in highest earthworm growth rate and humification of the waste mixture as reflected by a C: N ratio of < 12, polymerization index (PI) or humic acid/fulvic acid ratio of > 1.9, and a humification index of >13 for the cow dung waste paper mixtures. A germination test carried out also revealed that the resultant vermicompost had no inhibitory effect on the germination of tomato, carrot, and radish. Extractable P increased with stocking density up to 22.5 g-worm kg-1 feedstock, suggesting that for maximum P release from RP enriched wastes, a high stocking density should be considered. Informed by an earlier study which demonstrated that RP improved vermidegration, a follow up study was done to determine the optimum amount of rock phosphate necessary for efficient vermidegradation of cow dung waste paper mixtures while ensuring a phosphorus rich vermicompost. The results showed that addition of RP at rates ≤ 1% P as RP efficiently enhanced the bioconversion of cow dung waste paper mixtures as reflected by low C: N ratio, high polymerization index (PI), HI and HR used as maturity indicators for matured compost. Final vermicompost products obtained at minimum amounts of RP application rates resulted highly humified vermicompost with finer morphological structure, with no inhibitory effect on the germination of tomato, carrot, and radish similar to the ones obtained at higher RP rates. The findings suggest that 1%P as RP application rate is optimum for efficient vermidegradation of cow dung waste paper mixtures. Since P or Ca happen to be the most prevalent elements in most rock phosphate used for compost enrichment, a study was carried out to determine if P or Ca in RP is predominantly responsible for the improved biodegradation of cow-dung waste paper mixture observed during vermicomposting. Phosphorus sources in form of triple superphosphate (TSP), phosphoric acid (PHA) and Ca in form of calcium chloride (CaCl2) salt were compared with rock phosphate. The results from the study indicated that TSP, a water soluble P source, resulted in greater and faster degradation of the waste mixtures than RP while the Ca source had the least effect. With TSP incorporation the compost maturity C: N ratio of 12 was reached within 28 days while RP, PHA and CaCl2 needed 42, 56 and more than 56 days, respectively. The results indicated that P was largely responsible for the enhanced bioconversion of the waste mixtures. This appeared linked to the effect of P to stimulate microbial growth as reflected by higher microbial biomass carbon levels where water soluble P sources were applied. The C: N ratios of the final vermicomposts at day 56 were 10, 11.5, 13, 14, and 23 for TSP, RP,PHA, Control (No P added) and CaCl2 treatments, respectively. Although TSP gave superior superior performance, RP may still be the preferred additive in the vermicomposting of cow dung waste paper mixtures as it is cheaper and produces mature compost in a shorter period of 8 weeks. Generally, the results of this study have shown that the vemidegradation of cow dung waste paper mixtures can be optimized through adoption of an E. fetida stocking density of 12.5g- worm kg-1 and an RP incorporation rate of 1% P as RP. However, higher rates of RPincorporation may be adopted where final vermicomposts with higher P fertilizer value are desired. Phosphorus appears to be the RP constituent responsible for its ability to enhance the vermidegradation of cow dung waste paper mixtures. Future studies should explore the effectiveness of other P-bearing minerals for their effectiveness in enhancing vemidegradation.
17
Barnett, G. M. (Gordon M. ). "Feed additives and animal waste phosphorous reactions". Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=41322.
Testo completoAbstract (sommario):
Organic phosphorus (P$ sb{ rm o}$) in farm animal wastes must be mineralized to inorganic P for subsequent plant use. This study was conducted to determine if feed additives affect P$ sb{ rm o}$ mineralization, manure decomposition, and plant growth. Feed additives in aqueous systems affected the P mineralization of inositol hexaphosphate by phytase and of adenosine monophosphate by alkaline phosphatase. Pronounced effects were produced by bacitracin and both enzymes and by neomycin on phytase. Feed additives in dairy cattle (Bos taurus L.) manure produced effects on microbial activity as measured by gas production that differed from those produced on fecal phosphatase activity. Additives applied directly or with manure to Ste. Rosalie clay, Greensboro loam, or silica sand had no effect on barley (Hordeum vulgare L.) yield but did produce additive, rate, growth medium, and manure dependent effects on plant P concentration and soil phosphatase activity. Therefore, each feed additive must be independently evaluated to determine its effect on biological systems.
18
Norrish, Shane. "Soil and water interactions controlling wheat crop response to phosphorus fertiliser in north-western New South Wales". View thesis, 2003. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20051013.115006/index.html.
Testo completo
19
Андрієнко, Ніна Ігорівна, Нина Игоревна Андриенко, Nina Ihorivna Andriienko, Сергій Васильович Вакал, Сергей Васильевич Вакал e Serhii Vasylovych Vakal. "Использование алжирских фосфоритов в качестве сырья для производства фосфорных минеральных удобрений". Thesis, Издательство СумГУ, 2004. http://essuir.sumdu.edu.ua/handle/123456789/23589.
Testo completo
20
Mpabanga, Nkosi. "The effect of phosphorus fertilizer application on growth, biomass and nutritive value of Pigeon pea (Cajanus cajan (L.) Millsp.) varieties in Alice, South Africa". Thesis, University of Fort Hare, 2017. http://hdl.handle.net/10353/6180.
Testo completoAbstract (sommario):
Low soil fertility has been identified to be among the major causes of low pasture quantity and quality. Scarcity of high quality forage mainly during the dry season threatens animal productivity in some areas of South Africa, thus the need for identifying livestock feed alternatives. Pigeon pea is a woody legume that has continually been an important shrub in agroforestry and can provide protein-rich livestock feed during times of shortage. Soil fertility to support the production of pigeon pea can be enhanced by application of fertilisers. Therefore, this study was carried out firstly, to determine the effect of phosphorus fertiliser on the growth performance and biomass production of three pigeon pea varieties, and secondly, to investigate the influence of phosphorus application on the nutrient and anti-nutrient content of three pigeon pea varieties. The field experiment was done at the University of Fort Hare research farm in Alice, South Africa. The factors investigated were three pigeon pea varieties namely Chitedze 1, Chitedze 2 and CIMMYT 1 and three phosphorus fertiliser application rates of 0, 40 and 60 kg P/ha. The study was a 3× 3 factorial experiment set up in a randomised complete block design and was replicated three times. The growth performance attributes evaluated in this study include the number of branches, plant height and root collar diameter. Root collar diameter was not significantly (p>0.05) different among the pigeon pea varieties and phosphorus levels. Likewise, the application of phosphorus was not significant (p>0.05) on plant height and the number of branches of all the varieties. However, when P level was varied, there were significant differences among the varieties, and so were the interaction (p<0.05) between variety and phosphorus on plant height and the number of branches. There was no significant (p>0.05) difference among the phosphorus levels on the fresh leaf yield of Chitedze 1 and Chitedze 2, but phosphorus application at 40 kg P/ha increased the fresh leaf yield of CIMMYT 1. Phosphorus application at 60 kg P/ha increased (p<0.05) the dry matter content of Chitedze 1 and Chitedze 2. Furthermore, the results of the trial show that the application of 40 kg P/ha and 60 kg P/ha increased (p<0.05) the dry matter yield of the varieties CIMMYT 1 and Chitedze 2, respectively. The effects of phosphorus application on the nutrient composition of the three pigeon pea varieties varied. The composition of hemicellulose of all the varieties was significantly (p<0.05) increased by the application of 40 kg P/ha. Conversely, the concentration of crude protein, phosphorus, copper and iron, and the calcium to phosphorus ratio of all the pigeon pea varieties was not significantly (p>0.05) affected by phosphorus application and there was no interactive effect of variety and phosphorus. The proximate compositions of fat, total non-structural carbohydrates, ash, neutral detergent fibre, acid detergent fibre, cellulose, neutral detergent insoluble nitrogen, acid detergent insoluble nitrogen of the pigeon pea varieties varied significantly (p<0.05) at different phosphorus application levels. There was an interactive (p<0.05) effect of variety and the level of phosphorus on the concentration of calcium (Ca), potassium (K), magnesium (Mg), sodium, zinc, manganese, and the K/(Ca+Mg) ratio. The digestible dry matter, dry matter intake and the relative feed value were significantly (p<0.05) different among the pigeon pea varieties at varying phosphorus levels. The anti-nutrient composition of Chitedze 2 was not significantly (p>0.05) affected by phosphorus application but the concentration of phenols and saponins of Chitedze 1 was significantly (p<0.05) increased when 60 kg P/ha was applied, but these anti-nutrients were reduced (p<0.05) for CIMMYT 1 at 60 kg P/ha. It can be concluded that phosphorus application influences the biomass production and chemical composition while the optimum phosphorus level vary among the pigeon pea varieties.
21
Conceição, Fabiano Tomazini da. "Comportamento geoquímico de radionuclídeos e metais pesados em solos da Bacia do Rio Corumbataí (SP) /". Rio Claro : [s.n.], 2004. http://hdl.handle.net/11449/103021.
Testo completoAbstract (sommario):
Orientador: Daniel Marcos BonottoBanca: Marta Silvia Maria Mantovani
Banca: Sonia Maria Barros de Oliveira
Banca: Gilberto José Garcia
Banca: Jairo Roberto Jiménez-Rueda
Resumo: Este trabalho visou estudar o comportamento geoquímico de radionuclídeos e metais pesados em solos de uso agrícola na bacia do Rio Corumbataí (SP). A concentração e variabilidade natural em rochas sedimentares na bacia do Rio Corumbataí segue a tendência Ca > Mg > K > Na, com baixa concentração natural de metais pesados e radionuclídeos. A distribuição das taxas de dose nos solos mostra que ocorre uma maior taxa de exposição na região sul da bacia do Rio Corumbataí, onde há aplicação de fertilizantes fosfatados, corretivos agrícolas e vinhaça em plantações de cana-de-açúcar. Metais pesados e radionuclídeos existentes nos fertilizantes fosfatados e corretivos agrícolas são adicionados anualmente nas plantações de cana-de-açúcar, mas se usados de acordo com as taxas recomendadas, não aumentam suas concentrações em solos para níveis perigosos. Assim, há baixa transferência destes elementos dos solos para a cana-de-açúcar na bacia do Rio Corumbataí, não oferecem nenhum risco ao ecossistema e à saúde do animal e do homem. Palavras-chave: Radionuclídeos e metais pesados, Solos e fertilizantes, Plantações de canade- açúcar, Cadeia alimentar.
Abstract: The purpose of this research was to study the geochemical behavior of radionuclides and heavy metals in soils of agricultural use at Corumbataí River basin (SP). The natural concentration and variability in sedimentary rocks at Corumbataí river basin follow the trend Ca > Mg > K > Na, with the concentration of heavy metals and radionuclides. The distribution of exposure rate in soils shows the occurrence of higher values towards south of the Corumbataí river basin, region where are applied phosphate fertilizers, amendments and vinhaça in sugar cane crops. Heavy metals and radionuclides incorporated in phosphate fertilizers and amendments are annually added during the fertilization process in the sugar cane crops, but if they are utilized in accordance with the recommended rate, they do not rise the concentration levels in soils up to hazards levels. Thus, they are lower transferred from soils to sugar cane at Corumbataí river basin, not offering hazard to the ecosystem and animal or human health.
Doutor
22
Bernd-Steffes, Dawn E. "Effects of phosphorus fertilization on growth and survival of Liatris pycnostachya, Physostegia virginiana, and Sporobolus heterolepis seedlings in a prairie restoration project". Virtual Press, 2000. http://liblink.bsu.edu/uhtbin/catkey/1189407.
Testo completoAbstract (sommario):
The effects of phosphorus fertilization on the growth and survival of Liatris pycnostachya, Physostegia virginiana, and Sporobolus heterolepis seedlings were examined in a prairie restoration project. Treatment included fertilizing once at the time of planting. Plant responses were measured on two soil types, Bono (very high phosphorus levels, lower and flatter) and Morley (very low phosphorus levels, on a slight hill with some slope). P fertilization did not increase the growth of any species on either soil type, although results may have been limited by the effects of surrounding plant competition. Only one significant difference in plant growth was observed between fertilized and unfertilized plots; control Liatris pycnostachya and Physostegia virginiana in the Bono soils produced more shoots than fertilized plants of the same species. P- fertilized Liatris pycnostachya in Morley soil had significantly higher survivorship than unfertilized plants. In contrast, P-fertilized Physostegia virginiana in the Bono soil had the significantly lower survivorship than unfertilized plants. For the other species on either soil type, the survivorship was not significantly different. Because P-fertilization produced very limited benefit, and even adverse plant responses in some cases, the recommendation of this study is that P-fertilization should not be applied at the time of planting of prairie restoration projects.Department of Biology
23
Conceição, Fabiano Tomazini da [UNESP]. "Comportamento geoquímico de radionuclídeos e metais pesados em solos da Bacia do Rio Corumbataí (SP)". Universidade Estadual Paulista (UNESP), 2004. http://hdl.handle.net/11449/103021.
Testo completoAbstract (sommario):
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conceicao_ft_dr_rcla.pdf: 3191625 bytes, checksum: acbc3e9009e76a6712eb2befd4d5dc95 (MD5)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Este trabalho visou estudar o comportamento geoquímico de radionuclídeos e metais pesados em solos de uso agrícola na bacia do Rio Corumbataí (SP). A concentração e variabilidade natural em rochas sedimentares na bacia do Rio Corumbataí segue a tendência Ca > Mg > K > Na, com baixa concentração natural de metais pesados e radionuclídeos. A distribuição das taxas de dose nos solos mostra que ocorre uma maior taxa de exposição na região sul da bacia do Rio Corumbataí, onde há aplicação de fertilizantes fosfatados, corretivos agrícolas e vinhaça em plantações de cana-de-açúcar. Metais pesados e radionuclídeos existentes nos fertilizantes fosfatados e corretivos agrícolas são adicionados anualmente nas plantações de cana-de-açúcar, mas se usados de acordo com as taxas recomendadas, não aumentam suas concentrações em solos para níveis perigosos. Assim, há baixa transferência destes elementos dos solos para a cana-de-açúcar na bacia do Rio Corumbataí, não oferecem nenhum risco ao ecossistema e à saúde do animal e do homem. Palavras-chave: Radionuclídeos e metais pesados, Solos e fertilizantes, Plantações de canade- açúcar, Cadeia alimentar.
The purpose of this research was to study the geochemical behavior of radionuclides and heavy metals in soils of agricultural use at Corumbataí River basin (SP). The natural concentration and variability in sedimentary rocks at Corumbataí river basin follow the trend Ca > Mg > K > Na, with the concentration of heavy metals and radionuclides. The distribution of exposure rate in soils shows the occurrence of higher values towards south of the Corumbataí river basin, region where are applied phosphate fertilizers, amendments and vinhaça in sugar cane crops. Heavy metals and radionuclides incorporated in phosphate fertilizers and amendments are annually added during the fertilization process in the sugar cane crops, but if they are utilized in accordance with the recommended rate, they do not rise the concentration levels in soils up to hazards levels. Thus, they are lower transferred from soils to sugar cane at Corumbataí river basin, not offering hazard to the ecosystem and animal or human health.
24
Sigrist, Andrew B. (Andrew Bernard). "Influence of incubating liquid hog manure and monocalcium phosphate on phosphorus availability and fractionation". Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=69518.
Testo completoAbstract (sommario):
Incubation mixtures of liquid hog manure (LHM), with and without monocalcium phosphate (MCP) were added to an Ormstown silty clay loam and a Ste. Rosalie clay. Ryegrass (Lolium multiflorum Lam.) was cultivated in a pot study in order to determine yield, total P uptake and soil P content as affected by various P and manure treatments.Aeration of LHM with MCP was successful in reducing ammonia volatilization by 62.4%. However, for both soils, neither of the treatments; LHM amended and aerated with MCP and applied at 32 t ha$ sp{-1}$ LHM containing 513 kg $ rm P sb2O sb5 ha sp{-1}$ from MCP nor LHM aerated without MCP applied at 32 t ha$ sp{-1}$ LHM, plus 513 kg $ rm P sb2O sb5 ha sp{-1}$ from MCP, significantly affected ryegrass yields compared to the lone addition of MCP fertilizer (513 kg $ rm P sb2O sb5 ha sp{-1}).$ Total P uptake in ryegrass was significantly higher for the incubated treatments in the Ste. Rosalie soil alone.
Although additions of LHM or MCP and LHM-MCP combinations affected Mehlich-III and Hedley P fractions, the incubation of MCP with LHM did not significantly increase either inorganic- or organic-P fractions when compared to MCP alone. Therefore, premixing MCP with the LHM had no effect on improving P availability in either the Ormstown or Ste. Rosalie soils.
25
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.
26
Landry, Christine. "Phosphorus fertilization and mycorrhizae influence soil phosphorus dynamics, corn nutrition and yield under reduced-tillage practices". Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=115705.
Testo completoAbstract (sommario):
Grain corn (Zea mays L.) production occupies more farmland than any other annual crop in Quebec and is expanding demand from the livestock sector and the emerging bioethanol industry. Corn production requires high nutrient inputs and intensive tillage (IT). Many producers have thus switched to conservation tillage systems like ridge-tillage (RT) to overcome soil compaction and erosion problems that are common in IT systems. However, fertilizer guidelines developed for IT soils are used in RT although RT adoption greatly modifies phosphorus (P) dynamics. Lower fertilizer P requirements are expected because arbuscular mycorrhizal (AM) symbiosis known to enhance plant P nutrition are minimally disrupted under RT, compared to IT systems. A two-year study was conducted on a commercial farm in the Monteregie region (Quebec, Canada) to investigate the effects of P fertilizer rates and soil P-saturation status on corn early growth, nutrition and yield. Surface soil plant-available P was monitored in situ with anionic exchange membranes (P AEM) from seeding to the end of July. The effects of indigenous AM fungi on corn parameters and rhizosphere soil P pools were also investigated in untreated (AMNI) or AM-inhibited fungicide-treated (AMI) soils. Quebec's P fertilizer guidelines underestimated the soil P fertility in studied soils. Adding inorganic P (Pi) did not improve the early corn P nutrition, growth or yield, and had little impact soil PAEM. Variations in PAEM were better explained by climatic variables. AMNI corn had similar early development and high yield, regardless of whether P fertilizer was applied, whereas AMI plants needed P fertilizer to produce optimal yield. AMNI corn had reduced dependence on Pi inputs due to more efficient uptake of soil solution P i in surface and rhizosphere soils during the first 22 days after seeding (DAS), In the rhizosphere, available-Pi pool appeared to be used first to replenish the resin-P pool, but over the longer term, AM symbiosis also enhanced NaHCO3-Po mobilization through a mechanism that remains unclear. Deeper understanding of the mechanisms by which AM fungi alter soil P dynamics will contribute to the development of more sustainable P fertilizer programs for RT systems.
27
Sommerville, David W. "Phosphorus fertilization : effects on asparagus yield, and soil microbial parameters". Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=80876.
Testo completoAbstract (sommario):
Asparagus (Asparagus officinalis) is a perennial crop well suited to grow in Quebec. Despite high demand for this crop, asparagus production is declining because of asparagus root rot disease that is caused by Fusarium spp. Phosphorus is one of the most important nutrients for the production of healthy asparagus roots that may resist infection by Fusarium. The objective of this study was to determine the effects of phosphorus (P) applications on asparagus yield and soil microbial parameters. Plots receiving 0 to 200% of the P recommendation, based on the Centre de reference en agriculture et agroalimentaire du Quebec (CRAAQ) guidelines, did not differ significantly (p < 0.05) in first year yield or plant tissue concentrations. However, asparagus receiving no fertilizer had 2 to 3 times higher arbuscular mycorrhizal colonisation of roots than other treatments in May 2003. Fresh marketable yield was negatively correlated to Fusarium incidence (p = 0.0091 r = -0.51) suggesting that plants with higher yields are less susceptible to Fusarium symptoms and that producers should avoid over-harvesting low yielding plants to reduce Fusarium spread in the field. Soil microbial activity was not affected consistently by P fertilizers because of high variability in the field.
28
Xie, Rongjing. "Ortho- and pyrophosphate sorption effects on zinc transformations in three Quebec soils". Thesis, McGill University, 1988. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=75928.
Testo completoAbstract (sommario):
Crop-available zinc is affected by P-Zn interactions in soils. Orthophosphate (OP) additions may decrease or have no effect, while pyrophosphate (PP) may increase or have no effect on Zn solubility. Mechanisms involved in the interactions are not well understood and need to be quantified on agricultural soils subjected to P fertilization.Top and sub-samples from three Quebec agricultural soils were equilibrated with OP or PP solutions, then with Zn solutions, and finally with solutions containing neither P nor Zn. The first equilibration evaluated P sorption effects on soil cation exchange capacity (CEC), the second equilibration evaluated Zn sorption (Zn$ sb{ rm s}$) after P sorption, and the third Zn desorption (Zn$ sb{ rm D}$) as related to added P. Subsequently, Zn fractions were extracted sequentially with KNO$ sb3$ (Zn$ sb{ rm KNO3}$), NaOH (Zn$ sb{ rm NaOH}$) solutions and concentrated HNO$ sb3$ + H$ sb2$O$ sb2$ (Zn$ sb{ rm HNO3}$). Autoclaved soils were used for OP and PP comparisons, and non-autoclaved soils were used for OP determinations.
Autoclaving reduced dithionite-citrate extractable Fe and Al materials. In both autoclaved and non-autoclaved soils, one mmole sorbed P as PP or OP resulted in increases in CEC from 0.52-1.24 mmole (+). Comparison between OP and PP in the autoclaved soils indicated that the increased CEC per mmole sorbed was greater with sorbed OP than with PP, while at the same rate of P addition, the absolute increased CEC was more with sorbed PP than with OP due to greater P sorption as PP compared to OP. Both sorbed OP or PP in autoclaved soils and sorbed OP in non-autoclaved soils increased specific Zn sorption in association with oxide materials. The effect was more significant with PP than with OP, as indicated by the observations: (1) P sorption increased Zn sorption but reduced Zn desorption, (2) P sorption reduced KNO$ sb3$- but increased NaOH- and HNO$ sb3$-extractable Zn, and (3) P sorption increased the difference between Zn sorbed and Zn extracted with KNO$ sb3$. These effects were more significant in coarser than finer textured soils. Results suggested that Zn fertilizers should be separated from P fertilizers to avoid enhanced Zn sorption and reduced Zn desorption.
29
Gichangi, Elias Maina. "Enhancing phosphorus availability in some phosphate fixing soils of the Transkei region, South Africa using goat manure". Thesis, University of Fort Hare, 2007. http://hdl.handle.net/10353/80.
Testo completoAbstract (sommario):
Low availability of soil phosphorus (P) caused by strong sorption of P is a major constraint to agricultural production in most South African soils, particularly those from the high rainfall areas. The aim of this study was therefore to investigate whether combined addition of goat manure with inorganic P fertilizers could enhance P availability in some P fixing soils of the Transkei region, South Africa. The study addressed the following specific objectives (i) to assess P sorption capacities and requirements of selected soils and their relationship with selected soil properties and single point sorption test, (ii) to assess the effects of goat manure and lime addition on P sorption properties of selected P fixing soils (iii) to assess the temporal changes in concentration of inorganic and microbial biomass P fractions following application of inorganic fertilizer P with goat manure in a laboratory incubation experiment, and, (iv) to assess the effects of goat manure application with inorganic phosphate on inorganic and microbial biomass P fractions, P uptake and dry matter yield of maize. Sorption maxima (Smax) of seven soils examined ranged from 192.3 to 909.1 (mg P kg-1) and were highly and positively correlated with sorption affinity constant (r = 0.93, p = 0.01) and organic C (r = 0.71, p = 0.01). The amount of P required for maintaining a soil solution concentration of 0.2 mg P l-1 ranged from 2.1 to 123.5 mg P kg-1 soil. Soils collected from Qweqwe (a Cambisol), Qunu (an Acrisol), Ncihane (a Luvisol) and Bethania (a Ferralsol) had lower external P requirement values and were classified as lower sorbers, whereas soils from Ntlonyana (a Planosol), Chevy Chase (a Ferralsol) and Flagstaff (a Ferralsol) were classified as moderate sorbers. The results suggested that P availability could be compromised in 43 percent iii of the soils studied and that measures to mitigate the adverse effects of P sorption were needed to ensure that P is not a limiting factor to crop production, where such soils are found. Goat manure addition at varying rates (5, 10 and 20 tha-1 dry weight basis) to two of the moderately P fixing soils from Chevy Chase and Flagstaff, reduced P sorption maxima (Smax) compared to the control treatment. Phosphate sorption decreased with increasing amounts of goat manure in both soils but the extent of reduction was greater on Chevy Chase soil than on Flagstaff soil. The relative liming effects of the different rates of goat manure followed the order 20 t GM ha-1 > 10 t GM ha-1 > 5 t GM ha-1. In a separate experiment, addition of inorganic P at varying rates (0, 90, 180, and 360 kg P ha-1) to Flagstaff soil increased labile P fractions (resin P, biomass P and NaHCO3-Pi) and the increases were greater when goat manure was co-applied. The control treatments contained only 17.2 and 27.5 mg P kg-1 of resin extractable P in the un-amended and manure amended treatments, respectively which increased to 118.2 and 122.7 mg P kg-1 on day 28 of incubation. Biomass P concentration was increased from 16.8 to 43.9 mg P kg-1 in P alone treatments but the fraction was greatly enhanced with manure addition, increasing it from 32.6 to 97.7 mg P kg-1. NaOH-Pi was the largest extractable Pi fraction and ranged from 144.3 to 250.6 mg P kg-1 and 107.5 to 213.2 mg P kg-1 in the unamended and manure amended treatments, respectively. Dry matter yield and P uptake by maize grown in the glasshouse were highly and significantly (p = 0.05) correlated with the different P fractions in the soil. The correlations followed the order resin P (r = 0.85) > NaOH-Pi (r = 0.85) > NaHCO3-Pi (r = 0.84) >> biomass P (r = 0.56) for dry matter yield at 6 weeks after planting. At 12 weeks after planting, goat manure had iv highly significant effects on resin P and biomass P but had no effect on NaHCO3-Pi and NaOH–Pi. The combination of biomass P, resin P and NaHCO3-Pi explained 75.8 percent of the variation in dry matter yield of which 63.0 percent of the variation was explained by biomass P alone. The greatest increase in biomass P occurred when added P was co-applied with 5 or 10 tha-1 goat manure. The predictive equation for maize dry matter yield (DM) was: DM (g) = 1.897 biomass P + 0.645 resin P (r = 0.73). Resin P was the fraction that was most depleted due to plant uptake and decreased by 56 to 68 percent between the 6th week and the 12th week of sampling indicating that it played a greater role in supplying plant available P. The results therefore suggested that the use of goat manure may allow resource poor farmers to use lower levels of commercial phosphate fertilizers because of its effect to reduce soil P sorption. In addition, higher increases in biomass P due to manure addition observed at lower rates of added P indicated that goat manure has potential for enhancing bioavailability and fertilizer use efficiency of small inorganic P applications.
30
Derkintis, Tadas. "Sertifikuotų ekologiškų fosforo trąšų įtaka dirvožemio ir žemės ūkio augalų elektrocheminėms savybėms". Master's thesis, Lithuanian Academic Libraries Network (LABT), 2009. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2009~D_20090615_115155-18806.
Testo completoAbstract (sommario):
Darbo tikslas – nustatyti fosforo trąšų įtaką dirvožemio elektrocheminių parametrų kaitai bei miežių grūdų kokybės parametrams.
Darbo uždaviniai:
o nustatyti sertifikuotų ekologiškų fosoforo trąšų fosforitmilčių įtaką dirvožemio elektrocheminėms savybėms;
o nustatyti sertifikuotų fosforo trąšų įtaką žemės ūkio augalų grūdų elektrocheminėms savybėms.
Darbo objektas – Lietuvos žemės ūkio universiteto Agroekologijos centro ekologinės gamybos ūkio dirvožemis bei jame auginti vasariniai miežiai.
Darbo rezultatai. Lietuvos žemės ūkio universiteto Agroekologijos centro ekologinės gamybos ūkyje atlikus sertifikuotų fosforo trąšų įtakos dirvožemio elektrocheminėms savybėms tyrimus, nustatyta, kad patręšus P60 fosforitmičių norma esminiai padidėjo dirvožemio pH rodiklio reikšmė, lyginant su netręštu dirvožemiu bei tręšimu P90 ir P120 normomis. Tiriant dirvožemio savitojo elektrinio laidžio reikšmes prieš tręšimą fosforo trąšomis pavasarį ir po vasarinių miežių derliaus nuėmimo, nustatyta, kad dirvožemio savitojo elektrinio laidžio reikšmės sumažėjo esminiai. Ištyrus dirvožemio savitąjį elektrinį laidį rudenį po tręšimo fosforo trąšomis, nustatyta, kad dirvožemio savitasis elektrinis laidis esminiai padidėjo, lyginant su dirvožemio ėminiais, paimtais po vasarinių miežių nupjovimo, bet negauta esminių skirtumų, lyginant su dirvožemio ėminiais paimtais pavasarį prieš vasarinių miežių tręšimą. Patręšus didžiausia tirta P120 fosforo trąšų norma, esminiai padidėjo dirvožemio redokso... [toliau žr. visą tekstą]The thesis aims at defining the effect of phosphatic fertilizers on the change of electrochemical parameters of the soil and the quality parameters of barleycorn. The goals of the thesis are as follows: • determination of the effect of bone meal as a certified organic phosphatic fertilizer on the electrochemical parameters of the soil. • determination of the effect of certified phosphatic fertilizers on the electrochemical parameters of the crop grain. The soil of the organic farm of the Agro-ecological Centre of the Lithuanian University of Agriculture and spring barley grown therein constitute fall within the scope of the thesis. Findings. Research of the effect of certified phosphatic fertilizers on the electrochemical parameters of the soil in the organic farm of the Agro-ecological Centre of the Lithuanian University of Agriculture shows that application of the standard P60 bone meal resulted in a considerable increase of the pH value of the soil, as compared to unfertilized soil or use of the standard P90 and P120. The analysis of the values of soil conductivity before application of phosphatic fertilizers in spring and after reaping of spring barley reveals that the values of soil conductivity decreased to a remarkable extent. After testing of soil conductivity in autumn after use of phosphatic fertilizers it was established that soil conductivity, as compared to the soil samples taken after reaping of spring barley, considerably increased, however, testing shows no... [to full text]
31
Lukhele, Nomagugu Precious. "Site-specific environmental risk assessment for phosphorus runoff". Thesis, University of Limpopo, 2014. http://hdl.handle.net/10386/1291.
Testo completoAbstract (sommario):
Thesis (MSc. Agriculture (Soil Science)) -- University of Limpopo, 2014Phosphorus (P) runoff from agricultural sites and the subsequent loading into surface water bodies contribute to eutrophication. Environmental concerns associated with P loading in soil have motivated the need for the development of a proper tool that will allow farmers to identify agricultural areas or management practices that have the greatest potential to accelerate eutrophication. The objective of the study was to determine the spatial variability of soil test P, soil loss potential of the farm, P application rate and methods, and map P runoff risk across the field. This study was conducted in Vierfontein Boerdery in Kriel, Mpumalanga province, South Africa (longitude 29.11258833 and latitude -26.27104340). The field was under dryland cultivation and planted to yellow maize that was rotated with soybeans. Soil samples were taken at georeferenced locations in a 100 x 100 m grid for soil analysis. Spatial layers of soil P distribution, soil loss potential as well as application rate and method were created in ArcGIS software. These layers were used as input factors in a P index model to identify areas in the farm that are vulnerable to P runoff. Results indicated a variation in soil test P. Although soil test P variation was not statistically different at P≤0.05, variation had both agronomic and environmental implications. This variation could be attributed to differences in site-specific conditions and management practices. Furthermore, soil loss potential across the study site predicted by the Revised Universal Soil Loss Equation (RUSLE) showed variation with a range of 3-15 tons/ha/yr. This variation was attributed to differences in topographic variations in the study site. There is a need for best management practices that control soil erosion to minimize P runoff into water bodies. KEYWORDS: Eutrophication, Geographic Information System, Phosphorus best management practises, Phosphorus runoff index, Soil erosion, Site-specific management.
32
Fan, Mingxiang. "Urea and acidic phosphate interactions in fertilizer microsites and their effect on corn (Zea mays L.) yield and nutrient use efficiency". Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=41334.
Testo completoAbstract (sommario):
Fertilizer applications of urea and triple superphosphate (TSP) suffer from low efficiency for corn production. Band or broadcast application of urea with acidic-P fertilizers may increase fertilizer efficiency. Urea and acidic-P fertilizer interactions in soil-fertilizer microsites were investigated using two Quebec soils. Adding acidic phosphates such as TSP and monoammonium phosphate (MAP) to urea reduced pH in microsites, urea hydrolysis, NH$ sb3$ volatilization, and increased soil NH$ sb4$- and NO$ sb3$-N contents. Ammonia loss decreased as P$ rm sb2O sb5$: urea-N ratios increased. Adding urea to P fertilizer increased soil pH and P sorption when using CaCl$ sb2$ as the electrolyte. Urea application increased 0.5 M NaHCO$ sb3$ extractable P. Banding urea with TSP caused dissolution of organic matter in soils, and increased P diffusion and P concentration in soil solution sampled with filter paper or in 1 M KCl extraction. Two years of field experiments demonstrated that banding urea with TSP or MAP increased soil extractable P (Mehlich-3), N and P nutrient uptake, plant growth and development of corn. Greater P fertilizer efficiencies and higher yields were achieved by banding urea-acidic P fertilizers.
33
Yusiharni, Baiq Emielda. "An evaluation of chicken litter ash, wood ash and slag for use as lime and phosphate soil amendments". University of Western Australia. Faculty of Natural and Agricultural Sciences, 2007. http://theses.library.uwa.edu.au/adt-WU2007.0078.
Testo completoAbstract (sommario):
[Truncated abstract] Standard AOAC methods of chemical analysis have been used to characterize and evaluate the industrial byproducts; partly burnt chicken litter ash (CLA), totally burnt chicken litter ash (CLAT), wood ash (WA) and iron smelting slag for use as a combined liming agent and phosphate fertilizer. Rock phosphate has this function and was included for comparison purposes. All the byproducts had pH values above 9 and a liming capacity above 90% of pure lime, as a result, these materials will be effective as liming agents. Total P concentrations for CLA, CLAT, slag, and WA were 3.6%, 4.75%, 0.26%, and 0.44% respectively indicating that they could be used as P fertilizers when applied at the high rates required for liming soils. ... The RE values for all the materials relative to monocalcium phosphate (100%) for the first harvest are as follows, 50% for dicalcium phosphate, 31% for rock phosphate, 7% for partly burnt chicken litter ash, 7% for totally burnt chicken litter ash and 1% for wood ash and slag. The RE values for the second harvest were 100% for monocalcium phosphate, 80% for dicalcium phosphate, 40% for rock phosphate, 10% for partly burnt chicken litter ash, 8% for totally burnt chicken litter ash and 2% for wood ash and slag. Data for subsequent harvests are not reported due to the death of many plants. Clearly chicken litter ash has appreciable value as a phosphate fertilizer whereas wood ash and slag are ineffective. Explanations for these differences in effectiveness are discussed in the text. An evaluation of the liming effect of the byproducts indicates that they may be used as a soil amendment on acid soils and are nearly as effective as standard lime (CaCO3). Byproducts are also sources of other plant nutrients so they may be regarded as a form of compound fertilizer and liming agent.
34
Lucas, P. W. "Fertilizer phosphate-ammonium interactions in soil". Thesis, University of York, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374186.
Testo completo
35
Митова, И. И., Ю. А. Ахмед e Р. Чутуркова. "Оценка факторов рабочей среды при производстве фосфорных удобрений". Thesis, Сумский государственный университет, 2013. http://essuir.sumdu.edu.ua/handle/123456789/48081.
Testo completoAbstract (sommario):
Сделана оценка факторов рабочей среды при производстве фосфорных удобрений в "Агрополихиме" АД – в цехе "Фосфорная кислота" и в цехе "Тройной фосфат". Ведущее место по своей выраженности занимают химические вредные факторы. Кроме этого, внимание направлено на физико- химический фактор пыли и физический фактор шума.
36
Shandyba, A. B., D. M. Shpetny e A. V. Vasilushenko. "Production of environmental fertilizers by Ukrainian phosphate industry". Thesis, Sumy State University, 2016. http://essuir.sumdu.edu.ua/handle/123456789/46861.
Testo completoAbstract (sommario):
The fertilizer industry uses a wide range of production technologies, which are considered under engineering and environmental aspects. The traditional composition ration of N, P, K had changed to more using the additional microcomplex and organic components. The objective of this study was to evaluate agronomic and environmental effectiveness of the new mineral-organic generation fertilizers by comparing it with the other fertilizers such as the super phosphate (as P source) or ammophos of traditional trade marks.Technical feasibility of the phosphate fertilizer industry has been demonstrated by using native raw materials and local wastes.
37
Braga, Graziela. "Eficiência de fosfatos com solubilidade variável em água em solos com capacidade de fixação de fósforo induzida". Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/11/11140/tde-29062006-114403/.
Testo completoAbstract (sommario):
O presente trabalho constou de dois experimentos, ambos realizados em casa de vegetação do Departamento de Solos e Nutrição de Plantas da ESALQ/USP com delineamento experimental de blocos ao acaso, nos quais utilizaram-se amostras de um Latossolo Amarelo adicionando-se ou não um gel de ferro (Fe), estabelecendo assim condições distintas de capacidade de fixação de fósforo (CFF) para um mesmo solo. As fontes de P testadas foram: (i) fosfato monocálcio p.a. (FMC), que foi utilizado como fonte padrão, (ii) superfosfato simples com baixa solubilidade em água (low-grade SSP, LG SSP), (iii) multifosfato magnesiano (MFM), (iv) termofosfato (TERMO), e (v) fosfato natural de Arad (FN). A hipótese central estudada foi a de que algumas fontes de fósforo com baixa solubilidade em água utilizadas no Brasil possuem maior eficiência agronômica relativa em solos de elevada capacidade de fixação de P. O experimento 1 teve como objetivo comparar e avaliar a liberação de P das fontes em diferentes situações de acidez e fixação de P. Neste estudo não foi utilizado planta. Os tratamentos envolveram cinco fontes de P (FMC; LG SSP; MFM; TERMO; FN), seis doses (0, 12,5; 25; 50; 100 e 200 mg kg-1 P), duas condições de solo (sem e com aplicação de gel de Fe) e dois níveis de acidez (pHCaCl2 4,6 e 5,6). O número total de tratamentos foi de 120 (5 fontes x 6 doses x 2 condições de CFF x 2 níveis de acidez), com três repetições, totalizando assim, 360 unidades experimentais. Amostras de terra foram coletadas 30 dias após a montagem do experimento para avaliar o teor de fósforo no solo, utilizando a resina trocadora de íons como extrator. De forma geral observaram-se maiores valores do índice de eficiência relativa das fontes de baixa solubilidade em água nos solos com indução da CFF. No experimento 2 o objetivo principal foi avaliar a eficiência agronômica relativa (EAR) das fontes de P. Realizaram-se dois cultivos de milho que seguiram o esquema [(2 x 5 ) + 2 ], ou seja, duas condições de solo (sem e com gel de Fe), cinco fontes de P (FMC; LG SSP; MFM; TERMO; FN), duas testemunhas sem P e três repetições (36 unidades experimentais). Nos dois cultivos observou-se um decréscimo na produção de matéria seca, e P acumulado, com o FMC na condição de alta CFF, além disso, ocorreu o aumento da EAR das fontes de baixa solubilidade em água com a indução da CFF. Os resultados dos dois estudos sugerem que geralmente as fontes com baixa solubilidade em água apresentam maiores valores de eficiência relativa quando se induziu o aumento da CFF. Esta informação, adaptada através de experimentação regional adequada de campo, poderá levar a um melhor manejo das fontes de fósforo e ainda auxiliar na tomada de decisão por parte dos empresários rurais com relação a fontes disponíveis de P.The study was carried out through two experiments conducted at the greenhouse of the Soil and Plant Nutrition Department, ESALQ/USP, utilizing experimental outline as blocks and a Yellow Latossol, with the addition or not of an iron gel to vary the soil phosphorus (P) fixation capacity (PFC). The P sources tested were: (i) reagent grade monocalcium phosphate (MCP), used as the standard source of P, (ii) low-grade single superphosphate with medium water solubility (LG SSP), (iii) magnesium multiphosphate (MMP), (iv) termophosphate (TERMO), and (v) Arad phosphate rock (PR). The hypothesis tested was that "some P sources, with low water solubility, may have higher relative agronomic effectiveness (RAE) in soils with high PFC". Experiment 1 aimed to evaluate and compare the P released from the sources in different scenarios of soil acidity and PFC. In this study plants were not used as indicators but an extractor of bioavailable P. The treatments consisted of five P sources, six rates of P (0, 12,5; 25; 50; 100 e 200 mg P Kg-1 of soil), two soil conditions as related to PFC (without and with the addition of an iron gel) and two soil pH levels. The total number of treatments was 120, with three replicates, totalizing 360 experimental units. Soil samples were collected 30 days after soil incubation with the P sources and analyzed following the exchange resin as the extractor. In general, higher relative index were observed for the alternative sources of P (low water solubility) in the soil with induced PFC. Experiment 2 was designed to provide information related to the RAE utilizing two short corn plant crops as indicator. The experimental outline was of two soil condition as related to PFC (without and with addition of the iron gel), five P sources, two controls, and three replicates, totalizing 36 experimental units. Only one soil pH condition was tested in this case (with lime added to pH CaCl2 5.6). Both corn crops showed a decrease in dry-matter yield and P uptake by the plants with the MCP applied in the soil with higher PFC. The RAE was in general higher for the lower water soluble P sources in the soil with induced PFC. The results of both experiments suggested that, in general, P sources with lower water solubility present higher relative effectiveness when the soil PFC was induced by the addition of the iron gel. The information, once adapted to local field experimentation, can lead to a more adequate management of the P sources, as well may serve to guide farmers in taking decisions as related to sources to be utilized in their agricultural fields.
38
Benedito, Daniela da Silva. "Eficiência agronômica de fontes alternativas de fósforo e modelo de predição do uso de fosfatos naturais". Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/11/11140/tde-08112007-095724/.
Testo completoAbstract (sommario):
Os fertilizantes fosfatados (FF) mais utilizados na agricultura são solúveis em água, e requerem enxofre elementar e concentrados apatíticos de elevada qualidade para produção, conduzindo à subutilização dos depósitos de fosfato (perdas elevadas de P no beneficiamento). Conseqüentemente, é necessário estudar as fontes alternativas de P. Neste trabalho foram estudadas quanto à: (i) revisão de literatura que tenta mostrar a situação atual no Brasil e no mundo; (ii) produção alternativa de fonte de P que integra matéria orgânica e RF (Humifert); e (iii) utilização de software para predizer a eficiência agronômica (EA) de RF, relativamente às fontes de P solúveis em água. Na revisão da literatura foram enfatizados: tratamento térmico, acidulação parcial, compactação ou mistura com FF solúveis em água, tratamentos com resíduos orgânicos e/ou microrganismos. Outros aspectos apontaram: (i) condições gerais para utilizar fontes de P de elevada solubilidade em água e alternativas; (ii) manejo de solos prevendo solubilização de formas de P nativo e aumento na EA de fontes de P através de cultivos precedentes ou microrganismos; (iii) calcinação de RFs do tipo Ca-Al-P (crandallita); e (iv) necessidade de pesquisas com fontes alternativas de P em condições de casa-de-vegetação e campo. Quanto ao processo Humifert, um reator foi construído para trabalhar em escala de bancada. Os objetivos foram gerar informações sobre produção dos fertilizantes "Humifert" e testar a EA dos mesmos. Diversos testes foram conduzidos quanto às condições de operação do equipamento, como tempo de reação e solubilidade dos materiais produzidos. Dois experimentos agronômicos foram conduzidos em casa-de-vegetação, relacionando os resultados dos produtos obtidos no equipamento com fonte padrão de P. Esse processo conduz a desempenho agronômico superior da RF quando comparada a mesma sem submissão às reações. Embora algumas vantagens em aumento de produção devido ao Humifert, a solubilidade e os resultados agronômicos indicam necessidade de mais pesquisas para adequar as reações, para obter fontes de P de melhor qualidade. O software para predizer a eficiência das RFs denomina-se "Phosphate Rock Decision Support System" (PRDSS) e foi desenvolvido com colaboração entre "IFDC" e "IAEA". O objetivo final é predizer a EA de RF específica relativamente a fontes de P de elevada solubilidade em água, considerando solo, características da RF, manejo do solo e clima na localidade. O experimento foi conduzido em Rondonópolis, em um LV com pH em água de 5,2, teor muito baixo de P e capacidade média de adsorção de P. As fontes de P utilizadas foram superfosfato simples, RF de Araxá e de Gafsa, aplicadas a lanço e incorporadas em 15 cm de solo, nas doses 60, 120 e 240 kg ha-1 de P2O5 total. Um controle foi adicionado para cada fonte de P. Os resultados de EAR para soja no campo foram de 100%, 51% e 97% para o SSP, RF Araxá e Gafsa, respectivamente. Os valores de EAR preditos pelo PRDSS foram de 33% e 100% para a RF Araxá e Gafsa, respectivamente, sendo consideradas boas estimativas da EAR real em condições brasileiras, inicialmente comprovando a aplicabilidade deste software para uso futuro.The most utilized phosphate fertilizers (PF) in agriculture are the water-soluble sources, that require elemental sulfur and high quality apatite concentrates for the production, leading to the subutilization of phosphate deposits (high losses of P during the beneficiation). Consequently, it is necessary to study the alternative sources of P. In this work they were studied as related to: (i) literature review trying to show the present situation in Brazil and worldwide, (ii) alternative production of a P source combining organic matter and PR (Humifert), and (iii) utilization of software to predict the agronomic effectiveness (AE) of PR, related to water-soluble P sources. For the literature review were emphasized: thermal treatment, partial acidulation, compaction with high water-soluble PF, organic residues and/or microrganisms treatments. Other aspects targeted: (i) general conditions to utilize high water-soluble P sources and alternatives, (ii) management of soils foreseeing the solubilization of forms of native P and increase in AE of P sources through previous crops or microrganisms, (iii) calcination of PRs of the type Ca-Al-P (crandallite), and (iv) requirement for research with different sources of P in greenhouse and field conditions. As related to the Humifert process a reactor was built to work in bench scale. The objectives were to generate information relative to the production of the "Humifert" fertilizers and test the AE of them. Several tests were applied as related to the operating conditions of the equipament, as reaction time and solubility. Two agronomic experiments were conducted in a greenhouse, relating the results of the products obtained in the equipament with a standard source of P. The process lead to higher agronomic performance of the PR, when comparing it without submission to the reactions. Although some advantages in increase of production due to the Humifert, the solubility and agronomic results indicate that more research is necessary to adequate the reaction to obtain better quality P sources. The software to predict PR effectiveness is called "Phosphate Rock Decision Support System (PRDSS)" and was developed in collaboration between "IFDC" and "IAEA". The final objective is to predict the RAE of a specific PR, as related to WSP sources, taking into consideration soil, PR characteristics, soil management and clima at locality. Our experiment was conducted in Rondonopolis, in an Oxisol with pH 5.2 in water, very low content of P and medium P adsorption capacity. The P sources utilized were the single superphosphate, the Araxa PR and Gafsa, all applied broadcasted to the soil into the 15 cm soil layer, in rates 60, 120 and 240 kg ha-1 of total P2O5. A control was added for each P source. The results for RAE for soybean at field condition were 100%, 51% and 97% for the SSP, Araxa PR and Gafsa, respectively. The RAE predicted by the PRDSS were of 33% and 100% for Araxa PR and Gafsa, respectively, which can be considered good estimates of the real RAE at Brazilian conditions, initially attesting the feasibility of this software for future use.
39
Compaoré, Emmanuel N. "Contribution à la caractérisation et à la gestion de la fertilité phosphatée des sols ferrugineux tropicaux". Vandoeuvre-les-Nancy, INPL, 1996. http://www.theses.fr/1996INPL115N.
Testo completoAbstract (sommario):
La fertilité phosphorique du sol est une contrainte majeure à l'établissement d'une production agricole soutenue dans les sols ferrugineux tropicaux d'Afrique de l'ouest. Cette étude est consacrée à l'amélioration du statut phosphaté des sols ferrugineux tropicaux les plus représentatifs de cette zone. Quatre vingt quatre échantillons de terre, prélevés au Burkina Faso sont utilisés pour cette étude. La fertilité phosphorique des terres a été caractérisée par trois méthodes d'analyse chimique et par la méthode des cinétiques d'échanges isotopiques. L’efficacité agronomique des phosphates naturels du Burkina, de son dérivé partiellement acidulé et d'un compost provenant du Burkina Faso a été mesurée en présence ou non d'une légumineuse, Vigna unguculata et d'une céréale, Zea mays. Les résultats ont permis de mettre en évidence l'extrême carence en P biodisponible des sols ferrugineux du Burkina Faso, les valeurs moyennes des facteurs intensité et capacité des terres non fertilisées sont respectivement de 0,007 mg p/l et 0,21 mg p/kg. Le facteur capacité de la majorité des sols est supérieur à 0,2, ce qui correspond à de faibles pouvoirs fixateurs. En dépit de la mise en culture continue sans restitution on observe une apparente stabilité des paramètres caractéristiques du P biodisponible. Le phosphate naturel de Kodjari s'est révélé inefficace ; son coefficient réel d'utilisation (CRU%) est de 0,4% malgré l'utilisation d'une légumineuse fixatrice d'azote ; son arrière effet est négligeable. Le compost s'est aussi montré peu efficace. Par contre le BPA comme le TSP se sont bien comportés avec des CRU% respectivement de 10% et de 20%. Pour accroitre le potentiel de production l'utilisation limitée d'engrais soluble-eau est pour le moment incontournable
40
Francois, A. Joyce. "Composting phosphorus fertilizer with organic wastes to stablize the fertilizer against fixation by phosphate-fixing soils". Thesis, University of Oxford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.236297.
Testo completo
41
Kulay, Luiz Alexandre. "Uso da análise de ciclo de vida para a comparação do desempenho ambiental das rotas úmida e térmica de produção de fertilizantes fosfatados". Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-26102017-112209/.
Testo completoAbstract (sommario):
Dada sua importância para o crescimento de diversas culturas, o fósforo encontra uso regular na produção de fertilizantes. Entretanto, o fato desse elemento apresentar-se na natureza em uma forma não assimilável pelos vegetais, fez com que a indústria de fertilizantes fosse forçada a desenvolver processos para sua dissolução. Esses processos costumam, em geral, ser agrupados segundo duas grandes rotas: a rota úmida e a rota térmica. Os processos que constituem a rota úmida caracterizam-se por promover a digestão do mineral de fósforo por meio de ácidos minerais tais como o sulfúrico e o fosfórico. Por conta desse tratamento são obtidos os superfosfatos simples e triplo. Já os processos compreendidos pela rota térmica valem-se, por sua parte, de energia térmica para modificar a estrutura da rocha fosfatada, a partir do que serão gerados os chamados termofosfatos. As rotas úmida e térmica já foram comparadas em diversas ocasiões, em geral segundo critérios de cunho técnico e econômico. O presente trabalho realiza também a referida comparação, agora porém sob o ponto de vista de desempenho ambiental, empregando, para tanto, a técnica de Análise de Ciclo de Vida (ACV). Selecionou-se como representante da rota úmida o superfosfato triplo (TSP), enquanto que o termofosfato magnesiano fundido (FMP) foi usado para retratar a rota térmica. Para efeito da execução de ambos os estudos de ACV, tomou-se por função para o TSP e para o FMP, a capacidade dessesprodutos em fornecer fósforo às plantas. No que se refere à definição dos sistemas de produto, decidiu-se adotar uma abordagem do tipo \"cradle to gate\" para a aplicação da ACV. Em razão desse fato, o sistema de produto de TSP passou a contemplar as etapas de lavra e concentração da rocha fosfática, as produções de ácido sulfúrico e ácido fosfórico e a manufatura em si desse fertilizante fosfatado. ) Os subsistemas auxiliares de transporte, e das gerações de energia elétrica e de gás natural foram também considerados no estabelecimento do referido sistema de produto. O sistema de produto do FMP foi estruturado segundo a mesma abordagem, passando por conta disso a ser composto pelos subsistemas de lavra e de britagem da rocha fosfática, pelo transporte de serpentinito, pelas gerações de energia elétrica e de gás natural, e pela produção em si do fertilizante. Por fim, para que fosse possível fornecer um quadro preciso do desempenho ambiental dos sistemas sob avaliação, houve-se por bem selecionar as categorias de impacto de Aquecimento Global (PAG), Depleção de Camada de Ozônio (PDCO), Toxicidade Humana (PTH), Ecotoxicidade Aquática (PEa), Acidificação (PAc) e Eutrofização (PEu). A realização de estudos de ACV segundo essas e outras premissas mostrou que o desempenho do sistema de produto de TSP foi superior ao do FMP para todas as categorias de impacto selecionadas, excetuando-se os potenciais de Acidificação e de Eutrofização. Em termos do Potencial de AquecimentoGlobal, o FMP mostrou-se quatro vezes mais agressivo ao meio ambiente que seu homólogo fosfatado. Esse quadro se repete também para a Ecotoxicidade Aquática; desde o ponto de vista dessa categoria de impactos, a produção de TSP traz efeitos lesivos sobre o meio ambiente com uma magnitude 3,3 vezes menor que se o mesmo elemento fosse disponibilizado como FMP. Por outro lado, no que se refere à Eutrofização, por meio da qual são de fato medidos os impactos ambientais gerados pelas perdas de fósforo ao longo de ambos os processamentos, o FMP apresentou melhor desempenho ambiental que o TSP.Given its importance to the growth of several crops, the element phosphorous is regularly used for the production of fertilizers. Nevertheless, the fact that this element is found in Nature in a non-assimilable form has forced the fertilizer industry to develop processes for its dissolution. These processes are usually divided in two major groups: the wet route and the thermal route. The processes that constitute the wet route characteristically digest the phosphate rock using mineral acids such as the sulfuric acid and the phosphoric acid. In this treatment are produced, respectively, the single superphosphate and the triple superphosphate. On the other hand, the processes belonging to the thermal route use thermal energy to modify the structure of the phosphate rock generating the so-called thermophosphates. The wet and thermal routes have been compared in several occasions, usually according to technical and economic criteria. This study also performs such a comparison, but now on an environmental performance approach, using for this the Life Cycle Assessment methodology (LCA). The triple superphosphate (TSP) was chosen to represent the wet route whereas the fused magnesium thermophosphate (FMP) was chosen to reflex the thermal route. In both LCA studies the function of the products was deemed to be to supply phosphorous to crops. The product systems were defined using a \"cradle-to-gate\" approach. Therefore the TSP product system contemplates:the mining and concentration of the phosphate rock, the production of sulfuric and phosphoric acids and the TSP manufacture itself. The auxiliary subsystems of transportation and the electricity and natural gas generation subsystems were also considered in the above-mentioned system. ) The FMP product system was structured in a similar way and contemplates: the mining and crushing of the phosphate rock, the serpentinite transportation, the electricity and natural gas generation and the FMP manufacture itself. Finally, in order to give a picture as accurate as possible of the environmental performance of the systems under evaluation, the following impact categories were chosen: Global Warming (GWP), Ozone Layer Depletion (OLDP), Human Toxicity (HTP), Aquatic Ecotoxicity (AETP), Acidification (AP) and Eutrophication (EP). The LCA studies have shown that the TSP product system performed better than the FMP product system in all the selected impact categories but Acidification and Eutrophication. In terms of Global Warming Potential, the FMP was shown to be four times more aggressive to the environment than TSP. This scenario repeats itself also for Aquacic Ecotoxicity. In this category, the TSP has an effect 3.3 times lower than the effect of the FMP. On the other hand, regarding Eutrophication, through which are in fact measured the environmental impacts generated by phosphorous losses during both product systems, FMP has presented a better performance.
42
Woldetsadik, Kebede. "Shallot (Allium cepa var. ascolonicum) responses to plant nutrients and soil moisture in a sub-humid tropical climate /". Alnarp : Dept. of Crop Science, Swedish Univ. of Agricultural Sciences, 2003. http://epsilon.slu.se/a367.pdf.
Testo completo
43
Van, der Merwe Petrus. "Phosphorus phyto-availability and fertilizer value of petrochemical and municipal wastewater sludges". Diss., University of Pretoria, 2014. http://hdl.handle.net/2263/46060.
Testo completoAbstract (sommario):
A growing population, urbanization and an increase in the number of
industries is causing an increase in sewage sludge (SS) that needs to be
either beneficially used or disposed of. Application of SS to agricultural lands
is a well-known practice but the plant available phosphate and phosphate
fertilizer value of SS has been of concern. This is especially due to the wide
variety of soils that SS is applied to and the different phosphate removal
processes that sewage waste water undergoes at the water care works and
the source used to produce SS.
Phosphate phyto-availability and phosphate fertilizer value of petrochemical
and municipal wastewater sludges (SS) were determined in four different soils
using an incubation study over 168 days, a pot trial over 42 days and a field
trial over one season. Phosphate phyto-availability was determined/calculated
by means of an incubation approach. Soils were incubated with sludge as well
as mono ammonium phosphate (MAP). The soils were then subjected to a
Bray-1 extraction after a certain time (42 days, 168 days). The relative
phosphate fertilizer value (RPFV) was then expressed as a percentage of the
Bray-1 extractability of the sludge-amended soil, relative to the MAP-amended
soil. The influence of soil properties, especially clay content, and sludge
properties namely phosphate extraction method (chemical and biological)
from waste water stream, was investigated to determine the effect on phytoavailability
and fertilizer value of phosphate in SS-amended soil. Soil
properties were the dominant factor determining plant available phosphate,
where plant available phosphate decreased with increasing clay content,
irrelevant of the type of treatment. There were, however, significant differences between the chemical and biologically removed SS, where the
biologically removed SS had higher plant available phosphate.
The RPFV % of the SS was comparable to MAP in terms of its plant
availability. Wetting and drying cycles in the pot trial influenced the plant
available phosphate from the SS, where the chemically treated sludge
showed in general lower plant availability. The RPFV % of the biologically
removed phosphate sludges was better than that of MAP and that of the
chemically phosphate removed sludge were lower.
Application of all the different sludge types resulted in a positive reaction on
plant available phosphate for all the soils. All the trials were conducted at pH
of about 5.5. However, it is expected that biologically P removed sludge will
perform better in acid soils. The reason being that ferric phosphate in the
chemically treated sludge is less soluble under pH conditions lower than 5.5
than above it.Dissertation (MScAgric)--University of Pretoria, 2014.
tm2015
Plant Production and Soil Science
MScAgric
Unrestricted
44
McKean, S. J. "Phosphate desorption characteristics of some tropical soils". Thesis, University of Reading, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234447.
Testo completo
45
Ottman, Mike, Jason Rovey, Ayman Mostafa e Worku Burayu. "Phosphorus Fertilizer Rate Effect on Alfalfa Yield and Soil Test P, Buckeye, 2014". College of Agriculture, University of Arizona (Tucson, AZ), 2015. http://hdl.handle.net/10150/560411.
Testo completoAbstract (sommario):
10 pp.Phosphorus is the primary fertilizer nutrient needed by alfalfa in Arizona. The objective of this study is to determine the effect of P fertilizer rate on alfalfa yield and soil test P. A phosphorus fertilizer rate study was conducted with alfalfa in Buckeye, AZ where 11-52-0 was applied at 0, 200, 400, and 800 lb fertilizer/acre in February, 2014 after the first cutting. Alfalfa hay yield was increased by phosphorus fertilizer application up to the cutting on July 30, but not thereafter. No differences in yield were found among the fertilizer rates of 200,400, and 800 lb 11-52-0/acre. Soil test phosphorus increased directly proportional to fertilizer rate, but eventually decreased close to deficient levels 3-5 months after fertilizer application. It is not known if additional fertilizer applications throughout the season would increase yield. Fertilizer rates higher than 200 lb 11-52-0/acre were not beneficial under the conditions of this study.
46
Gao, Lu. "Phosphorus Reclamation from Municipal Wastewater Sludge for Fertilizer Production". Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/36712.
Testo completoAbstract (sommario):
The increasing population with its associated rising food demand requires more agricultural fertilizers to maintain the harvest for food security. However, the natural calcium carbonate phosphate mineral (carbonate apatite) used to produce phosphorus (P) fertilizer is a non- renewable ore. Therefore, in this study, the objective is to extract the inorganic polymeric phosphate (polyphosphate: polyP) P-component in waste activated sewage sludge (WAS) from Ottawa’s municipal wastewater plant (ROPEC). Once extracted, the goal was to break down the polyP to inorganic phosphate (Pi) to produce carbonate apatite.
PolyP is a P-component in WAS because a group of wastewater microorganisms called polyphosphate-accumulating organisms uptake phosphate and generate intracellular polyP stores during aerobic digestion in municipal wastewater treatment plant processes. The total acidic, oxidative P content of WAS was measured. PolyP was extracted and quantified to estimate the fraction of total P as polyP in WAS. Different polyP extraction methods were undertaken. It was determined that the complicated composition and weight fractions of TWAS, including iron phosphate, complicated polyP extraction and Pi measurement.
Lessons learned were applied towards preliminary batch and continuous precipitation of carbonate apatite with the product slurry from the anaerobic digestion process at ROPEC. Limestone was tested as an inexpensive calcium carbonate source for carbonate apatite precipitation. The dissolution of calcium and carbonate from limestone was assessed, and it was determined that further optimization is required. Preliminary work indicated that the calcium- carbonate solution from limestone could precipitate synthetic carbonate apatite from anaerobic digester material. This synthetic carbonate apatite product may lead to mitigating the impending limitations on natural carbonate apatite availability for P-fertilizer production.
47
Harmassi, Mehrez. "Valorization of phosphate from industrial and domestic effluents as by-products for fertilizers production". Doctoral thesis, Universitat Politècnica de Catalunya, 2016. http://hdl.handle.net/10803/398248.
Testo completoAbstract (sommario):
Phosphorus in wastewater is mainly present as inorganic phosphate forms and is commonly removed through chemical co-precipitation using Al(III) and Fe(III) salts. However, precipitation is expensive and generates a waste to be disposed. If the recovery of phosphorus is the target objective the solution could be based on the integration of specific chemical processes or physico-chemical treatment process to recover phosphorous as pure mineral phases or supported onto low-cost inorganic sorbents.
Recovery of phosphate from diluted streams has been evaluated by integration of a pre-concentration step using P-selective sorbents to provide concentrated effluents of phosphate (e.g. from 0.1 to 2 g P-PO43-/L) typically at alkaline pH values due to the use of alkaline solutions in the regeneration step (e.g 1% NaOH).
In this study, phosphorus recovery as hydroxyapatite (Hap) from alkaline phosphate concentrates (0.25 to 1 g P-PO43-/L) using calcium chloride solutions in batch reactors was evaluated. When pH was kept constant in alkaline values (from 8 to 11.5), Hap precipitation efficiency was improved. At pH 11.5, higher phosphorus precipitation rate was registered but lower degree of crystallinity was observed. The increase of the total initial phosphate concentration lead to the formation of Hap powders with higher degree of crystallinity and crystal diameter, but also lower mean particle size.
Afterwards, the detrimental effects of the presence of magnesium (II) in synthetic brines on hydroxyapatite precipitation were also evaluated. Two synthetic brines with Mg/Ca molar ratios of 2.2 and 3.3 were continuously fed to reach a Ca/P molar ratio of ~1.67 to promote Hap formation. For both brines, inhibition of Hap precipitation and formation of the amorphous mineral phases of Ca-, Mg- and Ca/Mg-phosphates were observed at pH >9.5. Mg(II) severely inhibited phosphate precipitation, allowing the formation of amorphous calcium phosphate from meta-stable clusters due to Mg(II) incorporation into Ca-phosphate. In the experiments at pH 8, the formation of stable nanometre-sized pre-nucleation clusters promoted nucleation inhibition, even in supersaturated solutions.
On the other hand, phosphate P(V) recovery by using low-cost reactive inorganic materials with improved efficiency in terms of equilibrium and kinetics has been also evaluated. The integration of powder inorganic adsorbents fly ashes and zeolitic materials for selective removal of phosphate provided phosphorus (P) containing by-products with fertilizing properties. Fly ash samples from two different coal power stations and with different CaO(s) content (Los Barrios (FA-LB)) and (Teruel (FA-TE)) were evaluated on phosphate removal from aqueous solutions. P(V) recovery, in the expected pH conditions (6 to 9) of wastewater treatment plant (WWTP) secondary effluents, proceeds as combination of the dissolution of CaO(s) and formation of brushite (CaHPO4(s)) onto the fly ash particles avoiding the formation of more insoluble Ca-phosphates as hydroxyapatite with a limited fertilizing properties. Removal kinetics data were well described as diffusion-based process and the CaO(s) dissolution was discarded as the rate-controlling step. A powder zeolitic material synthetized from fly ash (NaP1-NA) and its calcium modified form (CaP1-NA) were also studied as sorbent materials for the recovery phosphate from treated waste water effluents. The sorption capacity of both zeolites on the expected pH for waste water effluents (pH from 7 to 9) was slightly dependent on pH. The stability of the loaded phosphate zeolites samples as fertilizer was evaluated by extraction experiments.
Finally, the performance of Ca-activated powder zeolite (CaP1) on removing P(V) was evaluated by integrating the sorption step and the solid phase recovery by using an hybrid sorption-ultrafiltration system using a hollow fibre module.El fósforo presente en las aguas residuales, mayoritariamente en formas inorgánicas, es eliminado a través de co-precipitación con sales de Al (III) y Fe (III) sales suponiendo un coste en reactivos y la imposibilidad de recuperarlo. Con objeto de desarrollar procesos de recuperación de P (V) para cumplir con los requisitos legislativos futuros se ha evaluado la integración de los procesos químicos de precipitación en reactores agitados o sobre adsorbentes inorgánicos selectivos a aniones fosfato. Una primera alternativa evaluada ha sido la recuperación de fosfato en forma de hidroxiapatita (HAp) utilizando concentrados alcalinos (0.2 -2 g P-PO43-/L a pH 12) obtenidos en procesos de desorción de adsorbentes y resinas de intercambio y utilizando disoluciones de Ca(II). La eficiencia del proceso de precipitación de HAp incrementa con el incremento de pH (de 8 a 11.5). siendo máxima a pH 11,5 pero con una pérdida de cristalinidad. El incremento de la concentración inicial de fosfato favorece la formación de Hap con un incremento del tamaño de los cristales y de la cristalinidad. Se evaluaron los efectos de la presencia de magnesio (II) en los concentrados de cloruro de calcio en la precipitación de Hap utilizando dos salmueras sintéticas con relaciones molares Mg/Ca de 2,2 y 3,3. La presencia de Mg (II) inhibe la precipitación de HAp favoreciendo la formación de fases de fosfato de calcio, fosfato de magnesio y fosfato de calcio y magnesio en general amorfas debido a incorporación de iones Mg(II) a valores de pH > 9,5. A valores de pH 8 la precipitación supuso, la formación de clusters estables de pre-nucleación de tamaño nanométrico que promueven la inhibición de la nucleación, incluso en disoluciones sobresaturadas. Una segunda vía de recuperación de fosfato se basó en el uso de adsorbentes inorgánicos reactivos ricos en Ca(II), como cenizas volantes y zeolitas sintetizadas a partir de cenizas volantes, para su valorización directa como fuentes de fertilización de liberación controlada. Se han evaluado dos muestras de cenizas volantes de plantas de combustión de carbón que se caracterizan por diferentes contenidos de CaO (s). La recuperación de P(V) en las condiciones esperadas de pH, en efluentes de tratamiento secundarios de estaciones de depuración, tiene lugar a través de una disolución de CaO (s) y la formación de brushita (CaHPO4(s)) sobre la partículas de las cenizas volantes evitando la formación de fosfatos de calcio más insolubles como como Hap. El proceso de extracción de P(V) se describe por un proceso con una cinética controlada por difusión de los iones fosfato en la partícula de adsorbente y donde la reacción de disolución de CaO (s) no es la etapa de control de la velocidad de recuperación de P(V). En una segunda fase se evaluaron una zeolita sódica sintetizada a partir de cenizas volantes (NaP1-NA) y su forma cálcica (CaP1-NA) comprobándose que su capacidad de adsorción está influenciada por el pH y mostrando máximas capacidades de adsorción a pH 8. El proceso va acompañado por la adsorción inicial de los iones fosfato y la formación de precipitados de brushita como en el caso de las cenizas volantes. Los ensayos de disponibilidad de P(V) en las muestras de cenizas volantes y de zeolitas utilizando ensayos de especiación y fraccionamiento indicaron que podrían ser utilizadas como fertilizantes de liberación controlada de P(V). Por último, el rendimiento del proceso de adsorción de P(V) con las muestras de zeolitas activadas con Ca (CAP1) se evaluó mediante la integración de la etapa de sorción y la recuperación de fase zeolita mediante el uso de un sistema de híbrido de adsorción y separación por membranas de ultrafiltración usando módulos de fibra hueca.
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SILVA, Fernando Bruno Vieira da. "Inputs of heavy metals and rare earth elements in soils via phosphate fertilizers and correctives". Universidade Federal Rural de Pernambuco, 2018. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/7319.
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Phosphate fertilizers and corrective are significant sources of soil contamination by heavy metals and rare earth elements, and long-term cultivated soils can accumulate heavy metals above the maximum permissible limits. In this sense, the objectives of the study were (i) to evaluate the potential contamination of Brazilian soils by heavy metals and rare earth via phosphate fertilizers and corrective; (ii) to evaluate the accumulation of heavy metals in soils intensively cultivated with sugarcane, as well as to identify the possible sources of contamination. Initially, were performed total digests of 53 representative samples of P-containing fertilizers and commercialized in Brazil. Concentrations of As, Cd, Cr, Hg and Pb were investigated in fertilizers, which are elements regulated by national legislation. Also the additions of these metals to Brazilian soils were estimated based on the annual consumption and the average concentrations verified in each product. Subsequently, 60 samples of surface soils from areas cultivated with sugarcane were collected, these areas had a long history of use. In the soils, the environmentally available metals (Cd, Cr, Cu, Ni, Pb and Zn) were evaluated, as well as the physico-chemical characterization. The contents of metals in the soils were compared with the guiding values of quality; correlated with soil properties and; subjected to multivariate statistical analyzes to trace the origin of the metals. Finally, the total and soluble concentrations of Ce, La, Nd, Pr, Sm, Sc, Eu, Y, Dy, Gd, Yb, Er, Tb, Ho and Lu were investigated in 60 supplies samples (phosphate fertilizer, and limestone) used in Brazilian agriculture. In addition, the contributions of these elements to Brazilian soils were estimated through the use of phosphate fertilizers and soil correctives. The results of the study showed that Cd in phosphate rocks are the most worrisome, and that in the medium term the heavy metals present in fertilizers containing P do not represent environmental risk. However, the intensive application of phosphate fertilizers in soils cultivated with sugarcane promoted the accumulation of Cd above the guiding values of quality, and in some cases the soils represented a potential risk to human health. With regard to rare earths, it was observed that the solubility of these elements in phosphate fertilizers is dependent on the raw material used in industry (igneous or sedimentary). The annual additions of these elements to Brazilian soils are > 4000 t year-1 and that Ce, La, Nd and Y are the most worrisome. Limestone proved to be a significant source of Gd for agricultural soils. Therefore, soils that continuously receive high doses of these inputs are probably enriched with ETRs.
Fertilizantes fosfatados e corretivos são fontes significativas de contaminação do solo por metais pesados e elementos terras raras, e, solos cultivados por um longo tempo podem acumular metais pesados acima dos limites máximos permissíveis. Nesse sentido, o estudo teve por objetivos (i) avaliar o potencial de contaminação dos solos brasileiros por metais pesados e terras raras via fertilizantes fosfatados e corretivos; (ii) avaliar o acúmulo de metais pesados em solos intensivamente cultivados com cana-de-açúcar, como também identificar as possíveis fontes de contaminação. Inicialmente, foram realizadas digestões totais de 53 amostras representativas de fertilizantes contendo P e comercializadas no Brasil. As concentrações de As, Cd, Cr, Hg e Pb foram investigadas nos fertilizantes, que são os elementos regulamentados pela legislação nacional. Adicionalmente, as adições destes metais aos solos brasileiros foram estimadas baseadas no consumo anual e nas concentrações médias verificadas em cada produto. Posteriormente, 60 amostras de solos superficiais de áreas cultivadas com cana-de-açúcar foram coletadas, estas áreas tinham um longo histórico de uso. Nos solos, os teores ambientalmente disponíveis dos metais (Cd, Cr, Cu, Ni, Pb e Zn) foram avaliados, assim como as caracterizações físico-químicas. Os teores dos metais nos solos foram comparados com os valores orientadores de qualidade; correlacionados com as propriedades dos solos e; submetidos às análises estatísticas multivariadas para traçar a origem dos metais. Por fim, as concentrações totais e solúveis de Ce, La, Nd, Pr, Sm, Sc, Eu, Y, Dy, Gd, Yb, Er, Tb, Ho e Lu foram investigadas em 60 amostras de insumos (fertilizante fosfatado, gesso e calcário) utilizados na agricultura brasileira. Além disso, os aportes destes elementos aos solos brasileiros foram estimados através do uso de fertilizantes fosfatados e corretivos do solo. Os resultados do estudo demonstraram que Cd em rochas fosfatadas são os mais preocupantes, e, que em médio prazo os metais pesados presentes nos fertilizantes contendo P não representam risco ambiental. Contudo, a aplicação intensiva de fertilizantes fosfatados nos solos cultivados com cana-de-açúcar promoveu o acúmulo de Cd acima dos valores orientadores de qualidade, e em alguns casos os solos representaram potencial risco à saúde humana. Com relação aos terras raras, observou-se que a solubilidade destes elementos nos fertilizantes fosfatados é dependente da matéria prima utilizada na indústria (ígnea ou sedimentar). As adições anuais destes elementos aos solos brasileiros são > 4000 t ano-1 e que Ce, La, Nd e Y são os mais preocupantes. O calcário se mostrou uma fonte significativa de Gd para os solos agrícolas. Desta forma, os solos que recebem continuamente elevadas doses destes insumos, provavelmente, estão enriquecidos com ETRs.
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Mancarella, Silvia <1990>. "Sewage sludge hydrolysates and organic waste as alternative phosphate fertilizers in a circular economy strategy". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amsdottorato.unibo.it/8654/1/Mancarella_Silvia_tesi.pdf.
Testo completoAbstract (sommario):
Phosphorus (P) is one of the main plant nutrients, but it has very low solubility due to strong bonds with Al and Fe in acidic soils and with Ca and Mg in alkaline soils. The higher food demands has led to an increase of the use of phosphate fertilizers, mainly derived from phosphate rocks, which are predicted to be depleted in the next decades. Thus, there is the improving need to close the P cycle in order to reduce the P input from mineral source, recycling P rich organic products such as animal manure and human excreta. The aim of this work was to study the P availability for plants in calcareous soil of different bio-waste and to develop a new fertilizer from sewage sludge, with high P recovery and high P use efficiency. Different bio-waste were tested in a soil–plant system with different results in term of P solubility and plant growth, mainly caused by the metal concentration and the organic matter in the products. Later, two sludge products were used as raw sources for a new liquid fertilizer. Different chemical and enzymatic hydrolyses were tested on both sludge. The best solution in term of P recovery and low heavy metal extraction was then used in a soilless cultivation of lettuce and in a soil-plant system. The soil solved the problems encountered in the soilless cultivation, showing promising results for the hydrolysates as alternative phosphate fertilizers to the chemical ones in a circular economy strategy.
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Tejos, Dante Pinochet. "The residual effect of applications of phosphate fertilizer measured by the Olsen method". Thesis, University of Reading, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308579.
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