This thesis compares the in situ water balance of common annual production systems (wheat, lupin, subclover and serradella) with a grazed perennial system (lucerne) at a site in the Avon Catchment, Western Australia. Using a physically-based water balance approach the value of a plant based solution in redressing the hydrological imbalance that has become a feature of much of the dryland agricultural region of Western Australia is investigated. The effectiveness of lucerne in providing greater available storage for buffering large rainfall events, as compared to the annual systems, is illustrated. Continued transpiration following out-of-season rainfall events maintains a larger available storage capacity. In contrast, the annual systems that are fallow over summer only withdrew a small fraction of water by soil evaporation between rainfall events. Under annual systems, the profile moisture store was sequentially increased to the extent that additional increments of rainfall could potentially contribute to deep drainage. A particular focus of this study has been to investigate the presence of soil constraints to root growth, and to assess how these constraints affect the water balance. A site survey indicated the soil penetration resistance was sufficient to impose a physical constraint to root growth. Published literature on the site shows soil acidity is also at a level imposing chemical constraints to root growth. A root growth model “Rootmodel”, for predicting root growth with and without soil constraints is examined in detail as a method for providing root growth parameters for inclusion into the numerical water balance model, SWIM based on Richard’s equation. Functions developed from “Rootmodel” adequately describe the effect of profile limitations to root growth, such as soil strength, moisture availability and temperature. Recommendations are made for inclusion of a growth suppressing function in “rootmodel” based on the chemical limitation of low pH. The effects of soil acidity on the root growth of several species is investigated experimentally and the resultant root data provided a reference point by which the simplified prediction of root growth built into SWIM could be adjusted using a linear reduction function. A similar linear reduction function is also employed to impose a physical constraint in the form of high penetration resistance.

L'objectif de cette thèse est de développer la théorie du contrôle stochastique et ses applications en dynamique des populations. D'un point de vue théorique, nous présentons l'étude de problèmes de contrôle stochastique à horizon fini sur des processus de diffusion, de branchement non linéaire et de branchement-diffusion. Dans chacun des cas, nous raisonnons par la méthode de la programmation dynamique en veillant à démontrer soigneusement un argument de conditionnement analogue à la propriété de Markov forte pour les processus contrôlés. Le principe de la programmation dynamique nous permet alors de prouver que la fonction valeur est solution (régulière ou de viscosité) de l'équation de Hamilton-Jacobi-Bellman correspondante. Dans le cas régulier, nous identifions également un contrôle optimal markovien par un théorème de vérification. Du point de vue des applications, nous nous intéressons à la modélisation mathématique du cancer et de ses stratégies thérapeutiques. Plus précisément, nous construisons un modèle hybride de croissance de tumeur qui rend compte du rôle fondamental de l'acidité dans l'évolution de la maladie. Les cibles de la thérapie apparaissent explicitement comme paramètres du modèle afin de pouvoir l'utiliser comme support d'évaluation de stratégies thérapeutiques. / The main objective of this thesis is to develop stochastic control theory and applications to population dynamics. From a theoritical point of view, we study finite horizon stochastic control problems on diffusion processes, nonlinear branching processes and branching diffusion processes. In each case we establish a dynamic programmic principle by carefully proving a conditioning argument similar to the strong Markov property for controlled processes. Then we deduce that the value function is a (viscosity or regular) solution of the associated Hamilton-Jacobi-Bellman equation. In the regular case, we further identify an optimal control in the class of markovian strategies thanks to a verification theorem. From a pratical point of view, we are interested in mathematical modelling of cancer growth and treatment. More precisely, we build a hybrid model of tumor growth taking into account the essential role of acidity. Therapeutic targets appear explicitly as model parameters in order to be able to evaluate treatment strategies.

La production de synthons aromatiques fluorés, utilisés comme intermédiaires dans la synthèse de molécules à visée thérapeutique et phytosanitaire, connaît un essor considérable ces dernières années. Par ailleurs, peu de réactions de fluoration catalytique en phase gaz par échange Cl/F sont développées pour la préparation de ces composés. Celles-ci sont pourtant plus économiques et plus respectueuses de l’environnement que les procédés en chimie organique classique.La faisabilité de cette réaction a été mise en évidence pour la fluoration de la 2-chloropyridine (molécule modèle simple) en 2-fluoropyridine, en présence d’un catalyseur solide (fluorure métallique) et d’HF à 300°C. Différents fluorures métalliques (LaF3, MgF2, SrF2, CaF2, BaF2, Ba1-xLaxF2+x, AlF3, Cr2O3 fluoré) de surfaces spécifiques significatives sous HF et de propriétés acides variables, ont tout d’abord été préparés. A partir des mesures d’activités sur la fluoration de la 2-chloropyridine, une corrélation entre la force d’acidité de Lewis des matériaux et leurs performances catalytiques a été établie et un mécanisme réactionnel a été proposé. L’échange Cl/F est favorisé par des matériaux de force d’acidité faible, tels que ceux qui contiennent du baryum.Enfin cette réaction a été généralisée à la fluoration d’autres chloropyridines substituées pour déterminer la réactivité selon la position de l’atome de chlore sur le cycle pyridinique et l’influence de groupements électro attracteurs (-Cl, -CF3). Les positions en ortho de l’atome d’azote sont toujours les plus réactives. Alors que les positions méta ne sont pas réactives, il est possible d’activer la position para dans des conditions plus drastiques. / The production of fluorinated aromatic synthons, used as building-blocks for the synthesis of more elaborated molecules for therapeutic and phytosanitary goals, has been increased since past years. Besides, only few catalytic fluorination reactions by Cl/F exchange in gas phase are developed for the preparation of these synthons. However, these reactions are cheaper and more environmentally friendly than conventional organic chemistry processes.The feasibility of this reaction was established in this work for the fluorination of 2-chloropyridine (as a simple model molecule) into 2-fluoropyridine, with a solid catalyst (metal fluoride) and HF at 300°C. Various metal fluorides (LaF3, MgF2, SrF2, CaF2, BaF2, Ba1-xLaxF2+x, AlF3, fluorinated Cr2O3) with significant specific surface areas under HF atmosphere and tunable acid properties, was firstly prepared. The catalytic test carried out on 2-chloropyridine allow us to point out a correlation between strength of Lewis acidity of catalysts and their catalytic performances and to propose a reaction mechanism. Cl/F exchange is promoted by catalysts with weak strength of acidity and particularly those containing barium.Eventually, the reaction was generalized to the fluorination of other substituted chloropyridines in order to determine the reactivity according to the position of the chlorine atom on the pyridine ring and the influence of electron withdrawing groups (-Cl, -CF3). Ortho positions are always the most reactive. Whereas meta positions remain completely inactive, it is possible to activate the para position under more drastic conditions.

Das Hauptaugenmerk dieser Arbeit liegt auf einer Pilotstudie zur Darstellung von Eisen(III)fluorid (FeF3) unter Verwendung von Sol-Gel-Syntheserouten. Eine modifizierte fluorolytische Sol-Gel-Synthese wurde entwickelt um bi-acide auf FeF3 basierende Materialien zu erhalten. Die Synthese erzeugt Hydroxygruppen, die potentiellen Brønsted-sauren Zentren, auf der Oberfläche der klassischen Lewissäure FeF3. Im Anschluss wurde Magnesiumfluorid (MgF2) als Matrix eingesetzt. Verglichen mit FeF3 zeigen ternäre FeF3-MgF2 bemerkenswert hohe Oberflächen und verbesserte Porosität. Das Wichtigste jedoch ist, das hauptsächlich starke Lewis- und mittelstarke Brønsted-saure Zentren auf der FeF3-MgF2 vorhanden sind. Des Weiteren wurden, unter Verwendung anderer Erdalkalimetallfluoride (CaF2 oder SrF2) und Zinkfluorid (ZnF2) als Matrix, Serien ternärer Fluoridmaterialien synthetisiert und systematisch untersucht. Durch Charakterisierung der FeF3-MF2-Oberflächen konnten systematische Veränderungen hinsichtlich Größe der Oberfläche, Porosität und Azidität festgestellt werden. Mit abnehmender Atomnummer (von Sr zu Mg) erhöht sich die Stärke der sauren Zentren, während die mittlere Porengröße dramatisch abnimmt. Darüber hinaus führt ein größeres M-zu-Fe-Verhältnis generell zu kleineren Porengrößen und höheren Oberflächen. Diese Ergebnisse implizieren, dass die Eigenschaften ternärer FeF3-MF2 durch Veränderung der MF2-Matrix oder des M-zu-Fe-Verhältnisses einstellbar sind. Schlussendlich konnte anhand einer Modellreaktion, der Isomerisierung von Citronellal zu Isopulegolen, die katalytische Aktivität der bi-aziden Zentren der auf FeF3 basierenden Materialien nachgewiesen werden. Zusätzlich wurde in dieser Arbeit diskutiert wie Oberfläche, Porosität und Azidität gemeinsam die katalytische Aktivität von FeF3-MgF2 bestimmen. Diese Arbeit beweist damit die Realisierbarkeit der Synthese neuer nanoskopischer Metallfluoride mit gewünschten Oberflächeneigenschaften. / This work serves as a pilot study on the development of iron(III) fluoride (FeF3) based materials with surface bi-acidity. A modified fluorolytic sol-gel route was established to prepare the bi-acidic FeF3-based materials. The synthesis procedure introduced hydroxyls, the potential Brønsted acid sites, on the surface of a classic Lewis acid, FeF3. Subsequently, magnesium fluoride (MgF2) was used as matrix. Comparing with FeF3, the ternary FeF3-MgF2 showed remarkable high surface area and enhanced porosity. Most importantly, strong Lewis and medium strong Brønsted acid sites were found predominant on the FeF3-MgF2 surface. Next a series of ternary fluoride materials were synthesised and studied systematically, using other alkaline earth metal fluorides (CaF2 or SrF2) as well as zinc fluoride (ZnF2) as matrices. Surface characterisation of FeF3-MF2 revealed systematic changes in their surface area, porosity, and surface acidity. With decreasing atom numbers (from Sr to Mg), strengths of surface acidic sites and surface area increased, while the average pore size decreased drastically. Moreover, higher M-to-Fe ratio generally resulted in smaller pore size and larger surface area. These findings imply that the properties of ternary FeF3-MF2 are tunable by changing the MF2 matrix or the M-to-Fe ratio or both. Last but not least, in the model reaction, isomerisation of citronellal to isopulegols, FeF3-based materials were highly active due to their bi-acidity. Finally this work discussed how surface area, porosity, and surface acidity jointly determined the catalytic activity of FeF3-MF2. In conclusion, this work demonstrates the feasibility to synthesise novel nanoscopic metal fluorides with desirable surface properties.

Aluminiumfluorid (HS-AlF3), das mit Hilfe des Sol-Gel-Verfahrens unter nicht-wässrigen Bedingungen hergestellt wird, weist eine extrem große Oberfläche und eine hohe Lewis-Acidität auf, die mit den stärksten bekannten Lewis-Säuren wie SbF5 und ACF vergleichbar ist. Diese ungewöhnlichen Eigenschaften werden im Ergebnis einer neuen Sol-Gel-Synthese erhalten, die die Fluorolyse eines Aluminium-Alkoxids durch wasserfreien Fluorwasserstoff in organischen Lösungsmitteln zur Grundlage hat. Das zunächst in einer amorphen, katalytisch inaktiven Vorstufe mit großer Oberfläche gebildete Gel wird nach anschließender Trocknung mit gasförmigen Fluorierungsmitteln nachfluoriert, wobei die aktive Form des HS-AlF3 erhalten wird. Im Rahmen der vorliegenden Arbeit wurden alle Schritte dieses Syntheseweges untersucht und die Ergebnisse einschließlich einer detaillierten Analyse der erhaltenen Materialien diskutiert. Des Weiteren wurde HS-AlF3 durch eine Imprägnierungs-Methode auf das Trägermaterial Al2O3 aufgetragen, wobei verschiedene Beladungen mit HS-AlF3 getestet wurden. Die Eigenschaften des HS-AlF3/Al2O3 als Lewis-Säure-Katalysator wurden mittels der Dismutierung von CHClF2 und der Isomerisierung von CBrF2CBrFCF3 bestimmt. Die Herstellung von AlFyOx mit Hilfe des Sol-Gel-Verfahrens ist ebenfalls beschrieben, wobei das Produkt amorph ist und eine große Oberfläche von bis zu 240 m2/g aufweist. / Aluminum fluoride (HS-AlF3) prepared via sol-gel synthesis route under non-aqueous conditions exhibits high surface area and an extremely strong Lewis acidity, comparable with some of the strongest known Lewis acids such as SbF5 and ACF. The basis of its unusual properties is the sol-gel fluorination of aluminum alkoxide with anhydrous HF in organic solvents yielding first an amorphous catalytically inactive precursor with high surface area, which can be dried and eventually post-fluorinated to get HS-AlF3. In this thesis, all steps of the synthesis route were thoroughly investigated. The results of these investigations together with detailed analysis of the obtained materials are reported and discussed. HS-AlF3 supported on Al2O3 with different HS-AlF3 loadings was prepared by wet impregnation method. The properties of the HS-AlF3/Al2O3 samples as Lewis acid catalyst were evaluated for CHClF2 dismutation and CBrF2CBrFCF3 isomerization. The preparation of AlFyOx via sol-gel method is also reported. AlFyOx prepared is amorphous and have high surface are up to 240 m2/g.

Made available in DSpace on 2017-07-25T19:29:44Z (GMT). No. of bitstreams: 1 Itacir Feldhaus.pdf: 550488 bytes, checksum: 13f0af90b9e23ee384c7dd7fe7d06acb (MD5) Previous issue date: 2006-03-17 / The effects of surface liming and nitrogen application on soil chemical attributes, on the dry matter production of black oats and on the root growth, mineral nutrition and grain yield of corn, under a no-till system, were evaluated in a field trial carried out on a loamy Typic Hapludox, in Ponta Grossa, State of Paraná, Brazil. A randomized complete block, split-plot design was employed, with three replications. The plots received four treatments of lime: no lime, 4, 8 and 12 t ha-1 of dolomitic lime applied on the surface before the sowing of the oats. In the subplots were employed four treatments of nitrogen: without nitrogen, 60, 120 and 180 kg ha-1 of nitrogen spread out manually at tillering of oat plants. After 110 days of the application, liming provided soil acidity correction to a depth of 20 cm, with effects of larger magnitude in the uppermost soil layer (0-5 cm). After 330 days of the application, liming raised pH and reduced the potential acidity (H+Al) to a depth of 20 cm, reduced Al3+ to a depth of 40 cm and raised bases saturation to a depth of 60 cm. The treatments of N promoted acidification of the uppermost soil layers and raised the levels of N-Mineral in the uppermost soil layers 60 days after the application, and in the subsoil 280 after the application. The levels of Ca2+ in the uppermost layers were reduced with N application, but there was no correlation between NO3 - leaching and the amelioration in the subsoil chemical attributes with liming. The dry matter production of oats was not affected by the treatments of liming and N. The root growth of the corn cultivated in succession was also not affected by the treatments. Liming increased the Ca and S levels in the leaves and in the grains of corn, respectively, and reduced the leaf Mn content. The treatments of N fertilization increased the content of N in the grains and of Mn in the leaves and in the grains of corn. Liming had no effect in the dry matter production, grain yield and content of oil and protein of corn. The N treatments had no effect in the dry matter production, but raised the grain yield and the content of oil and protein of corn. / Os efeitos da calagem superficial e da adubação nitrogenada nas alterações químicas do solo, na produção de massa seca de aveia preta e no crescimento radicular, nutrição mineral e rendimento de grãos da cultura do milho, em sistema plantio direto, foram avaliados em um experimento realizado em Latossolo Vermelho Distrófico textura média, em Ponta Grossa (PR). O delineamento experimental empregado foi o de blocos ao acaso em parcelas subdivididas, com três repetições. As parcelas receberam quatro tratamentos de calagem: sem calcário, 4, 8 e 12 t ha-1 de calcário dolomítico na superfície antes da semeadura da aveia. Nas subparcelas foram empregados quatro tratamentos de adubação nitrogenada: sem N, 60, 120 e 180 kg ha-1 de N aplicados a lanço no perfilhamento da aveia. Aos 110 dias após a aplicação, a calagem proporcionou correção da acidez do solo até a profundidade de 20 cm, apresentando efeito de maior magnitude na camada superficial do solo (0-5 cm). Aos 330 dias após a aplicação, a calagem elevou o pH e reduziu a acidez potencial até a profundidade de 20 cm, reduziu o Al3+ até a profundidade de 40 cm e elevou a saturação por bases até a profundidade de 60 cm. As doses de N promoveram acidificação das camadas superficiais do solo e elevaram os teores de N-Mineral nas camadas superficiais aos 60 dias após a aplicação, e nas do subsolo, aos 280 dias após a aplicação. Houve redução dos teores de Ca2+ nas camadas superficiais com a adubação nitrogenada, mas não houve correlação entre a lixiviação de NO3 - e as melhorias nos atributos químicos do subsolo pela calagem. A produção de massa seca de aveia não foi influenciada pelos tratamentos de calagem e de N. Também não houve efeito dos tratamentos sobre o crescimento radicular do milho cultivado em sucessão à aveia. A calagem aumentou a concentração de Mg e de S nas folhas e nos grãos de milho, respectivamente, e reduziu a concentração foliar de Mn. Os tratamentos de adubação nitrogenada aumentaram a concentração de N nos grãos e de Mn nas folhas e nos grãos de milho. A calagem não influenciou a produção de massa seca, o rendimento de grãos e a concentração de óleo e de proteína de milho. Os tratamentos de N não afetaram a produção de massa seca, mas aumentaram o rendimento de grãos e o teor de óleo e de proteína de milho

Made available in DSpace on 2017-07-25T19:29:46Z (GMT). No. of bitstreams: 1 Helio Antonio Wood Joris.pdf: 1043981 bytes, checksum: 109199b60a4616b0e907e5a0a8e16d26 (MD5) Previous issue date: 2011-02-11 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The effects of soil acidity in a no-till system need to be further investigated under drought. The corn performance in response to surface application of lime, as affected by aluminum genotypic tolerance and soil moisture was evaluated in a sandy clay loam Typic Hapludox, in Ponta Grossa, Parana State, Brazil. The study was carried out in a field experiment and in undisturbed soil columns. In a field experiment, the changes in soil chemical attributes at 0-5, 5-10, 10-20, 20-40 and 40-60 cm depths, and the nutrition, export and nutrient uptake, above ground biomass and grain yield of corn in 2008-2009 were evaluated after surface application of lime at rates of 0, 4, 8 and 12 t ha-1 in 2004, in a randomized complete block with three replications. Undisturbed soil columns were removed from plots that received lime rates, and another experiment was carried out on them, testing two hybrids, one aluminum-sensitive and another moderately sensitive to aluminum, and two moisture levels, simulating the presence and absence of water stress. Surface liming ameliorated soil acidity in all depths studied, and improved root environment throughout profile. Corn root growth was influenced by lime application, mainly at 0-10 cm depth. Liming had a positive effect on nutrition, export and nutrient uptake, resulting in a significant increase in corn grain yield. In the undisturbed columns, soil amendment by surface liming benefited root growth, nutrient uptake and dry matter production of corn plants, mainly in a water stress condition. In general, there was no difference in the response of both sensitive hybrid and moderately sensitive hybrid to aluminum toxicity with liming. It is concluded that the corn crop performance is ameliorated by the reduction in soil acidity through surface liming under no-till, but the corn crop development is little influenced by soil acidity when water availability is adequate. However, in a water stress condition, the soil acidity severely compromises the corn crop development under no-till system. The effects of soil acidity in a no-till system need to be further investigated under drought. The corn performance in response to surface application of lime, as affected by aluminum genotypic tolerance and soil moisture was evaluated in a sandy clay loam Typic Hapludox, in Ponta Grossa, Parana State, Brazil. The study was carried out in a field experiment and in undisturbed soil columns. In a field experiment, the changes in soil chemical attributes at 0-5, 5-10, 10-20, 20-40 and 40-60 cm depths, and the nutrition, export and nutrient uptake, above ground biomass and grain yield of corn in 2008-2009 were evaluated after surface application of lime at rates of 0, 4, 8 and 12 t ha-1 in 2004, in a randomized complete block with three replications. Undisturbed soil columns were removed from plots that received lime rates, and another experiment was carried out on them, testing two hybrids, one aluminum-sensitive and another moderately sensitive to aluminum, and two moisture levels, simulating the presence and absence of water stress. Surface liming ameliorated soil acidity in all depths studied, and improved root environment throughout profile. Corn root growth was influenced by lime application, mainly at 0-10 cm depth. Liming had a positive effect on nutrition, export and nutrient uptake, resulting in a significant increase in corn grain yield. In the undisturbed columns, soil amendment by surface liming benefited root growth, nutrient uptake and dry matter production of corn plants, mainly in a water stress condition. In general, there was no difference in the response of both sensitive hybrid and moderately sensitive hybrid to aluminum toxicity with liming. It is concluded that the corn crop performance is ameliorated by the reduction in soil acidity through surface liming under no-till, but the corn crop development is little influenced by soil acidity when water availability is adequate. However, in a water stress condition, the soil acidity severely compromises the corn crop development under no-till system. / Os efeitos da acidez do solo em sistema plantio direto precisam ser mais investigados em situações de seca. O comportamento da cultura do milho em resposta à aplicação superficial de calcário, considerando a tolerância genotípica ao alumínio e a umidade do solo foi avaliado em um estudo realizado em Latossolo Vermelho distrófico textura média, em Ponta Grossa (PR). O trabalho foi realizado em área experimental no campo e em colunas indeformadas de solo, coletadas na mesma área experimental. No campo, após a aplicação superficial de calcário em 2004, nas doses 0, 4, 8 e 12 t ha-1, em um delineamento de blocos completos ao acaso com 3 repetições, avaliaram-se as alterações nos atributos químicos do solo nas profundidades de 0-5, 5-10, 10-20, 20-40 e 40-60 cm, o crescimento radicular, a nutrição e extração de nutrientes, a massa seca da parte aérea e a produção de grãos de milho, cultivado em 2008-2009. Nas parcelas que receberam as doses de calcário, foram retiradas colunas indeformadas de solo para a realização de outro experimento, o qual envolveu a utilização de dois híbridos, um sensível e outro moderadamente sensível ao alumínio, e dois níveis de umidade do solo, simulando ausência e presença de deficiência hídrica. A calagem superficial corrigiu a acidez do solo em todas as camadas estudadas e proporcionou melhoria no ambiente radicular em todo o perfil. O crescimento radicular do milho foi favorecido pela aplicação de calcário, principalmente na camada de 0-10 cm. A calagem exerceu efeito positivo sobre a nutrição e extração de nutrientes, refletindo em aumento da produção de grãos de milho. Nas colunas indeformadas de solo, a correção do solo pela calagem na superfície beneficiou o crescimento radicular, a extração de nutrientes e a produção de massa seca das plantas de milho, principalmente em situação de deficiência hídrica. Em geral, não houve diferença na resposta à calagem dos híbridos sensível e moderadamente sensível ao alumínio. Concluiu-se que a cultura do milho é beneficiada pela correção da acidez por meio da calagem na superfície em plantio direto, porém a acidez não exerce grande limitação no desenvolvimento da cultura quando há adequada disponibilidade hídrica. Em situação de restrição hídrica, entretanto, a acidez do solo prejudica severamente o desenvolvimento do sistema radicular e a produção da cultura do milho em sistema plantio direto.

Made available in DSpace on 2017-07-25T19:29:58Z (GMT). No. of bitstreams: 1 Maik Rodrighero.pdf: 828244 bytes, checksum: b17d81b60eaad6eff20ad64666064e48 (MD5) Previous issue date: 2012-12-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / To control soil acidity in no-till systems, lime is broadcast on the surface without incorporation. In order to test the hypothesis that the source and particle size of the corrective influence the soil reaction and crop response to lime on the surface in no-till system, two experiments were conducted in Tibagi (PR), one in clayey Oxisol and another in sandy Litholic Neosol. A randomized complete block design was used in a factorial 2 × 2 × 4 with three replications, in each experiment. The treatments consisted of four rates of lime on the surface, estimated to raise the base saturation of the topsoil (0-20 cm), at 50, 70 and 90%; two sources of lime were used, calcitic and dolomitic,and two ranges of lime material effective calcium carbonate equivalent (ECCE), range B (ECCE 60-75%) and range D (ECCE > 90%). In both experiments, the lime was applied on the soil surface in August 2010. During the spring-summer season in 2010- 11 and 2011-12, corn and soybean were grown on the clayey soil, and soybean and corn on the sandy soil, respectively. After 12 months of liming, soil chemical analyses were performed in samples taken at the 0-5, 5-10, 10-20, 20-40, and 40-60 cm depths. Leaf samples of corn and soybean were taken during crop flowering, in the second year of cultivation, for foliar diagnosis. Grain yields of corn and soybean, in both experiments,were evaluated in two years, after the physiological maturity, and grain moisture was corrected to 130 g kg-1. Surface application of lime in both soils, after 12 months, promoted amelioration of soil acidity mainly in the 0-5 cm layer and, to a lesser extent in the 5-10 cm, regardless of the source and range of lime ECCE. Calcitic lime showed a stronger reaction than dolomitic lime in the soil surface layers. The extraction with cation exchange resin overestimated the exchangeable Ca and Mg content in relation to the 0.1 mol L-1 KCl solution when coarser grain size lime was applied on the surface. Surface liming increased the Ca-leaf content, especially with the use of calcitic lime, and Mg-leaf content mainly with the use of dolomitic limestone, and reduced Mn and Zn contents in the leaves, regardless of the source of lime, in the corn and soybean crops. Grain yields of corn and soybean in clayey Oxisol and corn in sandy Litholic Neosol were increased with the lime rates, but were not affected by sources and ECCE ranges of material lime. Surface application of lime in soils under no-till was proved of fundamental importance to maximize crop grain yield, regardless of the lime source being calcitic or dolomitic, or the ECCE range, B or D of the material lime. / No sistema plantio direto, a correção da acidez é feita por meio da aplicação de calcário na superfície sem incorporação. Com a hipótese de que a fonte e a granulometria dos corretivos interferem na reação do solo e na resposta das culturas à calagem superficial em plantio direto, foram realizados dois experimentos em Tibagi (PR), sendo um em Latossolo Vermelho argiloso e outro em Neossolo Litólico arenoso, no período de 2010 a 2012. O delineamento empregado, em cada experimento, foi o de blocos completos ao acaso, em esquema fatorial 2 × 2 × 4, com três repetições. Os tratamentos foram constituídos de quatro doses de calcário na superfície, estimadas para elevar a saturação por bases do solo (0–20 cm), a 50, 70 e 90%; duas fontes de calcário, calcítico e dolomítico; e duas faixas de poder relativo de neutralização total (PRNT), faixa B (PRNT de 60 a 75%) e faixa D (PRNT > 90%). Nos dois experimentos, o calcário foi aplicado a lanço sobre a superfície do solo em agosto de 2010. Realizaram-se dois cultivos em 2010–11 e 2011–12, com milho e soja no solo argiloso, e soja e milho no solo arenoso. Após 12 meses da aplicação, análises químicas de solo foram realizadas em amostras coletadas nas camadas de 0–5, 5–10, 10–20, 20–40 e 40–60 cm de profundidade. Amostras de folhas de milho e soja foram coletadas por ocasião do florescimento das culturas, no segundo ano de cultivo, para fins de diagnose foliar. A produtividade de grãos de milho e soja, nos dois experimentos, foi avaliada, nos dois anos, após a maturação fisiológica, corrigindo-se a umidade dos grãos para 130 g kg-1 de água. A aplicação superficial de calcário nos dois solos, após 12 meses, promoveu correção da acidez principalmente na camada de 0-5 cm e, em menor grau, na de 5-10 cm, independentemente da fonte e da faixa de PRNT dos corretivos. O calcário calcítico apresentou maior reação do que o calcário dolomítico nas camadas superficiais do solo. A extração com a resina de troca catiônica superestimou os teores de Ca e Mg trocáveis em relação à solução de KCl 1 mol L-1 quando houve aplicação superficial de calcário com granulometria mais grossa. A calagem superficial aumentou as concentrações de Ca-foliar, principalmente com a utilização de calcário calcítico, e de Mg-foliar,especialmente com o uso de calcário dolomítico, e reduziu os teores foliares de Mn e Zn, independentemente da fonte de calcário, nas culturas de milho e soja. As produtividades de milho e soja, no Latossolo argiloso, e de milho, no Neossolo arenoso,foram aumentadas com as doses de calcário, mas não foram influenciadas pelas fontes e faixas de PRNT dos corretivos. A calagem superficial em solos sob plantio direto se mostrou de fundamental importância para maximizar a produtividade de grãos das culturas, independentemente da fonte de calcário, calcítico ou dolomítico, e da faixa, B ou D, de PRNT dos corretivos.

Made available in DSpace on 2017-07-25T19:30:02Z (GMT). No. of bitstreams: 1 Andre Carlos Auler.pdf: 1218277 bytes, checksum: aedcd75095720ba4b41e7ad48e647731 (MD5) Previous issue date: 2014-07-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Liming is the practice used to correct soil acidity and its reaction is dependent on the mode of application of the lime. The addition of lime to the soil with the tilling is an alternative for increasing his reaction. However, tillage alters its structure and processes occurring in it. The aim of this study was to evaluate the influence of liming of liming in three modes of application of limestone (on the surface, incorporated with plowing and harrowing and subsoiling and disking) on the physico-hydrical attributes of a Dystrudept. For this, an experiment was installed in the field with banded design, with treatments in a factorial arrangement (3 × 2). Treatments formed from the combination of two rates of lime (0 and 15 Mg ha-1) and three modes of application of limestone (on the surface, incorporate with plowing and harrowing and subsoiling and harrowing). Undisturbed and disturbed soil samples were collected at 0-0.10 and 0.10-0.20 m layers between plant rows of corn 18 months after installation of the experiment. The water-dispersed clay (WDC), flocculation degree (FD), bulk density (BD), total porosity (TP), water retention curves, pore size distribution curve, particle size and soil chemical properties were determined order to diagnose the effects of liming the soil studied. Liming effects on the physico-hydrical attributes of the soil were restricted to 0-0.10 m layer. The WDC and the FD were influenced by tillage, but not by liming. When liming was performed on the surface, there was a reduction of the DB and increased TP. In all modes of application of limestone, liming increased water retention and altered the distribution of pores. To conclude, the changes in physico-hydrical attributes of the soil were mostly due to the increase of pH and replacement of aluminum by calcium and magnesium in the exchange complex. / A calagem é a prática empregada na correção da acidez do solo e sua reação depende do modo de aplicação do corretivo. A incorporação de calcário com o revolvimento do solo é uma alternativa para o aumento da reação. Porém, a mobilização do solo altera a sua estrutura e os processos que nela ocorrem. O objetivo deste trabalho foi avaliar a influência da calagem em três modos de aplicação do calcário (na superfície, incorporada com aração e gradagem e com subsolagem e gradagem) nos atributos físico-hídricos de um CAMBISSOLO HÁPLICO Alumínico. Para isso, instalou-se um experimento em campo com delineamento em faixas, com tratamentos em arranjo fatorial (3 × 2). Os tratamentos constituíam-se da combinação de duas doses de calcário (0 e 15 Mg ha-1) e três modos de aplicação do calcário (na superfície, incorporado com aração e gradagem e subsolagem e gradagem). Amostras indeformadas e deformadas de solo nas camadas 0-0,10 e 0,10-0,20 m foram coletadas nas entrelinhas da cultura do milho 18 meses após a instalação do experimento. Foram avaliados os teores de argila dispersa em água (ADA), grau de floculação (GF), densidade do solo (Ds), porosidade total (Pt), curvas de retenção de água, curva de distribuição de poros, granulometria e atributos químicos do solo. Os efeitos da calagem sobre os atributos físico-hídricos do solo foram restritos à camada 0-0,10 m. A ADA e o GF foram influenciados pelo modo de aplicação do calcário, mas não pela calagem. Quando a calagem foi realizada na superfície, ocorreu redução da DS e aumento da Pt. Em todos os modos de aplicação do calcário, a calagem aumentou a retenção de água e alterou a distribuição de poros. Concluiu-se que as alterações nos atributos físico-hídricos do solo foram em sua maioria decorrentes do aumento do pH e da substituição do alumínio por cálcio e magnésio no complexo de troca.

Made available in DSpace on 2017-07-25T19:30:47Z (GMT). No. of bitstreams: 1 Adriano Haliski.pdf: 1087998 bytes, checksum: 06568ec8622f2204e3d6d86c65fa29a8 (MD5) Previous issue date: 2015-02-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Nitrogen fertilization can increase the efficiency of surface liming on soil acidity correction and benefit crop production in long term no-till systems. Because the soil organic matter content under no-till is high, especially in the soil surface layers, the aluminum (Al) toxicity may be low, even in high acidity conditions. This study was carried out with the purpose of evaluate the soil chemical attributes, grain yield, and critical levels for the development of soybean after surface application of lime and ammoniacal nitrogen (N-NH4NO3) in crops of autumn-winter predecessors. The experiment was conducted in Ponta Grossa, Parana State, Brazil, on a loamy, kaolinitic, thermic Typic Hapludox (Oxisol) under long term continuous no-till (26 years). The experimental design used was a randomized block, in a split plot arrangement, with three replications. In the plots, were applied, in May 2004, four rates of lime on the soil surface (0, 4, 8, and 12 t ha-1) and, in the subplots, were applied annually, since 2004, four rates of N-NH4NO3 (0, 60, 120 and 180 kg ha-1) in top dressing in the black oat or wheat crops. In crop rotation was used corn, soybeans or beans in the spring-summer season and black oat or wheat in the autumn-winter season. Soybean was sown in November 2007 (cv. CD 214 RR), 2009 (cv. CD 206 RR), 2010 (cv. BMX Apolo RR), 2012 (cv. NA 5909 RG), and 2013 (cv. BMX Ativa RR). Soil samples were collected annually before soybean sowing at the 0–0.05, 0.05–0.10, and 0.10–0.20 m depths. Surface liming increased pH and the contents of exchangeable Ca2+ and Mg2+, and reduced the content of exchangeable Al3+ to a depth of 0.20 m. Nitrogen fertilization reduced pH and the contents of exchangeable Ca2+ and Mg2+, especially to a depth of 0.10 m, and increased the content of exchangeable Al3+ to a depth of 0.20 m. Surface application of lime increased the soybean grain yields for all N-NH4NO3 rates used in black oat or wheat crops. In unlimed plots, acidification caused by nitrogen fertilization severely limited the soybean grain yield. The critical levels of pH in CaCl2, base saturation, exchangeable Al3+, and Al3+ saturation in the 0–0.20 m layer for soybean production were 4.9, 33%, 8.0 mmolc dm-3, and 30%, respectively. Surface application of lime proved to be a key practice to ensure high soybean yields when high ammoniacal fertilizer rates are applied frequently in no-till systems. / A adubação nitrogenada pode aumentar a eficiência da calagem superficial na correção da acidez do solo e beneficiar a produção das culturas em longo prazo no sistema plantio direto. Como no sistema plantio direto os teores de matéria orgânica são elevados, especialmente nas camadas superficiais do solo, a toxicidade de alumínio (Al) pode ser baixa, mesmo em condições de alta acidez. Este trabalho foi realizado com o objetivo de avaliar as alterações químicas do solo, a produtividade, e os níveis críticos para o desenvolvimento da cultura da soja após aplicação superficial de calcário e de nitrogênio amoniacal (N–NH4NO3) nas culturas antecessoras de outono–inverno. O experimento foi realizado em Ponta Grossa (PR), em um Latossolo Vermelho distrófico textura média manejado há 26 anos sob plantio direto no momento da instalação. O delineamento experimental foi o de blocos ao acaso, em parcelas subdivididas, com três repetições. Nas parcelas, foram aplicadas, em maio de 2004, quatro doses de calcário dolomítico na superfície (0, 4, 8 e 12 t ha-1) e, nas subparcelas, foram aplicadas, anualmente, desde 2004, quatro doses de N–NH4NO3 (0, 60, 120 e 180 kg ha-1) em cobertura nas culturas de aveia preta ou trigo. Na rotação de culturas foram utilizados milho, soja ou feijão na estação de primavera–verão e aveia preta ou trigo na estação de outono–inverno. A soja foi cultivada em novembro de 2007 (cv. CD 214 RR), 2009 (cv. CD 206 RR), 2010 (cv. BMX Apolo RR), 2012 (cv. NA 5909 RG) e 2013 (cv. BMX Ativa RR). Amostras de solo foram coletadas anualmente, antes da semeadura de soja, nas camadas de 0–0,05, 0,05–0,10 e 0,10– 0,20 m. A aplicação superficial de calcário elevou o pH e os teores de Ca2+ e Mg2+ trocáveis, e reduziu o teor de Al3+ trocável até a profundidade de 0,20 m. A adubação nitrogenada diminuiu o pH e os teores de Ca2+ e Mg2+ trocáveis, principalmente até a profundidade de 0,10 m, e elevou o teor de Al3+ trocável até a profundidade de 0,20 m. A aplicação superficial de calcário aumentou a produtividade de grãos de soja para todas as doses de N–NH4NO3 empregadas nas culturas de aveia preta ou trigo. Nas parcelas sem calagem, a acidificação provocada pela adubação nitrogenada limitou severamente a produtividade de grãos de soja. Os níveis críticos de pH em CaCl2, saturação por bases, Al3+ trocável e saturação por Al 3+, na camada de 0–0,20 m, para a produção de soja foram 4,9, 33%, 8,0 mmolc dm-3 e 30%, respectivamente. A calagem na superfície mostrou ser uma prática fundamental para garantir altos tetos de produtividade de soja quando altas doses de nitrogênio amoniacal são aplicadas com frequência no sistema plantio direto.