O processo Humifert é uma alternativa para produção de compostos fertilizantes fosfatados, com solubilização mais lenta do que os fertilizantes tradicionais, resultando em um tempo de nutrição da planta maior. No processo, utilizam-se rochas fosfáticas com algum tipo de limitação para o aproveitamento normal, seja pelos teores menores, seja por dificuldades de tratamento industrial dos minérios, além de materiais orgânicos. O objetivo deste trabalho foi melhorar o equipamento existente no Instituto de Geociências, para tornar possível condições de produção de NOx, no Processo Humifert, capaz de produzir um teor de fósforo disponibilizado em condições controladas de processo. Empregando-se planejamento estatístico de experimentos foi possível selecionar as variáveis de entrada mais importantes ao processo (agitação da mistura de rocha fosfática, matéria orgânica e umidade, A codificada; temperatura de oxidação da amônia, B codificada; umidade da mistura, C codificada; porosidade da placa difusora, D codificada; vazão do ar auxiliar, E codificada). A análise estatística, também, permitiu construir modelos de regressão nos quais as influências das variáveis de processo foram sentidas na solubilidade do fósforo nos extratores: ácido cítrico, solução 2% (Pácido cítrico); água, (Págua); citrato neutro de amônio mais água, (PCNA+água). Estas últimas variáveis aqui denominadas de variáveis de saída ou de resposta. A manipulação dos referidos modelos permite obter o fertilizante de acordo com as necessidades da cultura e do solo. O estudo, também, permitiu concluir que a maior quantidade de fósforo disponível nos compostos organofosfatados foi o solúvel em ácido cítrico, portanto, a maior quantidade de compostos gerados encontra-se na melhor condição de disponibilidade pela planta. / Humiphert process is an alternative used for producing phosphated compound fertilizers with a slower solubilization when compared to other traditional fertilizers, resulting in a longer period of plant nutrition. During the process, phosphatic rocks are used along with some sort of limitation according to the normal development, both by their lower content percentage and by treatment of difficulties of industrial ores, besides organic materials. This work aim to improve an equipment existing at the Instituto de Geociências in order to find out the best process condition to produce NOX in Humifert process. This way, the process is able to produce an available phosphorus content under process conditions controlled. The process variables were select by using of experimental design. These variables were: agitation of phosphatic rock mixture (rock, organic material and humidity), A coded; ammonia oxidation temperature, B coded; humidity of mixture, C coded; porosity of the diffusing board, D coded; auxiliary air, E coded. Statistical analysis also allowed to build regression models in which the influences of process variables were felt in the solubility of phosphorus in the extractors: 2% solution of citric acid (Pacid Citric), water (Pwater); ammonium neutral citrate plus water (PCNA + water). These last variables here called output variable or response. The manipulation of these models allows to obtain the fertilizer according to the needs of the crop and soil. The study still conclude that the greater amount of available phosphorus in compound was soluble in citric acid, therefore, a greater amount of compounds generated is in the best condition of availability for the plant. The study still conclude that the greater amount of available phosphorus in the organophosphated compounds were soluble in citric acid. Therefore, the greater amount of compounds generated is in the best condition of availability for the plant.

[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.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2003. / Härtill 5 uppsatser.

Os solos brasileiros apresentam baixa disponibilidade de fósforo (P). Devido à natureza mineralógica desses solos, a adubação é uma tarefa difícil, em função dos processos de adsorção específica e precipitação, que causam baixa recuperação do P aplicado. Os fertilizantes totalmente acidulados (FTA), com praticamente todo P solúvel em água, são as fontes mais utilizadas no Brasil. Porém, a utilização dessas fontes, pode não ser o mais indicado para esses solos. Teoricamente, o fertilizante fosfatado ideal possibilitaria suprir a demanda inicial da planta, apresentando ainda liberação lenta durante o ciclo da cultura, resultando em cinética de liberação do P mais ajustada a demanda das culturas. Com base nessa premissa, objetivou-se com esse trabalho avaliar a eficiência de fertilizantes fosfatados produzidos por meio da mistura no mesmo grânulo de FTA, fosfato natural reativo de Bayóvar (FN) e enxofre elementar (S0). Os fertilizantes foram avaliados em experimentos de incubação, casa de vegetação e campo. O estudo de incubação foi conduzido com objetivo de avaliar a difusão, disponibilidade e produtos de reação do P e S dos fertilizantes: fosfato monoamônico (MAP), superfosfato triplo (SFT) e MES (MicroEssentials®); e os fertilizantes produzidos: MAP+FN, MAP+FN+S0[2:1], MAP+FN+S0[1:1], SFT+FN e SFT+FN+S0[2:1], obtidos por meio da granulação dos FTA com o FN, na relação 1:1, com base no P total das fontes, com ou sem adição de S0 na composição. Os fertilizantes produzidos com MAP proporcionaram maiores difusões e disponibilidade do P, do que os fertilizantes com SFT. O S0 melhorou a difusão e disponibilidade do P dos fertilizantes produzidos, principalmente nos fertilizantes contendo MAP. Dois experimentos foram conduzidos em casa de vegetação, destacando-se como objetivos principais: estudar a proporção entre os FTA o FN e a presença do S0 na mistura; quantificar o efeito do S0 no aumento da absorção de P do FN, utilizando o 32P e avaliar os fertilizantes com S0 na composição em fornecer S para a cultura do milho, comparando-os com fertilizantes comerciais. Nos fertilizantes com 50% de MAP ou SFT, o aumento na absorção de P dos fertilizantes em função da adição do S0 foi de 26 e 18%, respectivamente. Os fertilizantes com S0 na composição foram menos eficientes no fornecimento de S para o milho do que o S0 aplicado em pó, mas, foram mais eficientes do que o fertilizante contendo S0 pastilhado com bentonita. O estudo de campo foi conduzido com a cultura da soja em um Latossolo Vermelho na região do Cerrado, município de Itiquira-MT. Os fertilizantes avaliados foram: MAP, FN, MAP+FN, MAP+FN+S0[2:1] e MAP+FN+S0[1:1], aplicados a lanço e localizado. Os fertilizantes MAP+FN[2:1] e MAP+FN[1:1] obtiveram eficiência agronômica superior à do MAP+FN e semelhantes à do MAP. Os fertilizantes produzidos com S0 na composição apresentam potencial para serem utilizados na agricultura, podendo ser fontes alternativas aos FTA, ainda com fornecimento de S. Este foi provavelmente o primeiro estudo de campo utilizando essa associação. Outros estudos, em outras condições de solo e clima, devem ser realizados para confirmar a viabilidade do uso dessas fontes. / Brazilian soils has low phosphorus (P) availability. Due to the mineralogical composition of these soils, fertilization is a challenge, because of the specific adsorption and precipitation processes, causing low P recovery from fertilizers. Fully acidulated P fertilizers (FAP), practically with all P soluble in water, are the most used sources in Brazil. However, they may not be the most appropriate sources for these soils. Theoretically, the ideal phosphate fertilizer would be the one which supplies the initial plant demand as well as releases slowly P during the crop cycle, allowing better synchronization between the plant demand and dissolution of P source. Based on this premise, the aim of this study was to evaluate the efficiency of phosphate fertilizers produced by mixture of FAP, Bayóvar phosphate rock (PR) and elemental sulfur (S0) in the same granule. The fertilizers were evaluated in incubation, greenhouse and field trials. The incubation study was carried out to evaluate the diffusion, availability and reaction products of P and S from the fertilizers: monoammonium phosphate (MAP), triple superphosphate (TSP) and MES (MicroEssentials®); and the produced fertilizers: MAP+PR, MAP+PR+S0[2:1], MAP+PR+S0[1:1], TSP+PR and TSP+PR+S0[2:1], obtained by granulation of FAP with PR in the ratio 1:1, based on total P content, with or without S0 in the composition. Fertilizers with MAP in the composition resulted in better P diffusion and availability than the fertilizers with TSP. The S0 improved the P diffusion and availability mainly from fertilizers produced with MAP. Two experiments were carried out in greenhouse, with the objectives to: study the FAP and PR ratio and S0 presence in the mixture; quantify the S0 effect for increasing the P uptake from PR, using 32P; and evaluate the fertilizers with S0 in the composition to provide sulfur (S) for maize, comparing them with commercial sources. The S0 presence in the granule improved the P uptake on 26 and 18% from the fertilizers produced with 50 % from MAP or TSP, respectively. The fertilizers with S0 in the composition were less efficient than powdered S0 providing S to maize, but they were better than commercial fertilizer with bentonite+S0. The field trial was carried out with soybean in an Oxisol in Cerrado region, Itiquira-MT. The fertilizers evaluated were: MAP, PR, MAP+PR, MAP+PR+S0[2:1] and MAP+PR+S0[1:1] applied in band or broadcast. The fertilizers MAP+PR+S0[2:1] and MAP+PR+S0[1:1] were better than MAP+PR and similar to MAP on soybean yield and agronomic efficiency. Fertilizers produced by MAP+PR and S0 in the same granule can be potential sources to be used in agriculture, could be alternative sources for FAP, moreover can supply S to crops. Probably this was the first study using the abovementioned association. Other studies in others soils and weather conditions should be carried out to confirm the potential use of these sources.

Made available in DSpace on 2016-02-26T12:59:38Z (GMT). No. of bitstreams: 1 CarlosAlbertoViviani.pdf: 236119 bytes, checksum: 3dcbb110fd6868afb511ae48c8ebdfbe (MD5) Previous issue date: 2006-06-08 / To take better advantage of the P applied along the year and of the soil residual by the adequate use of lime, especially in soils cultivated and manured for many years, may be an economically viable practice, as lime is much less expensive than phosphate fertilizers, which may imply important increment in the profit margin for the farmer. Two experiments were carried out in green house at the College of Agricultural Sciences of the Federal University of Dourados, Dourados, State of Mato Grosso do Sul, Brazil, with the following objectives: to evaluate the effect of the increase in the soils pH and application of phosphate fertilizers and lime in the sowing lines in clayey latosoils with high fertility levels, on the availability of P in the soil and the accumulation of this element in soy bean plants ant to obtain values for the most adequate pH for the soy bean crop with respect to the absorption of P. The experimental design used was of randomized blocks, in 4x2x2 factorial scheme, with four repetitions, as follows: Four levels of pH (original pH of each soil 6.0, 6.5, and 7.0, in CaCl2 0,01 mol L-1), two doses of P (0 and 21.82 mg dm-3), and two doses of lime (0 and 100 mg dm-3) respectively for a red dystrophic Latosoil (LVd) from the southern highland plane, and red dystrophic Latosoil (LVdf) from Ponta Porã, in the State of Mato Grosso do Sul, Brazil. In each experimental unit (4,0 dm-3 vase), four cv.BRS 133 soy bean plants was grown up till flower emergence. The following was evaluated: weight of dry matter, content of P in the aerial part of the plant and P remaining in the soil. The availability of P in the soil, evaluated by the content of P extract from the ion exchange resin, increased significantly with the pH of the soil. For the PVdf a significant interaction between pH and doses of P, was observed, with the P content of the soil increasing with pH and with the application of P. For LVd an interaction between pH and doses of lime applied in the sowing line was observed, and in its absence a tendency to an increase in the P content in the soil with pH was observed. The P remaining in the soil was significantly reduced by the increase in pH in both soils. In both experiments with increase of the pH of the soil an increase in the production of dry matter and accumulation of P in the aerial part of the plant was observed. In clayey latosoils and with high P content the increase in pH increases the availability of phosphorus, leading to a higher production of soy bean dry matter / O melhor aproveitamento do P aplicado no ano e do residual do solo favorecido pelo uso adequado de calcário, especialmente em solos cultivados e adubados por muitos anos, pode ser uma prática economicamente viável, uma vez que o calcário tem custo muito inferior aos adubos fosfatados, podendo significar importante incremento na margem de lucro do agricultor. Foram realizados dois experimentos em casa de vegetação da Faculdade de Ciências Agrárias da Universidade Federal da Grande Dourados, com os seguintes objetivos: avaliar o efeito do aumento do pH do solo e da aplicação de adubo fosfatado e calcário na linha de plantio em dois latossolos argilosos, com elevados níveis de fertilidade, sobre a disponibilidade de P no solo e o acúmulo desse elemento em plantas de soja e obter valores de pH do solo mais adequados para a cultura da soja em relação à absorção de P. O delineamento experimental utilizado foi o de blocos casualizados, em esquema fatorial 4x2x2, com quatro repetições, sendo: quatro níveis de pH (pH original de cada solo, 6,0, 6,5 e 7,0, em CaCl2 0,01mol L-1), duas doses de P (0 e 21,82 mg dm-3) e duas doses de calcário (0 e 100 mg dm-3), respectivamente para um Latossolo Vermelho distrófico (LVd) de Chapadão do Sul - MS e um Latossolo Vermelho distroférrico (LVdf) de Ponta Porã - MS. Em cada unidade experimental (vaso de 4,0 dm-3), cultivaram-se quatro plantas de soja cv. BRS 133 até a floração. Avaliou-se: peso da massa seca, teor e acúmulo de P na parte aérea; teor de P e P remanescente no solo. A disponibilidade de P no solo, avaliada pelos teores de P extraídos pela resina de troca iônica, aumentou significativamente com o pH dos solos. Para o LVdf houve interação significativa entre pH e doses de P, os teores de P no solo aumentaram com o pH e com a aplicação de P. Para o LVd houve interação entre pH e doses de calcário aplicado na linha de plantio, e na ausência desse houve tendência de aumento dos teores de P no solo com o pH. O P remanescente foi significativamente reduzido pelo aumento do pH em ambos os solos. Nos dois experimentos, com o aumento do pH do solo houve incremento na produção de massa seca e de P acumulado na parte aérea da soja. Em solos argilosos e com alto teor de P a elevação do pH aumenta a disponibilidade de P, proporcionando maior produção de massa seca de soja

Made available in DSpace on 2016-02-26T12:59:18Z (GMT). No. of bitstreams: 1 CarlosAlbertoViviani.pdf: 236119 bytes, checksum: 3dcbb110fd6868afb511ae48c8ebdfbe (MD5) Previous issue date: 2006-06-08 / To take better advantage of the P applied along the year and of the soil residual by the adequate use of lime, especially in soils cultivated and manured for many years, may be an economically viable practice, as lime is much less expensive than phosphate fertilizers, which may imply important increment in the profit margin for the farmer. Two experiments were carried out in green house at the College of Agricultural Sciences of the Federal University of Dourados, Dourados, State of Mato Grosso do Sul, Brazil, with the following objectives: to evaluate the effect of the increase in the soils pH and application of phosphate fertilizers and lime in the sowing lines in clayey latosoils with high fertility levels, on the availability of P in the soil and the accumulation of this element in soy bean plants ant to obtain values for the most adequate pH for the soy bean crop with respect to the absorption of P. The experimental design used was of randomized blocks, in 4x2x2 factorial scheme, with four repetitions, as follows: Four levels of pH (original pH of each soil 6.0, 6.5, and 7.0, in CaCl2 0,01 mol L-1), two doses of P (0 and 21.82 mg dm-3), and two doses of lime (0 and 100 mg dm-3) respectively for a red dystrophic Latosoil (LVd) from the southern highland plane, and red dystrophic Latosoil (LVdf) from Ponta Porã, in the State of Mato Grosso do Sul, Brazil. In each experimental unit (4,0 dm-3 vase), four cv.BRS 133 soy bean plants was grown up till flower emergence. The following was evaluated: weight of dry matter, content of P in the aerial part of the plant and P remaining in the soil. The availability of P in the soil, evaluated by the content of P extract from the ion exchange resin, increased significantly with the pH of the soil. For the PVdf a significant interaction between pH and doses of P, was observed, with the P content of the soil increasing with pH and with the application of P. For LVd an interaction between pH and doses of lime applied in the sowing line was observed, and in its absence a tendency to an increase in the P content in the soil with pH was observed. The P remaining in the soil was significantly reduced by the increase in pH in both soils. In both experiments with increase of the pH of the soil an increase in the production of dry matter and accumulation of P in the aerial part of the plant was observed. In clayey latosoils and with high P content the increase in pH increases the availability of phosphorus, leading to a higher production of soy bean dry matter / O melhor aproveitamento do P aplicado no ano e do residual do solo favorecido pelo uso adequado de calcário, especialmente em solos cultivados e adubados por muitos anos, pode ser uma prática economicamente viável, uma vez que o calcário tem custo muito inferior aos adubos fosfatados, podendo significar importante incremento na margem de lucro do agricultor. Foram realizados dois experimentos em casa de vegetação da Faculdade de Ciências Agrárias da Universidade Federal da Grande Dourados, com os seguintes objetivos: avaliar o efeito do aumento do pH do solo e da aplicação de adubo fosfatado e calcário na linha de plantio em dois latossolos argilosos, com elevados níveis de fertilidade, sobre a disponibilidade de P no solo e o acúmulo desse elemento em plantas de soja e obter valores de pH do solo mais adequados para a cultura da soja em relação à absorção de P. O delineamento experimental utilizado foi o de blocos casualizados, em esquema fatorial 4x2x2, com quatro repetições, sendo: quatro níveis de pH (pH original de cada solo, 6,0, 6,5 e 7,0, em CaCl2 0,01mol L-1), duas doses de P (0 e 21,82 mg dm-3) e duas doses de calcário (0 e 100 mg dm-3), respectivamente para um Latossolo Vermelho distrófico (LVd) de Chapadão do Sul - MS e um Latossolo Vermelho distroférrico (LVdf) de Ponta Porã - MS. Em cada unidade experimental (vaso de 4,0 dm-3), cultivaram-se quatro plantas de soja cv. BRS 133 até a floração. Avaliou-se: peso da massa seca, teor e acúmulo de P na parte aérea; teor de P e P remanescente no solo. A disponibilidade de P no solo, avaliada pelos teores de P extraídos pela resina de troca iônica, aumentou significativamente com o pH dos solos. Para o LVdf houve interação significativa entre pH e doses de P, os teores de P no solo aumentaram com o pH e com a aplicação de P. Para o LVd houve interação entre pH e doses de calcário aplicado na linha de plantio, e na ausência desse houve tendência de aumento dos teores de P no solo com o pH. O P remanescente foi significativamente reduzido pelo aumento do pH em ambos os solos. Nos dois experimentos, com o aumento do pH do solo houve incremento na produção de massa seca e de P acumulado na parte aérea da soja. Em solos argilosos e com alto teor de P a elevação do pH aumenta a disponibilidade de P, proporcionando maior produção de massa seca de soja

A eficiência do fosfato natural (FN) pode ser melhorada se aplicado junto com uma fonte de elevada solubilidade em água. O presente trabalho constou de quatro experimentos realizados em casa-de-vegetação do Laboratório de Fertilidade do Solo do CENA/USP, nos quais cultivaram-se plantas de milho (Zea mays L.) e de soja [Glycine max (L.) Merr.] em amostras de um Latossolo Vermelho Amarelo distrófico utilizando-se o método da diluição isotópica de 32P para: a) verificar se o efeito de uma fonte de P de elevada solubilidade em água no aumento da disponibilidade do P do FN é fisiológico (disponibilidade inicial de P) ou químico (acidificação), b) avaliar o efeito das doses e das proporções das misturas de superfosfato triplo com fosfatos naturais, e c) comparar a eficiência do fosfato natural de Patos de Minas com o de Gafsa aplicados com o SFT. As fontes de P usadas foram o superfosfato triplo (SFT) como fonte padrão e fosfatos naturais (FNs) de Patos de Minas e de Gafsa. A aplicação de uma fonte de P solúvel em água juntamente com fosfato natural melhorou o aproveitamento do fósforo do FN tanto pelo milho como pela soja, embora esse efeito seja pequeno para o fosfato natural de Patos. Para o milho, a simples presença de P na forma solúvel em água na fase inicial de desenvolvimento não melhorou o aproveitamento do P da fonte natural, provavelmente por causa do menor período de tempo de desenvolvimento das plantas em relação à soja, no qual efeito foi significativo. A compactação do FN de Gafsa com SFT aumentou o aproveitamento do P do FN para o milho comparado à aplicação deste localizado no solo e na soja esse efeito foi maior obtendo aproveitamento superior ao do FN de Gafsa misturado ao solo. Assim, a maior utilização do P do FN pela soja ocorreu tanto pelo efeito químico quanto fisiológico. A aplicação localizada do SFT proporcionou resultado melhor do que quando este fertilizante foi misturado ao solo, ocorrendo o contrário para o fosfato natural. As doses de fósforo aplicadas com as misturas de superfosfato triplo com os FNs não afetaram o aproveitamento do P do fosfato natural pelo milho e pela soja, enquanto que o aumento do SFT nas proporções das misturas aumentaram significativamente o aproveitamento do P dos fosfatos naturais. Ao contrário do FN de Patos, o aproveitamento de P do FN de Gafsa quando misturado na proporção 80 SFT: 20 FN, na soja, foi tão eficiente quanto o SFT aplicado sozinho. / The efficiency of phosphate rock (PR) can be improved applying it together with watersoluble P fertilizer. Four experiments were carried out in the greenhouse of the Soil Fertility Laboratory, CENA/USP (Centro de Energia Nuclear na Agricultura - Universidade de São Paulo), with maize (Zea mays L.) and soybean [Glycine max (L.) Merr.] grown in a dystrophic Typic Haplustox using 32P dilution technique to: a) verify if the increasing effect of water-soluble P source on PR phosphorus availability is physiological (initial higher P availability) or chemical (acidification), b) evaluate the effect of rate and proportion of triple superphosphate (TSP) mixed with PR, and c) compare the efficiency of Patos de Minas with of Gafsa PR applied with TSP. The P sources utilized were the TSP as standard P source and Patos de Minas and Gafsa PR. The application of a water-soluble P source improved the PR phosphorus utilization efficiency by maize and soybean, although this effect was small for the Patos PR. For maize, the simple presence of P in water-soluble form at initial stage of plant growth did not increase the PR phosphorus utilization, probably due to the short growing period in relation to soybean, in which the effect was significant. The compaction of Gafsa PR with TSP increased the absorption of PR P by maize plants. Compared to its localized application in the soil this effect was bigger in soybean plants, obtaining better efficiency than the Gafsa PR mixed in the soil. Therefore, the increased PR P utilization by soybean plants occurred by both chemical and physiological effect. The localized application of TSP promoted better results than when this fertilizer was mixed in the soil, unlike with PR. The increasing rate of P applied in mixed form (TSP and PR) did not affect the PR P utilization by the crops, while the increasing proportion of TSP in the mixture increased the absorption of PR P. The Gafsa PR, when mixed with TSP in proportion 80 TSP: 20 PR, was as efficient as the TSP applied sole.

L'utilisation de machines lourdes et la fertilisation des sols ont été la solution pour améliorer le rendement agricole et augmenter les aires des sols cultivés. Les pays émergeants Est-Méditerranéens souffrent d'un manque crucial des législations et des règlementations qui organisent l'usage des fertilisants chimiques. Cela est principalement dû à l'insuffisance des données sur les caractéristiques des sols et les pratiques agricoles. La fertilisation excessive est devenue une source potentielle de contamination des sols par les éléments traces métalliques (ETM) susceptible de migrer vers les différentes chaines alimentaires. Dans ce cadre, l'Institut de Recherches Agronomiques Libanais (IRAL) avait comme préoccupation principale d'évaluer les risques associés aux apports en ETM issus des engrais phosphatés en usage dans des sols de nature alcaline sous un climat aride à semi-aride. Ainsi, l'investigation sur les engrais phosphatés commercialisés au Liban et les pays voisins ont montré que le cadmium est porté principalement dans une phase sulfate quand cette dernière est présente dans les engrais. L'apport moyen annuel du Cd, Cu, Pb et Zn aux sols est trouvé inferieur aux limites recommandées dans certains pays comme le Brésil et la Grande-Bretagne. Cependant, dans le contexte régional où l'étude est réalisée, cet apport est relativement élevé quand la nature alcaline du sol est prise en considération. Ainsi, une norme établie pour un sol acide n'est pas nécessairement adaptable dans un sol alcalin, sachant que ce dernier est un milieu favorable pour stabiliser les ETM et limiter leurs disponibilités. Les Lactuca sativa (laitues), étant une espèce amplement consommée dans les pays du bassin méditerranéen, ont été choisis comme une espèce cible dans l'objectif de suivre la distribution du cadmium dans les différents tissus de l'espèce et le coefficient de partage entre les compartiments eau, sol et plante. Les effets de la densité des sols, en présence du cadmium et des engrais phosphatés ont été étudiés dans des colonnes de sols cultivés par les laitues. Les caractères morphologiques et physiologiques de la plante, la mobilité du cadmium dans le sol et son transfert vers les laitues, la population microbienne (le nombre de bactéries totaux, champignons totaux, bactéries résistantes au cadmium BRC et micro-organismes solubilisant le phosphore MSP) et l'activité enzymatique des phosphatases alcalines (ALP) et acides et les déshydrogénases (DHA) ont été suivis. La présence du Cd et du phosphore dans le sol a diminué la mobilité du cadmium et la compaction a augmenté l'accumulation du Cd dans la partie aérienne des laitues et l'infiltration des nitrates. La combinaison entre la compaction du sol, la présence de cadmium et du phosphore en même temps a montré une diminution du nombre de bactéries, des champignons totaux et de l'activité d'ALP mais une augmentation du nombre de MSP, de BRC et de l'activité de la phosphatase acide est notablement identifiable. En absence de toute matrice d'interaction avec les ETM et les fertilisants phosphatés autre que les laitues, les effets du cadmium et de l'engrais phosphatés ont été évalués sur les caractères morphologiques et physiologiques des laitues en culture hydroponique et sur l'absorption du cadmium par ces laitues. En présence d'engrais phosphaté, la culture des laitues en hydroponie avait une influence positive sur le développement de ce végétal plus qu'en culture dans le sol. Malgré la croissance rapide des laitues en hydroponie, ce système est désormais une source de cadmium disponible aux laitues puisque ce métal est transféré des racines vers la partie aérienne de Lactuca sativa en induisant des changements morphologiques. / Soil compaction and contamination with heavy metals were the response of the use of heavy machinery and phosphate fertilization to improve and expand agricultural productivity. The Eastern Mediterranean emerging countries suffer from lack in legislations and regulations organizing the chemical fertilizers use. This is due to the insufficient data on soil characteristics and agricultural practices. Thus, excessive fertilization can be considered as potential sources of soil contamination by trace metals susceptible to be transferred to the different food chains. One of the main occupations of the Lebanese Agriculture Research Institute (LARI) was to evaluate the associated risks to the trace metals inputs coming from phosphate fertilizers. The investigation of phosphate fertilizers used in Lebanon and neighboring countries showed that cadmium is well bonded to sulfate-phase when sulfate is present in the fertilizers. The annual average of the deposition of Cd, Cu, Pb and Zn in soil was found lower than the recommended limits in some countries like Brazil and Britain but such contribution is relatively high when considering the alkaline nature of the soil. Thus, norms and legislations for acidic soil cannot be necessarily adaptable and used for alkaline soil knowing that such soil is the best environment to stabilize the metals and limit their bioavailability. Lactuca sativa (lettuce), widely consumed specie in Mediterranean countries, has been chosen as target specie to be studied in order to follow cadmium in different parts of the plants and its partition between water, soil and plants. The effects of the compaction, cadmium and phosphate fertilizers were evaluated on morphological and physiological characteristics of Lactuca sativa cultivated in columns. Cadmium mobility in soil and its transfer to lettuce, the microbial population (the number of total bacteria, total fungi, cadmium resistant bacteria CRB and phosphate solubilizing microorganisms PSM) and the enzymatic activities of alkaline phosphatase (ALP), acid phosphatase and dehydrogenase activity (DHA) were also studied. Cadmium mobility was decreased in the soil amended with cadmium and phosphorus and compaction increased the Cd accumulation in the lettuce's aerial part and the nitrate infiltration. A decrease of the number of total bacteria, fungi, ALP and an increase in the number of PSM, CRB and acid phosphatase activity were observed in the treatment where the soil was compacted and amended with cadmium and phosphate fertilizers. In absence of any interactive matrix with the metals and the phosphate fertilizers other than the lettuces, the effects of cadmium and phosphate fertilizer were evaluated on morphological and physiological characteristics of lettuces grown in hydroponic culture. Cadmium absorption and transfer to aerial part was also studied. The lettuces development's was important in the hydroponic culture more than in soil cultivation in presence of phosphate fertilizer. Despite the rapid growth of lettuces in hydroponic culture, this system is a potential source of bioavailable cadmium that is absorbed by lettuces and transferred to roots and aerial parts conducting to morphological changes.

Afin d'établir l'impact et le risque lié aux fertilisants chimiques depuis leur fabrication jusqu'à leur amendement sur la contamination des sols par les éléments traces métalliques, une étude de leur mobilité et leur transfert s'avère nécessaire. L'objectif de ce travail de thèse était d'évaluer la source de contamination du sol par les éléments traces autour de l'industrie des fertilisants chimiques et suivre l'évolution temporelle de la mobilité et du transfert de ces éléments dans un profil du sol agricole amendé par des engrais phosphatés du type simple superphosphate (SSP) ou du phosphogypse. Pour cela nous avons utilisé des techniques permettant la caractérisation structurale et minéralogique des sols collectés comme la diffraction des rayons X et la microscopie électronique. Puis une caractérisation chimique des sols collectés concernant la concentration totale des éléments traces et des éléments majeurs a été établie. Comme la mobilité n'est pas stable au cours du temps dépendant de plusieurs paramètres physico-chimiques comme le pH, le potentiel redox, la teneur en matière organique, une extraction séquentielle a été adoptée le long de l'étude au cours du temps et dans le profil du sol amendé jusqu'à une profondeur de 55 cm. En outre, l'absorption des éléments traces par les plantes cultivées sur le terrain agricole amendé par les engrais ou le phosphogypse a été analysée au cours du temps afin d'évaluer le risque lié à la chaîne alimentaire et plus particulièrement la chaîne alimentaire humaine induisant des effets négatifs sur la santé. Une comparaison entre l'application du phosphogypse et celle des engrais a été mise en évidence à la finalité de ce travail / To determine the impact and risk of chemical fertilizers, from their manufacture to their amendment, on soil contamination by trace metals, the study of their mobility and transfer would be necessary. The objective of this work was to evaluate the source of soil contamination by trace elements around the industry of chemical fertilizers, and to follow the temporal evolution of mobility and transfer of these elements in the profile of agricultural soil amended by superphosphate (SSP) fertilizers or phosphogypsum. To achieve our objective, we used techniques allowing the determination of structural and mineralogical characterization of collected soil samples, such as X-ray diffraction and electron microscopy. Chemical characterization related to the total concentration of trace and major elements of collected soils was established. As mobility was unstable over time, depending on several physico-chemical parameters such as pH, redox potential, and organic matter content, a sequential extraction was adopted throughout the study over time in the amended soil profile to a depth of 55 cm. In addition, the absorption of trace elements by agricultural crops cultivated over land amended with fertilizer or phosphogypsum was analyzed over time to assess the risk of their transfer to the food chain, especially the human food chain, imposing health hazards. A comparison between the effects of the application of phosphogypsum and phosphate fertilizer was carried out in concluding this work

Développement de méthodes analytiques pour l’évaluation de l'impact de l'industrie de fertilisants chimiques sur le milieu marin / Development of Analytical methods for the evaluation of the impact of phosphate fertilizer industry on marine environment