A obstrução de emissores tem sido considerada como um dos principais problemas do sistema de irrigação por gotejamento, sendo a obstrução de origem física a forma mais comum de ocorrência. A obstrução pode causar aos sistemas de irrigação por gotejamento redução da uniformidade de distribuição de água e da vida útil do sistema, tornando-se necessário uma metodologia para avaliar os efeitos causados pela obstrução sobre os sistemas de irrigação. Salienta-se que não há atualmente uma norma técnica em vigor que estabeleça os requisitos para avaliar a sensibilidade de emissores à obstrução causada por partículas sólidas. Contudo, um procedimento de ensaio elaborado pela equipe do laboratório francês Laboratoire d\'Études et Recherches sur les Matériels d\'Irrigation/Institut national de recherche en sciences et technologies pour l\'environnement et l\'agriculture (LERMI/IRSTEA) tem sido utilizado para a avaliação de produtos comerciais há aproximadamente 40 anos. Considerado apropriado pelo laboratório e por empresas, esse procedimento tem sido indicado para elaboração de uma norma técnica subsequente à realização de estudos para avaliação metodológica. Dessa forma, o objetivo deste trabalho foi realizar um estudo para avaliar o protocolo de ensaios utilizado pelo LERMI/IRSTEA, a fim de contribuir com a validação da metodologia e colaborar com resultados científicos que amparem um procedimento normatizado de ensaio. Para avaliar a metodologia foram realizados três ensaios, considerados como repetições, utilizando quatro modelos de tubos gotejadores (Drip-Tech 1,2 e 1,6 L h-1 e Taldrip 0,6 e 1,7 L h-1). Na realização dos experimentos foi utilizado material de obstrução originado de solo natural, preparado por meio de destruição da matéria orgânica, dispersão da argila e peneiramento do solo. O ensaio foi divido em quatro fases, com diferentes concentrações e faixas granulométricas do material de obstrução. As concentrações utilizadas em cada fase foram: 125, 250, 375 e 500 mg L-1. As faixas granulométricas adicionadas foram: < 75, 75-125, 125-212, 212-500 &mu;m para as fases um, dois, três e quatro, respectivamente, sendo que o material de obstrução permaneceu em reservatório com agitação constante a fim de manter as partículas em suspensão. Os resultados demonstraram que os modelos de gotejadores Drip-Tech 1,2 e 1,6 L h-1 obstruíram na quarta fase de ensaio. O modelo Taldrip 0,6 L h-1 mostrou-se muito sensível à obstrução logo na primeira fase de ensaio apresentando obstrução de emissores no primeiro dia. O modelo Taldrip 1,7 L h-1 não obstruiu em nenhuma das fases sendo considerado um emissor resistente à obstrução para as condições experimentais avaliadas. Embora a obstrução dos modelos de gotejadores avaliados tenha ocorrido sempre em uma determinada fase, a variabilidade dos resultados de grau de obstrução entre repetições foi elevada. A principal hipótese que justifica esse resultado é que fatores não controlados exerceram influência significativa nos processos de obstrução durante os experimentos. Considera-se que o procedimento de ensaio deve ser aprimorado por meio da identificação e controle de outros fatores relevantes para o processo de obstrução (como pH, concentração de partículas, cloração da água), a fim de que os resultados sejam mais precisos e o procedimento de ensaios torne-se mais representativo. / Clogging of emitters has been considered a major problem in drip irrigation systems and solid particles are reported as the most common source of such problems. Clogging of emitters may decrease water distribution uniformity and system lifespan, which become needed a methodology to assess the effects of clogging of drippers on irrigations systems. There is not standard available that states requirements to assess the sensitivity of emitters to clogging caused by solid particles. However, a clogging test procedure developed by the French laboratory Laboratoire d\'Études et Recherches sur les Matériels d\'Irrigation/Institut national de recherche en sciences et technologies pour l\'environnement et l\'agriculture LERMI/IRSTEA about 40 years ago has been employed to evaluate drippers. According to the laboratory and their customers, that is an appropriate testing procedure which represents field conditions, and has been indicate like standard, after studies to assess of methodology. The purpose of this research was to evaluate the clogging test procedure used by LERMI/IRSTEA in order to contribute for the methodology validation and to present scientific results that support development of a standardized clogging test protocol. Experiments were organized in three repetitions, in which four models of drippers were tested (Drip-Tech 1.2 e 1.6 L h-1 e Taldrip 0.6 e 1.7 L h-1). The solid particles compound employed during clogging tests was prepared from samples of natural soil that were submitted to a preparation procedure consisting of destruction of organic matter, clay dispersion, and sieving. The clogging test procedure is divided into four stages. The following concentrations of particles were tested: 125, 250, 375 and 500 mg L-1. The ranges of particle sizes tested were: <75, 75-125, 125-212, and 212-500 &mu; m to the stages one, two, three and four, respecting, wherein the particles remained in the tank with constant agitation to keep the particles in suspension. Drippers model Drip-tech 1.2 L h-1 and 1.6 L h-1 were considered to clog during the fourth stage of the tests. The dripper Taldrip 0.6 L h-1 was sensitive to clogging in the first stage with clogging emitters in the first day. The dripper Taldrip 1.7 L h-1 did not clog during the tests so that it seems to be a model of low sensitivity to clogging caused by solid particles in the experimental conditions assessed. In respect of the testing procedure, although clogging of drippers had been identified always in a given stage of the test, most of times the variability in clogging rate among repetitions was excessive. Probably non-controlled factors exerted significant influence on clogging processes during experiments. The clogging test procedure needs improvements by identifying and controlling other relevant factors associated with clogging processes (as pH, concentration of particles, chlorination water) in order the results are more accurate and the test procedures become more representative.

A obstrução de emissores tem sido considerada como um dos principais problemas do sistema de irrigação por gotejamento, sendo a obstrução de origem física a forma mais comum de ocorrência. A obstrução pode causar aos sistemas de irrigação por gotejamento redução da uniformidade de distribuição de água e da vida útil do sistema, tornando-se necessário uma metodologia para avaliar os efeitos causados pela obstrução sobre os sistemas de irrigação. Salienta-se que não há atualmente uma norma técnica em vigor que estabeleça os requisitos para avaliar a sensibilidade de emissores à obstrução causada por partículas sólidas. Contudo, um procedimento de ensaio elaborado pela equipe do laboratório francês Laboratoire d\'Études et Recherches sur les Matériels d\'Irrigation/Institut national de recherche en sciences et technologies pour l\'environnement et l\'agriculture (LERMI/IRSTEA) tem sido utilizado para a avaliação de produtos comerciais há aproximadamente 40 anos. Considerado apropriado pelo laboratório e por empresas, esse procedimento tem sido indicado para elaboração de uma norma técnica subsequente à realização de estudos para avaliação metodológica. Dessa forma, o objetivo deste trabalho foi realizar um estudo para avaliar o protocolo de ensaios utilizado pelo LERMI/IRSTEA, a fim de contribuir com a validação da metodologia e colaborar com resultados científicos que amparem um procedimento normatizado de ensaio. Para avaliar a metodologia foram realizados três ensaios, considerados como repetições, utilizando quatro modelos de tubos gotejadores (Drip-Tech 1,2 e 1,6 L h-1 e Taldrip 0,6 e 1,7 L h-1). Na realização dos experimentos foi utilizado material de obstrução originado de solo natural, preparado por meio de destruição da matéria orgânica, dispersão da argila e peneiramento do solo. O ensaio foi divido em quatro fases, com diferentes concentrações e faixas granulométricas do material de obstrução. As concentrações utilizadas em cada fase foram: 125, 250, 375 e 500 mg L-1. As faixas granulométricas adicionadas foram: < 75, 75-125, 125-212, 212-500 &mu;m para as fases um, dois, três e quatro, respectivamente, sendo que o material de obstrução permaneceu em reservatório com agitação constante a fim de manter as partículas em suspensão. Os resultados demonstraram que os modelos de gotejadores Drip-Tech 1,2 e 1,6 L h-1 obstruíram na quarta fase de ensaio. O modelo Taldrip 0,6 L h-1 mostrou-se muito sensível à obstrução logo na primeira fase de ensaio apresentando obstrução de emissores no primeiro dia. O modelo Taldrip 1,7 L h-1 não obstruiu em nenhuma das fases sendo considerado um emissor resistente à obstrução para as condições experimentais avaliadas. Embora a obstrução dos modelos de gotejadores avaliados tenha ocorrido sempre em uma determinada fase, a variabilidade dos resultados de grau de obstrução entre repetições foi elevada. A principal hipótese que justifica esse resultado é que fatores não controlados exerceram influência significativa nos processos de obstrução durante os experimentos. Considera-se que o procedimento de ensaio deve ser aprimorado por meio da identificação e controle de outros fatores relevantes para o processo de obstrução (como pH, concentração de partículas, cloração da água), a fim de que os resultados sejam mais precisos e o procedimento de ensaios torne-se mais representativo. / Clogging of emitters has been considered a major problem in drip irrigation systems and solid particles are reported as the most common source of such problems. Clogging of emitters may decrease water distribution uniformity and system lifespan, which become needed a methodology to assess the effects of clogging of drippers on irrigations systems. There is not standard available that states requirements to assess the sensitivity of emitters to clogging caused by solid particles. However, a clogging test procedure developed by the French laboratory Laboratoire d\'Études et Recherches sur les Matériels d\'Irrigation/Institut national de recherche en sciences et technologies pour l\'environnement et l\'agriculture LERMI/IRSTEA about 40 years ago has been employed to evaluate drippers. According to the laboratory and their customers, that is an appropriate testing procedure which represents field conditions, and has been indicate like standard, after studies to assess of methodology. The purpose of this research was to evaluate the clogging test procedure used by LERMI/IRSTEA in order to contribute for the methodology validation and to present scientific results that support development of a standardized clogging test protocol. Experiments were organized in three repetitions, in which four models of drippers were tested (Drip-Tech 1.2 e 1.6 L h-1 e Taldrip 0.6 e 1.7 L h-1). The solid particles compound employed during clogging tests was prepared from samples of natural soil that were submitted to a preparation procedure consisting of destruction of organic matter, clay dispersion, and sieving. The clogging test procedure is divided into four stages. The following concentrations of particles were tested: 125, 250, 375 and 500 mg L-1. The ranges of particle sizes tested were: <75, 75-125, 125-212, and 212-500 &mu; m to the stages one, two, three and four, respecting, wherein the particles remained in the tank with constant agitation to keep the particles in suspension. Drippers model Drip-tech 1.2 L h-1 and 1.6 L h-1 were considered to clog during the fourth stage of the tests. The dripper Taldrip 0.6 L h-1 was sensitive to clogging in the first stage with clogging emitters in the first day. The dripper Taldrip 1.7 L h-1 did not clog during the tests so that it seems to be a model of low sensitivity to clogging caused by solid particles in the experimental conditions assessed. In respect of the testing procedure, although clogging of drippers had been identified always in a given stage of the test, most of times the variability in clogging rate among repetitions was excessive. Probably non-controlled factors exerted significant influence on clogging processes during experiments. The clogging test procedure needs improvements by identifying and controlling other relevant factors associated with clogging processes (as pH, concentration of particles, chlorination water) in order the results are more accurate and the test procedures become more representative.

Eco-tourism activities specifically, sometimes have very negative environmental impacts. One such activity which has been observed to have severe negative impacts is driving in dirt tracks (ungravelled natural soil) by game drive vehicles in private game reserves and some National Parks (Nortjé 2005; Laker 2009). It has also been observed that the severity of the impacts and the resilience (recovery potential) of the affected areas differ widely between different areas. It is strongly linked to the properties and qualities of different soils. This study has shown that off-road driving (ORD) has the same effects, and to a greater extent, if it is not well managed and judiciously controlled. Wild animals tend to concentrate in areas with the most nutritious en most palatable vegetation. Consequently these are also the areas where predators, e.g. lion, leopard and cheetah are most likely to be found. It can be expected that these will be the areas with the highest frequencies of ORD in order to get close to these animals. In many landscapes these are the areas which are the most vulnerable to negative impacts by actions like ORD and have the lowest resilience. It has also been observed during game drives and personal communications at several occasions that there is tremendous ignorance amongst tourists regarding the negative environmental impacts of certain activities. This study proved that ORD have strong negative impacts on vegetation recovery, soil resilience and root density distribution through soil crusting and sub-soil compaction. An important finding is that these negative impacts are during both dry and wet soil conditions. Game drive vehicles driving off-road damages the surface soil structure, which lead to soil crust formation and sub-surface compaction. A highly significant result is that most crusting and sub-soil compaction occurred during the first pass of the game drive vehicle, irrespective of the soil type and tyre pressure, thus rewriting the current guidelines for ORD of the South African National Parks, SANParks. Furthermore, results of this study indicated that a significant area in the flood plains of the Makuleke Contractual Park is impacted by ORD. The impacts are serious if one looks at the amount of land that an ORD vehicle can disturb. One of the recommendations would thus be to drive in the same tracks when driving off-road, and lower the tyre pressures. Driving in the same tracks is known as "controlled-traffic" in the agricultural industry. Controlled traffic is very important to minimize compaction. Driving in the same University of Pretoria etd Nortjé, G.P. (2013) tracks during off-road incidents does not significantly affect the degree of compaction under the tracks, but greatly reduces the compacted area. Further results indicated a strong lateral effect of the vehicle tracks, in most cases the whole area between the two tyre tracks as well as up to a distance outside of the vehicle tracks, thus increasing the total area disturbed by ORD. Comparing these vehicle impacts with animal path resulted in some important findings. Animals only caused a soil crust with soil strength values much lower than that of vehicles. The effects of animals are also much more vertical than lateral as with vehicles. Another important finding is the role that historical human activities play in such study areas and how it may influence results. The results in this study are aggravated by the historical human activities in this study area, as indicated. These historical activities were the main cause of the surface crusting, and the resultant low vegetation growth in the area. This, therefore, explains partially the relatively high control values and also the soil’s higher susceptibility to compaction due to vehicle ORD. The root density trials had very interesting and important results. Significant differences occurred between mean root density fractions across all tyre pressures at all three trial sites. The trend is that an increase in tyre pressure causes a decrease in root density distribution. These results show clearly that even lower tyre pressures are harmful, but are more environmental friendly than higher tyre pressures. Results of the second part of the study with regards to tourists' perceptions on ORD, and the impact of their activities on the environment, showed that the majority of tourists areignorant when it comes to the impacts of their activities on soil and vegetation. Tourists' had significantly variable demographic characteristics. Tourists' environmental perceptions varied, but a significant majority of tourists agreed that ORD has a negative impact on the environment. Contradictions exist between what they know or perceive as being damaging and what they prefer to act on. Results indicate a need for improved visitor education on the possible negative impacts of demands for ORD, and a need for government intervention with regards to the enforcement of legal measures to control ORD. The results also indicate that game guides and tourism operators can play a major role in educating the tourists. The results demonstrate that both an understanding of the chemical and physical factors influencing soil compaction, as well as tourists' environmental views are important in formulating a management strategy to control and manage these impacts. / Thesis (PhD)--University of Pretoria, 2014. / gm2014 / Animal and Wildlife Sciences / unrestricted

Tyrimo tikslas - nustatyti ir įvertinti Lietuvoje ekologiškai ūkininkaujančių ir pagal rengiamą LR ŽŪM konkursą pretenduojančių tapti „Pažangiausias ekologiniais ūkiais“, dirvožemių turtingumą augalams prieinamomis maisto medžiagomis ir susiformavusių agrofitocenozių agrarinę būklę. Tyrimo objektas – Lietuvos skirtingų regionų ekologinės gamybos ūkių, pretenduojančių tapti “ Pažangiausiais ekologiniais ūkiais“ dirvožemiai ir suformuotos agrofitocenozės. Tyrimų metodika. 2007–2009 metais LR ŽŪM organizuoto konkurso metu renkant „Pažangiausius ekologinius ūkius“, iš ekologinių ūkių laukų buvo imami dirvožemio ėminiai ir atlikta agrocheminė dirvožemio analizė, taip pat nustatytas agrofitocenozių dominančių tankis ir segetinės floros kiekis. Dirvožemio pH nustatytas potenciometriniu metodu, judrieji P2O5 ir K2O – Egnerio – Rimo – Domingo (A – L) metodo ištraukoje. Agrofitocenozių įvertinimui pasirinktas ekspedicinių tyrimų analitinis metodas. Tyrimo rezultatai. Atlikus tyrimus didžiausias judriojo kalio ir judriojo fosforo kiekis rastas Vakarų Lietuvos gamtinėje dirvožeminėje zonoje. Mažiausias kiekis – Baltijos aukštumų gamtinėje dirvožeminėje zonoje. Judriuoju kaliu ir judriuoju fosforu turtingiausi Šiaulių, Telšių ir Tauragės apskričių ekologinių ūkių dirvožemiai. Humusu turtingiausi Vakarų Lietuvos gamtinės dirvožeminės zonos dirvožemiai Mažiausias ekologinių ūkių agrofitocenozių dominantėse segetinės floros kiekis buvo Kauno, Panevėžio ir Tauragės apskrityse... [toliau žr. visą tekstą] / The subject of research – to identify and evaluate the richness of soil in the nutrients suitable for plants and the agrarian state of the formed agrophytocenoses of the ecological farms of Lithuania and the candidates for the status of the Leading ecological farms under the competition organized by the Ministry of Agriculture of the Republic of Lithuania. The aim of the research. The soils and agrophytocenoses of the ecological farms of different regions of Lithuania seeking to become the Leading ecological farms. Methods of the research. In 2007–2009, during the competition for the name of the Leading ecological farms organized by the Ministry of Agriculture of the Republic of Lithuania, the soils of the fields of the ecological farms were sampled and undergone the agrochemical soil analysis. There also was determined the density of the agrophytocenoses and the amount of segetal flora. The soil pH was determined using the potentiometric method, the mobile P2O5 and K2O – using the Egner-Riem-Domingo method. The field analytical method was used to evaluate the agrophytocenoses. The results of the research. The tests showed that the area of natural soil of the western Lithuania contained the maximum amount of mobile potassium and mobile phosphorus. The minimum amount was found in the area of natural soil of Baltic Heights. The soils of the ecological farms of Šiauliai, Telšiai and Tauragė regions have the maximum content of mobile potassium and mobile... [to full text]

Made available in DSpace on 2014-06-11T19:32:18Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-04-16Bitstream added on 2014-06-13T20:23:26Z : No. of bitstreams: 1 silvafilho_ep_dr_rcla.pdf: 2048803 bytes, checksum: b4e24e2206750a30458668a0d7848401 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O histórico das modificações do uso da terra em Rondônia, e mais especificamente no município de Porto Velho, mostra transformações de grandes áreas de florestas em pastagens com rápida degradação de seus solos. A criação extensiva de gado de corte é a principal causa da ocupação e uso das terras no Estado. O objetivo deste trabalho foi avaliar a degradação ambiental associada à compactação dos solos por pisoteio animal. Foram considerados solos em pastagens degradadas, com vinte anos de pastejo, e florestas naturais em manchas contínuas de um Latossolo Amarelo Distrófico (LAd) e um Argissolo Vermelho Amarelo Distrófico plíntico (PVAd). A avaliação da densidade máxima e umidade ideal, obtida pelo Ensaio de Proctor, bem como observações referentes às diferenças da densidade aparente e a umidade dos solos, em seus limites inferior e superior de água disponível, registraram valores de compactação acima de 2,5 MPa indicando um nível prejudicial ao desenvolvimento radicular de algumas espécies. A resistência mecânica à penetração nas duas classes de solos ocorreu entre 0 – 10 cm com aumento entre 11 - 20 cm de profundidade, sendo que o Latossolo mostrou-se mais compactado em ambiente de pastagem que o Argissolo. As taxas de infiltração básica nas áreas de pastagens e de florestas evidenciaram diferenças entre os ambientes e seus solos, com reduções da infiltração básica nas áreas de pastagens do Latossolo. Influências antrópicas próximas das áreas de pastagens apresentaram-se como fatores associados na distribuição dos altos índices de compactação detectados. Os resultados obtidos evidenciaram de forma satisfatória os índices mais e menos significativos de caráter físico e químico da fertilidade para as áreas de pastagens e comparativamente as de floresta, permitindo detectar as áreas mais compactadas e suas relações aos... / The history of land use changes in Rondônia, and more specifically the city of Porto Velho, shows transformations of large forest areas into pastures with rapid soils degradation. The extensive beef cattle creation is the main cause of the occupation and land use in the state. The objective of this study was to evaluate the environmental degradation associated with soil compaction by cattle trampling. It was considered soils in degraded pastures, with twenty years of grazing, and natural forest patches in a continuous Oxisol Distrophic (LAd) and a Ultisol (Red Yellow Distrophic Plinthic – PVAd). The maximum density and optimum moisture content evaluation obtained by the Proctor test and observations relating to differences in bulk density and soil moisture on its lower and upper limits of available water, recorded values of compaction above 2.5 MPa indicating a detrimental level to root development for some species. The mechanical resistance to penetration in the two soil classes occurred between 0 to 10 cm with an increase between 11 to 20 cm deep, and the Oxisol was more compressed in a pasture environment than in the Ultisol. The basic infiltration rates in pasture areas and forests showed differences between environments and soils, with reductions of basic infiltration in Oxisol pasture areas. Anthropogenic influences near pasture areas were factors associated in the distribution of high compaction indexes detected. The obtained results showed as satisfactory manner the most and least significant indexes for physical and chemical nature of fertility in pasture areas compared to forest, allowing to detect the most compressed areas and their relationship to physical and chemical parameters considered in this study.

Orientador: Luiz Roberto Cottas / Banca: Marilia Locatelli / Banca: Evaristo Castro Junior / Banca: Juércio Tavares de Mattos / Banca: Jairo Roberto Jiménez Rueda / Resumo: O histórico das modificações do uso da terra em Rondônia, e mais especificamente no município de Porto Velho, mostra transformações de grandes áreas de florestas em pastagens com rápida degradação de seus solos. A criação extensiva de gado de corte é a principal causa da ocupação e uso das terras no Estado. O objetivo deste trabalho foi avaliar a degradação ambiental associada à compactação dos solos por pisoteio animal. Foram considerados solos em pastagens degradadas, com vinte anos de pastejo, e florestas naturais em manchas contínuas de um Latossolo Amarelo Distrófico (LAd) e um Argissolo Vermelho Amarelo Distrófico plíntico (PVAd). A avaliação da densidade máxima e umidade ideal, obtida pelo Ensaio de Proctor, bem como observações referentes às diferenças da densidade aparente e a umidade dos solos, em seus limites inferior e superior de água disponível, registraram valores de compactação acima de 2,5 MPa indicando um nível prejudicial ao desenvolvimento radicular de algumas espécies. A resistência mecânica à penetração nas duas classes de solos ocorreu entre 0 - 10 cm com aumento entre 11 - 20 cm de profundidade, sendo que o Latossolo mostrou-se mais compactado em ambiente de pastagem que o Argissolo. As taxas de infiltração básica nas áreas de pastagens e de florestas evidenciaram diferenças entre os ambientes e seus solos, com reduções da infiltração básica nas áreas de pastagens do Latossolo. Influências antrópicas próximas das áreas de pastagens apresentaram-se como fatores associados na distribuição dos altos índices de compactação detectados. Os resultados obtidos evidenciaram de forma satisfatória os índices mais e menos significativos de caráter físico e químico da fertilidade para as áreas de pastagens e comparativamente as de floresta, permitindo detectar as áreas mais compactadas e suas relações aos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The history of land use changes in Rondônia, and more specifically the city of Porto Velho, shows transformations of large forest areas into pastures with rapid soils degradation. The extensive beef cattle creation is the main cause of the occupation and land use in the state. The objective of this study was to evaluate the environmental degradation associated with soil compaction by cattle trampling. It was considered soils in degraded pastures, with twenty years of grazing, and natural forest patches in a continuous Oxisol Distrophic (LAd) and a Ultisol (Red Yellow Distrophic Plinthic - PVAd). The maximum density and optimum moisture content evaluation obtained by the Proctor test and observations relating to differences in bulk density and soil moisture on its lower and upper limits of available water, recorded values of compaction above 2.5 MPa indicating a detrimental level to root development for some species. The mechanical resistance to penetration in the two soil classes occurred between 0 to 10 cm with an increase between 11 to 20 cm deep, and the Oxisol was more compressed in a pasture environment than in the Ultisol. The basic infiltration rates in pasture areas and forests showed differences between environments and soils, with reductions of basic infiltration in Oxisol pasture areas. Anthropogenic influences near pasture areas were factors associated in the distribution of high compaction indexes detected. The obtained results showed as satisfactory manner the most and least significant indexes for physical and chemical nature of fertility in pasture areas compared to forest, allowing to detect the most compressed areas and their relationship to physical and chemical parameters considered in this study. / Doutor

This research work concentrate on developing digital soil maps to support field based plant phenotyping research. We have developed soil organic matter content (OM), cation exchange capacity (CEC), natural soil drainage class, and tile drainage line maps using topographic indices and aerial imagery. Various prediction models (universal kriging, cubist, random forest, C5.0, artificial neural network, and multinomial logistic regression) were used to estimate the soil properties of interest.