Готові списки джерел за темами / Soil conservation Tropics

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Добірка наукової літератури з теми "Soil conservation Tropics"

Автор: Grafiati

Опубліковано: 10 грудня 2022

Оновлено: 29 січня 2023

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Статті в журналах з теми "Soil conservation Tropics"

Hurni, Hans. "Soil conservation for small farmers in the Humid Tropics." Soil Technology 4, no. 4 (December 1991): 391–92. http://dx.doi.org/10.1016/0933-3630(91)90017-h.

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Dilshad, M., JA Motha, and LJ Peel. "Surface runoff, soil and nutrient losses from farming systems in the Australian semi-arid tropics." Australian Journal of Experimental Agriculture 36, no. 8 (1996): 1003. http://dx.doi.org/10.1071/ea9961003.

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Most soils suitable for dryland agriculture in north-west Australia occur in the Daly Basin. These are sesquioxidic soils which include red, yellow and grey earths, and soils related to yellow and red earths. The potential, for these arable soils to be degraded by highly erosive rainfalls, common to the region, is high. Farming practices strongly influence the soil surface characteristics (vegetation cover, roughness, soil strength), which in turn control surface runoff, and sediment detachment and transport. In studies conducted during 1984-89 in the Daly Basin, conventionally tilled catchments, produced 1.5-2 times more runoff and lost 1.5-6 times more soil than their no-tillage counterparts (all catchments were within soil conservation banks). In these conventionally tilled catchments, soil loss was <8.1 t/ha.year. Other studies in the region have shown that, without soil conservation banks, soil loss can be around 100/ha.year under conventional tillage. Little work, however, has been undertaken on farms in the Australian semi-arid tropics to study the movement of nutrients and herbicides (in ionic and adsorbed forms) and further research is warranted.

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Laryea, K. B. "Rainfed Agriculture: Water Harvesting and Soil Water Conservation." Outlook on Agriculture 21, no. 4 (December 1992): 271–77. http://dx.doi.org/10.1177/003072709202100405.

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Cultivated rainfed agricultural lands contribute substantially to food production in the semi-arid tropics, but crop yields depend on the vagaries of the weather, particularly the variable onset and cessation of rainfall. Increased crop yields can be stabilized and the soil resource base conserved if runoff water from periodic intensive rainfall can be harvested, stored and used to supplement crop water requirements during periods of drought.

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Singer, M. J. "Soil Conservation for Small Farmers in the Humid Tropics (FAO Soils Bulletin 60)." Journal of Environmental Quality 20, no. 1 (January 1991): 311. http://dx.doi.org/10.2134/jeq1991.00472425002000010055x.

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Kumar, Suresh, Dharam Raj Singh, Alka Singh, Naveen Prakash Singh, and Girish Kumar Jha. "Does Adoption of Soil and Water Conservation Practice Enhance Productivity and Reduce Risk Exposure? Empirical Evidence from Semi-Arid Tropics (SAT), India." Sustainability 12, no. 17 (August 27, 2020): 6965. http://dx.doi.org/10.3390/su12176965.

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This paper assessed the impact of soil and water conservation practices on farm productivity and risk exposure using data from 1204 plots in the semiarid tropics of India. A probit model was used to assess the determinants of adoption of soil bunds. We employed a moment-based approach for estimating crop revenue, its variability and downside risk exposure, i.e., crop failure. Furthermore, we also used a doubly robust method for assessing the impact of soil bunds on crop revenue, its variability and downside risk. Matching and propensity-based methods were also used to check robustness. The results show that training, access to credit and extension services are key determinants of adoption of soil bunds. Furthermore, the results also suggest that soil bunds not only improve the crop revenue but also reduce its variability. Most interestingly, we show that soil bunds also reduce the chances of downside risk, i.e., crop failure. Therefore, in view of increasing climate change and variability in the semiarid tropics, it can be suggested that soil bunds could be an important adaptation strategy for improving productivity and reducing risk exposure. This paper supports the investment in soil and water conservation technologies for sustaining the livelihood of resource-poor farmers of ecologically fragile regions such as the semiarid tropics.

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Martins Filho, J. B., K. C. Cunha Meneses, A. L. Brito Filho, C. E. L. Feitosa, and M. F. Farias. "Soil-water physical attributes under different managements systems in the humid tropics in Maranhão." Scientific Electronic Archives 13, no. 9 (September 1, 2020): 38. http://dx.doi.org/10.36560/13820201030.

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This study was conducted to evaluate the physical properties modifications of an Oxisol under different conditions of use and management. The research was conducted at Fazenda Sítio Novo and in native forest area, respectively in the municipalities of São Benedito do Rio Preto/MA and Chapadinha/MA. The research followed a completely randomized design with 3 treatments and 4 replications, with the following uses and management: no-tillage (PD); conventional planting (CP) and native forest (MN). The following physical properties were analyzed: bulk density, porosity and soil moisture and penetration resistance at depths of 0.0-0.20 m and 0.20-0.40 m. The water properties analyzed were: basic infiltration velocity, total soil water capacity and vertical hydraulic conductivity. The soil presented higher density and low conservation of moisture in PD and PC. Native forest presented higher total porosity and higher conservation of soil moisture. Total soil water capacity was higher in MN (39.89 mm) followed by PC (25.33 mm) and PD (18.84 mm). The uses and management employed in the soils analyzed on the farm reflect the degradation of the physical properties of the soil in relation to native forest.

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Manrique, Luis A. "Soil management and conservation in the tropics: Indigenous and adapted technology." Communications in Soil Science and Plant Analysis 24, no. 13-14 (August 1993): 1617–44. http://dx.doi.org/10.1080/00103629309368905.

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Cogle, AL, RJ Bateman, and DH Heiner. "Conservation cropping systems for the semi-arid tropics of North Queensland, Australia." Australian Journal of Experimental Agriculture 31, no. 4 (1991): 515. http://dx.doi.org/10.1071/ea9910515.

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A farming systems project was commenced in the semi-arid tropics of north-eastern Australia to assess the cropping potential and reliability of a newly developing region. Emphasis was placed on evaluation of conservation cropping systems, since it was expected that these would be the most successful and protective uses of the land. This paper discusses the agronomy of peanuts, maize and sorghum grown under different conservative cropping practices (reduced tillage, no tillage, ley) on the soil (red earth) most likely to be developed for large-scale cropping in the region. Crop yields with all practices were limited by establishment difficulties including high soil temperatures, poor weed control and climatic variability. Reduced tillage was more successful than no tillage due to higher yields in dry years; however, in wet years no tillage produced similar yields. The ley cropping system may have some advantages in this environment for integrated production and resource protection.

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Chin, Lai Mun, and Vui Ling Clemente Michael Wong. "Tropical Soil Bacterial Diversity in Sabah, Malaysia." Sains Malaysiana 51, no. 2 (February 28, 2022): 451–60. http://dx.doi.org/10.17576/jsm-2022-5102-10.

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Bacteria are an essential biological component of soil function that plays fundamental roles in biogeochemical cycling, soil quality improvement, habitat-shaping, and ecosystem conservation. It is therefore important to have a good record of soil bacteria in the tropics in order to monitor future changes that may occur due to global warming and other factors. However, extremely limited data are available on the diversity of bacteria in soils in some tropical Borneo regions such as Sabah, Malaysia. This research, therefore, was undertaken to determine the bacterial diversity of soils from various locations in Sabah, Malaysia. Ten soil samples (n=10) were collected around Sabah. 16S rDNA of bacterial DNA extracted from soils were amplified and analysed using the Denaturing Gradient Gel Electrophoresis (DGGE). A total of 100 dominant and well-defined DNA fragments observed in the DGGE gel were extracted, sequenced, and aligned. The results indicated that 93 different bacterial operational taxonomic units (OTUs) representing bacteria from 8 different phyla were present. The most abundant phyla in the analysed Sabah soils were Proteobacteria followed by Acidobacteria, Firmicutes, Actinobacteria, Planctomycetes, Verrucomicrobia, Chloroflexi, and Bacteroidetes. The examined soils of Sabah and Peninsular Malaysia had similar dominant phyla in general, except that the most dominant phylum in Peninsular Malaysia soils is the Acidobacteria instead of Proteobacteria. These baseline data generated from this work are important and can be used to track bacterial diversity shifts due to soil or environmental changes in the future.

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Pandey, C. B., R. C. Srivastava, and R. K. Singh. "Soil Nitrogen Mineralization and Microbial Biomass Relation, and Nitrogen Conservation in Humid-Tropics." Soil Science Society of America Journal 73, no. 4 (July 2009): 1142–49. http://dx.doi.org/10.2136/sssaj2008.0182.

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Більше джерел

Дисертації з теми "Soil conservation Tropics"

Amorim, Andreia Pereira. "Uso de indicadores químicos na avaliação da qualidade do Argissolo vermelho amarelo distrocoeso em um sistema de cultivo em aleias." Universidade Federal do Maranhão, 2016. http://tedebc.ufma.br:8080/jspui/handle/tede/1652.

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Fundação de Amparo à Pesquisa e ao Desenvolvimento Científico e Tecnológico do Maranhão (FAPEMA)
The use of chemical indicators used to evaluate soil quality in a growing alley cropping can identify the causes of land degradation in agricultural systems of the Amazon, the conversion of forest to these agricultural systems, incompatible with soil and climatic conditions of this region. This degradation is considered one of the greatest threats to the rainforest due to depletion of phosphorus (P), the decline in soil organic matter (SOM) and the loss of basic cations. two kinds of high quality waste were used: (Leucaena leucocephala and Gliricidia sepium), and two species of low quality waste (Clitoria fairchildiana and Acacia mangium). The 1600m2 area was sampled for carrying out chemical analysis and fractionation of organic matter and soil phosphorus. The SOM was separated by density fractionation soil. Fractionation of P in soil was carried out with extraction solutions. The experimental design was randomized blocks: leucena + sombrero (L + S); leucena + acacia (L + A); gliricidia + acacia (G + A); gliricidia + sombrero (G + S) and control treatment without pulses with five treatments and eight repetitions. The corn was used as test culture. Legumes were pruned to 50 cm of soil waste materials were added to the surface and then the corn was sown. All soil samples of the experiment in alleys had low pH values. The results show statistical differences between treatments when to soil organic matter (SOM). The highest levels were found in the treatment leucena + sombrero (L + S), but did not influence the carbon stock of Fractions Take Free (FLL), Intra-aggregate fractions (FLI) and MOP MOS, which showed no statistical difference. Therefore, in accordance cutting alleys, most of the P found in inorganic form, and was also found in fractions moderately labile and difficult. The results indicate that the fractions of P and organic matter are important indicators to evaluate changes in the degree of land degradation in the humid tropics. These results also indicate that the intensive and continuous use of annual crops in soils of the regions of the Amazon without any conservation practice can be considered as a high risk to the sustainability of agricultural systems, mainly because of increased active and potential acidity, reducing labile organic matter and depletion of organic P pools, leading to soil degradation. Soil fertility, physical properties and available P are responsible for the variability of soil degradation. Considering that small farmers are responsible for 70% of agricultural production in the country, the sustainable management of these soils, usually of low fertility by agroecological alley cropping of legumes is an alternative to agriculture as socioeconomic and environmental benefits.
O uso de indicadores químicos serve para avaliar a qualidade do solo em um sistema de cultivo em aleias. A degradação do solo de sistemas agrícolas da Amazônia, pela conversão da floresta para esses sistemas agrícolas, incompatíveis com as condições edafoclimáticas desta região é considerada uma das maiores ameaças para os solos tropicais devido à depleção de fósforo (P), a diminuição da matéria orgânica do solo (MOS) e a perda de cátions básicos. Esta Tese teve o objetivo de avaliar os principais indicadores químicos de qualidade do solo (matéria orgânica e seus compartimentos, pH, frações do fósforo (P), potássio (K) e o somatório de cálcio (Ca) e magnésio trocáveis (Mg)) após dois anos de plantio em um ARGISSOLO VERMELHO AMARELO Distrocoeso sobre um sistema de cultivo em aleias. Foram utilizadas duas espécies de alta qualidade de resíduos: (Leucaena leucocephala e Gliricídia sepium), e duas espécies de baixa qualidade de resíduos (Clitoria fairchildiana e Acacia mangium). A área de 1600m2 foi amostrada, para realização das análises químicas (IAC, 2001) e fracionamento densimétrico e granulométrico da MOS (MACHADO, 2002). O fracionamento de P no solo foi realizado com soluções extratoras, conforme Hedley et al. (1982) com as modificações de Condron et al. (1985), adaptado de Gatiboni (2003). O delineamento experimental foi em blocos casualisados com cinco tratamentos e oito repetições: leucena+sombreiro (L+S); leucena+acácia (L+A); gliricídia+acácia (G+A); gliricídia+sombreiro (G+S) e tratamento controle sem leguminosas. O milho foi utilizado como cultura teste. As leguminosas foram podadas a 50 cm do solo e seus resíduos foram adicionados à superfície e em seguida o milho foi semeado. Todas as amostras do solo do experimento em aleias apresentaram valores baixos de pH. Houve diferenças estatísticas entre os tratamentos para a MOS. Os maiores teores foram encontrados no tratamento leucena+sombreiro (L+S), mas não influenciou nos estoque de carbono das Frações Leve Livre (FLL), Frações Intra-agregadas (FLI) e Matéria Orgânica Particulada (MOP) da MOS, que não apresentaram diferença estatística. Por conseguinte, após o corte das aleias, a maior parte do P foi encontrada numa forma inorgânica, e também foi encontrada nas frações moderadamente e dificilmente lábeis. Os resultados indicam que as frações de P e matéria orgânica são importantes indicadores para avaliar mudanças no grau de degradação da terra nos trópicos úmidos. Estes resultados indicam também que o uso intensivo e contínuo das culturas anuais nos solos das regiões da Amazônia sem nenhuma prática conservacionista pode ser considerado como um risco elevado para a sustentabilidade dos agrossistemas, principalmente por causa do aumento da acidez ativa e potencial, a redução da matéria orgânica lábil e o esgotamento dos pools de P orgânico, levando à degradação do solo. A fertilidade do solo, propriedades físicas e P disponível são responsáveis pela variabilidade da degradação do solo. Considerando-se que os pequenos agricultores respondem por 70% da produção agrícola no país, a adoção do manejo sustentável dos solos cultivados, geralmente de baixa fertilidade natural com sistema em aleias de leguminosas é uma alternativa para a agricultura com benefícios socioeconômicos e ambientais.

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Milne, Eleanor. "Soil conservation in relation to maize productivity on sub-tropical red soils in Yunnan Province, China." Thesis, University of Wolverhampton, 2001. http://hdl.handle.net/2436/93882.

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Agricultural land in China is being degraded, with soil erosion becoming an increasing problem. In Yunnan Province, south-west China, there is a long history of soil erosion due to soil type, climate, anthropogenic influence and because 95% of the Province is mountainous. Population pressure and lack of flat land necessitate cultivation of steep slopes. The Yunnan Government prohibits cultivation of slopes >25°, however policy enforcement would result in food shortages in the Province, due to a lack of suitable land <25°. Therefore, the most appropriate way to curb soil erosion in Yunnan is to devise affordable agronomic means of reducing soil loss, which do not decrease crop productivity on sloping land currently under cultivation. At present, very little research has addressed these issues. A research project, building on existing work from 1993-1996, was initiated in 1998. The aim was to test the hypothesis that contour cultivation and contour cultivation plus straw mulch decrease runoff and soil erosion rates on sloping land in Yunnan Province under maize cultivation and to assess the impact of these conservation measures on maize productivity and soil nutrient status. Thirty runoff plots, located on three different slope angles (I 3°, II 10° and III 27°), in three groups of 10, were used to examine three cropping treatments in a replicated plot design in 1998 and 1999. Treatments were downslope cultivation (control), contour cultivation and contour cultivation plus straw mulch. In addition, there was an unreplicated bare plot in each group. Runoff and soil loss were measured on a storm-by-storm basis. Soil nutrient status was measured at the beginning and end of each cropping season. Crop growth parameters and soil physical properties were measured throughout the cropping seasons (21/05–7/10 in 1998 and 22/05–2/10 in 1999). In 1998, seasonal rainfall was 1024 mm, ~28% greater than the 30-year mean. Soil loss was significantly reduced by contour cultivation on Slopes I and II. On Slope I, downslope cultivation produced 3.07 t ha-1 soil loss and contour cultivation reduced this by 81.4 %. On Slope II, downslope cultivation produced 19.11 t ha-1 and contour cultivation reduced this by 58.0%. The addition of straw mulch gave a further, nonsignificant, reduction on both slopes. On Slope III, downslope cultivation and contour cultivation produced 6.92 and 6.29 t ha-1 of soil loss, respectively, with contour cultivation plus straw mulch having 99.4% less erosion than downslope cultivation. In the much drier 1999 season, no treatment significantly reduced soil loss on Slope I. Contour cultivation significantly reduced soil loss on Slopes II and III. On Slope II, downslope and contour cultivation produced 11.52 t ha-1 of soil loss and contour cultivation reduced this by 85.8%. On Slope III, downslope and contour cultivation produced 8.62 and 0.23 t ha-1, respectively; a reduction of 97.3% by contour cultivation. The addition of straw mulch did not further decrease soil loss. Treatment effects on soil nutrient status varied between the two years. At the end of the 1998 season, there was significantly higher soil available N under contour cultivation plus straw mulch on all three slopes (Slopes I and II P <0.001, Slope III P <0.05), an effect that was not found in 1999. At the end of the 1999 season, soil available K was significantly (P <0.001) higher under contour cultivation plus straw mulch on Slope III. In both years, contour cultivation plus straw mulch significantly reduced soil temperature. However, this did not result in yield reductions in comparison with the control. There was an increase in soil moisture content under contour cultivation plus straw mulch during dry periods, which was particularly noticeable in 1999. In 1998, there were no significant treatment effects on grain or shoot yield. In 1999, on Slope II, contour cultivation plus straw mulch significantly increased grain yield by 50.3% compared with the downslope treatment (P <0.05). In 1999, contour cultivation plus straw mulch also significantly increased leaf plus stem yield on Slopes I and II by 12.4 and 36.8%, respectively. It is concluded that on ≤10° slopes, contour cultivation alone is a suitable soil conservation measure. However, use of straw mulch would benefit soil moisture and nutrient status and could, therefore, increase crop yield. On ≥27° slopes, it is recommended that contour cultivation plus straw mulch be used as a soil conservation measure to ensure maximum soil conservation, even in extreme rainfall conditions.

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Arevalo-Mendez, Ignacio. "Soil conservation with leguminous cover crops following deforestation of tropical steepland." Thesis, Loughborough University, 1998. https://dspace.lboro.ac.uk/2134/33228.

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The steeplands of Central America are being systematically deforested as population pressure dictates a need for an increase in subsistence agriculture. The combined effect of high rainfall and lack of conservation measures leads to high levels of soil erosion. In order to assess sustainable soil conservation technology, research was conducted in the mountainous agricultural area of Guinope, Honduras. Runoff and soil loss from a number of plots that were established on various ground slopes and under different land uses were measured during the 1994 and 1995 seasons. Natural and fired woodland were assessed to provide an indication of both baseline conditions and those associated with the initial stage of deforestation. Against these, the impacts of agriculture involving maize - Zea mays L.- with and without two leguminous cover crops - Mucuna sp. and Canavalia ensiformis (l)DC. - were assessed on ground sloping at 6, 11 and 18 degrees. Seasonal runoff under natural pine forest is shown to be 10 % that of maize agriculture on similar slopes while fired forest is 49 %. Of the cover crops, after a second year Mucuna is the most protective when intercropped with maize, giving runoff on 18 degree slopes which is 47 % that of maize grown by itself, compared with 51 % for Canavalia. On 11 degree slopes, Canavalia offers greater protection but here the difference between the two cover crops is marginal Soil erosion can be shown to be a function of ground slope. For maize grown by itself, soil losses from 6 and 11degree slopes are 13 % and 23 % those from 18 degree slopes. On two years of research Canavalia is more stable in giving protection. On 18 degree slopes, soil loss where Mucuna is intercropped is 43 % that under maize alone while for Canavalia it is 47 %. By comparison, the natural forest loses much less than 1 % that of the maize fields. This study clearly shows the vulnerability of steep lands that are being clear-felled. It also demonstrates the considerable advantages of using extensive green soil conservation technology in reducing soil erosion and prolonging the usefulness of land. This extends to relieving the pressure on virgin forest in a situation where population growth discourages long periods fallow as part of a form of shifting cultivation.

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Barton, Andrew P. "Soil erosion and conservation on arable sub-tropical ultisols in Yunnan province, China." Thesis, University of Wolverhampton, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310709.

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Mulengera, Matthew Kagorobha. "Soil loss prediction in the semi-arid tropical savanna zone : a tool for soil conservation planning in Tanzania." Thesis, University of Newcastle Upon Tyne, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318175.

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Gonçalves, Daniel Ruiz Potma. "Soil carbon balance in long-term no-till in a sub-tropical environment." Universidade Estadual de Ponta Grossa, 2018. http://tede2.uepg.br/jspui/handle/prefix/2525.

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Solos podem ser uma fonte ou um dreno de CO2 atmosférico, dependendo do seu sistema de manejo. Atualmente, o uso do solo e mudança de uso do solo emitem 1,3 ± 0,5 Pg C ano-1, equivalente a 8% das emissões globais. Técnicas como a agricultura de baixa emissão de C têm sido desenvolvidas para sequestrar C nos solos e reduzir a emissão de gases do efeito estufa. Porém, além dos desafios políticos e sociais envolvendo a doção destes sistemas, ainda há muita incerteza sobre o seu real potencial de mitigação. Assim, os objetivos desse estudo foram: i) Quantificar as fontes históricas e atuais de emissão de gases do efeito estufa na região dos Campos Gerais do Paraná, Brasil; ii) quantificar o potencial das melhores práticas de manejo agrícola baseadas nos três pilares da agricultura de conservação: Solo permanentemente coberto, plantio direto e rotação de culturas, em longo prazo (30 anos) para sequestrar carbono no solo, utilizando a fazenda Paiquerê (localizada na região dos Campos Gerais) como um modelo de sucesso; iii) estimar o impacto da adoção das melhores práticas de manejo nas áreas agrícolas da região e globalmente onde adequadas pelos próximos 100 anos utilizando os modelos Century e Roth-C. As fontes de gases do efeito estufa foram apresentadas como um inventário e mostraram que as emissões históricas (1930 – 2017) foram 412,18 Tg C, no qual as mudanças de uso do solo contribuíram com 91% (376,2±130 Tg C). As florestas sequestraram 51.7 ± 23.9 Tg C em 0.6 Mha em 47 anos (1.8 Tg C Mha-1 ano-1) e o plantio direto sequestrou 30.4 ± 23.9 Tg C em 1.9 Mha em 32 anos (0.5 Tg C Mha-1 ano-1). Ambos os modelos tiveram uma boa performance e o modelo Century foi mais eficiente em simular os estoques de carbono do solo, o resíduo médio da simulação foi 10 Mg C ha−1 (13%) para n = 91. O resíduo do modelo aumentou com a quantidade de óxidos no solo, sugerindo que a inclusão do controle mineralógico pode reduzir o viés de simulação. As predições do Century mostraram que o sistema tem potencial para mitigar 13 anos de emissões regionais (330 Tg C em 100 anos) ou 105 anos de emissões do setor agricultura, floresta e pecuária (40 Tg em 100 anos) na região. Da mesma forma, globalmente o sistema apresenta um potencial para sequestrar 2,5 ± 0.02 Pg C na profundidade 0–20 cm e 11,7 ± 3 Pg C na profundidade 0-100 cm em 86 milhões de ha distribuídos por todo o mundo. Este valor é equivalente à 11% das emissões globais dos setores agricultura, floresta e pecuária e mudanças de uso do solo. Assim, a nossa metodologia possa ser utilizada como um modelo para divulgar o potencial da agricultura conservacionista em sequestrar C nos solos e suportar políticas públicas que visem à mitigação das emissões de gases do efeito estufa.
Soils can be a source or sink of atmospheric CO2, according to land use and management. Currently the land use and land use change (LULUC) emits 1.3 ± 0.5 Pg carbon (C) year-1, equivalent to 8% of the global annual emission. Techniques such as low carbon agriculture, has been developed to sequester C in soils and reduce greenhouse gas (GHG) emissions. However, besides political and social challenges for the system adoption, there’s still great uncertainty related to its real mitigation potential. This study aimed: i) Quantify the historical and current main sources of GHG emissions for Campos Gerais region in Paraná state, Brazil; ii) quantify the potential of long term (30 years) agricultural best management practices, based on the three pillars of conservative agriculture: permanent soil cover, crop rotation and no-till, to sequester C in soils, using Paiquerê farm (located in Campos Gerais region) as a successful model; iii) estimate the impact of best management practices adoption in the region croplands and globally for the next 100 years where is suitable using Century and Roth-C models. The GHG emission sources were presented as an inventory and showed that historical (1930 – 2017) GHG emissions in the region was 412.18 Tg C, in which LULUC contributes 91% (376.2±130 Tg C). Forestry sequestered 51.7 ± 23.9 Tg C in 0.6 Mha in 47 years (1.8 Tg C Mha-1 year-1) and no-till sequestered 30.4 ± 23.9 Tg C in 1.9 Mha in 32 years (0.5 Tg C Mha-1 year-1). Both models performed well, and Century was more efficient for simulate the SOC stocks, the mean residue was 10 Mg C ha−1 (13%) for n = 91. The model residue increased along with the oxides content in the soil clay fraction, suggesting that mineralogical control inclusion can reduce the model simulation bias. Century predictions showed that the system currently practiced at Paiquerê farm have the potential to mitigate 13 years of regional total emissions (330 Tg C in 100 years) or 105 years of agriculture, forestry and other land use (AFOLU) sector emissions (40 Tg in 100 years) in the region. In the same way, it has the potential to sequester 2.5±0.02 Pg C at 0-20 cm and 11.7±3 Pg C at 0-100 cm soil depth in 86 million ha globally. This is equivalent to 11% of global annual emissions from LULUC sector. In this way, our methodology can be used as a model to access the potential of conservation agriculture to sequester C and support public policies aiming to mitigate GHG emissions.

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NISTI, MARCELO B. "Lixiviação de metais e radionuclídeos em solos tropicais condicionados com fosfogesso." reponame:Repositório Institucional do IPEN, 2016. http://repositorio.ipen.br:8080/xmlui/handle/123456789/27137.

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O fertilizante fosfatado brasileiro é obtido pela reação por via úmida da rocha fosfática de origem ígnea com ácido sulfúrico concentrado, obtendo como produto final, o ácido fosfórico e como resíduo, o fosfogesso, que é estocado em pilhas, a céu aberto, junto às instalações produtoras. Parte do fosfogesso vem sendo utilizada na agricultura como condicionador de solos, devido a sua alta solubilidade, podendo melhorar a estrutura do solo, reduzir a erosão do solo, aumentar os níveis de enxofre e fósforo disponíveis e melhorar a composição dos fertilizantes. Mas a presença de radionuclídeos e metais no fosfogesso impõem restrições sobre o uso na agricultura. Para garantir uma utilização segura, é importante estimar a lixiviação dos radionuclídeos e metais presente no fosfogesso. O objetivo deste trabalho foi estudar a disponibilidade dos radionuclídeos relevantes do ponto de vista radiológico (238U, 232Th, 226Ra, 228Ra, 210Pb e 210Po) e dos metais (As, Cd, Cr, Ni, Se, Hg e Pb) presentes no fosfogesso de procedência brasileira, levando em consideração sua aplicação em solo agricultável. Para esta finalidade, foi desenvolvido um protocolo experimental em escala de laboratório, no qual colunas foram preenchidas com misturas de solos arenosos e argilosos típicos brasileiros condicionados com fosfogesso. A essas colunas foi adicionada água, a fim de se alcançar uma extração branda desses elementos. Foi implantado um procedimento analítico para a determinação sequencial dos radionuclídeos de interesse na solução obtida na lixiviação. As frações disponíveis foram obtidas utilizando-se a razão entre as concentrações dos radionuclídeos no lixiviado e as concentrações dos radionuclídeos nas amostras de solo, solo condicionado com fosfogesso e fosfogesso. Os valores de concentração dos radionuclídeos 238U, 232Th, 226Ra, 228Ra, 210Pb e 210Po obtidos no fosfogesso das duas procedências variaram de 86 Bq kg-1 a 352 Bq kg-1. As concentrações de 226Ra e 228Ra obtidas no fosfogesso ficaram abaixo do limite máximo permitido pela resolução da Comissão Nacional de Energia Nuclear, atendendo às condições necessárias para o seu uso na agricultura. Os resultados obtidos para os metais As, Cd, Cr, Ni, Pb, Se e Hg no fosfogesso foram inferiores ao limite máximo para condicionador de solo e para fertilizantes estabelecidos pelo Ministério da Agricultura, Pecuária e Abastecimento, atendendo às condições necessárias para o seu uso na agricultura. Os radionuclídeos 226Ra, 210Pb, 210Po e 228Ra apresentaram frações disponíveis nos solos e solos condicionados com fosfogesso variando de 0,05% a 1,2%; para o 238U e 232Th as frações disponíveis apresentaram valores inferiores a 0,05%. Os metais apresentaram frações disponíveis nos solos e solos condicionados com fosfogesso variando de 0,05% a 1,07%. Os resultados obtidos para a fração disponível de metais e radionuclídeos no solo condicionado com fosfogesso demostraram que mesmo utilizando concentrações de fosfogesso dez vezes acima da dose recomendada, a disponibilização foi desprezível. Pode-se concluir que a utilização do fosfogesso como condicionador de solos é viável, no que concerne a disponibilidade dos metais e radionuclídeos estudados.
Tese (Doutorado em tecnologia Nuclear )
IPEN/D
Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP

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Razafimbelo, Tantely. "Stockage et protection du carbone dans un sol ferrallitique sous systèmes en semis direct avec couverture végétale des Hautes Terres malgaches." Phd thesis, Ecole nationale superieure agronomique de montpellier - AGRO M, 2005. http://tel.archives-ouvertes.fr/tel-00772088.

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Stocker du carbone (C) dans le sol représente à la fois des enjeux agronomiques (amélioration des propriétés physico-chimiques du sol) et environnementaux (réduction de la quantité de C02 atmosphérique). A Madagascar, le stockage et la protection de C dans le sol, sous systèmes de culture en semis direct avec couverture végétale (SCY) sont étudiés sur un dispositif de longue durée (11 ans) de la région d'Antsirabe, Hautes Terres malgaches). Quatre systèmes sont étudiés: un système en labour conventionnel (Conventional-tillage) [CT mis, rotation maïs {Zea mays L.)-soja (Glycine max. L.)]. et trois systèmes en SCY sans travail du sol (No-tillage, NT) [NT mis, rotation maïs-soja; NT rn/m-d. rotation maïs-maïs avec une couverture végétale de Desmodium uncinatum ; et NT h/s-k. rotation haricot (Phaseolus vulgaris)-soja avec une couverture de Pennissetum c/andestinum]. Les résidus de récoltes sont exportés de la parcelle pour CT mis alors qu'ils sont restitués pour les NT. Les résultats montrent des teneurs en C significativement plus élevées sous systèmes NT par rapport à CT à 0-5 et 5-10 cm de profondeur. Au-delà de 10 cm de profondeur. les deux modes de gestion ne sont plus différents. Les valeurs de stocks de C à masse équivalente indiquent des stockages annuels élevés pour les systèmes NT étudiés. de 0.7 à 1,0 Mg C.haI.anI pour la couche de 0-20 cm. Ce stockage annuel élevé sous systèmes NT est en grande partie attribué à l'importante quantité de biomasse restituée par ces systèmes. par rapport au système labouré. Les teneurs en C élevées sous NT s'accompagnent d'une teneur élevée en macroagrégats (MA) stables à l'eau, de 16 à 33 % plus élevée par rapport à CT, à 0-5 et 5-10 cm. Ces macroagrégats stables contribuent à plus de 80 % à la différence de teneur en Centre systèmes NT et CT. Ceci pourrait induire une protection physique du C se trouvant à l'intérieur des agrégats contre la minéralisation microbienne. Les fractionnements granulo-densimétriques effectués sur ces échantillons permettent de localiser le C stocké sous NT. A 0-5 cm, 30 à 40 % du C stocké sont associés aux matières organiques particulaires internes aux agrégats stables (MOPi) de taille supérieure à 50 urn et 40 à 60 % aux fractions fines de taille inférieure à 50 urn, A 5-10 cm, 60 à 90 % du C stocké sont localisés dans les fractions fines " 50 urn) du sol. Si la matière organique associée aux fractions fines du sol est protégée physico-chimiquement contre la minéralisation microbienne par son adsorption sur les particules minérales du sol. les MOPi sont protégées physiquement par leur emprisonnement à l'intérieur des agrégats. Par ailleurs, la déprotection de ces MOPi, par broyage grossier " 200 urn) du sol total ou par broyage fin " 50 urn) des macro- et mésoagrégats, ne révèle. qu'une faible quantité de C protégé physiquement (de 26,2 à 54,0 I-lgC.g-1 sol). Ceci pourrait s'expliquer par le fait que ces MOPi, comme le montrent les observations au microscopie électronique à balayage, sont recouvertes et imprégnées de fractions fines qui les protègent physico-chimiquement contre la minéralisation microbienne malgré la destruction des agrégats. En conclusion. pour le sol argileux considéré ici, les systèmes SCY testés s'avèrent très efficaces pour stocker du C dans le sol. Ce C stocké est relativement stabilisé puisqu'H est protégé, au moins physico-chimiquement. contre la minéralisation microbienne.

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Benavides, Francisco. "Policy alternatives for balancing conservation and agricultural expansion in the tropics." 2005. http://digital.library.okstate.edu/etd/umi-okstate-1541.pdf.

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Книги з теми "Soil conservation Tropics"

Manrique, Luis A. Soil management and conservation in the tropics. Honolulu, Hawaii: Manrique International Agrotech, 1993.

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Lal, R. Soil erosion in the tropics: Principles and management. New York: McGraw-Hill, 1990.

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Sheng, Ted C. Soil conservation for small farmers in the humid tropics. Rome: Food and Agriculture Organization of the United Nations, 1989.

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Kerr, John M. Indigenous soil and water conservation in India's semi-arid tropics. London: International Institute for Environment and Development, 1993.

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Williams, Gerald G. Soil and water conservation for small farm development in the tropics. Washington, D.C: Peace Corps, Information Collection and Exchange, 2000.

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Sustainable management of soil resources in the humid tropics. Tokyo: United Nations University Press, 1995.

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Tamin, Noraini M. An annotated field guide to tropical eco-engineering. Kuala Lumpur: Institute of Ocean and Earth Sciences, University of Malaya, 2008.

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Milne, Eleanor. Soil conservation in relation to maize productivity on sub-tropical red soils in Yunnan Province, China. Wolverhampton: University of Wolverhampton, 2001.

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Barton, Andrew P. Soil erosion and conservation on arable sub-tropical ultisols in Yunnan Province, China. Wolverhampton: University of Wolverhampton, 2000.

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Taller Internacional Regional Hacia Conceptos Integrales en la Conservación de Suelos y Aguas en la Zona Andina (1997 Centro Internacional de Agricultura Tropical). Conservación de suelos y aguas en la zona andina: Hacia el desarrollo de un concepto integral : memorias del Taller Internacional Regional Hacia Conceptos Integrales en la Conservación de Suelos y Aguas en la Zona Andina, celebrado en el Centro Internacional de Agricultura Tropical, en octubre de 1997. Cali, Colombia: Centro Internacional de Agricultura Tropical, 1999.

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Частини книг з теми "Soil conservation Tropics"

Siyag, Panna Ram. "Soil and Water Conservation Works." In Afforestation, Reforestation and Forest Restoration in Arid and Semi-arid Tropics, 91–107. Dordrecht: Springer Netherlands, 2013. http://dx.doi.org/10.1007/978-94-007-7451-3_5.

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Lal, R. "Effective Conservation Farming Systems for the Humid Tropics." In Soil Erosion and Conservation in the Tropics, 57–76. Madison, WI, USA: American Society of Agronomy and Soil Science Society of America, 2015. http://dx.doi.org/10.2134/asaspecpub43.c4.

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El-Swaify, S. A., and E. W. Dangler. "Rainfall Erosion in the Tropics: A State-of-the-Art." In Soil Erosion and Conservation in the Tropics, 1–25. Madison, WI, USA: American Society of Agronomy and Soil Science Society of America, 2015. http://dx.doi.org/10.2134/asaspecpub43.c1.

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Sheng, T. C. "Erosion Problems Associated with Cultivation in Humid Tropical Hilly Regions." In Soil Erosion and Conservation in the Tropics, 27–39. Madison, WI, USA: American Society of Agronomy and Soil Science Society of America, 2015. http://dx.doi.org/10.2134/asaspecpub43.c2.

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Dunne, Thomas, and William Dietrich. "Sediment Sources in Tropical Drainage Basins." In Soil Erosion and Conservation in the Tropics, 41–55. Madison, WI, USA: American Society of Agronomy and Soil Science Society of America, 2015. http://dx.doi.org/10.2134/asaspecpub43.c3.

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Schiller, John M., Chaiyasit Anecksamphant, and Suwit Sujanin. "Development of Areas of Shifting Cultivation in North Thailand “Thai-Australia Land Development Project”." In Soil Erosion and Conservation in the Tropics, 77–96. Madison, WI, USA: American Society of Agronomy and Soil Science Society of America, 2015. http://dx.doi.org/10.2134/asaspecpub43.c5.

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Sanchez, Pedro A. "A Legume-based, Pasture Production Strategy for Acid Infertile Soils of Tropical America." In Soil Erosion and Conservation in the Tropics, 97–120. Madison, WI, USA: American Society of Agronomy and Soil Science Society of America, 2015. http://dx.doi.org/10.2134/asaspecpub43.c6.

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Hudson, N. W. "Soil Conservation Research and Training Requirements in Developing Tropical Countries." In Soil Erosion and Conservation in the Tropics, 121–33. Madison, WI, USA: American Society of Agronomy and Soil Science Society of America, 2015. http://dx.doi.org/10.2134/asaspecpub43.c7.

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Foster, G. R., W. C. Moldenhauer, and W. H. Wischmeier. "Transferability of U.S. Technology for Prediction and Control of Erosion in the Tropics." In Soil Erosion and Conservation in the Tropics, 135–49. Madison, WI, USA: American Society of Agronomy and Soil Science Society of America, 2015. http://dx.doi.org/10.2134/asaspecpub43.c8.

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Powlson, David S., Penny R. Hirsch, and Philip C. Brookes. "The role of soil microorganisms in soil organic matter conservation in the tropics." In Managing Organic Matter in Tropical Soils: Scope and Limitations, 41–51. Dordrecht: Springer Netherlands, 2001. http://dx.doi.org/10.1007/978-94-017-2172-1_5.

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Тези доповідей конференцій з теми "Soil conservation Tropics"

Russo, Wanderley Camargo, Alcindo Pereira dos Santos Filho, Celso Rodrigues da Silveira Filho, Cláudio dos Santos Amaral, Maurício Martines Sales, Carlos Alberto Lauro Vargas, Patrícia de Araújo Romão, and Diego Tarley Ferreira Nascimento. "Susceptibility to Erosion of Pipeline Rights-of-Way in Tropical Soils: Case of a Brazilian Pipeline." In ASME 2013 International Pipeline Geotechnical Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/ipg2013-1935.

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TRANSPETRO is responsible, among other activities, by operation and maintenance of pipelines throughout Brazil. Particularly in the Midwest region the company operates the OSBRA pipeline, which moves about 8.7 Mm3/years of fuel and covers approximately 1,000 km long, predominantly in tropical soils. Erosive processes are significant and constitute the main geotechnical occurrence in OSBRA pipelines rights-of-way. In order to identify the susceptibility to erosion of the area close to the pipelines were developed basic thematic maps, that overlaid will help in identifying homogeneous zones in terms of existing material susceptibility. The mapping is being accompanied by an extensive endeavor of field inspections along the pipeline rights-of-way, that comprised geotechnical investigations, verifying the conditions of use and soil management, the conservation status of existing drainage works and geotechnical characterization of soil samples of major geological formations, including erodibility tests. The methodology is being developed in ArcGIS frame, starting from the morphometric analysis and the use of Digital Elevation Models (DEM), aiming to understanding superficial flow conditions (acceleration and concentration) and consequent soil loss. The modeling results will be compared with historical occurrences erosive 15 (fifteen) years of pipeline operation, seeking for an adherence on various geological, topographical and meteorological tested. The methodology will improve further procedures for identifying potential erosions in tropical soils and will allow to anticipating preventive maintenance in the most susceptible locals the pipeline rights-of-way, suggesting mitigation measures best suited for each type of potential erosive mechanism.

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Odina, Lanre, and Roger Tan. "Seismic Fault Displacement of Buried Pipelines Using Continuum Finite Element Methods." In ASME 2009 28th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2009. http://dx.doi.org/10.1115/omae2009-79739.

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In deep waters, pipelines are usually installed exposed on the seabed, as burial is generally not required to ensure on-bottom stability. These exposed pipelines are nevertheless susceptible to seismic geohazards like slope instability at scarp crossings, soil liquefaction and fault movements which may result in failure events, although larger diameter pipelines are generally known to have good tolerances to ground deformation phenomena, provided the seismic magnitudes are not too onerous. Regardless of the pipeline size, these seismic geohazard issues are usually addressed during the design stage by routing the pipeline to avoid such hazardous conditions, where possible. However, extreme environmental conditions like hurricanes or tropical cyclones, which are typically experienced in the Gulf of Mexico and Asia-Pacific regions, are also factors which can cause exposed pipelines to be susceptible to large pipeline displacements and damage. Secondary stabilisation in the form of rock dump is sometimes employed to reduce the hydrodynamic loads from high turbidity currents acting on the pipeline. However, rock dumping (or burying the displaced pipeline) on a fault line could again pose a threat to its integrity following a seismic faulting event. The traditional method of assessment of a buried pipeline subjected to seismic faulting is initially carried out using analytical methods. Due to the limitations of these techniques for large deformation soil movement associated with fault displacement, non-linear finite element (FE) methods are widely used to assess the pipeline integrity. The FE analysis typically idealises the pipeline using discrete structural beam-type elements and the pipeline-soil interaction as discrete non-linear springs, based on the concept of subgrade reactions proposed by Winkler. Recent research from offshore pipeline design activities in the arctic environment for ice gouge events have however suggested that the use of the discrete Winkler element model leads to over-conservative results in comparison to the coupled continuum model. The principal reason for the conservatism is related to the poor modeling of realistic surrounding soil behaviour for large deformation events. This paper discusses the application of continuum FE methods to model the fully coupled seabed-buried pipeline interaction events subject to ground movements at active seismic faults. Using the continuum approach, a more realistic mechanical response of the pipeline is established and can be further utilised to confirm that calculated strains are within allowable limits.

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