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Carbono no solo em sistemas integrados de produção agropecuária no Cerrado e na transição Cerrado - Amazônia / Soil carbon under integrated agricultural production systems in the Brazilian savannah (Cerrado) and in the Cerrado-Amazon transition zoneOliveira, Janaína de Moura 26 June 2015 (has links)
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Previous issue date: 2015-06-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Integrated crop-livestock (iCL) and integrated crop-livestock-forest (iCLF)
systems are pointed out as potential soil carbon sinks. However, there are few scientific
studies that evaluated the real contribution of these production systems. This work
included two studies. The first was to evaluate soil carbon accumulation and its origin in
iCLF in the transition zone of the Cerrado-Amazon biomes; the second aimed to calibrate
and validate the CQESTR model for the Cerrado ecosystem and to evaluate the effect of
soil management practices, including iCL and various scenarios on soil organic carbon
(SOC) over time. For the first study two areas under iCLF (iCLF1 and iCLF3, with one
and three rows of Eucalyptus urograndis by hedgerow, respectively) were selected. They
were cultivated in this system since 2009 in Nova Canaã do Norte, MT. A continuous
pasture was used as reference. Soil samples were taken from eight layers (0.0 to 1.0 m) for
the evaluation of the bulk density, texture, total C and N and δ¹³C. The second study was
conducted in the Cerrado biome. The evaluated areas (Paddock 4 - P4 and Paddock 5 - P5
has been being managed in iCL since 2000. Bulk density and the organic matter content
were determined for the 0.0-0.1 and 0.1-0.3 m layers. The CQESTR is a process based
model which simulates the effect of climate, crop rotation and tillage management
practices on SOC. The model was calibrated with P5 data and validated with P4 data. Its
performance was evaluated using statistical regression analysis and the root mean square
deviation (MSD). For the first study, the soil C stocks and isotopic composition were
affected by the implementation of the iCLF system. The forest component was an
important factor for soil C accumulation for both areas under iCLF. The N can be a
limiting factor for C accumulation. We concluded that iCLF affected soil C and N stocks in
the short term, however, longer iCLF deployment time would be necessary to elucidate the
impact of iCLF in the long-term. In the second study model calibration was performed by
adjusting the basic decomposition rate coefficient. The measured and simulated values
were significantly correlated with an MSD of 2.11, indicating that the model captured
spatial-temporal dynamics of SOC in the topsoil. However, CQESTR underestimated SOC
for the 0,1-0,3 m layer, probably due to lack of site specific grass or crop root biomass and
distribution data under tropical conditions. Additional calibration is required to improve
prediction of SOC stabilization process in the subsoil layers of tropical soils. In the long
term (20 years), for the superficial (0,0-0,1 m) soil layer, the model simulated C
accumulation in iCL and C loss in soybean/corn grain production system independently of
the use of zero-tillage or conventional tillage in either of these systems under Cerrado
conditions. / Os sistemas de integração lavoura-pecuária (iLP) e integração lavourapecuária-
floresta (iLPF) são apontados como potenciais acumuladores de carbono no solo.
Entretanto, ainda há poucos estudos científicos que avaliaram a real contribuição desses
sistemas de produção. O presente trabalho incluiu dois estudos para avaliação desses
sistemas. O primeiro teve por objetivo avaliar a acumulação e a origem do carbono do solo
em iLPF na região de transição dos biomas Cerrado-Amazônia; e o segundo estudo teve
por objetivo calibrar e validar o modelo CQESTR para o ecossistema Cerrado bem como
avaliar o efeito de práticas de manejo do solo, incluindo iLP e vários cenários no carbono
orgânico do solo (COS) ao longo do tempo. Para o primeiro estudo foram selecionadas
duas áreas sob iLPF (iLPF1 e iLPF3, sistemas com uma linha e três linhas de Eucalyptus
urograndis por renque, respectivamente) cultivadas nesse sistema desde 2009 e uma
pastagem no município de Nova Canaã do Norte, MT. Amostras de oito camadas (0,0-1,0
m) foram tomadas para avaliação da densidade, textura, teor de C e N total e δ¹³C. O
segundo estudo foi conduzido no bioma Cerrado, em área que vem sendo manejada em iLP
desde 2000. Foram avaliadas duas áreas, os Piquete 4 (P4) e Piquete 5 (P5). A densidade
do solo e o teor de matéria orgânica foram determinados para as camadas 0,0-0,1 e 0,1-0,3
m. O CQESTR é um modelo de simulação de C baseado em processos que simula o efeito
do clima, rotações de cultura e práticas de manejo no COS. O modelo foi calibrado com
dados do P5 e validado com P4. Seu desempenho foi avaliado usando análise estatística de
regressão e o desvio médio quadrático (MSD). No primeiro estudo, a composição isotópica
do solo e os estoques de C foram afetados pela implantação do sistema iLPF. O
componente florestal foi importante fator na acumulação de C em ambas as áreas sob
iLPF. O N pode ser um fator limitante para a acumulação de C. Conclui-se que o iLPF
afeta os estoques de C e N do solo no curto prazo, entretanto, novas avaliações com maior
tempo de implantação do iLPF poderiam auxiliar na elucidação do comportamento desses
elementos no sistema em longo prazo. No segundo estudo, a calibração do modelo foi
realizada pelo ajuste do coeficiente da taxa de decomposição básica. Os valores simulados
e medidos foram significativamente correlacionados com um MSD de 2,11, indicando que
o modelo capturou satisfatoriamente a dinâmica temporal do COS na camada superficial.
Entretanto, o CQESTR subestimou o COS para a camada subsequente 0,1-0,3 m,
provavelmente devido às diferenças na biomassa e distribuição de raízes de gramíneas de
clima tropical e temperado. Calibração adicional é requerida para melhorar a predição do
COS e processos de estabilização nas camadas subsuperficiais de solos tropicais. Para a
camada 0,0-0,1 m, em longo prazo (20 anos), o modelo simulou acumulação de C em iLP e
decréscimo de C em sistema de produção com sucessão soja/milho, tanto sob plantio direto
quanto preparo convencional em condições do Cerrado.
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Recycling of wood- and peat-ash – a successful way to establish full plant cover and dense birch stand on a cut-away peatlandHuotari, N. (Noora) 18 October 2011 (has links)
Abstract
Mechanical harvesting of peat changes the original mire ecosystem completely, and without active measures these areas may remain non-vegetated even for decades. Afforestation is one of the most popular after-use options for cut-away peatlands in Finland since it has both economic and aesthetic values. Recycling of wood-ash as a fertilizer has been studied extensively in peatlands drained for forestry. Wood-ash is reported to promote tree growth in these areas without any significant negative impact to the environment and could, therefore, be a suitable option also on cut-away peatlands. However, the environmental effects of ash-fertilization on cut-away areas and on ground vegetation are not fully understood.
The impact of wood- and peat-ash application on the early establishment of ground vegetation and downy birch (Betula pubescens) seedlings and on post-fertilization element concentrations in plants and peat substrate were studied in a cut-away peatland. Six treatments of wood-ash, peat-ash, biotite or Forest PK-fertilizer were replicated in three blocks in different mixtures and quantities corresponding to 50 kg ha-1 of phosphorus.
All the fertilizers accelerated the revegetation of the bare peat surface significantly, whereas the establishment of plants in the unfertilized area was non-existent even several years after the peat harvesting had ceased. The most striking difference between the wood- and peat-ash-fertilizers and the commercial Forest PK-fertilizer was the extensive coverage of fire-loving moss species in all the areas where ash was spread. Wood- and peat-ash application also accelerated the germination and early establishment of downy birch seedlings more efficiently than the PK-fertilizer. Ground vegetation proved to be highly important in increasing the early biomass production and carbon sequestration on ash-fertilized cut-away peatland. In addition, the below-ground biomass was equal to the above-ground biomass, or even greater.
Both wood- and peat-ash fertilization ensured an adequate level of nutrients for the early establishment of ground vegetation and birch seedlings in a cut-away peatland. The mosses and herbaceous plants proved to have a major role in retaining the nutrients and heavy metals that otherwise might have leached away from the ash-fertilized cut-away site during the early stages of the afforestation. Although both wood- and peat-ash proved to be suitable for the initial fertilization of afforested cut-away peatlands, a later application of nutrients may be needed to guarantee the growth in a energy-wood stand of downy birch over its entire rotation. / Tiivistelmä
Turvetuotannon päätyttyä jäljelle jäävä suopohja on aluksi täysin paljas ja vailla maaperän siemenpankkia. Kasvipeitteen luontainen uudistuminen voi viedä jopa vuosikymmeniä. Ympäristönhoidollisesti onkin tärkeää, että suopohjat otetaan uuteen käyttöön mahdollisimman nopeasti tuotannon päätyttyä. Metsitys on tällä hetkellä suosituin suopohjien jälkikäyttömuoto Suomessa. Suopohjan turpeessa on tyypillisesti runsaasti typpeä, mutta niukasti muita kasvuun tarvittavia ravinteita. Puutuhka on osoittautunut pitkäaikaisissa metsäojitettujen turvemaiden tutkimuksissa kilpailukykyiseksi vaihtoehdoksi kaupallisille lannoitteille. Energiantuotannon sivutuotteena syntyvä puu- ja turvetuhka voisi soveltua hyvin myös suopohjien lannoitteeksi. Tuhkan käytöstä lannoitteena turvetuotannosta vapautuneilla suopohjilla ei kuitenkaan ole riittävästi tutkimustietoa.
Tässä työssä tutkittiin puu- ja turvetuhkan vaikutuksia turvetuotannosta vapautuneen suopohjan kasvittumiseen ja puun taimien alkukehitykseen viiden ensimmäisen kasvukauden ajan. Lisäksi tutkittiin kasvillisuuden ravinne- ja raskasmetallipitoisuuksien muutoksia sekä turpeen ravinteisuutta lannoituksen jälkeen.
Kaikki lannoitteet nopeuttivat merkittävästi kasvillisuuden muodostumista paljaalle suopohjalle, kun taas lannoittamaton alue pysyi kasvittomana. Tuhkalannoitetuille alueille syntyi nopeasti laajoja palopaikoilla viihtyvien pioneerisammalten kasvustoja, jotka peittivät ja samalla sitoivat paljaan ja irtonaisen turvemaan pinnan. Tuhkalannoitus edisti myös koivun taimien alkukehitystä tehokkaammin kuin kaupallinen Metsän PK-lannoite. Sammalista ja ruohovartisista kasveista muodostuva aluskasvillisuus ylitti puuntaimet selvästi biomassan määrässä ja toimi metsityksen alkuvaiheessa puuntaimia merkittävämpänä hiilensitojana. Lisäksi kasvien maanalainen biomassa oli maanpäällistä biomassaa suurempi.
Sekä puu- että turvetuhka takasivat riittävän määrän ravinteita energiapuumetsikön alkukehitykselle. Aluskasvillisuus osoittautui tärkeäksi tuhkasta liukenevien ravinteiden ja raskasmetallien sitojaksi metsityksen alkuvaiheessa. Vaikka sammalten kadmiumpitoisuudet nousivat tuhkalannoituksen seurauksena, ne olivat kuitenkin alhaisia Suomessa aiemmin mitattuihin sammalten yleisiin pitoisuuksiin suhteutettuna. Tuhkalannoitus ei lisännyt haitallisten raskasmetallien pitoisuuksia koivun taimien ja ruohovartisten kasvien lehdissä ja varsissa. Tutkimuksen tulokset tukevat puu- ja turvetuhkan käyttöä energiapuumetsiköiden alkuvaiheen lannoitteena turvetuotannosta vapautuneilla suopohjilla.
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Stav půdního organického uhlíku a změny půdní organické hmoty na Novohradsku / Status of soil organic carbon and changes in soil organic matter in NovohradskoBOROVKA, Jan January 2018 (has links)
The aim of the diploma thesis was to evaluate the content of soil organic carbon in the area of Novohradsko. Soil organic carbon was monitored in its stable (SOC) and labile (WSOC) form, followed by the total organic carbon stock (Cpool). These soil parameters were determined in soils of different land cover types (forest, arable land, grassland) in the area formed by the catchments of Pasecký, Bedřichovský, Váčkový and Veverský stream. Data obtained in 2001, 2007 and 2014 were statistically analysed and the comparison of the data from different catchments was conducted. The results show the impact of different land use on the amount of soil organic carbon. In general, a higher amount of soil organic carbon were found in soils of grassland and forest soils, whereas a lower amounts were found in arable land. The comparison and the time development analysis show that there is a trend of the increase in quantity of stable fraction of soil organic carbon in all categories of land cover over the whole monitored period. The opposite trend of a continuous decrease over the whole of the monitored period in all categories of land cover was observed in amounts of labile fraction of soil organic carbon. It can be said that there is an increase in the stock of a stable fraction of soil organic carbon due to lower losses of the labile fraction of soil organic carbon in forest soils, arable soils and soils of grassland.
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Integração lavoura pecuária: efeitos no solo, na forragem, modelagem e simulação econômica / Crop - livestock: effects on soil, fodder, economic modeling and simulationMUNIZ, Luciano Cavalcante 30 July 2010 (has links)
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Previous issue date: 2010-07-30 / When approaching the crop-livestock integration (CLI) theme, the present thesis
had as one of its main objectives to evaluate the alterations in the soil-plantanimal-
environment components exercised by the crop and pasture rotation
dynamics in crop and livestock integration system. Two adjacent areas, one
representing the natural environment (original cerrado vegetation) and other the
degraded pastures served as reference ( control ) to the inferences performed.
The experiment was performed at a 92 ha area, divided into six paddocks of
approximately 15 ha, where the annual crops and pastures rotation was made.
The soil samplings were collected at the 0-10, 10-20, 20-30, 30-40 and 40-50 cm
layers. There was an increase in the carbon contents of the microbial biomass, in
the microbial quotient and in the organic matter on the soil and reduction in the
metabolic quotient at the pastures chronological sequence environments, at the
crop-livestock integration system, in comparison with the degraded pasture. The
different pastures stages within the crop-livestock integration system stocked the
average of 17,67 Mg ha-1 carbon more than the degraded pasture up to a 50 cm
depth. The Cerrado contained the most carbon stock and the degraded pasture
the least among all the environments studied. There was a significant decrease in
the phosphor and potassium contents in relation to the pasture age increase and
an increase in the calcium and magnesium contents. Micronutrients contents
among the treatments evaluated presented values above the demand for capim-
Marandu. The capim-Marandu samplings were performed in five different seasons
of the year (winter, beginning and end of spring, summer and autumn).
Quantitative and qualitative alterations at the forage were observed during the
experimental period. Changes on the structural components green leaf, green
stem and dead material, as well as on DM (Dry Matter), GP (Gross Protein), TDN
(Total Digestive Nutrients) and FND (Fiber in Neutral Detergent) contents, among
others, characterized the forage on the different periods. The qualitative variations
among the forages are of high magnitude, being outlined the significant drop on
GP (Gross Protein) and TDN (Total Digestive Nutrients) contents according to the
pasture maturity development. All pastures chronological sequence treatments,
after 2,5 years of crop, resulted in favorable evaluations, having P1 treatment as
the best investment option with NPV (Net Present Value) equals to R$144,34
followed by P2 treatment with R$112,61 and P3 with R$58,54, indicating to be a
favorable Project. There is indication on the present work that the biggest loss in
relation to the obtained economic advantages happens already from the second
year after the pastures establishment. Such results may constitute important
implications at CLI systems planning. Carbon bonus at pasture based animal
production system may be a financial incentive for the producer to join the
pastures rotation with annual crops. Nevertheless it is necessary that studies are
performed to quantify emissions of gases responsible for greenhouse in order to
verify whether the result represents a bonus or an environmental onus to the
producer. / A presente tese, ao abordar o tema integração lavoura-pecuária (ILP), teve
como um de seus principais objetivos avaliar as alterações nos componente
solo-planta-animal-ambiente exercidas pela dinâmica de rotação de culturas e
pastagens em sistema de integração lavoura e pecuária. Duas áreas
adjacentes, uma representativa do meio ambiente natural (vegetação de
cerrado original ) e outra de pastagens degradadas, serviram de referência
( controle ) às inferências realizadas. O experimento foi realizado numa área de
92 ha, dividida em seis piquetes de aproximadamente 15 ha, onde foi feita a
rotação de culturas anuais e pastagens. As amostras de solo foram coletadas
nas camadas 0-10, 10-20, 20-30, 30-40 e 40-50 cm. Houve aumento nos teores
de carbono da biomassa microbiana, no quociente microbiano e na matéria
orgânica no solo e redução no quociente metabólico nos ambientes da
cronossequência das pastagens, no sistema integração lavoura-pecuária, em
comparação com a pastagem degradada. As diferentes fases das pastagens
dentro do sistema de integração lavoura-pecuária estocaram, em média, 17,67
Mg ha-1 mais carbono que a pastagem degradada até a profundidade de 50 cm.
O Cerrado conteve o maior, e a pastagem degradada o menor estoque de
carbono entre todos os ambientes estudados. Houve um decréscimo
significativo nos teores de fósforo e potássio com o aumento da idade da
pastagem e aumento nos teores de cálcio e magnésio. Os teores dos
micronutrientes entre os tratamentos avaliados apresentaram valores acima da
exigência para o capim-Marandu. As amostras de capim-Marandu foram
realizadas em cinco épocas do ano (inverno, início e final da primavera, verão e
outono). Alterações quantitativas e qualitativas na forragem foram observadas
durante o período experimental. Mudanças nos componentes estruturais folha
verde, colmo verde e material morto, bem como nos teores de matéria seca
(MS), proteína bruta (PB), nutrientes disponíveis totais (NDT) e fibra em
detergente neutro (FDN), entre outros, caracterizaram a forragem nos
diferentes períodos. As variações qualitativas entre as forrageiras são de alta
magnitude, destacando-se a queda significativa nos teores de PB e NDT, com
o avanço da maturidade da pastagem. Todos os tratamentos da
cronossequência das pastagens, após 2,5 anos de lavoura, resultaram em
avaliações favoráveis, sendo o tratamento P1 a melhor opção de investimento,
com valor presente líquido (VPL) igual a R$ 144,34, seguido pelo tratamento P2
com R$ 112,61 e P3 com R$ 58,54, indicando tratar-se de projeto favorável. Há
indicação no presente trabalho que a maior perda em relação às vantagens
econômicas obtidas ocorre já a partir do segundo ano após o estabelecimento
das pastagens, podendo constituir implicações importantes no planejamento de
sistemas de ILP. O bônus de carbono no sistema de produção animal a pasto
pode ser um incentivo financeiro para o produtor aderir à rotação de pastagens
com culturas anuais. Porém é preciso que sejam realizados estudos que
quantifiquem as emissões de gases responsáveis pelo efeito estufa, para
verificar se o balanço representa um bônus ou um ônus ambiental para o
produtor.
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Reconstructions de changements environnementaux dans les archives lacustres par imagerie hyperspectrale / Reconstitutions of environmental changes in lacustrine archives by hyperspectral imagingVan Exem, Antonin 11 July 2018 (has links)
Les lacs piègent des particules sédimentaires au fil du temps de manière à former des archives sédimentaires. Tracer l’origine des particules archivées avec une résolution stratigraphique particulièrement détaillée conduit à reconstituer une ou des informations paléoenvironnementales permettant d’identifier les changements environnementaux passés. Afin de décrypter ces informations, les techniques d’analyse des carottes sédimentaires nécessitent d’identifier des marqueurs de leur composition à haute résolution. L’imagerie l’hyperspectrale demeure une des rares techniques capables de représenter ces marqueurs en deux dimensions pour caractériser les variations de la composition du sédiment et les structures stratigraphiques les plus fines. Dans ce mémoire, le potentiel de l’imagerie est mis en valeur à travers l’étude de plusieurs cas. L’objectif est de reconstituer des changements environnementaux à partir de l’origine des matières organiques (MO) sédimentaires à hauterésolution rapidement et sans destruction des archives. Plusieurs marqueurs hyperspectraux permettant de comprendre l’origine des MO sont développés sur deux sites d’étude choisis pour leur potentielle signature organique sédimentaire. Dans un environnement méditerranéen, les apports en MO détritique dans les sédiments du lac Bresson tracent les épisodes d'incendie du couvert forestier alors que les variations de carbone organique total (COT) dans une série d’archives sédimentaires reconstruisent les fluctuations de l’érosion glaciaire dans un lac arctique. Dans ces deux cas, la MO d’origine détritique est tracée pour la première fois par une méthode non-destructive et le traçage de la MO issue de la productivitéprimaire aquatique (plus classique) est amélioré par un nouvel indice spectroscopique. Ces marqueurs sont validés par des méthodes utilisées en routine (HPLC, comptage des particules de charbon, pyrolyse Rock-Eval 6) puis calibrés par ces techniques pour reconstruire des concentrations en COT à haute résolution. L’imagerie hyperspectrale permet donc de tracer lacomposition sédimentaire, voire des variations géochimiques, pour quantifier l'origine des apports organiques. Ces résultats apparaissent comme prometteurs et fournissent les bases essentielles pour développer l'utilisation en routine de cette nouvelle technique afin de reconstituer finement les changements environnementaux passés. / Over time, lakes trap sedimentary particles that form sedimentary reserves. Tracing the origin of those particles with a precise stratigraphic resolution, involves reconstituting one or more paleo environmental information thus allowing the identification of past environmental changes. Decrypting that information requires a sedimentary carrot analysis technic to identify their high resolution composition indicators. Hyperspectral imagery remains one of the rare technics capable of showing those indicators in a two dimensional form so as to characterize the variations in the composition of the sediment as well as the finer stratigraphic structures. In comparison to the methods used routinely, hyperspectral imagery is a highresolution (nanometers resolution) technic that does not destroy the core of the sediment and is time efficient (1 hour per meter of sediment). In this thesis, the potential of the high resolution imagery is highlighted through the study of several case studies. The aim is to reconstitute environmental changes based on the origin of high resolution sedimentary organic matter (OM) quickly whilst preserving their history. Several hyperspectral indicators have been developed on two carefully chosen study sites to understand the origins of those OM. Those sites were chosen based on their potential sedimentary organic signature. In a Mediterranean environment, detrital OM inputs in the Bresson lake give a history of the various forest fires whereas the organic carbon variations in a series of reserve sediments, reconstruct the fluctuations of glacier erosion in an artic lake. In both cases, the OM of detrital origin is traced for the first time through a non-destructive method. Tracing OM issued from Primary aquatic production is improved with a new spectroscopic index. These indicators are validated by the methods routinely used (HPLC and RE6) then are calibrated by these technics in order to rebuilt high resolution COT concentrations. Hyperspectral imagery allows to trace the sedimentary composition and to see geo chemical variations in order to quantify the origin of organic inputs. Those results seem promising and bring essential foundations to develop the routine use of this new technic in order to reconstitute accurately past environmental changes.
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