Soil Biogeochemistry: From Molecular to Ecosystem Level Using Terra Preta and Biochar as Examples

2014 ◽  
pp. 18-57
Keyword(s):  
Soil Biogeochemistry ◽  
Terra Preta ◽  
Ecosystem Level

Variabilidade espacial de atributos físicos do solo em terra preta de índio sob cultivo de café conilon

2017 ◽  
Vol 12 (2) ◽  
pp. 260
Author(s):  
Pedro Cardoso Mota Júnior ◽  
Milton Cesar Costa Campos ◽  
Bruno Campos Mantovanelli ◽  
Uilson Franciscon ◽  
José Mauricio Da Cunha
Keyword(s):  
Terra Preta ◽  
Terra Preta De Indio ◽  
Terra Preta De Índio

A conversão de ecossistemas naturais em sistemas agrícolas provoca alterações significativas nos atributos do solo, associado ao crescente desmatamento na região amazônica influenciando a desestabilidade do ecossistema. Dessa forma, objetivou-se com este estudo avaliar a variabilidade espacial dos atributos físicos do solo em área de terra preta de índio (TPI) sob cultivo de café Conilon. Foi demarcado um grid amostral com dimensões de 88 × 64 m, com espaçamento regular de 8 m, perfazendo um total de 88 pontos amostrais. Foram coletadas amostras estruturadas e indeformadas nas camadas de 0,00-0,05; 0,05-0,10; 0,10-0,20 e 0,20-0,30 m. Realizaram-se as seguintes análises físicas: granulometria, estabilidade de agregados, carbono orgânico total (COT), estoque de carbono (EstC), macroporosidade (MaP), microporosidade (MiP), densidade do solo (Ds), porosidade total (PT), resistência do solo à penetração (RP) e umidade volumétrica (θ). Os resultados foram submetidos à análise estatística descritiva e geoestatística. As TPI’s apresentam grande potencial que podem subsidiar o aumento na produção, visto que estes solos apresentam excelente condição que se refere aos atributos físicos, sendo que nas camadas avaliadas estes não apresentaram nenhuma restrição e impedimento ao sistema radicular da cultura.

Ecosystems processes

2018 ◽  
Author(s):  
Karen J. Esler ◽  
Anna L. Jacobsen ◽  
R. Brandon Pratt
Keyword(s):  
Ecosystem Function ◽  
Mineral Nutrients ◽  
Structure And Function ◽  
Water Dynamics ◽  
Ecosystem Level ◽  
Key Drivers ◽  
And Function ◽  
Mediterranean Type Ecosystems

Ecosystems are assemblages of organisms interacting with one another and their environment (Chapter 1). Key to the functioning of ecosystems is the flow of energy, carbon, mineral nutrients, and water in these systems. The numerous processes involved are chiefly driven by climate, soil, and fire (Chapter 2). In cases where the key drivers are the same in different areas, then ecosystems should converge in their structure and function, which has been a motivation for comparing across mediterranean-type climate (MTC) regions. Convergence of MTC regions has been evaluated, but such comparisons at the ecosystem level are challenging because ecosystems are complex and dynamic entities. Here we review carbon, nutrient, and water dynamics of mediterranean-type ecosystems in the context of ecosystem function. As nutrients in soils are low in some MTC regions, we review how this has led to unique adaptations to meet this challenge.

Soil biogeochemistry across Central and South American tropical dry forests

2021 ◽  
Author(s):  
Bonnie G. Waring ◽  
Mark E. De Guzman ◽  
Dan V. Du ◽  
Juan M. Dupuy ◽  
Maga Gei ◽  
...  
Keyword(s):  
Tropical Dry Forests ◽  
South American ◽  
Dry Forests ◽  
Soil Biogeochemistry

scholarly journals Terra Preta Properties in Northwestern Amazonia (Colombia)

2021 ◽  
Vol 13 (13) ◽  
pp. 7088
Author(s):  
Juan Manuel Orozco-Ortiz ◽  
Clara Patricia Peña-Venegas ◽  
Sara Louise Bauke ◽  
Christian Borgemeister ◽  
Ramona Mörchen ◽  
...  
Keyword(s):  
Amazon Basin ◽  
Sequential Fractionation ◽  
Polycarboxylic Acids ◽  
Terra Preta ◽  
Population Sizes ◽  
Colombian Amazon ◽  
Property Changes ◽  
New Evidence ◽  
Total P ◽  
Microbial Residue

Whereas many researchers still approach Terra Preta (TP) as a soil category, new evidence suggests that TP refers to a directional grading of soil property changes (i.e., color, pH, nutrients, etc.) within human-made soils, originating from human activities in pre-Columbian times. Currently, most TP research focuses on the Brazilian part of the Amazon basin, but only little information is available on TP soils in the Colombian Amazon. Here, we sampled four TP and surrounding soils in the Colombian Amazon region at different soil depths and analyzed them for (i) general soil properties such as color, pH and texture, (ii) soil organic carbon and black carbon (BC) contents, the latter using benzene polycarboxylic acids as molecular marker, (iii) phosphorus availability based on sequential fractionation, and (iv) microbial residue contents using amino sugars. Our data from Colombia’s middle Caquetá River and Leticia confirmed that SOC, BC, and total P were present in significantly higher concentrations in the TP areas than the surrounding soils, while pH values and microbial residue contents were unchanged. The enrichment of P forms comprised both easily extractable and stable P pools, which both dominated to a different degree, both in TP and adjacent soils. The different degree of SOC, BC and P enrichment suggests different amounts of waste disposal by the ancient populations at different TP sites, now warranting further research for reconstructing ancient population sizes from TP chemical analyses.

scholarly journals Biological Control of Pest Non-Marine Molluscs: A Pacific Perspective on Risks to Non-Target Organisms

Insects ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 583
Author(s):  
Carl C. Christensen ◽  
Robert H. Cowie ◽  
Norine W. Yeung ◽  
Kenneth A. Hayes
Keyword(s):  
Biological Control ◽  
Environmental Impacts ◽  
Pacific Islands ◽  
Generalist Predators ◽  
Snail Species ◽  
Marine Mollusk ◽  
The Pacific ◽  
History Of ◽  
Ecosystem Level ◽  
Scientific Framework

Classic biological control of pest non-marine mollusks has a long history of disastrous outcomes, and despite claims to the contrary, few advances have been made to ensure that contemporary biocontrol efforts targeting mollusks are safe and effective. For more than half a century, malacologists have warned of the dangers in applying practices developed in the field of insect biological control, where biocontrol agents are often highly host-specific, to the use of generalist predators and parasites against non-marine mollusk pests. Unfortunately, many of the lessons that should have been learned from these failed biocontrol programs have not been rigorously applied to contemporary efforts. Here, we briefly review the failures of past non-marine mollusk biocontrol efforts in the Pacific islands and their adverse environmental impacts that continue to reverberate across ecosystems. We highlight the fact that none of these past programs has ever been demonstrated to be effective against targeted species, and at least two (the snails Euglandina spp. and the flatworm Platydemus manokwari) are implicated in the extinction of hundreds of snail species endemic to Pacific islands. We also highlight other recent efforts, including the proposed use of sarcophagid flies and nematodes in the genus Phasmarhabditis, that clearly illustrate the false claims that past bad practices are not being repeated. We are not making the claim that biocontrol programs can never be safe and effective. Instead, we hope that in highlighting the need for robust controls, clear and measurable definitions of success, and a broader understanding of ecosystem level interactions within a rigorous scientific framework are all necessary before claims of success can be made by biocontrol advocates. Without such amendments to contemporary biocontrol programs, it will be impossible to avoid repeating the failures of non-marine mollusk biocontrol programs to date.

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