The GrassSyn dataset: Soil organic carbon stocks in Brazilian grassy ecosystems.

Although ecosystem management and restoration are known to enhance carbon storage, limited knowledge of ecosystem-specific soil organic carbon (SOC) stocks and processes hinders the development of climate-ready, biodiversity-focused policies. Baseline SOC stocks data for specific ecosystems is essential. This paper aims to: (i) examine SOC stock variability across major grassy ecosystems in Brazil and (ii) discuss data limitations and applications.

Impact of climatic seasons on the dynamics of carbon, nitrogen and mercury in soils of Brazilian biomes affected by gold mining.

Land use change, especially mining activities, contributes to anthropic CO emissions, leading to decreased carbon (C) storage and loss of biodiversity. Artisanal gold mining associated with the use of mercury (Hg) for amalgamation may change soil organic matter (SOM) contents, and the release of Hg into the environment generates serious environmental problems. Changes in soil biogeochemistry due to C loss and seasonal climate fluctuations affect Hg dynamics and can either increase or decrease its availability.

Carbon savings from sugarcane straw-derived bioenergy: Insights from a life cycle perspective including soil carbon changes.

Sugarcane straw removal for bioenergy production will increase substantially in the next years, but this may deplete soil organic carbon (SOC) and exacerbate greenhouse gas (GHG) emissions. These aspects are not consistently approached in bioenergy life cycle assessment (LCA). Using SOC modeling and LCA approach, this study addressed the life cycle GHG balance from sugarcane agroindustry in different scenarios of straw removal, considering the potential SOC changes associated with straw management in sugarcane-cultivated soils in Brazil.

Intentional creation of carbon-rich dark earth soils in the Amazon.

Fertile soil known as Amazonian dark earth is central to the debate over the size and ecological impact of ancient human populations in the Amazon. Dark earth is typically associated with human occupation, but it is uncertain whether it was created intentionally. Dark earth may also be a substantial carbon sink, but its spatial extent and carbon inventory are unknown.

Slash and burn management and permanent or rotation agroforestry systems: A comparative study for C sequestration by century model simulation.

Understanding the effects of agroforestry systems (AFs) on soil organic carbon (SOC) requires long-term experiments, but scenarios simulations can anticipate the potential of these systems to sequester or lose carbon (C). This study aimed to simulate the SOC dynamics in slash and burn management (BURN) and AFs using the Century model. Data from a long-term experiment implemented in the Brazilian semiarid region were used to simulate SOC dynamics under BURN and AFs situations, and the natural vegetation (NV) "Caatinga" as a reference.

Linking land-use and land-cover transitions to their ecological impact in the Amazon.

Human activities pose a major threat to tropical forest biodiversity and ecosystem services. Although the impacts of deforestation are well studied, multiple land-use and land-cover transitions (LULCTs) occur in tropical landscapes, and we do not know how LULCTs differ in their rates or impacts on key ecosystem components. Here, we quantified the impacts of 18 LULCTs on three ecosystem components (biodiversity, carbon, and soil), based on 18 variables collected from 310 sites in the Brazilian Amazon.

Biochar aging: Impact of pyrolysis temperature on sediment carbon pools and the availability of arsenic and lead.

Arsenic (As) and lead (Pb) are potentially toxic elements capable of developing several diseases in human beings such as cancer. Several adsorbent materials, including biochars, have been adopted as alternative measures designed to reduce the availability of As and Pb in water. The retention capacity of potentially toxic elements in biochars varies according to time, feedstock, and the pyrolysis temperature to produce the biochar.

Soil biota shift with land use change from pristine rainforest and Savannah (Cerrado) to agriculture in southern Amazonia.

Southern Amazonia is currently experiencing extensive land use change from forests to agriculture caused by increased local and global demand for agricultural products. However, little is known about the impacts of deforestation and land use change on soil biota. We investigated two regions in southern Amazonia (rainforest and Savannah/Cerrado biomes), analysing soil biota community turnover based on 16S (Archaea and Bacteria) and 18S rRNA genes (Eukaryotes, including Fungi, Protists and Animalia) and correlating them with soil chemistry and land use intensity.

Biochar-based nitrogen fertilizers: Greenhouse gas emissions, use efficiency, and maize yield in tropical soils.

The sustainable development of agriculture depends on increasing N use efficiency (NUE) and consequently reducing N losses from different sources, such as NH volatilization, NO leaching, and NO emissions. While the chemical and physical properties of biochar (BC) in fertilizers have been evaluated to increase NUE, a lack of information exists regarding the effects of BC amendments in tropical soils. We performed a one-year field experiment with tropical soil to evaluate the effects of BC-based N fertilizers (BN) on maize yield and on greenhouse gas (GHG) emissions.

Changes in soil phosphorus pool induced by pastureland intensification and diversification in Brazil.

The adoption of more intensive and diversified pasture systems is a promising alternative to improve sustainability of grazing lands in Brazil. Phosphorus (P) is one of the main determinants of ecosystem function in these management systems; therefore, we assessed the effects of adopting more intensive and diversified pasture management systems on soil P dynamics in a set of field experiments. Treatments included fertilized pasture (FP), integrated crop-livestock (ICL), integrated livestock-forest (ILF), compared to conventional management systems (CS) under contrasting climatic conditions (tropical humid, tropical mesic and subtropical).

Dynamic biochar effects on nitrogen use efficiency, crop yield and soil nitrous oxide emissions during a tropical wheat-growing season.

The application of biochar to soil combined with synthetic fertilizers has been proposed for enhancing N availability to plants and crop yields while reducing nitrous oxide (NO) emissions. However, little is known about those interactions for tropical soils. Thus, this study evaluated the effects of sugarcane straw biochar on tropical soil attributes, crop productivity, NO emissions and N use efficiency.

Deep soils modify environmental consequences of increased nitrogen fertilizer use in intensifying Amazon agriculture.

Agricultural intensification offers potential to grow more food while reducing the conversion of native ecosystems to croplands. However, intensification also risks environmental degradation through emissions of the greenhouse gas nitrous oxide (NO) and nitrate leaching to ground and surface waters. Intensively-managed croplands and nitrogen (N) fertilizer use are expanding rapidly in tropical regions.

Vinasse application and cessation of burning in sugarcane management can have positive impact on soil carbon stocks.

Bioenergy crops, such as sugarcane, have the potential to mitigate greenhouse gas emissions through fossil fuel substitution. However, increased sugarcane propagation and recent management changes have raised concerns that these practices may deplete soil carbon (C) stocks, thereby limiting the net greenhouse gas benefit. In this study, we use both a measured and modelled approach to evaluate the impacts of two common sugarcane management practices on soil C sequestration potential in Brazil.

Phosphorus removal from eutrophic water using modified biochar.

Increasing problems related to water eutrophication, commonly caused by the high concentration of phosphorus (P), are stimulating studies aimed at an environmentally safe solution. Moreover, some research has focused on the reuse of P due to concerns about the end of its natural reserves. Biochar appears to be a solution to both problems and may act as a recovery of eutrophic/residual water with the subsequent reuse of P in agriculture, the purpose of which is to test such an assertion.

Poultry manure and sugarcane straw biochars modified with MgCl for phosphorus adsorption.

Increases in agricultural productivity associated to the crescent use of finite reserves of phosphorus improved the demand for ways to recycle and reuse this nutrient. Biochars, after doping processes, seem to be an alternative to mitigate the large use of P reserves. Sugarcane straw and poultry manure were submerged in an MgCl solution in a 1:10 solid/liquid ratio and subsequently pyrolyzed at 350 and 650 °C producing biochar.

Consensus, uncertainties and challenges for perennial bioenergy crops and land use.

Perennial bioenergy crops have significant potential to reduce greenhouse gas (GHG) emissions and contribute to climate change mitigation by substituting for fossil fuels; yet delivering significant GHG savings will require substantial land-use change, globally. Over the last decade, research has delivered improved understanding of the environmental benefits and risks of this transition to perennial bioenergy crops, addressing concerns that the impacts of land conversion to perennial bioenergy crops could result in increased rather than decreased GHG emissions. For policymakers to assess the most cost-effective and sustainable options for deployment and climate change mitigation, synthesis of these studies is needed to support evidence-based decision making.

Assessing the greenhouse gas emissions of Brazilian soybean biodiesel production.

Soybean biodiesel (B100) has been playing an important role in Brazilian energy matrix towards the national bio-based economy. Greenhouse gas (GHG) emissions is the most widely used indicator for assessing the environmental sustainability of biodiesels and received particular attention among decision makers in business and politics, as well as consumers. Former studies have been mainly focused on the GHG emissions from the soybean cultivation, excluding other stages of the biodiesel production.

Grassland management impacts on soil carbon stocks: a new synthesis.

Grassland ecosystems cover a large portion of Earths' surface and contain substantial amounts of soil organic carbon. Previous work has established that these soil carbon stocks are sensitive to management and land use changes: grazing, species composition, and mineral nutrient availability can lead to losses or gains of soil carbon. Because of the large annual carbon fluxes into and out of grassland systems, there has been growing interest in how changes in management might shift the net balance of these flows, stemming losses from degrading grasslands or managing systems to increase soil carbon stocks (i.

Loss of soil (macro)fauna due to the expansion of Brazilian sugarcane acreage.

Land use changes (LUC) from pasture to sugarcane (Saccharum spp.) crop are expected to add 6.4Mha of new sugarcane land by 2021 in the Brazilian Cerrado and Atlantic Forest biomes.

Soil Quality Indexing Strategies for Evaluating Sugarcane Expansion in Brazil.

Increasing demand for biofuel has intensified land-use change (LUC) for sugarcane (Saccharum officinarum) expansion in Brazil. Assessments of soil quality (SQ) response to this LUC are essential for quantifying and monitoring sustainability of sugarcane production over time. Since there is not a universal methodology for assessing SQ, we conducted a field-study at three sites within the largest sugarcane-producing region of Brazil to develop a SQ index (SQI).

Comparing how land use change impacts soil microbial catabolic respiration in Southwestern Amazon.

Land use changes strongly impact soil functions, particularly microbial biomass diversity and activity. We hypothesized that the catabolic respiration response of the microbial biomass would differ depending on land use and that these differences would be consistent at the landscape scale. In the present study, we analyzed the catabolic response profile of the soil microbial biomass through substrate-induced respiration in different land uses over a wide geographical range in Mato Grosso and Rondônia state (Southwest Amazon region).

Molecular characterization of soil organic matter from native vegetation-pasture-sugarcane transitions in Brazil.

Replacing pastures (PA) with sugarcane (SG) has been deemed an agronomically feasible strategy for sugarcane expansion in Brazil. However, there are some uncertainties about the environmental impacts regarding this land use change (LUC), mainly related to soil organic matter (SOM), a key factor of environmental sustainability of Brazilian ethanol. LUC-related losses of SOM can overcome the C savings from biofuels.

Soil carbon, nitrogen and phosphorus changes under sugarcane expansion in Brazil.

Historical data of land use change (LUC) indicated that the sugarcane expansion has mainly displaced pasture areas in Central-Southern Brazil, globally the largest producer, and that those pastures were prior established over native forests in the Cerrado biome. We sampled 3 chronosequences of land use comprising native vegetation (NV), pasture (PA), and sugarcane crop (SC) in the sugarcane expansion region to assess the effects of LUC on soil carbon, nitrogen, and labile phosphorus pools. Thirty years after conversion of NV to PA, we found significant losses of original soil organic matter (SOM) from NV, while insufficient new organic matter was introduced from tropical grasses into soil to offset the losses, reflecting in a net C emission of 0.

Net greenhouse gas emissions from manure management using anaerobic digestion technology in a beef cattle feedlot in Brazil.

As part of an agreement during the COP15, the Brazilian government is fostering several activities intended to mitigate greenhouse gas (GHG) emissions. One of them is the adoption of anaerobic digester (AD) for treating animal manure. Due to a lack of information, we developed a case study in order to evaluate the effect of such initiative for beef cattle feedlots.

Measuring and modeling nitrous oxide and methane emissions from beef cattle feedlot manure management: First assessments under Brazilian condition.

Intensive beef production has increased during recent decades in Brazil and may substantially increase both methane (CH(4)) and nitrous oxide (N(2)O) emissions from manure management. However, the quantification of these gases and methods for extrapolating them are scarce in Brazil. A case study examines CH(4) and N(2)O emissions from one typical beef cattle feedlot manure management continuum in Brazil and the applicability of Manure-DNDC model in predicting these emissions for better understand fluxes and mitigation options.