Açai seed biochar improves soil quality and black pepper seedling development in the Amazon region.

Sustainable management of the Amazon rainforest is fundamental for supporting life on earth because of its crucial role in sequestering carbon. One of the species grown in the forest is açaí (Euterpe oleracea), which is an important food and income source for its inhabitant. The acai seed, resulting from the processing of the fruit, is a solid organic residue, which has been an agent of undesirable environmental impacts such as natural landscape modifications, clogging sewers and water courses, eutrophication of surface waters.

Short-term restoration practices change the bacterial community in degraded soil from the Brazilian semiarid.

Land degradation by deforestation adversely impacts soil properties, and long-term restoration practices have been reported to potentially reverse these effects, particularly on soil microorganisms. However, there is limited knowledge regarding the short-term effects of restoration on the soil bacterial community in semiarid areas. This study evaluates the bacterial community in soils experiencing degradation (due to slash-and-burn deforestation) and restoration (utilizing stone cordons and revegetation), in comparison to a native soil in the Brazilian semiarid region.

Nickel sources affect soil biological properties but do not affect sorghum growth.

Nickel (Ni) is an essential element, but it can be phytotoxic in high concentration, which may be caused by high availability in soil solution. The objective of this study was to evaluate the effect of sources and doses of Ni applied to a dystrophic Red Latosol cultivated with sorghum on i) the availability of the metal in the soil; ii) the impact on biological and biochemical properties of the soil; iii) the absorption and distribution in sorghum plants; and iv) crop productivity. The experiment was carried out within a completely randomized design with two nickel sources [nickel(II) nitrate, Ni(NO) and nickel(III) oxide, NiO], three doses (35, 70, and 140 mg Ni kg soil), plus controls without Ni, with 3 replications.

Soil fertility impact on recruitment and diversity of the soil microbiome in sub-humid tropical pastures in Northeastern Brazil.

Soil fertility is key point to pastures systems and drives the microbial communities and their functionality. Therefore, an understanding of the interaction between soil fertility and microbial communities can increase our ability to manage pasturelands and maintain their soil functioning and productivity. This study probed the influence of soil fertility on microbial communities in tropical pastures in Brazil.

From desertification to restoration in the Brazilian semiarid region: Unveiling the potential of land restoration on soil microbial properties.

Land desertification poses a significant challenge in the Brazilian semiarid region, encompassing a substantial portion of the country. Within this region, the detrimental effects of human activities, particularly unsuitable anthropic actions, have resulted in diminished vegetation cover and an accelerated rate of soil erosion. Notably, practices such as overgrazing and the conversion of native forests into pasturelands have played a pivotal role in exacerbating the process of land desertification.

Soil and foliar Si fertilization alters elemental stoichiometry and increases yield of sugarcane cultivars.

Silicon (Si) fertilization is widely recognized to improve the development of crops, especially in tropical soils and cultivation under dryland management. Herein, our working hypothesis was that Si stoichiometry favors the efficient use of carbon (C), nitrogen (N), and phosphorus (P) in sugarcane plants. Therefore, a field experiment was carried out using a 3 × 3 factorial scheme consisting of three cultivars (RB92579, RB021754 and RB036066) and three forms of Si application (control without Si; sodium silicate spray at 40 mmol L in soil during planting; sodium silicate spray at 40 mmol L on leaves at 75 days after emergence).

Exploring the diversity and composition of soil microbial communities in different soybean-maize management systems.

Soybean-maize are cultivated in different management systems, such as no-tillage and pastures, which presents potential to add organic residues, and it can potentially impacts the soil microbial community present in these systems. Thus, this study aimed to examine the effects of different soybean-maize management practices on the diversity and composition of soil microbial communities. Specifically, 16 S rRNA amplicon sequencing was used to investigate whether the use of pasture species in a fallowing system influences microbial communities in a soybean-maize rotation system, as compared to conventional tillage and no-tillage systems.

Short-term responses of plant growth-promoting bacterial community to the herbicides imazethapyr and flumioxazin.

Imazethapyr and flumioxazin are widely recommended herbicides for soybean fields due to their broad-spectrum effects. However, although both herbicides present low persistence, their potential impact on the community of plant growth-promoting bacteria (PGPB) is unclear. To address this gap, this study assessed the short-term effect of imazethapyr, flumioxazin, and their mixture on the PGPB community.

Changes in the bacterial rare biosphere after permanent application of composted tannery sludge in a tropical soil.

Composted tannery sludge (CTS) promotes shifts in soil chemical properties, affecting microbial communities. Although the effect of CTS application on the bacterial community has been studied, it is unclear whether this impact discriminates between the dominant and rare species. This present study investigated how the dominant and rare bacterial communities respond over time to different concentrations of CTS application (0, 2.

Microbial communities in the rhizosphere of maize and cowpea respond differently to chromium contamination.

Chromium (Cr) contamination can affect microorganisms in the soil, but the response of the microbial community in the rhizosphere of plants grown in Cr-contaminated soils is poorly understood. Therefore, this study assessed the microbial community, by amplicon sequencing, in the rhizosphere of maize and cowpea growing in uncontaminated (∼6.0 mg kg Cr) and Cr-contaminated soils (∼250 mg kg Cr).

Tolerance and reduction of chromium by bacterial strains.

Bacteria have potential to tolerate and reduce metals. This study evaluated the potential of selected bacterial strains in tolerating and reducing chromium (Cr). Six bacterial strains (Rhizobium miluonense LCC01, LCC04, LCC05, and LCC69; Rhizobium pusense LCC43; and Agrobacterium deltaense LCC50) showed tolerance to Cr(VI) (16 and 32 μg mL), reduction potential of Cr(VI) (from 50 to 80%), and efficiency in producing exopolysaccharides.

Applications of Cr-rich composted tannery sludge in the soil decrease microbial biomass and select specific bacterial groups.

The tannery industries generate a solid waste known as tannery sludge, which is composed of organic and inorganic compounds, mainly chromium (Cr). When Cr is not removed from the tannery sludge, this solid waste is metal-rich and its application could affect the soil microorganisms. Alternatively, the composting of the tannery sludge can contribute to decreasing the concentration of Cr in the composted tannery sludge (CTS).

Environmental DNA Sequencing to Monitor Restoration Practices on Soil Bacterial and Archaeal Communities in Soils Under Desertification in the Brazilian Semiarid.

Soils from Brazilian semiarid regions are highly vulnerable to desertification due to their geology, climate, human actions, and intensive land use that contribute to desertification. Therefore, areas under desertification have increased in the Brazilian semiarid region and it has negatively changed the soil bacterial and archaeal communities and their functionality. On the other hand, although restoration strategies are expensive and there are few soils restoration programs, some practices have been applied to restore these soils under desertification.

Domestication of Lima Bean (Phaseolus lunatus) Changes the Microbial Communities in the Rhizosphere.

Plants modulate the soil microbiota and select a specific microbial community in the rhizosphere. However, plant domestication reduces genetic diversity, changes plant physiology, and could have an impact on the associated microbiome assembly. Here, we used 16S rRNA gene sequencing to assess the microbial community in the bulk soil and rhizosphere of wild, semi-domesticated, and domesticated genotypes of lima bean (Phaseolus lunatus), to investigate the effect of plant domestication on microbial community assembly.

Genetically related genotypes of cowpea present similar bacterial community in the rhizosphere.

Plant breeding reduces the genetic diversity of plants and could influence the composition, structure, and diversity of the rhizosphere microbiome, selecting more homogeneous and specialized microbes. In this study, we used 16S rRNA sequencing to assess the bacterial community in the rhizosphere of different lines and modern cowpea cultivars, to investigate the effect of cowpea breeding on bacterial community assembly. Thus, two African lines (IT85F-2687 and IT82D-60) and two Brazilian cultivars (BRS-Guariba and BRS-Tumucumaque) of cowpea were assessed to verify if the generation advance and genetic breeding influence the bacterial community in the rhizosphere.

Dataset for effects of the transition from dry forest to pasture on diversity and structure of bacterial communities in Northeastern Brazil.

The data included in this article supplement the research article titled "Forest-to-pasture conversion modifies the soil bacterial community in Brazilian dry forest Caatinga (manuscript ID: STOTEN-D-21-19067R1)". This data article included the analysis of 18 chemical variables in 36 composite samples (included 4 replicates) of soils from the Microregion of Garanhuns (Northeast Brazil) and also partial 16S rRNA gene sequences from genomic DNA extracted from 27 of these samples (included 3 best quality replicates) for paired-end sequencing (up to 2 × 300 bp) in Illumina MiSeq platform (NCBI - BioProject accession: PRJNA753707). Soils were collected in August 2018 in a tropical subhumid region from the Brazilian Caatinga, along with 27 composite samples from the aboveground part of pastures to determine nutritional quality based on leaf N content.

Dynamics of bacterial and archaeal communities along the composting of tannery sludge.

The process of composting has been proposed as a biological alternative to improve the quality of tannery sludge (TS) by the action of microbial communities. However, there is limited knowledge about the dynamic of these microbial communities during the composting process. This study assessed the responses of bacterial and archaeal communities during TS composting using the 16S rRNA sequencing.

Microbial co-occurrence network and its key microorganisms in soil with permanent application of composted tannery sludge.

Soil microbial communities act on important environmental processes, being sensitive to the application of wastes, mainly those potential contaminants, such as tannery sludge. Due to the microbiome complexity, graph-theoretical approaches have been applied to represent model microbial communities interactions and identify important taxa, mainly in contaminated soils. Herein, we performed network and statistical analyses into microbial 16S rRNA gene sequencing data from soil samples with the application of different levels of composted tannery sludge (CTS) to assess the most connected nodes and the nodes that act as bridges to identify key microbes within each community.

Distinct bacterial community structure and composition along different cowpea producing ecoregions in Northeastern Brazil.

Soil microbial communities represent the largest biodiversity on Earth, holding an important role in promoting plant growth and productivity. However, the knowledge about how soil factors modulate the bacteria community structure and distribution in tropical regions remain poorly understood, mainly in different cowpea producing ecoregions belonging to Northeastern Brazil. This study addressed the bacterial community along three different ecoregions (Mata, Sertão, and Agreste) through the16S rRNA gene sequencing.

Long-term effect of composted tannery sludge on soil chemical and biological parameters.

Composting has been recommended as a suitable alternative for recycling wastes and could improve tannery sludge (TS) before its use. However, the long-term application of composted tannery sludge (CTS) may bring concerns about its effects on soil properties and, consequently, on plants and environment, mainly when considering Cr contamination. In this study, we summarize the responses of soil chemical and biological parameters in a 10-year study with yearly applications of CTS.

Phytotoxicity and cytogenotoxicity of composted tannery sludge.

Tannery sludge (TS) contains high levels of organic matter and chemical elements, mainly chromium (Cr). This can increase its toxicity, rendering it unsuitable for application to soil. However, composting has been proposed as an alternative method for detoxifying TS before its addition to soil.

Responses of soil microbial biomass and enzyme activity to herbicides imazethapyr and flumioxazin.

The use of herbicides is important for controlling weeds in crops. However, they can present impacts on soil properties, such as biological properties. In this study, we evaluated the responses of soil microbial biomass and enzymes activity to the application of the herbicides imazethapyr and flumioxazin and their mixture in an experiment under laboratory conditions, using soils with a different history of use.

Dynamics of archaeal community in soil with application of composted tannery sludge.

Application of composted tannery sludge (CTS) could promote a shift in the structure of soil microbial communities. Although the effect of CTS on bacterial community has been studied, it is unclear how the composition and diversity of archaeal community respond to CTS amendment and which environmental factors drive the community over time. Here, we hypothesize that the Archaea structure and composition respond to CTS amendment over the time.

Protist species richness and soil microbiome complexity increase towards climax vegetation in the Brazilian Cerrado.

Biodiversity underlies ecosystem functioning. While aboveground biodiversity is often well studied, the belowground microbiome, in particular protists, remains largely unknown. Indeed, holistic insights into soil microbiome structures in natural soils, especially in hyperdiverse biomes such as the Brazilian Cerrado, remain unexplored.