A5061227352- Soil Carbon and Nitrogen Dynamics
- Mercury impact and mitigation studies
- Soil and Water Nutrient Dynamics
- Ruminant Nutrition and Digestive Physiology
- Mycorrhizal Fungi and Plant Interactions
- Peatlands and Wetlands Ecology
- Legume Nitrogen Fixing Symbiosis
- Soil Geostatistics and Mapping
- Arsenic contamination and mitigation
- Water Treatment and Disinfection
- Microbial Community Ecology and Physiology
- Bioenergy crop production and management
- Heavy metals in environment
- Agronomic Practices and Intercropping Systems
- Plant nutrient uptake and metabolism
- Soil erosion and sediment transport
- Crop Yield and Soil Fertility
- Agricultural pest management studies
- Composting and Vermicomposting Techniques
- Soil Management and Crop Yield
- Plant tissue culture and regeneration
- Heavy Metal Exposure and Toxicity
- Fluoride Effects and Removal
- Seed Germination and Physiology
- Water Quality Monitoring and Analysis
Texas A&M University
2009-2025
Mitchell Institute
2009-2022
Oak Ridge National Laboratory
2013-2017
Lawrence Berkeley National Laboratory
2013
Louisiana State University
2009
Microbial mercury (Hg) methylation transforms a toxic trace metal into the highly bioaccumulated neurotoxin methylmercury (MeHg). The lack of genetic marker for microbial MeHg production has prevented clear understanding Hg-methylating organism distribution in nature. Recently, specific gene cluster (hgcAB) was linked to Hg two bacteria.1 Here we test if presence hgcAB orthologues is reliable predictor capability microorganisms, necessary confirmation development molecular probes...
A global metagenome assessment reveals a low risk of methylmercury production in humans and high potential Arctic permafrost.
Rice cultivated on arsenic (As) contaminated-soils will accumulate variable grain-As concentrations, as impacted by varietal differences, soil variables, and crop management. A field-scale experiment was conducted to study the impact of intermittent continuous flooding As speciation microbial populations in rice rhizosphere compartments soils that were either historically amended with pesticide or unamended As. Rhizosphere-soil, root-plaque, pore-water grain quantified speciated, root-plaque...
Methylmercury (MeHg) is a bioaccumulative toxic contaminant in many ecosystems, but factors governing its production are poorly understood. Recent work has shown that the anaerobic microbial conversion of mercury (Hg) to MeHg requires Hg-methylation genes hgcAB and these can be used as biomarkers PCR-based estimators Hg-methylator abundance. In an effort determine reliable methods for assessing hgcA abundance diversity linking them concentrations, multiple approaches were compared including...
Soil organic and inorganic carbon (SOC & SIC) microbial community structure are key indicators of soil quality productivity in arid-saline soils. Salinity stress diminishing availability freshwater (FW) for irrigation major constraints improving indicators. Using treated wastewater (TW) implementing climate-smart cropping systems promising alternatives to replace usage intensive systems, however, impacts on the net-carbon sequestration potential not clearly understood. This field study was...
ABSTRACT Neurotoxic methylmercury (MeHg) is produced by anaerobic Bacteria and Archaea possessing the genes hgcAB , but it unknown how organic substrate electron acceptor availability impacts distribution abundance of these organisms. We evaluated impact amendments on mercury (Hg) methylation rates, microbial community structure, + microbes with sediments. Sediment slurries were amended short-chain fatty acids, alcohols, or a polysaccharide. Minimal increases in MeHg observed following...
Abstract Cover crops and manure are popular climate‐smart tools providing ecosystem services. However, their potential can be compromised by increased greenhouse gas (GHG) emissions during decomposition. Stable, carbon‐rich biochar potentially offset such effects. We investigated soil GHG the decomposition of different cover poultry litter (PL) with/without cotton biochar. Soil samples from an organic field were incubated in a 5 × 2 factorial design 2022 2023. Different collected experiment...
Open-source legacy data available for training soil organic carbon (SOC) models are limited and not uniformly distributed in space or time. While some process-based predict SOC changes, most of the large-scale data-driven modeling efforts overlook temporal shifts. Accounting expected drift allows us to increase accuracy dataset machine learning models. Here we present an approach creating proximity-based distance matrices using contiguous US (CONUS) generating spatially resolved shift...
Soil enzymes mediate key processes and functions of the soils, such as organic matter decomposition nutrient cycling in both natural agricultural ecosystems. Here, we studied activity five extracellular soil involved C, N, P-mineralizing process litter surface layer rainforest northwest region Colombian Amazon response those to land use change. The experimental study design included six sites for comparing long-term pasture systems native forest regeneration practices after pasture, within...
Storing carbon (C) within soils is significant for maintaining soil-health and reinforces the feedback loop of C loss from as CO2 to atmosphere. Seasonal variation with increased temperatures inconsistent precipitation climate change consequences also affect soil C-sequestration process globally. Soil-health management practices (SHMPs) such cover crops, crop residues manures increase organic components well soil-organic (SOC) pool in an agroecosystem. While, microbial-biomass (SMB) which...
Soil is a vital component of the ecosystem that drives holistic homeostasis environment. Directly, soil quality and health by means sufficient levels nutrients are required for sustainable agricultural practices ideal crop yield. Among these groups nutrients, carbon factor which has dominating effect on greenhouse phenomena thereby climate change rate its influence planet. It influences fertility other conditions like enriched nutrient cycling water retention forms basis modern ‘regenerative...
Abstract Investigating the impact of cover crops and manure on soil greenhouse gas (GHG) emissions is crucial for advancing our understanding climate‐smart potential organic management practices. This incubation experiment was conducted to investigate combined effects crop residue decomposition carbon dioxide (CO 2 ), nitrous oxide (N O), methane (CH 4 ) under simulated tillage conditions. Undisturbed cores, collected from an cotton ( Gossypium hirsutum L.) field experiment, were incubated...
There is a critical need to investigate how land application of dedicated biofuel oilseed meals affects soil ecosystems. In this study, mustard ( Brassica juncea ) and flax Linum usitatissimum seed sorghum-sudangrass Sorghum bicolor were added at levels 0, 1, 2.5, 5% (w/w). Both the type amendment rate affected organic C, total C & N, N mineralization. Mustard meal initially inhibited mineralization as compared flax, but >50% was mineralized within 51 d. Nitrogen similar for mustard,...
Microbial reduction of toxic hexavalent chromium (Cr(VI)) in-situ is a plausible bioremediation strategy in electron-acceptor limited environments. However, higher [Cr(VI)] may impose stress on syntrophic communities and impact community structure function. The study objectives were to understand the impacts Cr(VI) concentrations Cr(VI)-reduction potential groundwater at Hanford, WA. Steady state continuous flow bioreactors used grow native enriched with lactate (30 mM) continuously amended...
Organic fertilizers have been used in agriculture to improve soil fertility, promote plant growth and protection which improves crop productivity. A field experiment was conducted order study the effect of organic (compost its water extract) on yield barley production. The results achieved showed that either compost (T3) or dual application with extract (T4) as biofertilizers increased most parameters including straw well biological yield, number grains per spike grain income. With respect...
Intensive land-use change, the overgrazing of pastures, and poor soil management in Amazon region induce significant chemical degradation, causing alterations phosphorus (P) dynamics. Here, we studied changes P fractions availability throughout profile along a chronosequence composed four study areas representing typical transition from forest to pasture for extensive cattle ranching Colombian region: (i) Forest—Deforested—Pasture 4 years old Pasture established >25 after deforestation....
Application of date palm waste compost is quite beneficial in improving soil properties and crop growth. However, the effect its application on microbial communities less understood. High-throughput sequencing quantitative real-time PCR (qPCR) were used to evaluate composition a barley field during tillering, booting ripening stages. The results showed that treatment had highest bacterial fungal abundance, significantly altered richness (Chao1 index) α-diversity (Shannon communities....
The valorization of date palm wastes as bioresources has received little attention. In this context, the feasibility waste through composting and application effects on barley plants production under control condition was investigated. principal requirements for compost to be safely used are stability maturity that refer, respectively, microbial biomass activity's level, germination tests, plant growth bioassays or phytotoxicity. Indeed, phytotoxicity composted seed seedling researched....
Abstract Cover crops in organic cotton systems can offset the carbon loss typically observed conventional systems. However, their effects on greenhouse gas (GHG) emissions and soil microclimate are poorly understood. Our objective was to investigate of cover dioxide (CO 2 ), nitrous oxide (N O), methane (CH 4 ) moisture temperature dynamics To achieve this, we used static chamber techniques with sensors a field study near College Station, TX, from 2020 2022. tested were oat ( Avena sativa...