Enhanced retention of hydrophobic pesticides in subsurface soils using organic amendments.

The rapid global population growth since the early 2000s has significantly increased the demand for agricultural products, leading to widespread pesticide use, particularly organophosphorus pesticides (OPPs). This extensive application poses severe environmental risks by contaminating air, soil, and water resources. To protect groundwater quality, it is crucial to understand the transport and fate of these pesticides in soil and sediment.

Effects of biochar and compost addition in potting substrates on growth and volatile compounds profile of basil (Ocimum basilicum L.).

Background: Despite the optimal characteristics of peat, more environmental-friendly materials are needed in the nursery sector, although these must guarantee specific quantitative and qualitative commercial standards. In the present study, we evaluated the influence of biochar and compost as peat surrogates on yield and essential oil profile of two different varieties of basil (Ocimum basilicum var. Italiano and Ocimum basilicum var.

Soil Organic Matter Molecular Composition Shifts Driven by Forest Regrowth or Pasture after Slash-and-Burn of Amazon Forest.

Slash-and-burn of Amazon Forest (AF) for pasture establishment has increased the occurrence of AF wildfires. Recent studies emphasize soil organic matter (SOM) molecular composition as a principal driver of post-fire forest regrowth and restoration of AF anti-wildfire ambience. Nevertheless, SOM chemical shifts caused by AF fires and post-fire vegetation are rarely investigated at a molecular level.

Impact of Biochar Amendment on Soil Properties and Organic Matter Composition in Trace Element-Contaminated Soil.

The application of biochar as an organic amendment in polluted soils can facilitate their recovery by reducing the availability of contaminants. In the present work, the effect of biochar application to acid soils contaminated by heavy metal spillage is studied to assess its effect on the quantity and composition of soil organic matter (SOM), with special attention given to soil humic acids (HAs). This effect is poorly known and of great importance, as HA is one of the most active components of SOM.

Biochar ageing in polluted soils and trace elements immobilisation in a 2-year field experiment.

Biochar application to soils has become a focus of research during the last decade due to its high potential for C sequestration. Nevertheless, there is no exhaustive information on the long-term effects of biochar application in soils contaminated with trace elements. In this work, a 2-year field experiment was conducted comprising the application of different types of biochar to acidic and moderately acidic soils with high concentrations of As, Cu, Pb, Ba and Zn.

Recycling pyrolyzed organic waste from plant nurseries, rice production and shrimp industry as peat substitute in potting substrates.

Organic waste from greens of tomato plants, gardening substrate, rice husks and shrimp-derived chitin were pyrolyzed at 400 °C and 500 °C for 3 h, with the aim to elucidate the feasibility of using such products as replacement of peat in soilless gardening substrates. Characterization of the carbonized organic matter (COM) and the gardening substrate indicated that neither the peat nor the COMs provided the recommended levels of nutrients for the cultivation of tomato plants, although improvements could be obtained using COM/substrate mixtures. The toxicity thresholds for Zn were exceeded significantly by the COMs of the tomato greens and high boron levels were found for all the COMs except for those derived from chitin.

Influence of inorganic additives on wheat straw composting: Characterization and structural composition of organic matter derived from the process.

Metallic oxides and clay minerals have gained increasing interest as additives of composting due to their influence in greenhouse gas emissions reduction and their effectivity in the stabilization of carbon both in compost and soils, leading to a cleaner compost production and potentially C sequestrant amendments. In this study, wheat straw (WS) was co-composted with iron oxide and allophanic soil and their influence on WS composting and composition of the end-products was evaluated. WS compost and their humic like-substances (HS) fraction were characterized by chemical and spectroscopic analyzes.

Chemical, physical and morphological properties of biochars produced from agricultural residues: Implications for their use as soil amendment.

Biochar is a pyrogenous organic material resulting from the pyrolysis of organic residues, which is attracting the interest from researchers and farmers for its potential to sequester carbon and its use as soil ameliorant. Pyrolysis conditions and feedstock determine the properties of the biochars produced. In order to understand the relationship between these variables we analysed in detail the physical, chemical and surface characteristics of biochars produced from three contrasting agronomic residues abundantly generated in South Spain, such as rice husk (RH), olive pit (OP) and pruning remains of olive trees (mainly composed of olive branches and leaves; OB), using a temperature range from 350 to 600 °C and residence times from 0.

An examination of the role of biochar and biochar water-extractable substances on the sorption of ionizable herbicides in rice paddy soils.

The application of biochar as a soil amendment can increase concentrations of soil organic matter, especially water-extractable organic substances. Due to their mobility and reactivity, more studies are needed to address the potential impact of biochar water-extractable substances (BWES) on the sorption of herbicides in agricultural soils that are periodically flooded. Two paddy soils (100 and 700 years of paddy soil development), unamended or amended with raw (BC) or washed biochar (BCW), were used to test the influence of BWES on the sorption behavior of the herbicides azimsulfuron (AZ) and penoxsulam (PE).

Impact of wildfires on subsurface volcanic environments: New insights into speleothem chemistry.

Siliceous speleothems frequently reported in volcanic caves have been traditionally interpreted as resulting from basalt weathering combined with the activity of microbial communities. A characteristic feature in lava tubes from Hawaii, Azores and Canary Islands is the occurrence of black jelly-like speleothems. Here we describe the formation process of siliceous black speleothems found in a lava tube from La Palma, Canary Islands, Spain, based on mineralogy, microscopy, light stable isotopes, analytical pyrolysis, NMR spectroscopy and chemometric analyses.

Quantitative forecasting black (pyrogenic) carbon in soils by chemometric analysis of infrared spectra.

A detailed and global quantitative assessment of the distribution of pyrogenic carbon (PyC) in soils remains unaccounted due to the current lack of unbiased methods for its routine quantification in environmental samples. Conventional oxidation with potassium dichromate has been reported as a useful approach for the determination of recalcitrant C in soils. However, its inaccuracy due to the presence of residual non-polar but still non-PyC requires additional analysis by C solid-state nuclear magnetic resonance (NMR) spectroscopy, which is expensive and time consuming.

Mulching-induced preservation of soil organic matter quality in a burnt eucalypt plantation in central Portugal.

Mulching has amply proven its effectiveness to mitigate post-fire soil erosion but its impacts on soil organic matter (SOM) quality and quantity continue poorly studied. The present study addressed this knowledge gap for a eucalypt plantation in central Portugal that had been burnt and, immediately after the wildfire, mulched with 13.6 Mg ha of eucalypt logging residues some five years before.

Surfactant properties of humic acids extracted from volcanic soils and their applicability in mineral flotation processes.

Surface Tension (ST) of water solutions of humic acids extracted from volcanic ash derived soils (soil humic acids, S-HA), were measured under controlled conditions of pH (13.0), temperature (25 °C) and ionic strength (NaOH 0.1M) to establish the Critical Micellar Concentration (CMC).

Distribution of black carbon and black nitrogen in physical soil fractions from soils seven years after an intense forest fire and their role as C sink.

After vegetation fires, incorporation of pyrogenic organic matter (PyOM) into soil organic matter (SOM) shifts its composition toward higher aromaticity and to an increase of N-heterocyclic constituents, formerly introduced as black nitrogen (BN). To investigate the medium-term impact of these shifts on the quality of SOM and its role as an important C sink, the A horizon from soils of the fire-prone Sierra de Aznalcóllar (Southern Spain) were sampled 4 weeks and 7 years after a severe fire. The solid-state C and N nuclear magnetic resonance (NMR) spectra of the samples obtained 4 weeks after the fire indicated quick incorporation of PyOM into SOM.

Soil-borne fungi challenge the concept of long-term biochemical recalcitrance of pyrochar.

Pyrogenic organic matter (PyOM) is assumed to be biochemically recalcitrant, but recent studies indicated a quick decrease of PyOM in post-fire soils. Regardless erosion and abiotic degradation, microbial decomposition has been the explanation for this response, but no direct proof has been provided up to now. In the present study, we were able to demonstrate for the first time that the soil-borne fungus Fusarium oxysporum is not only colonizing the pore system of pyrochar (PyC) but is also involved in the degradation of its aromatic network.

Structure of melanins from the fungi Ochroconis lascauxensis and Ochroconis anomala contaminating rock art in the Lascaux Cave.

Two novel species of the fungal genus Ochroconis, O. lascauxensis and O. anomala have been isolated from the walls of the Lascaux Cave, France.

Effects of aging under field conditions on biochar structure and composition: Implications for biochar stability in soils.

The effects of aging on biochar (BC) properties, composition and carbon sequestration are still under debate. This study aimed at illustrating the qualitative alterations of five different BCs aged during a 24-month field experiment located in Southwest Spain. To determine the recalcitrance of each BC, physical fragmentation test, scanning electron microscopy, C NMR spectroscopy and CO-respiration experiments were performed.

Effect of biochar amendment on compost organic matter composition following aerobic composting of manure.

Biochar, a material defined as charred organic matter applied in agriculture, is suggested as a beneficial additive and bulking agent in composting. Biochar addition to the composting feedstock was shown to reduce greenhouse gas emissions and nutrient leaching during the composting process, and to result in a fertilizer and plant growth medium that is superior to non-amended composts. However, the impact of biochar on the quality and carbon speciation of the organic matter in bulk compost has so far not been the focus of systematic analyses, although these parameters are key to determine the long-term stability and carbon sequestration potential of biochar-amended composts in soil.

Post-fire recovery of soil organic matter in a Cambisol from typical Mediterranean forest in Southwestern Spain.

Wildfire is a recurrent phenomenon in Mediterranean ecosystems and contributes to soil degradation and desertification, which are partially caused by alterations to soil organic matter (SOM). The SOM composition from a Cambisol under a Mediterranean forest affected by a wildfire is studied in detail in order to assess soil health status and better understand of soil recovery after the fire event. The soil was sampled one month and twenty-five months after the wildfire.

Toward the Standardization of Biochar Analysis: The COST Action TD1107 Interlaboratory Comparison.

Biochar produced by pyrolysis of organic residues is increasingly used for soil amendment and many other applications. However, analytical methods for its physical and chemical characterization are yet far from being specifically adapted, optimized, and standardized. Therefore, COST Action TD1107 conducted an interlaboratory comparison in which 22 laboratories from 12 countries analyzed three different types of biochar for 38 physical-chemical parameters (macro- and microelements, heavy metals, polycyclic aromatic hydrocarbons, pH, electrical conductivity, and specific surface area) with their preferential methods.

Sorption of hydrophobic organic compounds to a diverse suite of carbonaceous materials with emphasis on biochar.

Carbonaceous materials like biochars are increasingly recognized as effective sorbent materials for sequestering organic pollutants. Here, we study sorption behavior of two common hydrophobic organic contaminants 2,2',5,5'-tetrachlorobiphenyl (CB52) and phenanthrene (PHE), on biochars and other carbonaceous materials (CM) produced at a wide range of conditions and temperatures from various feedstocks. The primary aim was to establish structure-reactivity relationships responsible for the observed variation in CM and biochar sorption characteristics.

Characterization and selection of biochar for an efficient retention of tricyclazole in a flooded alluvial paddy soil.

Biochars, from different organic residues, are increasingly proposed as soil amendments for their agronomic and environmental benefits. A systematic detection method that correlates biochar properties to their abilities to adsorb organic compounds is still lacking. Seven biochars obtained after pyrolysis at different temperatures and from different feedstock (alperujo compost, rice hull, and woody debris), were characterized and tested to reveal potential remedial forms for pesticide capture in flooded soils.

Relating physical and chemical properties of four different biochars and their application rate to biomass production of Lolium perenne on a Calcic Cambisol during a pot experiment of 79 days.

Three pyrolysis biochars (B1: wood, B2: paper-sludge, B3: sewage-sludge) and one kiln-biochar (B4: grapevine wood) were characterized by determining different chemical and physical properties which were related to the germination rates and to the plant biomass production during a pot experiment of 79 days in which a Calcic Cambisol from SW Spain was amended with 10, 20 and 40 t ha(-1) of the four biochars. Biochar 1, B2 and B4 revealed comparable elemental composition, pH, water holding capacity and ash content. The H/C and O/C atomic ratios suggested high aromaticity of all biochars, which was confirmed by (13)C solid-state NMR spectroscopy.

Hydrothermal carbonization of biomass residues: mass spectrometric characterization for ecological effects in the soil-plant system.

Hydrochars, technically manufactured by hydrothermal carbonization (HTC) of biomass residues, are recently tested in high numbers for their suitability as feedstock for bioenergy production, the bioproduct industry, and as long-term carbon storage in soil, but ecological effects in the soil-plant system are not sufficiently known. Therefore, we investigated the influence of different biomass residues and process duration on the molecular composition of hydrochars, and how hydrochar addition to soils affected the germination of spring barley ( L.) seeds.

Ammonoxidised lignins as slow nitrogen-releasing soil amendments and CO₂-binding matrix.

Nitrogen (N) is a major nutrient element controlling the cycling of organic matter in the biosphere. Its availability in soils is closely related to biological productivity. In order to reduce the negative environmental impact, associated with the application of mineral N-fertilizers, the use of ammonoxidised technical lignins is suggested.