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In Australia, quality standards for composts and potting mixes are defined by AS4454–2012 and AS3743–2012. These standards outline key parameters, including physicochemical properties, nutrient content, and plant toxicity. However, they do not address emerging pollutants like microplastics (< 1 mm). This study investigates the prevalence and characteristics of MPs in commercial plant growth substrates (PGS), including nineteen potting mixes and five composts, revealing a significant occurrence of MPs, with concentrations ranging from 233 to 7367 particles Kg−1 and an average of 1869 ± 109 particles Kg−1. MPs categorized by shape, size, and color, with fragments (491 ± 34 particles Kg−1), white colour (3700 ± 917 particles Kg−1), and size 500 µm being predominant. The polymer composition was diverse, with polyethylene being the most prevalent, followed by polypropylene and others. Polyterpene, Polyalkene, Pentaerythritol, and Propylene glycol were identified in PGS for the first time. The structural equation model showed that physicochemical properties like pH, EC, TOC, and heavy metals influence MPs abundance and characteristics. The Polymer Risk Index and Pollution Load Index indicated varying risk levels among the samples. These findings highlight the need to address MPs contamination in PGS to ensure ecosystem safety and human health. [Display omitted] • Microplastics in plant growth substrates ranged from 233 to 7367 particles Kg−1. • A total of nine different polymer types and three additives were identified. • Polyethylene was prevalent polymer categorized as white fragments and sized 500 µm. • Structural equation model finds factors driving microplastic abundance and features. • Study urges revising standards and regulations for plant growth substrate quality. [ABSTRACT FROM AUTHOR]

The issue of solid waste management has become worse as a result of rapid demographic growth and rising urbanisation. Therefore economical, efficient and quick yielding techniques are essential. In this study, composting of agro-wastes i.e., paddy straw, maize stover and vegetable waste with three strains of cellulolytic bacteria (CBC9, CBD4 and CBG2) was performed. The results showed that the C:N ratio of matured compost produced from bacterial inoculation ranged from 14–17:1, nitrification index (NI) ranged from 0.35 to 0.45, Cation exchange capacity (CEC) ranged from 76 to 88 cmol (P+) kg−1, whereas, total N, P and K content of composts increased by 75–127 %, 20–175% and 42–94%, respectively. The recovery of compost was highest in case of paddy straw compost (39%) produced from CBG2 inoculation which was followed by vegetable waste (38%) and maize stover compost (36%) produced from same bacterial inoculation. FT-IR, SEM and EDS studies suggested that final compost produced from inoculation of bacterial strain was more stabilized as compared to un-inoculated control, characterized by a decrease in aliphatic materials and an increase in aromatic groups, presumably related to bio-synthesis of humic substance. [Display omitted] • Cellulose degrading bacteria were efficient in degrading the agro-wastes. • Cellulose degrading bacteria reduced the C:N ratio of the organic wastes to 14–17:1. • Final composts were biologically active. • Impact of isolates on chemical properties during degradation was positive. • Composts were not phytotoxic in nature. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Composts with chicken feathers waste are source of keratinophilic fungi. • Fungal colonizing feathers in composts depend on keratin and non-keratin proteins. • The most dominant keratinophilic species in composts was Aphanoascus keratinophilus. • Strains Aphanoasus keratinophilus have a high keratinolytic activity. • Feather mass loss in pure culture of these fungus was 46%–83.5%. Abstract The aim of the study was to evaluate the diversity and activity of the group of keratinophilic fungi in two composts with different quantitative and qualitative composition of lignocellulosic waste and chicken feathers. From compost I, with a lower feather proportion (3%), and from compost II with a higher feather proportion (13%), 114 and 116 keratinophilic strains, and 318 and 330 non-keratinophilic were isolated, respectively. Among keratinophilic fungi, the majority, i.e., 75% and 85% (compost II and I, respectively) were fungi from the Chrysosporium group. Apart from keratinophilic fungi, native keratin in composts was also inhabited by non-keratinophilic fungi. The dominant in composts keratinophilic species, Aphanoascus keratinophilus , was evaluated for native feather keratin biodegradation in pure cultures. Randomly selected 13 A. keratinophilus strains and, for comparison, one T. terrestre strain, degraded 44–83% of chicken feathers after 4 weeks, which classified these fungi as highly keratinolytic. These fungi synthesized proteo- and keratinolytic enzymes, which was accompanied by the release of soluble proteins and amino acids as well as N and S feather mineralization products. Composts with chicken feathers are a good source of highly keratinolytic fungi that can be used for biodegradtion of keratin waste. [ABSTRACT FROM AUTHOR]

Sewage sludge was generally considered a significant reservoir of antibiotic resistance genes (ARGs) and could enter agricultural systems as fertilizer after composting. Soil types and the discrepancy of sludge composts could have influenced the fate of antibiotic-resistant bacteria (ARB) following the land application of sludge composts, which deserved to be clarified. Thus, the fate of ARB and ARGs following the land application of three types of sludge composts (A, B, and C) to three different soils (red soil, loess, and black soil) was investigated. The results showed that tetX , which was enriched the most during composting, did not affect the soil resistome, whereas tetG did. Soil types influenced the dynamics of ARB and ARGs significantly, whereas no significant difference was observed among compost types. The advantage of reducing ARGs during the composting process in compost B did not extend to land application. Land application of composts influenced the microbial community significantly at the early stage, but the microbial community returned to the control pattern gradually. Changes in the microbial community contributed more to the dynamics of ARGs in red and black soil compared with other factors, including co-selection from heavy metals, horizontal gene transfer, biomass and environmental factors, whereas horizontal gene transfer, reflected by intI1 levels, contributed the most in loess. [ABSTRACT FROM AUTHOR]

Composting is recognised a promising technology for recycling and adding value to agro-food wastes. There are, however, potential environmental risks associated with composting, such as the emission of greenhouse gases (GHGs). The aim of this study was to quantify the emissions of carbon dioxide, methane, nitrous oxide, nitric oxide and ammonia during composting of five agro-food wastes originated from the broccoli, chestnut, olive and grape industries, and to study the relationship between the emissions and the lignin, cellulose, hemicellulose and phenolic contents of the wastes. According to physicochemical indicators monitored during the process, all agro-food residues tested were suitable for composting, with chestnut in the top and broccoli in the bottom of the range. Composting of chestnut and olive led to higher carbon dioxide, methane and nitrous oxide emissions, whereas lower emissions were observed with white grape. A positive correlation was found between phenolics and nitric oxide ( r = 0.63; p < 0.01), but not with the other gases. Lignocellulose showed a positive correlation with nitrous oxide ( r = 0.51; p < 0.05), but not with carbon dioxide and methane. The accumulation of lignin was highest in the chestnut compost, which was associated with lower nitric oxide and ammonia emissions relative to the other waste materials. The results show that wastes with high lignocellulose can be managed using composting with additional benefits on the environment in relation to mitigating nitrogen losses. [ABSTRACT FROM AUTHOR]

Simulated golf greens were used to test the growth of creeping bentgrass ( Agrostis stolonifera L. ‘007′) receiving suboptimal chemical fertilization in sand based substrates amended with 15% peat (control), a commercial biochar, a commercial biochar-compost mixture (CarbonizPN-Soil), or seven formulated biochar-compost mixtures. Physical and chemical properties including pH, bulk density, pore space, compaction distance, nutrient content and water/nutrient retention capacity varied among the mixtures. The heights, root lengths, and fresh and dry weights of creeping bentgrass plants grown in polyvinyl chloride tubes containing the different substrate mixtures mimicking a United States Golf Association root zone were evaluated and compared. Forty days after seeding, plants grown in 5% biochar and 10% Metropolitan Water Reclamation District of Greater Chicago biosolids had significantly greater fresh weights, dry weights, and shoot heights than the control. Dry weights and shoot heights were also higher than the control in bentgrass grown in the 15% CarbonizPN-Soil mixture. Based on these results the addition of these two biochar-organic amendment mixtures would improve overall plant growth in sand-based root zones under reduced chemical fertilization. [ABSTRACT FROM AUTHOR]

Middle and near infrared (MIR and NIR) were employed to determine organic carbon (OC) and total nitrogen (TN) in different soil organic amendments including wastes, composts and mixtures of composts and organic wastes. Prediction models based on partial least squares (PLS) regression from the spectra of untreated samples were built. Different spectra preprocessing strategies were adopted and the best number of latent variable was evaluated using leave-one-out cross-validation. Attenuated total reflectance (PLS-ATR-MIR) and diffuse reflectance (PLS-DR-NIR) models were built and evaluated from root mean square error of cross validation and prediction (RMSECV and RMSEP), coefficients of determination for prediction (R 2 pred) and residual predictive deviation (RPD). ATR-MIR provided a better prediction capability than DR-NIR with RMSEP, R 2 pred and RPD values of 2.2%, 0.76 and 2.0 for OC and values of 0.2%, 0.82 and 2.4 for TN, respectively. [ABSTRACT FROM AUTHOR]

In this study, we developed a new electrochemical process to remove the salts from food wastes. The primary removal mechanisms are washing and electromigration. The screw speed and current were selected as the primary factors influencing the removal of salts. An experimental design was applied in order to determine the optimum conditions for the removal of salts and 82.7% of the salts were removed under some of these conditions. Based on the continuous operation of the apparatus, the criteria for the removal of salts in the food composts could be achieved. [ABSTRACT FROM AUTHOR]

Composts, incorporated in soils as amendments, may release organic contaminants during their decomposition. COP–Soil is presented here as a new model to simulate the interaction between organic contaminants and compost, using one module for organic matter and one for organic pollutants, with these modules being linked by several assumptions. Published results of laboratory soil incubations using labeled carbon pollutants from compost were used to test the model for one polycyclic aromatic hydrocarbon (PAH), two surfactants and one herbicide. Several simulation scenarios were tested using (i) the organic pollutant module either alone or coupled to the organic matter module, (ii) various methods to estimate the adsorption coefficients ( Kd ) of contaminants on organic matter and (iii) different degrading biomasses. The simulations were improved if the organic pollutant module was coupled with the organic matter module. Multiple linear regression model for Kd as a function of organic matter quality yielded the most accurate simulation results. The inclusion of specific biomass in the model made it possible to successfully predict the PAH mineralization. [ABSTRACT FROM AUTHOR]

Improvement of soil characteristics through the use of renewable inputs is fundamental to environmentally friendly farming systems. In the present study, the potential of improving soil properties and, consequently, growth of tomato ( Lycopersicon esculentum L.) seedlings through a direct incorporation of aromatic plant tissues into seedbeds is assessed. Dried spearmint ( Mentha spicata L.) and sage ( Salvia fruticosa Mill.) tissues are incorporated at different rates into the soil of experimental field plots. At 0, 20, 40, 60, and 90 days following incorporation, soil samples are removed from the plots and used as substrates in tomato seedbeds. Growth and physiological parameters of tomato seedlings (emergence, size of the most robust leaf, shoot length, dry weight, net photosynthetic rate, stomatal conductance, photosynthetic yield) as well as soil attributes (pH, nitrogen and organic carbon content, organic matter decomposition rate, microbial populations, changes in essential oil content) are monitored. Spearmint incorporation into the soil improved emergence, physiology and growth of tomato seedlings. This was not the case with sage. Soil microbial populations and organic matter decomposition increased with increasing rate of incorporated aromatic plant tissues, especially in the case of spearmint which exhibited a more prominent increasing trend. Soil pH was not affected, remaining within the range for optimum tomato growth. Further, C:N ratio increased, yet it did not inhibit tomato growth. Lastly, the observed decrease with time of the essential oil content in soil was dependent on the aromatic plant incorporated, and is discussed in relation to the beneficial effects of spearmint on tomato growth. The herein undertaken study demonstrates that incorporating intact spearmint tissues into the soil is a promising tool for improving tomato seedling production. This practice circumvents the arduous composting process and, therefore, it can be more cost-and-time-effective compared to the currently applied techniques. [ABSTRACT FROM AUTHOR]

Abstract: The effectiveness of compost supply at several doses (0, 50, 100, and 150t/ha) to a saline soil was studied using municipal solid waste (MSW) and palm waste (PW) composts. The experiment was carried out in pots under cultivation of Polypogon monspeliensis (halophyte forage species) and Hordeum vulgare (common forage species) and lasted three months. The investigation focused on some selected soil physico-chemical properties, soil microbial biomass, and ten soil enzymatic activities; Arylsulfatase (ARY), dehydrogenase (DEH), β-glycosidase (β-GLU), protease (PRO), urease (URE), invertase (INV), Fluorescein diacetate hydrolase (FDAH), catalase (CAT), acid and alkaline phosphatases (PHO). Both amendments improve markedly the saline soil quality. They ameliorate the physico-chemical properties. The increase of soil pH is regarded as an interesting fact and is usually proportional to the compost application rate. Electrical conductivity increased proportionally to the applied rates. Soil carbon and nitrogen amounts were also improved and the highest raise (7.5-folds) was noted for carbon. According to the substantial increase of the organic matter, levels of measured microbial biomass and several enzyme activities in saline soil were improved. DEH activity which proposed as a measure of overall microbial activity exhibited a significant increase only at dose 2 (100t/ha). Consequently, One hundred tones of composts per hectare, under which some enzymes exhibited an optimal of activity and metal accumulation can be minimized, appeared an interesting rate for saline soil amendment. [Copyright &y& Elsevier]

Abstract: Banana production has been severely hindered by fusarium wilt disease. The application of organic amendments to soil has been proposed as a strategy for management of the soil borne disease. The one-year effects of different composts and bio-organic fertilizer (BIO) on banana fusarium wilt disease incidence, crop yield, crop quality, and the soil microflora were investigated in field condition. A plate count method, real-time PCR, and PCR-DGGE were used to investigate the soil microflora. The BIO application more effectively controlled fusarium wilt disease. The highest total soluble sugars (TSS) to titratable acidity (TSS/TA) ratios, banana yield, culturable and total soil bacteria populations, and culturable actinobacteria population were observed from the BIO treatment. The ratio of bacteria to fungi (B/F) and actinomycetes to fungi (A/F) values from the plate count method and the B/F value from the real-time PCR analysis were also highest in the soils collected from the BIO application. Based on PCR-DGGE results, the soil bacteria structure was significantly altered in the soils collected from BIO treatment compared to the other treatments. All the results confirmed that application of bio-organic fertilizer could more effectively control fusarium wilt disease in field conditions by improving soil microbial communities. [Copyright &y& Elsevier]

Abstract: Multi-compartment soil carbon (C) simulation models such as RothC are widely used for predicting changes in C stocks of arable soils. However, rigorous routines for establishing entry pools that account for the diversity of exogenous organic matter (EOM) applied to croplands are still lacking. We obtained data on changes in soil C stocks after repeated applications of EOM from four long-term experiments (LTEs): Askov K2 (Denmark, 31 yrs), Qualiagro (France, 11 yrs), SERAIL (France, 14 yrs) and Ultuna (Sweden, 52 yrs). The adjustment of the partition coefficients of total organic C in EOM (EOM-TOC) into the labile, resistant and humified entry pools of RothC (f DPM, f RPM, f HUM, respectively) provided a successful fit to the accumulation of EOM-derived C in the LTE soils. Equations estimating the EOM partition coefficients in the RothC model were based on an indicator (I ROC) of the EOM-TOC potentially retained in soil. I ROC was derived from the C found in the soluble, lignin + cutin-like and cellulose-like Van Soest fractions and the proportion of EOM-TOC mineralized during 3 days of incubation. Using the EOM partition coefficients derived from these laboratory analyses resulted in RothC simulations with only slightly larger errors than simulations based on partition coefficients fitted from LTE soil data, except for EOMs that caused very large accumulations of C in soil (e.g. peat) possibly due to factors not accounted for in the RothC model, such as change in soil pH. The proposed partitioning of EOM-TOC allows the potential soil C storage after EOM applications to be predicted regardless of field location and specific composition of EOMs. [Copyright &y& Elsevier]

Abstract: An investigation was conducted to evaluate the potential of antagonistic cyanobacteria/bacterial cultures amended compost and compost tea preparations for suppressing diseases caused by plant pathogenic fungi Fusarium oxysporum, Pythium debaryanum, Pythium aphanidermatum and Rhizoctonia solani in tomato. Two types of microbe-fortified composts and the compost tea preparations, along with the recommended biological control (Trichoderma formulation) and chemical control (Thiram-Carbendazim), were used for inoculating the potting mixture. Comparative performance of the treatments revealed the superiority of both the composts/compost tea preparations in enhancing seed germination, seedling length and biomass in the fungi challenged treatments. The most effective control of the diseases was obtained by the composts amended with Anabaena oscillarioides C12 and Bacillus subtillis B5 and the compost tea preparations. Both treatments provided significantly better control than the other treatments in terms of reduction in disease severity, reduction of fungal load and enhancement of plant parameters. Our study reveals the efficacy of microbe-fortified composts for use in control of the studied root diseases caused by phytopathogenic fungi. [Copyright &y& Elsevier]

Abstract: This research aimed at assessing the chemical changes occurring in DOM extracted from different composting substrates by means of 13C CPMAS NMR spectroscopy. During composting a reduction of carbohydrates and an increase of aromatic, phenolic, carboxylic and carbonylic C were observed. The highest increase in alkyl C and the lowest increase in aromatic C were explained by the presence of hardly degradable pine needles in the substrate, whereas the highest reduction in carbohydrates and the highest increase of the alkyl C/O-alkyl C ratio were attributed to the presence of highly degradable materials such as spent yeast from beer production. [Copyright &y& Elsevier]

Abstract: The aim of this research was to study the potential utilization of containerized substrates developed from cattle manure compost (CMC) and synthetic aggregates (SA) on the growth and nutrition composition of ornamental French marigold (Tagetes patula). Unconventional SA were produced from low productive acidic red soil with paper waste and starch waste. CMC was prepared from cattle manure and wood chips. Growth substrates were prepared by mixing CMC at the rates of 0%, 20%, 40%, 60% and 100% with SA at 100%, 80%, 60%, 40% and 0%, respectively. Peat only was used as the control. The physical and chemical characteristics of all containerized substrates were analyzed. CMC–SA based substrates showed adequate physical and chemical properties compared to peat for their use as containerized substrates in horticulture. In relation to the plant growth in peat control, plants grown in the CMC–SA based substrates reached better growth and nutrition. The highest plant height, number of flowers per plant, shoot fresh weight, shoot dry weight, root length, root fresh weight and root dry weight obtained from the mixture of CMC and SA at 40% and 60% treatment were increased by 27.01%, 42.86%, 37.09%, 67.29%, 5.14%, 45.58% and 34.26%, respectively compared to peat control. The concentration of trace elements in plant tissues was far lower than the ranges considered phytotoxic for plants. Utilization of CMC and SA can be considered as alternative substrates to substitute the widely using expensive peat in horticulture. [ABSTRACT FROM AUTHOR]

Abstract: Effect of partial substitution of peat in growth media by sewage sludge sugarcane trash based compost (SSC) and synthetic aggregates (SA) on the physical and chemical characteristics of the growth media and on the growth and nutrition of lettuce (Lactuca sativa L.) grown in the substituted media was investigated under this study. SSC was produced from sugarcane trash and sewage sludge. Unconventional SA were produced by low productive acidic red soil with paper waste and starch waste. The treatments assayed were: SSC (40%)+Peat (60%), SA (40%)+Peat (60%), SSC (60%)+SA (40%), SSC (40%)+SA (20%)+Peat (40%) and SSC (40%)+SA (40%)+Peat (20%). Peat only was used as the control. The physical and chemical properties of all growing media were analyzed. SSC–SA based substrates showed adequate physical and chemical properties compared to peat for their use as growing media in horticulture. In relation to the plant growth in peat control, plants grown in the SSC–SA based substrates reached better growth and nutrition. The concentration of trace elements in plant tissues was far lower than the ranges considered phytotoxic for plants. Utilization of SSC and SA can be considered as an alternative media component to substitute the widely using expensive peat in horticulture. [Copyright &y& Elsevier]

Abstract: Humic-like acids (HLA) were extracted from compost at the beginning and after 70, 130 and 730days of maturation in order to be investigated for their ability to induce the transformation of 2,4,6-trimethylphenol under irradiation at 365nm. The rate of 2,4,6-trimethylphenol phototransformation in the presence of HLA (25mgl−1) varied within HLA0 <

Abstract: In this study, the effect of a partial substitution of peat for compost on the growth and nutrition of a native shrub (Pistacia lentiscus L.) was tested. Composts were prepared from pruning and municipal solid wastes or pruning waste and sewage sludge. For preparing growing media each compost was added at a rate of 40%, fresh pine bark at 20% or 40% and peat at 20%, 40% or 60%. Aqueous extracts from the substrates did not impair germination of cress (germination bioassay). In relation to plants growing in peat-based substrate (used as a control), plants of the compost-based substrates reached better growth and nutrition, especially when using the sewage sludge-based compost, and the P uptake was notably enhanced. The concentrations of trace elements were far lower than the ranges considered phytotoxic for vascular plants. Detrimental effect derived from using fresh pine bark was not observed. [Copyright &y& Elsevier]

Abstract: In Austria, farm animals are estimated to produce about 20×106 ton of excrements annually. In order to predict possible changes of the inorganic compositions of the target soils from various organic fertilizers, mean compositions of excrements, composts and sewage sludges have been compiled on a dry weight basis. Although the high amounts of K and P were beneficial, there were some high concentrations of Na in biogas residues and pig manures. Intense additions of Cu, Zn, and Se are reflected in high loads in the respective excrements, and these amounts in some instances exceeded the threshold limits for soil contamination. Selenium addition to arable soils can be regarded as beneficial, however, as Austria is a low Se area. Composts and sewage sludges were higher in Al and lithophilic trace elements than were the excrements. Factor analysis traced phosphates as the main source of Cd. Cr in processed matrices was significantly higher, and abrasion from tools should be considered in future investigations. Other unwanted trace elements, like Ni, Pb, As and Hg, were found at a rather low concentration. [Copyright &y& Elsevier]

Abstract: To inform decisions on improving the yields of African catfish Clarias gariepinus fingerlings in earthen ponds, the hypothesis that composts and leaks were partly responsible for usually low and variable fry survivals was tested, through comparison of treatments and simple regression. The occurrence of amphibians was significantly higher (P <0.05) and survival of fry was significantly lower (P <0.02) in ponds with composts than in those without. The survival of fry and fingerlings in earthen ponds was negatively correlated with their night leaking rates and regression analysis yielded the equations y =−13.31x +82.56 for fry and y =−6.97x +95.29 for fingerlings, where y is the survival of fry or fingerlings in a holding pond and x is the leaking rate of the pond. Realizing how negatively the existence of composts and leaks could affect the survival of fry and fingerlings, fertilizing unfenced ponds with composts and sterilizing nursery ponds by drying were proscribed. [Copyright &y& Elsevier]

Abstract: Animal compost, organic fertilizer and straw management are among the factors affecting soil fertility in organic cropping systems. However, few studies have compared the effects of organic amendments on soil fertility of organic paddy fields. We conducted a survey of organic farmers’ paddy fields to compare soil nutrients (N, P, K, Ca and Mg), nutrient budgets and partial factor productivity of N (PFPN), and to relate them to organic amendments. The study fields were located in the Higashi Okitama area (38°N, 140°E) of Yamagata prefecture, Japan, and organically managed by a group of farmers using their management standard. Soil samples from 40 rice fields were collected in October 2001. The fields were grouped into three types in terms of organic amendments: application of cattle/chicken compost and straw incorporation (CA), application of cattle composts and straw removal (CR), and straw incorporation only (FA). Purchased organic fertilizers were applied to all the fields. Most of the fields had received the same managements for 5 years or more prior to the survey. Organic amendments had significant effects on pools (the amount of nutrients to 0.4m depth) of Bray-2 P and NH4OAC extractable K, input, output and balances of the nutrients. Annual surpluses of N, P, K, Ca and Mg (+100, +102, +130, +133 and +33kgha−1, respectively) were found in the CA field due to the compost application, but K balance of the CR field was −27kgha−1. Nutrient budgets were well balanced in the FA field, but NH4OAC extractable K in the FA soil was lower than the medium range of the conventional soil diagnosis by 37mgkg−1, suggesting K depletion. The pools of Bray-2 P and NH4OAC extractable K were correlated with balances of P and K (r =0.597 and 0.540, P &#60;0.001), but those of NNM, total N and NH4OAC extractable Ca and Mg were not related with nutrient balances (P >0.05). PFPN of the FA fields (89kgkg−1) was twice as high as that of the CR and CA fields (45 and 37kgkg−1). The former value was comparable to PFPN (78kgkg−1) of conventional rice fields with mineral fertilizer use of the surrounding area. Two alternative scenarios for fine-tuning nutrient inputs in organic farming practices are better compost quality and reallocation of chicken/cattle compost among organic rice fields. [Copyright &y& Elsevier]

Quantitative electron paramagnetic resonance (EPR) method was applied to characterise radicals stabilised in polyphenolic matrices of various biogenic materials: lichens, mosses, composts, soils, peats, brown coals and sewage sludge sediments. The investigations were carried out on raw materials and extracted fractions of humic acids (HA). General trends of g value and spin concentration changes were found. These parameters in lichens strongly depend on lichen species and air pollution. Determination of the g value and semiquinone spin concentration allows to assess degree of transformation of organic matter in compost, soil, peat and lignite. Application of gaseous ammonia as a base penetrating the organic matrices extends the possibilities and usefulness of the method. Interaction of metal ions with humic materials is illustrated by interaction of VO2+ ion with peat and lignite HA as well as demineralised (raw and carbonised) brown coal. Our investigations demonstrate that quantitative EPR is a rapid and effective monitoring method to study the influence of various environmental factors on substances containing polyphenolic matrices. [ABSTRACT FROM AUTHOR]

The environmental problems associated with raw poultry manure application could be mitigated by stabilizing its nutrient and organic matter (OM) contents by composting before application to agricultural soils. In the present study, quantitative changes in physical, chemical, and microbial properties of poultry litter (a mixture of poultry manure, wood shavings, waste feed, and feathers) were studied in order to understand the composting process and evaluate the suitability of the composted product as a soil amendment. The poultry litter was composted in forced-aeration piles. Results of this study showed that the poultry litter went through physico-chemical and microbial changes similar to other composting systems, including changes like self-heating of the compost mass, relative increases in total Cu, Zn, P, K, and NOx−-N and decreases in microbial population numbers, C, OM, and extractable C, Cu, Zn, and NH4+-N contents. Despite differences in thermophilic temperatures at different locations of the forced-aeration piles, temperatures in these locations reached ambient level almost at the same time by day 128, indicating that the poultry litter was becoming stable. Nitrogen loss was a major problem during composting of poultry litter, even when the piles were not turned under the forced-aeration system. About 18 kg of the initial N (58% of the initial N) was lost during composting, which indicates that composting reduced the value of the poultry litter as N fertilizer. However, the composted litter contained a more humified (stabilized) OM compared with the uncomposted litter, which could enhance its value as a soil conditioner. In conclusion, composting of poultry litter converted the soluble nutrients to more stable organic forms, thereby reducing their bioavailability and susceptibility to loss when applied to crop fields. [Copyright &y& Elsevier]