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In this study, kitchen waste which is otherwise discarded or allowed to putrefy and pose environmental discomfort is co-composted with biochar to assess the effects of the biochar on the composting of kitchen waste as well as the quality of the final compost. To achieve this, biochar was composted with kitchen waste (w/w) in ratios of 10%, 20%, 30%, and 40% to determine its effect on composting process and the final compost product compared to cow dung-fortified kitchen waste as a control. Results indicate that pH and EC were not affected by biochar content during composting; however, biochar content had a profound effect on the attainment of thermophilic temperatures during composting, nitrification and other maturity/stability indexes such as germination index (GI), humification index (HI), degree of polymerization (DP) and HA/FA ratio. In effect, higher biochar content (more than 10% biochar/feedstock ratio) favored faster humification, higher available P and S content. [ABSTRACT FROM AUTHOR]

Biosurfactants account for about 12% of the global value of the surfactant market, which is currently dominated by synthetic surfactants obtained from fossil sources. Yet, the production of biosurfactants from renewable feedstock is bound to increase, driven by the increasing pressure from both society and governments for chemistry-based industries to become more ecofriendly and economically sustainable. A photo-chemical oxidation process is reported here, yielding new biosurfactants from urban biowaste in water that perform as a solvent and terminal oxidant reagent at room temperature without the addition of conventional oxidants and catalysts. Products with 200–500 kDa molecular weight are obtained. They lower the surface tension of water down to 34 mN/m at 0.5–2 g/L concentration. The estimated cost is rather low (0.1–1.5 EUR/kg), which is competitive with the cost of synthetic surfactants but much lower than the cost of the best-performing bacterial surfactants. For the implementation of the photo-chemical oxidation process at the industrial level, the results suggest that the new biosurfactants obtained in the present work may not reach the performance level of the best-performing bacterial surfactants capable of lowering the surface tension of water down to 28 mN/m. Yet, the biosurfactants produced by the photo-chemical process have a greater chance of being marketed on large scales. [ABSTRACT FROM AUTHOR]

The paper discusses the perspectives of further implementation of the autocatalytic properties of a soluble biopolymer (SBP) derived from municipal biowastes for the realisation of a biorefinery producing value-added bio-products for consumer use. The reaction of an SBP and water is reported to cause the depolymerisation and oxidation of the pristine SBP organic matter with the formation of carboxyl-functionalised polymers having lower molecular weight and CO2. These findings demonstrate the oxidation of the SBP via water, which could only occur through the production of O and OH radicals catalysed by the SBP. According to the adopted experimental plan, the anaerobic digestate supplied by an Italian municipal biowaste treatment plant was hydrolysed in pH 13 water at 60 °C. The dry product was re-dissolved in plain water at pH 10 and used as a control against the same solution with hydrogen peroxide at 0.1–3 H2O2 moles per SBP carbon mole added. The control and test solutions were kept at room temperature, in the dark or in a climatic chamber under irradiation with simulated solar light, until the pH of the solutions remained constant. Afterwards, the solutions were processed to recover and analyse the crude soluble products. The present work reports the results obtained for the control solution and for the test solutions treated in the presence and absence of H2O2, with and without pH control, in the dark and under irradiation with simulated solar light. [ABSTRACT FROM AUTHOR]

Composting is one of the best organic waste management techniques, with zero waste; however, it generates environmental impacts. The objective of this study was to evaluate the emission of NH3, N2O, CO2, and CH4 from the composting of olive, elderberry, and grape agro-food waste. The experiment was carried out using reactors receiving straw as control and three treatments receiving mixtures of straw and olive, elderberry, or grape wastes. The gas emissions were measured for 150 days, and the composition of the mixtures and composts was determined. The results showed NH3 and CH4 emissions were reduced by 48% and 29% by the Olive and Elderberry treatments, while only NH3 loss was reduced by 24% by the Grape treatment. Nitrous oxide, CO2, and GWP emissions were reduced by 46%, 32%, and 34% by the Olive treatment, while these losses were not reduced by the Elderberry or Grape treatments. It can be concluded olive waste can effectively reduce NH3 and GWP, while elderberry and grape wastes are also effective in reducing NH3, but not GWP. Thus, the addition of agro-food waste appears to be a promising mitigation strategy to reduce gaseous losses from the composting process. [ABSTRACT FROM AUTHOR]

Composting is one of the best organic waste management techniques, with zero waste; however, it generates environmental impacts. The objective of this study was to evaluate the emission of NH3, N2O, CO2, and CH4 from the composting of olive, elderberry, and grape agro-food waste. The experiment was carried out using reactors receiving straw as control and three treatments receiving mixtures of straw and olive, elderberry, or grape wastes. The gas emissions were measured for 150 days, and the composition of the mixtures and composts was determined. The results showed NH3 and CH4 emissions were reduced by 48% and 29% by the Olive and Elderberry treatments, while only NH3 loss was reduced by 24% by the Grape treatment. Nitrous oxide, CO2, and GWP emissions were reduced by 46%, 32%, and 34% by the Olive treatment, while these losses were not reduced by the Elderberry or Grape treatments. It can be concluded olive waste can effectively reduce NH3 and GWP, while elderberry and grape wastes are also effective in reducing NH3, but not GWP. Thus, the addition of agro-food waste appears to be a promising mitigation strategy to reduce gaseous losses from the composting process.

Reusing organic wastes in land applications would enhance the recovery of resources, following the concepts of the circular economy. The sugarcane-based sugar industry produces various by-products (e.g., sugarcane filter mud, molasses, and bagasse) that have the potential to contribute to crop production and soil fertility, owing to their high contents of organic matter and nutrients. Although the agricultural benefits of compost utilization in agriculture have been well-documented, to the best of our knowledge, few scientific data are currently available on the effects of sugarcane filter mud combined with the application of compost for increasing crop production. Thus, a field experiment was carried out to study how sugarcane filter mud, in combination with two compost sources, affected the growth and yield of sweet maize (Zea mays var. saccharata). We compared (i) two types of compost made from brassica residue and household waste applied at a rate of 9 t ha−1, and (ii) two application rates of sugarcane filter mud: 0 and 2 t ha−1 to two controls without any compost application: one with (+SFM) and one without (−SFM) sugar filter mud. The results highlighted that all crop growth and yield parameters benefited more from the domestic waste compost than from the brassica straw compost. Moreover, the addition of sugar filter mud to the compost further boosted the crop performance. Based on the above results, we concluded that the addition of sugarcane filter mud to locally available composts is a feasible approach for more sustainable production of sweet maize, combining efficient waste disposal and the provision of organic matter to the soil. [ABSTRACT FROM AUTHOR]

Cacao (Theobroma cacaoL.)yieldin Tumaco, Nariño, is one of the lowest in Colombia, making this activity unattractive to farmers, despite having one of the best cacaos in the world. Researchers affirm that proper crop management and nutrition of cacao plants are the most effective alternatives to increase cacao yields. Therefore, this research aims to evaluate the effect of organic and mineral fertilization on the yield of cacao clones in an agroforestry system for two years. We used a randomized complete block design by arranging treatments in split plots, being three cacao clones (CCL1, CCL2, and CCN51) the main plot and different fertilization regimes (chemical, organic, and a mixture of chemical and organic fertilizers) the subplots plus a control. The variables assessed were number of pods per tree, pod weight, number of grains per pod, fresh and dry grain weight ratio, and quality parameters of the dry grains. The results showed that the local clone CCL2 had a higher yield than the regional average (1.5 vs. 0.3 t, respectively) under mineral fertilization. The CCL2 and CCN51 exceeded the break-even point for cacao in Tumaco. The economic analysis further showed that for each Colombian peso invested in fertilizers for the regional clone CCL2, the farmer recovers COP 4.7. To sum up, the selection of outstanding regional clones together with their fertilization is a viable alternative to increase cocoa yield in Tumaco, Colombia.

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]

Following soil disturbances, establishing healthy roadside vegetation can reduce surface water runoff, improve soil quality, decrease erosion, and enhance landscape aesthetics. This study explores the use of organic soil amendments (OAs) as alternatives to conventional vegetation growth approaches, aiming to provide optimal compost mixing ratios for poor soils, and clarify guidelines for OAs' use in roadside projects. Three sandy loam soils and one loam soil were chosen for the study. Organic amendments included yard waste (Y), food waste (F), turkey litter and green waste-based (T) composts, and wood-derived biochar (B). Treatment applications targeted specific increases in the organic matter (OM) percentage of the soils. A selection of seven native species (grasses and forbs) in a total of 156 pots (4 control soils + 4 soils x 4 OAs x 3 application rates, all prepared in triplicates) was used for the pot study experiment. A significant correlation between electrical conductivity (soluble salts) in soil-OA blends and corresponding percent green coverage (%GC) was found. High salts from the T compost either delayed or curtailed growth. Notably, 3 out of the 4 soils amended with biochar exhibited rapid vegetation coverage during initial growth stages compared to other soil-OA blends but reduced the nitrogen (N) uptake and leaf area in black-eyed Susan (BES) plants. In contrast, N uptake was higher in the BES plants emerging from composts T, F, and Y compared to biochar. It is recommended to minimize concentrated manure-based (e.g., turkey litter) composts for roadside projects as an OM source, and alternatively, enriching wood-based biochar with nutrients when used as a soil amendment. Within the current study, composts such as F and Y were well-suited to establish healthy and long-lasting vegetation. [Display omitted] • Plant coverage negatively correlated with soil soluble salts content. • Soluble salts present in the manure-based compost impeded plant growth. • While biochar improved plant coverage, it also caused N deficiencies in the plants. • Composts made from food waste and yard waste were found suitable for roadsides. • A correlation was demonstrated between plant nitrogen and leaf area index. [ABSTRACT FROM AUTHOR]

Sustainable peat alternatives, such as composts and management residues, are considered to have beneficial microbiological characteristics compared to peat-based substrates. Studies comparing microbiological characteristics of these three types of biomass are, however, lacking. This study examined if and how microbiological characteristics of subtypes of composts and management residues differ from peat-based substrates, and how feedstock and (bio) chemical characteristics drive these characteristics. In addition, microbiome characteristics were evaluated that may contribute to plant growth and health. These characteristics include: genera associated with known beneficial or harmful microorganisms, microbial diversity, functional diversity/activity, microbial biomass, fungal to bacterial ratio and inoculation efficiency with the biocontrol fungus Trichoderma harzianum. Bacterial and fungal communities were studied using 16S rRNA and ITS2 gene metabarcoding, community-level physiological profiling (Biolog EcoPlates) and PLFA analysis. Inoculation with T. harzianum was assessed using qPCR. Samples of feedstock-based subtypes of composts and peat-based substrates showed similar microbial community compositions, while subtypes based on management residues were more variable in their microbial community composition. For management residues, a classification based on pH and hemicellulose content may be relevant for bacterial and fungal communities, respectively. Green composts, vegetable, fruit and garden composts and woody composts show the most potential to enhance plant growth or to suppress pathogens for non-acidophilic plants, while grass clippings, chopped heath and woody fractions of compost show the most potential for blends for calcifuge plants. Fungal biomass was a suitable predictor for inoculation efficiency of composts and management residues. [ABSTRACT FROM AUTHOR]

Sustainable peat alternatives, such as composts and management residues, are considered to have beneficial microbiological characteristics compared to peat-based substrates. Studies comparing microbiological characteristics of these three types of biomass are, however, lacking. This study examined if and how microbiological characteristics of subtypes of composts and management residues differ from peat-based substrates, and how feedstock and (bio)chemical characteristics drive these characteristics. In addition, microbiome characteristics were evaluated that may contribute to plant growth and health. These characteristics include: genera associated with known beneficial or harmful microorganisms, microbial diversity, functional diversity/activity, microbial biomass, fungal to bacterial ratio and inoculation efficiency with the biocontrol fungus Trichoderma harzianum. Bacterial and fungal communities were studied using 16S rRNA and ITS2 gene metabarcoding, community-level physiological profiling (Biolog EcoPlates) and PLFA analysis. Inoculation with T. harzianum was assessed using qPCR. Samples of feedstock-based subtypes of composts and peat-based substrates showed similar microbial community compositions, while subtypes based on management residues were more variable in their microbial community composition. For management residues, a classification based on pH and hemicellulose content may be relevant for bacterial and fungal communities, respectively. Green composts, vegetable, fruit and garden composts and woody composts show the most potential to enhance plant growth or to suppress pathogens for non-acidophilic plants, while grass clippings, chopped heath and woody fractions of compost show the most potential for blends for calcifuge plants. Fungal biomass was a suitable predictor for inoculation efficiency of composts and management residues.

Stem rot caused by Sclerotium rolfsii is one of the most devastating disease in tomato. An integrated management strategy implementing potential biotool is required to control this disease. Thus, five on-farm composts were evaluated for their ability to control tomato stem rot and to promote plant growth. The tested composts, except C1, were effective in decreasing disease severity from 31.2 to 56.2%, with a significant similarity between pathogen-inoculated plants treated with C3 and C4 and disease-free and untreated controls. Treatments with C2 and C4 had significantly enhanced most tomato growth parameters: stem diameter, and dry weights of aerial part and roots. A similar effect was noted for C3-based treatment on the plant height, the stem diameter, and the root dry weight where the recorded increments as compared to control were estimated at 16.9%, 23.8%, and 80%, respectively. Tested on S. rolfsii-free plants, compost C4was the most efficient in improving all tomato growth parameters by 28.8, 8.54, 92.2 and 80% in their height, stem diameter and aerial part and root dry weights, respectively. A similar significant effect was observed on tomato plants challenged with composts C2 and C3. This work demonstrated the ability of composts to control tomato stem rot and to enhance the plant growth. [ABSTRACT FROM AUTHOR]

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Reusing organic wastes in land applications would enhance the recovery of resources, following the concepts of the circular economy. The sugarcane-based sugar industry produces various by-products (e.g., sugarcane filter mud, molasses, and bagasse) that have the potential to contribute to crop production and soil fertility, owing to their high contents of organic matter and nutrients. Although the agricultural benefits of compost utilization in agriculture have been well-documented, to the best of our knowledge, few scientific data are currently available on the effects of sugarcane filter mud combined with the application of compost for increasing crop production. Thus, a field experiment was carried out to study how sugarcane filter mud, in combination with two compost sources, affected the growth and yield of sweet maize (Zea mays var. saccharata). We compared (i) two types of compost made from brassica residue and household waste applied at a rate of 9 t ha−1, and (ii) two application rates of sugarcane filter mud: 0 and 2 t ha−1 to two controls without any compost application: one with (+SFM) and one without (−SFM) sugar filter mud. The results highlighted that all crop growth and yield parameters benefited more from the domestic waste compost than from the brassica straw compost. Moreover, the addition of sugar filter mud to the compost further boosted the crop performance. Based on the above results, we concluded that the addition of sugarcane filter mud to locally available composts is a feasible approach for more sustainable production of sweet maize, combining efficient waste disposal and the provision of organic matter to the soil.

The effect of different composts and their chemical composition on soil C and N mineralisation and greenhouse gas (GHG) emissions was explored by determining NH4+ and NO3− dynamics and monitoring CO2, N2O and CH4 fluxes from amended soils under laboratory conditions. Eight different composted agro-industrial wastes were incubated with a clay soil for 55 days at 20 °C and 60% water-holding capacity (WHC). Mineralisation of the C added to the soils was directly correlated to C/N, total phenolic/N, gallic acid/N and NH4+ and negatively correlated with total organic N (TON) and lignin content of the composts. Soils amended with straw compost presented the highest C mineralised with significantly higher CO2 emissions throughout the incubation period. N mineralisation was only negatively correlated with C/N ratio and straw compost exhibited a significant and strong immobilisation when compared with the rest of treatments. The study demonstrates that the C/N ratio by itself is not suitable for predicting N mineralisation. The results revealed that composts with high initial soluble N contents and narrow C/N ratio, as in the case of coffee grounds, produce higher N2O emissions. With the exception of mimosa (Acacia dealbata) and coffee grounds that behave as sources of methane, soils amended with composts displayed an overall sink effect for methane. These findings reveal that the effect of compost incorporation on GHG emissions depends essentially on their chemical composition. [ABSTRACT FROM AUTHOR]

Rational use of methods and means of biological reclamation on drained lands creates conditions to obtain the planned harvest of good quality, to prevent soil degradation, and to provide possible detoxication of the soil cover, water sources, and agricultural products. This work shows the role of biological reclamation on drained lands based on the use of three classes of reclamation agents: organic fertilizers, fertilizing biological preparations, and phytoameliorants. The class of organic fertilizers is the most widely used on drained soils. It is dominated by manure, bird droppings, and compost formed on their basis. Technologies for compost production from organic materials are constantly improved, with the use of the method of biological aerobic solid-phase fermentation in particular. The product of bioconversion of organic materials—multipurpose compost—is characterized by a high content of nutrients (2.5–2.7% of total nitrogen; 2.0–2.2% of phosphorus; and 1.5–1.7% of potassium) and by a number of other favorable properties. The use of Galéga orientális as a phytoameliorant on drained lands enables the accumulation to 480 kg/ha of nitrogen per year due to the legume-rhizobial symbiosis. Biological products of a complex bioameliorative effect provide a favorable nutrition regime for crops cultivated on reclaimed soils. [ABSTRACT FROM AUTHOR]

Introduction: This paper presents the preliminary results of a study that aims to emphasize the compost effect, when used as fertilizer, in Aronia melanocarpa crops [...]

Soil amendments from peats, brown coals and composts produced from segregated biodegradable waste or biomass from fallow land can increase soil fertility and improve soil productivity. The aim of the study was to determine the possibility of using willow (Salix viminalis L.) biomass composts as a substrate component in horticulture. The objects of the research were composts produced from willow carried out in a pile under aerobic conditions. The addition of hay and mineral nitrogen (Nmin) was used to improve process efficiency. In order to verify the type and determine fertilizing value, basic chemical parameters were analyzed (pH, total contents of C, N and P) and a pot experiment was established to analyze the germination and growth of lettuce (Lactuca sativa L.). Changes in pH, an increase in total nitrogen content (TN), phosphorus (TP) and a decrease in TOC was observed in the investigated samples. Results of the experiment showed that the highest yield was obtained from the pots with the mixture of willow, hay and Nmin. Matured composts significantly stimulated the germination and growth of the test plants. It can be concluded that the addition of hay and Nmin significantly improved composting process and increased the fertilizing value of the investigated composts.

One of the main tasks for every certified organic vegetable producer is to grow healthy and well-developed transplants. The aim of this study was to examine different substrates designed for the production of organic tomato transplants. On the basis of preliminary experiments, seven substrates consisting of different parts of natural peat, vermicompost, shrub and tree leaves compost and zeolites were compared with standard commercial substrates using tomato (Solanum lycopersicum L.) transplants grown in pots. The data concerning plant height, number of leaves, fresh plant mass, appearance of flower buds were collected. The differences in the examined traits were not significant for the majority of substrates. The zeolite-based substrate with high peat and vermicompost content achieved the best results and its production for the market should be considered. Three zeolite-based substrates with high rates of vermicompost and compost should be used as a model for tomato transplants substrate preparation.

High nitrogen use efficiency (NUE) is important for improving crop yield. There are many nitrogen (N) fractions in soil and their uptake by crops varies. Most of the N that is taken up by plants is not native to the soil but usually from fertilizer added to the soil. However, the unbalanced use of fertilizers is currently an important issue that needs to be addressed. The objectives of this work were to determine the effects of using the recommended chemical fertilizers together with inorganic and organic amendments on (i) soil organic and inorganic N fractions, (ii) N uptake and use efficiency, and (iii) maize (Zea mays L.) dry matter production and ear yield. A randomized complete block design field trial, using maize as a test crop, was done with seven fertilizer treatments, each replicated thrice for two crop cycles. The treatments included different combinations of urea N, clinoptilolite zeolite (CZ), rice straw compost, and paddy husk compost. The variables of the study were soil N fractions, ear yield, and N use efficiency. Generally, the combined use of the recommended chemical fertilizers with CZ and organic amendments resulted in significantly higher soil N fractions, N use efficiency, and ear yield of maize for both crops. The two treatments with a 50% reduction in recommended chemical fertilizers, CZ, and rice straw compost or paddy husk compost (treatments four and six) are recommended instead of the 100% recommended chemical fertilizer treatment (treatment one). The organic materials used for these two treatments are abundantly available and will reduce the economic and environmental costs of applying large quantities of chemical fertilizers alone. [ABSTRACT FROM AUTHOR]

The aim of this study has been to evaluate the effect of sewage sludge and composted sewage sludge and municipal waste on the content of various forms of P in soil. The experiment scheme: C, control; NPK; FYM; DGSS, dried and granulated sewage sludge; CSS, composed sewage sludge; CSSS, composted sewage sludge and straw; CMMW, composted mixed municipal waste; CMGW, composted municipal green waste. The content of bound P was determined in the fractions: F1, easily soluble; F2, exchangeable; F3, organic; F4, carbonate; F5, stable organic-mineral and mineral bonds; and F6, residual. The NPK fertilisation as well as the soil fertilisation with organic substances raised the P-total content and of P bound in the fractions: F3, F4, F5 and F6. The highest amount of phosphorus in the studied soil was in fraction F3 (phosphorus in organic compounds) and the lowest in fraction F1 (phosphorus in the ionic form as H2PO4− and HPO42−). Composted sludge and straw introduced into the soil increased the content of readily soluble P (F1), while the NPK effect was reversed. NPK fertilisation and enhancement of soil organic matter (except CSSS, CMGW) led to a reduction of the P content in F2 fraction. The content of available P determined by the Egner-Riehm method depended on the content of C-organic, P-total and CEC soil. Among the determined phosphorus fractions, the content of available P was most strongly correlated with the content of P bound in the carbonate fraction (F4) and residual fraction (F6) and, less strongly, with the organic phosphorus fraction. [ABSTRACT FROM AUTHOR]

Technologies for the treatment of animal wastes and their environmental and economic advantages are discussed. Current study involves data on poultry, cattle and swine wastes with emphasis on biodigester and compost technologies. Techniques are used to mitigate the emission of greenhouse gases and the degradation of the environment with possible financial return by selling of carbon credit in the international market through the Kyoto protocol. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this meta-analysis and review study was to identify the original research works done on use of organic amendments against root-knot nematodes and to quantitatively analyse the effect of different organic amendment types, such as animal manure, composts, plant derivatives and plant residues, on root-knot nematodes in crops. Materials and methods: The original studies conducted on RKN control using organic amendments were identified using database and literature searches. The articles were screened and data were extracted. The publication bias of the studies was calculated. The soil amendments used in experiments were identified into four main organic amendment categories: plant residues, composts, animal manure and plant derivatives (powders, pellets or extracts produced from plant or plant parts). A meta-analysis was performed calculating the response ratios (effect size) of different organic amendments against RKN favouring plant performances. Results and discussion: All the amendment types, i.e. plant residues, composts, animal manures and plant derivatives, were found to be effective against RKN. Plant-based derivatives were the most effective against all RKN damage attributes followed by application of compost and animal manure. Poultry manure was the only effective animal manure to control RKN consistently based on the results. Plant residues were found to be the least effective against RKN; amongst these groups of organic amendments, the family Poaceae produced the most effective residues to control RKN. Conclusions: Organic amendment application generally reduced the RKN population and damage by 63 compared to untreated conditions. [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]

Soil amendments, such as composts and biochar, are currently widely used as substrates in container gardening. Although different types of wastes have been used in composting, formulating growing mediums for specific plants using different materials is necessary. In the present study, organic substrates comprising mixtures of (a) broiler chicken wastes composted with sugar bagasse, sawdust, urban tree, napier grass, or cotton residues, and (b) five different proportions of biochar (0%, 15%, 30%, 45%, and 60%) were used to produce mineral and flavonoid-rich parsley plants. The sawdust-based substrate led to the highest yields (27.86 g pot−1 on average), regardless of the amount of biochar added; however, this substrate resulted in plants with no appreciable antioxidant activities. Plants grown using the tree-based substrate had moderate yields (16.95 g pot−1), and the highest phenolic levels (e.g., 7.93 mg GAE g−1) and antioxidant activities (DPPH scavenging activity over 11.17 g TE g−1). Such activities were better described by the presence of apigenin-7-apiosylglucoside and diosmetin-apiosylglucoside. Moderate yields were also obtained with the cotton-based substrate; however, such yields were only obtained at biochar proportions greater than 30%; this substrate led to the highest K contents (47.19 g kg−1). The lowest yields (3.20 g pot−1) and N (20.96 g kg−1), P (1.33 g kg−1), K (33.26 g kg−1), and flavonoid (13.63 mg CE g−1) contents were obtained with the napier-based substrate. However, this substrate led to the production of parsley plants with the highest levels of anthocyanins (0.40 mg CGE g−1), which may have accumulated as stress sensors and defense components. The bagasse-based substrate also led to high yields and appreciable flavonoid contents with 60% biochar. In most cases, no linear relationship was found between the biochar amount and the chemical parameters evaluated. Overall, the substrates formulated using urban tree residues had higher suitability for parsley development than those formulated using sugar bagasse, sawdust, napier grass, or cotton residues.

Organic fertilization has been proposed as an alternative approach to supply nutrients for crops, in the frame of organic and sustainable agriculture, with the aim to decrease high inorganic fertilization rates, protect the environment and decrease production costs for farmers. Since different types of organic fertilizers, such as manures, olive mill wastewater (OMW), sewage sludge (SS), crushed pruning wastes, composts and cover crops, exist as soil amendments to improve soil fertility, enhance plant nutrition and sustain the productivity of tree crops, their role as biofertilizers has been fully analyzed under the most important published papers. In addition, the benefits and drawbacks of organic fertilization, in a comparative approach with inorganic fertilization, are presented and discussed. Within the most important advantages of organic fertilizers, the enhancement of beneficial soil microorganisms and the improvement in soil physical properties and fertility should be included, while their most important disadvantage is their inability to directly satisfy the prompt N nutritional needs of tree crops, due to slow N mineralization rates. Finally, some novel aspects on the interrelation among innovative organic fertilizers for tree crops, sustainable field management, crop productivity and fruit quality are also included in this review, under the light of the most important and recent research data existing in the literature, with the aim to provide recommendations and future directions for organic fertilizers by tree growers.

Mineral resources exploitation is one of the main causes of soil degradation and pollution. Restoration of mines after exploitation is a priority of mining companies. In this work, we studied the possibility of using the putrescible and minerals wastes from a limestone plant of Sika-Kondji to fertilize the topsoil. Agronomic tests were conducted with corn to validate the potential of composts compared to a control. The results indicate that composts C1 (green waste), C2 (green waste + food) and C4 (food + green wastes + limestone and clay) allowed a good growth of plants relative to control. Plants grown on C2 and C4 composts presented the best agronomic performance. These composts are rich in organic matter, nitrogen, phosphorus and potassium with a high electrical conductivity. These composts need to be improved and valued in the restoration program of Sika-Kondji mine.

Phosphorus (P) is one of the most important minerals required for plant growth occupying a strong position among soil macro nutrients. Soil P deficiency is often fulfilled by phosphate fertilizers. P deficiency in soils is due to less total P contents in the soil and fixation of added P from chemical fertilizers as well as other organic sources like manures. The response of plant under P stress or even when it is present in adequate amount is very mild. The basic constraint in the availability of P is its solubilization as it gets fixed both in acidic and alkaline soil. Soil fixed P can only be solubilized by phosphate solubilizing microorganisms (PSMs).These bacteria released different types of organic acids in the soil which make P soluble and available to plants. The potential of these PSMs to solubilize P varies and mainly depends upon mechanism adopted for solubilization, their molecular genetics as well as their ability to release P in soil. The PSMs, having all the characteristics of phytohormone production, nitrogen fixation, as well as, heavy metal decontamination and creating salt stress tolerance in plants, are quite rare for sustainable agriculture. Application of this environment friendly approach for increasing crop productivity as well as its impact on soil and plant health is discussed in this review which will not only open new avenues of research but also provide fruitful information about phosphate solubilizing microbes for sustainable agriculture development. [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]

Fertilization of soil is needed to fulfill the growing demand for livestock feed and human food requirements. However, fertilization has short and long-term impacts on the soil microbiota. These, in turn, may influence plant viability and growth. We investigated the soil microbiota of a 27-year field trial, focusing on the influences of mineral nitrogen (N) fertilization, different composts and combinations of compost plus mineral N as soil amendments. Two N rates (0 and 80 kg per ha) and four different composts (urban organic waste compost (OWC) green waste compost (GC), farmyard manure (MC) compost and sewage sludge compost (SSC)) were used. Soil samples for this study were taken in 2018 after the growing season of maize. In addition to maize yield, the effects on soil physicochemical properties and the soil microbiota were analyzed. There was a trend for increased maize yields for all fertilizers; however, only the application of GC and SSC in combination with mineral N fertilizer showed significant effects. The different organic amendments influenced physicochemical soil properties. Phosphorus concentrations were three times higher in plots receiving SSC (≈312 mg kg−1) and SSC + N (≈297 mg kg−1) than control (≈89 mg kg−1) or mineral N fertilizer (≈97 mg kg−1) alone. Magnesium concentrations in plots treated with SSC (≈74 mg kg−1) were lower compared to soils treated with GC and MC, respectively (≈135 mg kg−1 and 126 mg kg−1). Bacteria exceeded the fungal community in terms of both richness and diversity. While the bacterial community composition differed significantly among the treatments, the fungal community composition was rather unaffected. Our conclusion is that composts produced from various substrates serve as valuable nutrient sources for plants and can partially substitute mineral N. In addition, composts increased soil microbial biomass and modulated the composition of the soil’s microbial community.

One of the principles of the circular economy requires the effective recycling of organic waste, especially since its volume is increasing from year to year. Therefore, one of the best solutions to solve this problem is the composting of organic waste. This paper presents the results of a comparative study of 10 different composts in terms of their quality. The composts varied with regard to waste materials used for composting, the adopted composting method, and the degree of compost maturity. Both biological (seed germination rate and intensity of plant root growth) and chemical methods (contents of macro- and micronutrients, presence of heavy metals, as well as the quality and quantity of humus compounds) were applied to evaluate the fertilisers, providing comprehensive characteristics of individual composts. It was found that composts prepared on the basis of sewage sludge had the highest contents of macro- and micronutrients as well as heavy metals. In addition, these composts contained the greatest amounts of humic substances, although these were of low quality. These composts also strongly inhibited seed germination and plant root growth. The least desirable chemical composition was found for the composts based on yard trimmings and household wastes prepared in home composters. These composts contained good quality humus compounds and had a positive effect on seed germination and plant root growth.

High nitrogen use efficiency (NUE) is important for improving crop yield. There are many nitrogen (N) fractions in soil and their uptake by crops varies. Most of the N that is taken up by plants is not native to the soil but usually from fertilizer added to the soil. However, the unbalanced use of fertilizers is currently an important issue that needs to be addressed. The objectives of this work were to determine the effects of using the recommended chemical fertilizers together with inorganic and organic amendments on (i) soil organic and inorganic N fractions, (ii) N uptake and use efficiency, and (iii) maize (Zea mays L.) dry matter production and ear yield. A randomized complete block design field trial, using maize as a test crop, was done with seven fertilizer treatments, each replicated thrice for two crop cycles. The treatments included different combinations of urea N, clinoptilolite zeolite (CZ), rice straw compost, and paddy husk compost. The variables of the study were soil N fractions, ear yield, and N use efficiency. Generally, the combined use of the recommended chemical fertilizers with CZ and organic amendments resulted in significantly higher soil N fractions, N use efficiency, and ear yield of maize for both crops. The two treatments with a 50% reduction in recommended chemical fertilizers, CZ, and rice straw compost or paddy husk compost (treatments four and six) are recommended instead of the 100% recommended chemical fertilizer treatment (treatment one). The organic materials used for these two treatments are abundantly available and will reduce the economic and environmental costs of applying large quantities of chemical fertilizers alone.

Badania prowadzono w obszarze oddziaływania kopalni siarki w Jeziórku. Celem badań była ocena zmian odczynu, pojemności sorpcyjnej i zawartości przyswajalnych form fosforu, potasu i magnezu po 6 latach od przeprowadzenia rekultywacji. W doświadczeniu (poletka o powierzchni 15 m2) przeprowadzono rekultywację zdegradowanego gruntu wapnem poflotacyjnym, oraz kompostami: z osadu ściekowego, osadu ściekowego i popiołu z elektrociepłowni. Komposty w dawce suchej masy 180 t · ha-1 (6%), ustalonej w oparciu o rozporządzenie MŚ z 2001 roku, zastosowano w wariantach: kontrola (grunt rodzimy tylko zwapnowany); kompost z komunalnego osadu ściekowego; kompost z osadu ściekowego (80%) i popiołu (20%); kompost z osadu ściekowego (70%) i popiołu (30%). Na zrekultywowanych poletkach zasiano mieszankę traw rekultywacyjnych. Jednorazowe odkwaszenie i nawożenie gruntu i dalsze 6-letnie ekstensywne (bez nawożenia) użytkowanie wywarły zróżnicowany wpływ na kształtowanie właściwości rodzimego utworu bezglebowego. Bez względu na sposób rekultywacji, po sześciu latach użytkowania gruntu, w wierzchnich warstwach, zwiększyła się średnia zawartość przyswajalnego fosforu, zawartość przyswajalnego potasu nie uległa znacznym zmianom natomiast około 10-krotnie zmniejszyła się zawartość przyswajalnego magnezu.

The present work aims to study the potential valorization of composts exhausted cunicoles for aboveground vegetable plants. In a device complete random block with three repetitions, five composts in a pure state or in mixture and a witness are tested under tomato in seedbed except ground. They got results enable us to confirm that the composts are mature. As a whole, they have availability out of high water and a content of relatively weak air, whereas the substrates containing the peat-compost mixtures have physical properties close to the standards retained in Tunisia. The vegetative behavior of these plants with respect to the variation of the composition and the average size of the particles of the substrates shows a sensitivity of the seedlings to these parameters to the beginning of their growth. Majority of the mixtures containing peat-compost gave seedlings of quality, healthy, and homogeneous. The composts prepare well with a partial use in except ground.

Soil in Kalimantan Island is considered infertile. To obtain a reasonable crop yield a high input fertilizer package should be applied. The situation will be worsening when an open pit system of coal mining adopted. Failure in re-arranging the soil layers can result in decreasing soil fertility compared to original soil prior to mining. This study aimed to determine the improvement of soil fertility of a disposal without top soil by using composts from various sources, namely, the public garbage pile, commercial compost, and compost from kitchen waste. The experiment was conducted in a disposal area of a coal mining of PT AI. A series of application rate of compost was set. This was 0, 5, 10, and 20 tonne compost ha-1. A plot with top soil was involved for another control. Maize was selected as the plant indicator to evaluate the effect of treatments applied. It can be concluded that application of composts to reclamation area without top soil significantly improve soil fertility. Among the composts used, K-compost (compost from kitchen waste) was the best in improving soil fertility. There were some characters of the compost that had not enough to support maize yield. These were P, K, and pH. Addition of P and K fertilizers and lime material are needed. Of the equation coefficients obtained, the b coefficient of equation belong to K-compost was higher than of the others.

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]

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