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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]

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]

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.

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.

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. [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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]