Search Results (5)

Soil health is a critical factor in sustainable agriculture, particularly in fruit production, where fertilization strategies play a vital role in maintaining the soil quality and enhancing fruit production and quality. This study investigates the effects of different fertilization strategies on soil bacterial communities and honey pomelo (Citrus maxima) properties in Ji’an City, Jiangxi Province, China. Three fertilization treatments were compared: conventional fertilization (CF: botanical organic plus chemical compound fertilizers), organic material fermented fertilization (OF: organic material including duck manure fermented fertilizer plus chemical compound fertilizer), and a special honey pomelo fertilizer (SF: organic material fermented fertilizer only during the whole honey pomelo growing season). Soil samples were collected at two depths (0–20 cm and 20–40 cm) from nine plots (three treatments × three replicates) and analyzed for their soil properties, bacterial community diversity and composition, and fruit characteristics. The results indicate that the OF and SF significantly improved the soil pH, soil organic matter (SOM), and nutrient availability compared to the CF. Additionally, the OF and SF treatments led to a 13.6% and 16.6% increase in fruit weight, respectively, and higher bacterial diversity, although no significant differences were observed in fruit quality parameters such as vitamin C, soluble sugar, and titratable acid. Acidobacteriota, Proteobacteria, Actinobacteria, and Chloroflexi were the dominant bacterial phyla. The soil bacterial composition structures were significantly different among the different fertilization strategies, and were well explained by soil properties such as the pH, SOM, total phosphorus, and available nutrients. Our study suggests that applying fermented organic fertilizers which use duck manure as part of the raw materials, either alone or in combination with chemical compound fertilizers, increases honey pomelo fruit production and improves soil health, contributing to the sustainable development of orchards. Full article

The large-scale generation of vegetable waste in China has become a significant environmental concern. The traditional method of composting results in high nitrogen losses during the process and in the final product. To address this issue and shorten the composting period, this study investigated the effects of bamboo vinegar (BV) and a microbial inoculant (MI) on the physical and chemical properties of the compost and bacterial community composition during the composting process. The results revealed that the addition of BV and BV + MI decreased the time required to reach thermophilic temperatures and conserved nitrogen in the final product. Furthermore, it was found that the dominant nitrifying and denitrifying bacteria, as identified through 16S rDNA analysis, belonged to Nitrosomonas and Proteobacteria, respectively. BV and BV + MI reduced NH₃ and N₂O emissions, which suggested that BV is a beneficial composting agent that preserves nitrogen during the composting process. Full article

Anaerobic digestion of animal manure results in the production of renewable energy (biogas) and nutrient-rich biofertilizer. A further benefit of the technology is decreased greenhouse gas emissions that otherwise occur during manure storage. Since animal manure makes anaerobic digestion cost-efficient and further advance the technology for higher methane yields, it is of utmost importance to find strategies to improve bottlenecks such as the degradation of lignocellulose, e.g., in cattle manure, or to circumvent microbial inhibition by ammonia caused by the degradation of nitrogen compounds in, e.g., chicken, duck, or swine manure. This review summarizes the characteristics of different animal manures and provides insight into the underlying microbial mechanisms causing challenging problems with the anaerobic digestion process. A particular focus is put upon the retention time and organic loading rate in high-ammonia processes, which should be designed and optimized to support the microorganisms that tolerate high ammonia conditions, such as the syntrophic acetate oxidizing bacteria and the hydrogenotrophic methanogens. Furthermore, operating managements used to stabilize and increase the methane yield of animal manure, including supporting materials, the addition of trace elements, or the incorporation of ammonia removal technologies, are summarized. The review is finalized with a discussion of the research needed to outline conceivable operational methods for the anaerobic digestion process of animal manure to circumvent process instability and improve the process performance. Full article

Agricultural biogas plants are increasingly being used in Europe as an alternative source of energy. To optimize the sizing and operation of existing or future biogas plants, a better knowledge of different feedstocks is needed. Our aim is to characterize 132 common agricultural feedstocks in terms of their chemical composition (proteins, fibers, elemental analysis, etc.) and biochemical methane potential shared in five families: agro-industrial products, silage and energy crops, lignocellulosic biomass, manure, and slurries. Among the families investigated, manures and slurries exhibited the highest ash and protein contents (10.3–13.7% DM). High variabilities in C/N were observed among the various families (19.5% DM for slurries and 131.7% DM for lignocellulosic biomass). Methane potentials have been reported to range from 63 Nm³ CH₄/t VS (green waste) to 551 Nm3 CH₄/t VS (duck slurry), with a mean value of 284 Nm³ CH₄/t VS. In terms of biodegradability, lower values of 52% and 57% were reported for lignocelluloses biomasses and manures, respectively, due to their high fiber content, especially lignin. By contrast, animal slurries, silage, and energy crops exhibited a higher biodegradability of 70%. This database will be useful for project owners during the pre-study phases and during the operation of future agricultural biogas plants. Full article

This study investigated the occurrence and contamination risk of estrogens in livestock manure in Jiangsu Province, China. Four estrogens—estriol (E3), 17β-estradiol (17β-E2), bisphenol A (BPA), and 17α-ethinyloestradiol (EE2)—were detected in livestock manure from hens, ducks, swine, and cows. The respective mean concentrations of each estrogen found in these manures were 289.8, 334.1, 330.3, and 33.7 μg/kg for E3; 38.6, 10.9, 52.9, and 38.8 μg/kg for 17β-E2; 63.6, 48.7, 51.9, and 11.7 μg/kg for BPA; and 14.3, 11.3, 25.1, and 21.8 μg/kg for EE2. Estrogens were most frequently detected at high concentrations in the manure of finishing pigs, followed by the manure of growing pigs and piglets. Estrogens can be partially degraded after banking up for seven days; yet, great quantities of estrogens remain in livestock manure. The total estradiol equivalent quantity (EEQ_t) estimated to be present in aquatic environments but originating from livestock waste was 10.5 ng/L, which was greater than the hazard baseline value (1 ng/L) and also higher than the proposed lowest observable effect concentration (10 ng/L) of E2 in aquatic environments. The results of our study demonstrate that livestock waste is an important source of estrogens, which may potentially affect the hormonal metabolism of aquatic organisms. Full article