CF Treatment Research Articles

DOM hydrophilic components of organic fertilizers increased the soil nitrogen retention capacity and succession of the microbial community.

Application of organic fertilizers affects soil properties and microbial communities, which in turn alters soil N transformation processes. Unfortunately, it is not clear how the difference in the character of the organic fertilizer DOM affects the soil nitrogen retention capacity and its microbial processes. According to the principle of equal nutrients, the treatments of chemical fertilizer alone (treatment CF), chemical fertilizer with organic fertilizer DOM hydrophilic components (treatment H), and chemical fertilizer with organic fertilizer DOM hydrophobic components (treatment P) were set up, where the characteristics of soil nitrogen transformation and changes in microbial community structure were studied with soil culture conditions for 24 days. It was discovered that the addition of organic fertilizer DOM components (H and P) slowed nitrification rate and increased protease activity resulting in a higher NH4+-N content compared to the CF treatment. The DOM addition (H and P) increased the microbial biomass nitrogen (MBN) levels in the soil and increased the soil nitrogen pool capacity. Moreover, the carbon use efficiency of the hydrophilic components is higher than that of the hydrophobic components, resulting in its further increase in nitrogen reservoir capacity and higher nitrogen retention capacity. Network analysis showed that the addition of organic fertilizer DOM hydrophilic components increased network complexity and synergy between microorganisms. In combination with random forest analysis, it was shown that Sphingomonas and Massilia were key species influencing soil nitrogen retention capacity and nitrogen availability characteristics.

Drip fertigation with food waste biogas effluent in a humid area is possible but challenging due to increased soil soluble sodium

To assess changes in soil salinity and salinity leaching following rainfall when food waste biogas effluent was used as a fertilizer in a humid region, a field experiment was conducted in 2020–2022 focused on broccoli drip fertigation with different percentages of biogas effluent. Five treatments consisted of 0% (CF), 25% (T25), 50% (T50), 75% (T75), and 100% (T100) biogas effluent blended with fresh water, with the same total N, P, and K. The experiment included a control (CK) that consisted of drip irrigation without fertilizer. The electrical conductivity of soil saturation paste extract (ECe), soluble sodium, sodium adsorption ratio (SAR), cation ratio of structural stability (CROSS), and broccoli yield were monitored. Drip fertigation with biogas effluent (electrical conductivity=19.0 dS/m) increased soil salinity and the ECe rose as the biogas effluent percentage increased, especially in the 0–20 cm soil profile. The T25, T50, T75, and T100 treatment ECe values were 1.2–2.2 times those of the CF treatment. Soluble sodium, SAR, and CROSS increased during the fertilization season. However, compared with CF, 25–100% biogas effluent drip fertigation did not significantly affect broccoli yield. During the post season, the soil salinity was effectively leached by rainwater. After one study year of rotation, there was almost no significant difference in ECe between treatments, but the soluble sodium, SAR, and CROSS values were significantly higher in T100 than in the CF treatment. In other words, when the total applied fresh water amount (including rainfall and irrigation) is more than 45–48 times the biogas effluent application amount (i.e., irrigation with a biogas effluent concentration of ≤75%), it may not significantly increase the soil soluble sodium. In conclusion, drip fertigation with biogas effluent can be used for broccoli fertigation in humid areas, and treatment with≤ 75% biogas effluent is suggested. Combined with the local rainfall depth, a biogas effluent application depth of ≤ 28–30 mm/year may be feasible.

Synergistic Effects of N Fertilization and Irrigation on Soil Bacterial Community in Super Rice Paddies

Nitrogen reduction, in association with increased planting density and irrigation management, has been widely adopted in super rice cultivation systems to pursue higher yield with lower input. Here, soil microbial community structures under accurate N and water management were investigated after four years of experiments. Plot experiments were conducted with three treatments, including conventional farming practice (CF), reduced nitrogen with increased plant density (RNID), and reduced nitrogen with increased plant density and precise irrigation (RNIDPI). The results showed that RNID treatment increased soil bacterial diversity, enriched biomarker bacterial taxa, and altered bacterial community structure, with pH as the influential factor. The phylum Chloroflexi was enriched in the treatment of N reduction, while a higher ratio of Firmicutes was present in CF treatments. RNID treatment witnessed a low proportion of bacterial functional groups involved in nitrification and nitrate reduction. N fertilizer reduction with irrigation management increased rice yield (up to 22%) without changing the major soil fertility properties except for the increased pH and decreased ammonium N. The results suggest that N reduction, in association with increased plant density and accurate irrigation, is beneficial for super rice production.

Land reclamation increased organic P fractions and phosphatase activities, and strengthened the co-occurrence networks of phoD community in calcareous soils

Organic phosphorus (Po) is an important constituent of P pool. Soil phoD community is primarily involved Po transformation. However, influences of agriculturally-driven land-use change on different Po fractions, phosphatase activities and phoD community are largely unknown. Here, an investigation was carried out containing three treatments: vegetable field (VF), cropland (CF) and uncultivated land (UL). Various Po fractions were measured by Hedley’s sequential extraction and 31P-NMR methods. The activities of alkaline phosphomonoesterase (ALP), acid phosphomonoesterase (ACP), phosphodiesterase activity (PD) and phytase were assayed; the abundance, and diversity of phoD community and its co-occurrence networks were analyzed. Compared with the UL treatment, soil total organic P (total-Po) in the VF and CF treatments significantly increased by 75.9% and 53.0%, respectively, mainly attributed to the increases in NaHCO3-Po, NaOH-Po and C.HCl-Po. 31P-NMR spectra showed that, when land was reclaimed from uncultivated land into agriculture fields (i.e., VF and CF), myo-inositol hexaphosphate (myo-IHP), α-glycerophosphate (α-glyc) and β-glycerophosphate (β-glyc) were increased by 9.5, 3.9 and 2.0 times, respectively. The activities of ACP, ALP and PD in the VF and CF treatments were higher than in the UL treatment. The α-diversity of phoD community was also significantly increased by land reclamation. Moreover, the linkage between soil Po and Po-cycling-related biological parameters (ACP, ALP and PD and phoD community) was more pronounced by NaHCO3-Po and NaOH-Po than the Po fractions measured by 31P-NMR method. Topological parameters (edges, node degree, and betweenness centrality) of phoD community’s network in the VF and CF networks were higher than in the UL network, implying that land reclamation favored to construct a more cooperative network of phoD community. Collectively, our findings demonstrated that when uncultivated land was converted to cropland, soil Po was notably increased, and phoD community’s co-occurrence network was also strengthened. The outcomes of this study emphasize that when land was reclaimed from nature (uncultivated land) into agriculture fields, the fertilization strategy of organic combined with chemical fertilizers application was beneficial for improving P fertility and assembling organic P-cycling related community.

Decreases in Rhinology Care Utilization by People with Cystic Fibrosis on Highly Effective Modulator Therapy.

Many people with cystic fibrosis (PwCF) have chronic rhinosinusitis (CRS). CRS requires additional management beyond that of pulmonary disease and leads to increased utilization of healthcare resources. Elexacaftor/tezacaftor/ivacaftor (ETI) is a highly effective modulator therapy that has been shown to improve CRS in PwCF. However, the impact of ETI on rhinologic healthcare utilization is understudied. To compare rates of rhinologic healthcare utilization and procedures among PwCF prior to and after initiating ETI therapy. A single-center, cohort study investigating adult PwCF was performed in January 2023. Demographics, clinical characteristics, and data related to CF treatment were retrospectively abstracted. Characteristics of the cohort were compared over 2 periods: the 12-months prior to ETI initiation and the 12-months after ETI initiation. Post-ETI data were linearly extrapolated if a subject had not yet completed the full 12 months of ETI. Paired t-testing, Wilcoxon signed rank testing, and regression analysis were performed. Of 126 PwCF, 98 (77.8%) were on ETI therapy and 35 (27.7%) were both on ETI and concurrently followed by the rhinology service (ETI-ENT). Rhinology clinic visits (P = .007) and frequency of obtaining nasal cultures (P = .046) decreased for the ETI-ENT cohort after initiating ETI treatment. There were no significant changes in the number of endoscopic sinus surgeries (P = .452) performed. Beyond ETI use, regression analysis did not identify any factors associated with changes in utilization. Aspects of rhinology healthcare utilization by PwCF decreased after initiation of ETI therapy. Additional studies are needed to determine rhinologic healthcare requirements for PwCF who remain on ETI for the long-term and to evaluate larger cohorts of PwCF on ETI.

Croton tiglium L. seeds ameliorate loperamide-induced constipation via regulating gastrointestinal hormones and gut microbiota before and after processing

Ethnopharmacological relevanceCrotonis Fructus (CF), the seeds of Croton tiglium L., have been commonly used in the treatment of constipation for more than two thousand years in traditional Chinese medicine (TCM). CF needs to be processed before clinical use and Crotonis Semen Pulveratum (CP) is the processed cream of CF, which could reduce the drastic purgative action and gastrointestinal damages. However, the mechanism of CF and CP in the treatment of constipation is still unclear. Aim of the studyThis study was to evaluate the effects of CF and CP on loperamide-induced constipation and the underlying mechanism. Materials and methodsThe chemical compositions of CF and CP were analyzed by UPLC-Q-TOF-MS. Constipated mouse model was established by loperamide (9.6 mg/kg, b.w., i.g.) for two weeks. After successful modeling, the mice were treated with CF or CP (45.5 and 136.5 mg/kg, b.w., i.g.) once a day for seven days. The physiological status, defecation indices, defecation time, and intestinal propulsion rate in mice were measured. Histopathologic examination and serum biochemical parameters were further estimated. 16S rDNA gene sequencing was carried out to characterize the effects of CF and CP on intestinal microbiome structure. Spearman correlation analysis was also performed to explore the association between gut microbiotic abundance and serum indices. ResultsThe results verified the therapeutic effects of CF and CP on loperamide-induced constipation. CF and CP could significantly ameliorate the reduction of fecal number, fecal weight, fecal water content, and intestinal propulsion rate in mice with constipation, and the first stool defecation time was also obviously reduced. Moreover, CF and CP could regulate the secretion of gastrointestinal hormones and inflammatory factors induced by constipation. Histopathologic examination showed that CP was superior to CF in relieving pathological injury and inflammatory cell infiltration. According to 16S rDNA sequencing, CF and CP treatment could improve gut microbiota disturbance in mice with constipation and the abundance of opportunistic pathogens such as Parabacteroides, Parasutterella and Bacillus remarkably declined, while the levels of beneficial bacterial such as Candidatus_Arthromitus significantly increased. Besides, CP may play a better role in correcting the intestinal flora disorder than CF, which was more obvious in the high-dose group. In addition, phytochemical analysis revealed the presence of diterpenoids and alkaloids in CF and CP. ConclusionsCF and CP could ameliorate loperamide-induced constipation by regulating gastrointestinal hormones secretion, reducing the levels of inflammatory cytokines and improving the disturbance of gut microbiota. Moreover, CP was superior to CF in the enrichment of beneficial bacteria and reduction of harmful bacteria and histopathological damage induced by constipation, which may be related to the changes in the species and content of diterpenoids after processing. The study provides new evidence for the processing mechanism and clinical application of CF and CP.

Water management can alleviate the deterioration of rice quality caused by high canopy humidity

This study conducted a two-year field artificial intelligence (AI) greenhouse rice planting experiment with different canopy humidity (normal humidity, NH; high humidity, and HH) and irrigation regimes (continuous flooding, CF; drought cultivation, DC; alternate wetting-drying, AWD) to test whether high canopy humidity from heading to maturity deteriorates rice grain quality, whether appropriate water management can alleviate these adverse effects, and the related mechanisms. The results showed that compared with NH, HH significantly decreased the head rice rate while increasing the protein, amino acid, amylopectin, amylose, and chalkiness. Moreover, HH significantly decreased the peak viscosity, breakdown, and number of small starch granules, while increasing the setback, number of large starch granules, relative crystallinity, gelatinization temperature, and enthalpy. Under NH and HH, AWD treatment resulted in a higher head rice rate, peak viscosity, breakdown, key enzyme activities of starch synthesis, amylose, amylopecan, relative crystallinity, small starch granules, gelatinization temperature, and enthalpy than DC and CF treatments, while lower chalkiness, setback, protein, amino acid, and large starch granules were observed. HH increased the chalkiness by promoting the formation of large starch granules, thus reducing the milling quality. The increase in amylose and relative crystallinity further causes HH to deteriorate the cooking and eating quality. AWD could alleviate the deterioration of rice grain milling, appearance, and eating quality caused by HH by improving starch granules.

Biochar amendments to tropical paddy soil increase rice yields and decrease N2O emissions by modifying the genes involved in nitrogen cycling

Water management strategies are critical in regulating nitrous oxide (N2O) emissions from paddy soils under rice cultivation. Biochar is widely used as an amendment to decrease soil N2O emissions. However, the impacts of biochar amendment on N2O emissions under different water management strategies in paddy soils have not been investigated thoroughly, and the underlying mechanisms remain poorly understood. In particular, the effects of mid-season water drainage, a strategy used for water conservation, need to be better understood. In this study, a pot experiment was conducted including six treatments: alternating dry-wet conditions during the mid-season period without and with 2% (w/w) biochar (AWD1 and AWD2, respectively), continuous flooding during the mid-season period without (CF1) and with 2% (CF2) biochar, and regular mid-season drainage during the mid-season period without (CON1) and with 2% (CON2) biochar. All treatments received inorganic nitrogen, phosphorus and potassium fertilizers (NPK) administered in a split application. We found that fluxes of N2O emission peaked after the two fertilizers’ additions. No significant difference in the first N2O flux peak was found among different treatments. There also was no difference in the second N2O flux peak in both CF treatments, whereas biochar addition significantly decreased the second N2O flux peak in AWD2 and CON2 treatments. This was mainly due to increased nosZ gene copies and decreased ratios of denitrification and amoA genes to nosZ gene copies. Biochar amendments resulted in significant stimulation of nifH gene copies in the AWD2 treatment. Lastly, biochar increased rice yields in all treatments. Our study suggested that AWD2 was the optimal management strategy for mitigating N2O emissions and improving rice production in this tropical paddy soil.

The impact of fertilization on ammonia-oxidizing bacteria and comammox Nitrospira communities and the subsequent effect on N2O emission and maize yield in a semi-arid region.

The control of nitrous oxide (N2O) emissions through nitrification and the optimization of maize yield are important in agricultural systems. However, within the semi-arid region, the impact of fertilization on the function of nitrification communities and its connection with N2O emissions in the rhizosphere soil is still unclear. Our study investigates the influence of fertilization treatments on the communities of ammonia-oxidizing bacteria (AOB) and the complete ammonia oxidizers of the Nitrospira known as comammox (CAOB) in a maize agroecosystem. Nitrous oxide production, potential nitrification activity (PNA), maize yield, and nitrogen use efficiency (NUE) were determined for the same samples. The fertilizer treatments included a control group without fertilization (NA), inorganic fertilizer (CF), organic fertilizer (SM), combined inorganic and organic fertilizer (SC), and maize straw (MS). The SC treatment indicated a lower cumulative N2O emission than the CF treatment in the 2020 and 2021 cropping seasons. The AOB community under the CF, MS, and SM treatments was predominantly composed of Nitrosospira cluster 3b, while the SC treatment was associated with the comammox Nitrospira clade A.1 lineage, related to key species such as Ca. Nitrospira inopinata and Ca. Nitrospira nitrificans. Network analysis demonstrated a positive potential for competitive interaction between hub taxonomy and distinct keystone taxa among AOB and comammox Nitrospira nitrifiers. The structural equation model further revealed a significant positive association between AOB nitrifiers and N2O emission, PNA, soil pH, SOC, -N, and DON under organic fertilization. The keystone taxa in the comammox Nitrospira nitrifier and network Module II exhibited a positive correlation with maize productivity and NUE, likely due to their functional activities stimulated by the SC treatment. It is noteworthy that the AOB community played a more significant role in driving nitrification compared to the composition of comammox Nitrospira. Collectively, combined inorganic and organic fertilizer (SC) treatment exhibits high potential for reducing N2O emissions, enhancing maize productivity, increasing NUE, and increasing the sustainability of the nitrogen dynamics of maize agroecosystems in the semi-arid Loess Plateau.

Impacts of Partial Substitution of Chemical Fertilizer with Organic Fertilizer on Soil Organic Carbon Composition, Enzyme Activity, and Grain Yield in Wheat-Maize Rotation.

This study explored the effect of the long-term partial replacement of chemical fertilizer with organic fertilizer on soil organic carbon composition, enzyme activity, and crop yields in the wheat-maize rotation area of northern Anhui, China. This study also specified the proper amount of organic fertilizer replacement that should be used for chemical fertilizer. Different fertilization modes were used (no fertilization, CK; chemical fertilizer, CF; chemical fertilizer and straw returning, CF + S; chemical fertilizer, straw returning, and straw decomposition agent, CF + S + DA; 70% chemical fertilizer and 50% organic fertilizer, 70% CF + 50% OF; 70% chemical fertilizer, 50% organic fertilizer and straw returning, 70% CF + 50% OF + S; 50% chemical fertilizer and 100% organic fertilizer, 50% CF + 100% OF; and 50% chemical fertilizer, 100% organic fertilizer, and straw returning, 50% CF + 100% OF + S). Variations in the organic carbon composition, enzyme activity, soil pH, and crop yields in the wheat-maize rotation under different fertilization treatments were analyzed. The results showed that the replacement of chemical fertilizer with organic fertilizer results in improved crop yields in wheat-maize rotation. The long-term partial replacement of chemical fertilizer with organic fertilizer can increase the quality of soil humus, alleviate soil acidification, and improve soil enzyme activity. Straw returning and organic fertilizer application can considerably raise the activities of urease, acid phosphatase, and nitrate reductase in soil. The soil pH of the CF treatment was reduced compared to the CK treatment, while organic fertilizer application alleviated soil acidification when compared to CF treatment. Organic fertilization increases the total organic carbon content of the soil, which was 19.6~85.5% higher than in the CK treatment. Applying straw and organic fertilizer significantly increased the ratio of the humic/fulvic acid in the soil. The soil active carbon forms of the soil with the application of organic fertilizer and straw returning were significantly higher than those of the CK and CF treatments. This study suggests that the optimal fertilizer management option in northern Anhui's wheat-maize rotation area is to replace 50% of the chemical fertilizer with organic fertilizer, and to fully return straw to the field. This would include 150 kg N h·m-2, 60 kg P2O5 h·m-2, 50 kg K2O h·m-2, 6000 kg organic fertilizer h·m-2, and full straw return to the field.

Organic Fertilizer Substitution Promoted the Organic Carbon Sequestration in Calcareous Fluvisol: A Study Based on Acid Hydrolysis and Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR)

ABSTRACT This study aimed to elucidate the mechanism of substituting organic fertilizer for mineral fertilizer to increase calcareous fluvisol soil organic carbon. Four years of soil culture experiments were conducted, wheat yield, soil nutrients, soil organic carbon (SOC) and SOC fractions were measured and the compositional changes of SOC was analyzed by attenuated total reflectance-fourier transform infrared (ATR-FTIR) spectroscopy. Treatments included applying no fertilizer (CK), mineral N and P fertilizers (CF) and organic fertilizers to replace 6% (OF6), 12% (OF12), 18% (OF18) and 24% (OF24) of N and P under the same nutrient conditions. The results showed that the OF24 treatment was the best among the treatments employed. Compared with CF, wheat yield, SOC, microbial biomass carbon (MBC), labile fraction 1 (LOC1) and recalcitrant fraction (ROC) of OF24 increased by 10.4%, 24.4%, 66.3%, 43.2% and 30.7%, however, the labile fraction 2 (LOC2) decreased by 16.8%. ATR-FTIR results showed that the relative absorption intensity of OF24 treatment at 1,000 cm−1 band is lower than CK and CF treatment, other bands are higher than CK and CF treatment. Overall, OF24 treatment not only significantly increased wheat yield, but also increased the content of LOC1 and MBC. The increase of MBC can improve the soil microbial environment and promote the decomposition of LOC2, while also accelerate the turnover rate of soil carbon and then show the increase of ROC content and improve the proportion of the recalcitrant carbon pool.

Land reclamation increased labile and moderately labile P fractions and strengthened co‐occurrence network ofgcdcommunity in calcareous soils

AbstractLand reclamation significantly impacts the transformation and availability of phosphorus (P) in soils. P‐solubilizing microorganisms (PSMs) play key roles in activating soil P. However, the responses of PSMs to the buildup of P under land reclamation and the relationship between different P fractions and PSMs have not been clearly clarified. Here, an investigation was carried out containing three treatments: (i) vegetable field (VF), (ii) cropland (CF), and (iii) uncultivated land (UL). Different P fractions were measured; the abundance of stable oxygen isotope in phosphate of D.HCl‐Pi was determined. The diversity, composition, and co‐occurrence network of P‐solubilizing glucose dehydrogenase community (gcd) were analyzed. Compared with the UL treatment, soil total P in the treatments of VF and CF was significantly increased by 1.5 and 1.2 times, respectively. The proportions of labile and moderately labile P in the treatments of VF and CF were 151% and 58% higher than in the UL treatment. The α‐diversity ofgcdcommunity (i.e., Shannon and Chao1 indices) in the VF and CF treatments was significantly greater than in the UL treatment. The change ingcdcommunity structure was closely associated with resin‐Pi, NaHCO3‐Pi, and NaOH‐Pi. The nodes and edges in the co‐occurrence networks of VF and CF treatments were higher than in the UL treatment. Overall, a substantial amount of P was accumulated after land reclamation, which was more pronounced by labile and moderately labile P than non‐labile P; the complexity and robustness ofgcdcommunity's co‐occurrence network were notably strengthened by land reclamation.

Long-term fertilization enhances the activity of anaerobic oxidation of methane coupled to nitrate reduction and associated microbial abundance in paddy soils

Anaerobic oxidation of methane coupled to nitrate reduction (nitrate-coupled AOM) is performed by Candidatus Methanoperedens nitroreducens (M. nitroreducens)-related archaea, and is recently recognized as a crucial component of the global carbon cycle. The input of fertilizers is an essential agricultural practice that greatly impacts methane (CH4) production and emission. However, the significance of nitrate-coupled AOM in CH4 cycling and its response to fertilization in rice fields remain unclear. In this study, the potential nitrate-coupled AOM rates and the communities of M. nitroreducens-related archaea in rice fields were examined at different soil layers (0–10, 10–20, and 30–40 cm) at tillering, elongation, flowering, and ripening stages under three long-term fertilization treatments (CK-without fertilizer, CF-chemical fertilization, or CFS-chemical fertilization with straw incorporation). The results indicated that both CF (1.07 nmol 13CO2 g−1 d−1) and CFS (1.21 nmol 13CO2 g−1 d−1) treatments significantly promoted the potential nitrate-coupled AOM rates compared to CK (0.53 nmol 13CO2 g−1 d−1). A greater response of potential activity to fertilization was observed at plough layer (upper 20 cm) and during elongation stage. The abundance of M. nitroreducens-related archaea under CF (1.12 × 107 copies g−1) and CFS (1.62 × 107 copies g−1) treatments was significantly greater than that under CK (6.93 × 106 copies g−1). Conversely, the growth response of these archaeal to fertilization was stronger at deeper layer (30–40 cm). Moreover, no significant change was observed in the community composition of M. nitroreducens-related archaea among treatments. Correlation analysis suggested that the variations of soil organic carbon, NH4+, and NO3− contents caused by fertilization were key factors influencing the potential nitrate-coupled AOM rates and M. nitroreducens-related archaeal abundance. Our findings provide the first evidence for positive response of nitrate-coupled AOM to long-term fertilization, demonstrating its potential to act as an important process for mitigating CH4 emission in rice fields.

Effects of nitrogen reduction combined with bio-organic fertilizer on soil bacterial community diversity of red raspberry orchard.

Understanding soil bacterial diversity under nitrogen reduction is necessary for the crucial role in soil nitrogen cycling. However, the effects of combined fertilization on soil chemical properties, microbial community structure, and yield are unknown. This study was conducted to investigate the effect of nitrogen fertilizer reduction with bio-organic fertilizer on soil bacterial community diversity of red raspberry orchard. Six treatments were set in this study: NF-100%, NF-75%, NF-50%, NF-25% and CF, no nitrogen fertilizer and bio-organic fertilizer for CK. The bacterial community structures of soil were analyzed by 16S rRNA gene amplification high-throughput sequencing technology. Nitrogen fertilizer reduction with bio-organic fertilizer increased soil organic matter (SOM), total nitrogen (TN), alkali-hydrolyzable nitrogen (AN), available phosphorus (AP), available potassium (AK), and reduced soil pH. NF-50% and NF-25% treatments increased the yield of red raspberry. Nitrogen reduction combined with bio-organic fertilizer increased the relative abundance of copiotrophic bacteria and decreased the relative abundance of oligotrophic bacteria. The increase in copiotrophic bacteria in the soil of red raspberry orchard could indicate an increase in soil nutrient availability, which have positive implications for soil fertility and production. However, nitrogen fertilizer reduction with bio-organic fertilizer altered the abundance and diversity of soil bacteria, which was reduced compared to CF treatments. The PCoA analysis of the soil bacterial community showed that the community structure of NF-25% treatment was more different from other treatments, indicating that the fertilization method changed the community structure of soil bacteria. The results of a redundancy analysis showed that SOM, pH, AN, TN, and AP were the main factors affecting the microbial community structure. Overall, the reduction of nitrogen fertilizer with bio-organic fertilizer significantly increased the soil nutrient content, reduced the relative abundance and diversity of soil bacteria, increased the relative abundance of beneficial bacteria in the soil, changed the bacterial community structure of soil, increased production and created suitable soil conditions for the red raspberry growth.

Fate of 15N-labelled urea as affected by long-term manure substitution

Quantifying the fate of fertilizer nitrogen (N) is essential to develop more sustainable agricultural fertilization practices. However, the fate of chemical fertilizer N, particularly in long-term manure substitution treatment regimes, is not fully understood. The present study aimed to investigate the fate of 15N-labelled urea in a chemical fertilizer treatment (CF, 240 kg 15N ha−1) and N manure 50 % substitution treatment (1/2N + M, 120 kg 15N ha−1 + 120 kg manure N ha−1) in two continuous crop seasons, based on a 10-year long-term experiment in the North China Plain (NCP). The results showed that manure substitution greatly enhanced 15N use efficiency (15NUE) (39.9 % vs. 31.3 %) and suppressed 15N loss (6.9 % vs. 7.5 %) compared with the CF treatment in the first crop. However, the N2O emissions factor in the 1/2N + M treatment was increased by 0.1 % (0.5 kg 15N ha−1 for CF vs. 0.4 kg 15N ha−1 for 1/2N + M) compared with the CF treatment, although N leaching and NH3 volatilization rates decreased by 0.2 % (10.8 kg 15N ha−1 for CF vs. 5.1 kg 15N ha−1 for 1/2N + M) and 0.5 % (6.6 kg 15N ha−1 for CF vs. 2.8 kg 15N ha−1 for 1/2N + M), respectively. In which, only NH3 volatilization presented significantly difference between treatments. It is important to note that in the second crop, the residual 15N in soil (0–20 cm) remained mostly in the soil for the CF (79.1 %) and the 1/2N + M treatment (85.3 %), and contributed less to crop N uptake (3.3 % vs. 0.8 %) and leached losses (2.2 % vs. 0.6 %). This proved that manure substitution could enhance the stabilization of chemical N. These results suggested that long-term manure substitution effectively increases NUE, suppresses N loss, and improves N stabilization in soil, but negative impacts such as N2O emissions due to climate change should be investigated further.

P345 The clinical impact of reduced dose prescribing of elexacaftor/tezaxaftor/ivacaftor (ETI) in children with cystic fibrosis

Trikafta® ETI is a triple therapy cystic fibrosis transmembrane conductance regulator (CFTR) medication available in Australia for children over twelve years of age since April 1, 2022. Although it has been found to be a highly effective in the treatment of CF, some individuals require a reduced dose due to drug-drug interactions or significant co-morbidities.

P160 Effects of elexacaftor/tezacaftor/ivacaftor triple combination therapy on glycaemic control and body composition in patients with cystic fibrosis related diabetes

Cystic fibrosis related diabetes (CFRD) is the most common extra pulmonary complication of CF. CF transmembrane conductance regulator (CFTR) modulators are a group of new drugs for the treatment of CF and elexacaftor+/tezacaftor+/ivacaftor (ETI) triple combination therapy has been approved as first choice therapy in the treatment of patients with at least one copy of F508del mutation. Data on the effects of CFTR modulators on glucose metabolism in patients with or without CFRD are limited to small studies with conflicting results.

Optimal Straw Retention Strategies for Low-Carbon Rice Production: 5 Year Results of an In Situ Trial in Eastern China

Crop straw retention in the rice-based rotation cropland has been widely accepted as an effective method to improve soil quality in China. Rice–wheat rotation cropland is one the most prevalent rice-based rotation patterns, where it only exploits a small proportion of the total agricultural land yet feeds the majority of the Chinese population. Previous studies indicated that the incorporation of fore-rotating crop straw can effectively facilitate soil carbon sequestration in rice paddy fields. However, the application of crop straw may increase methane (CH4) emissions from rice paddies due to the anaerobic soil condition. To mitigate CH4 emissions from rice paddies while still preserving their soil carbon sequestration ability, a field experiment was conducted in the 2012–2016 rice growing seasons to determine the optimal low-carbon crop straw retention strategy. Five treatments with different wheat straw retention strategies were employed in this study, including non-fertilization and non-straw (Control), conventional fertilization without straw incorporation (CF), conventional fertilization with wheat straw incorporation (FS), slow-release fertilizer combined with wheat straw (SFS), and conventional fertilization with wheat-straw-derived biochar (FB). The results indicated that FS, SFS, and FB treatments significantly increased soil carbon sequestration in comparison with CF treatment. However, the increment of soil carbon sequestration was offset by raw wheat straw induced excess CH4 emissions under FS and SFS treatments. In contrast, the application of wheat-straw-derived biochar significantly promoted soil carbon sequestration, but showed no significant effect on CH4 emissions. Collectively, to the farmers, who aim to achieve agricultural carbon neutrality, the application of straw-derived biochar is worthy of consideration in rice cultivation processes.

Coupling amendment of biochar and organic fertilizers increases maize yield and phosphorus uptake by regulating soil phosphatase activity and phosphorus-acquiring microbiota

Biochar and organic fertilizers are important alternatives to mineral fertilizers. Thus, it is important to understand how the co-application of biochar and organic fertilizers influences crop productivity and soil-plant phosphorus (P) trade-offs. Herein, we conducted a field fertilization experiment for eight years with maize-cabbage rotation. This experiment contained five treatments: no fertilization (CK), mineral fertilizers (CF), CF + biochar (BF), 20% substitution of mineral nitrogen (N) with organic fertilizers (OF), and OF + biochar (BOF). The fertilization regimes of all plots were maintained since 2013. The results showed that soil P pool composition but not P bioavailability differed significantly between the five treatments. Compared with the CF treatment, soil labile-P content in the BF, OF, and BOF treatments significantly increased by 12–23% and soil stable-P content decreased by 13–19%. Besides, the soil moderately labile-P content in the OF and BOF significantly decreased by 40% and 10% and increased by 31% in the BF as compared to the CF. The activities of soil acid (ACP) and alkaline phosphatase (ALP) in the BF, OF, and BOF significantly increased by 8–44% and 16–49% respectively compared to the CK. Furthermore, the abundance of P-acquiring genes (bpp, phoD, phoX, ppx, ppk, and phnK) in the BF, OF, and BOF increased by 22–114% compared to the CK. Plant P uptake and maize yield were significantly correlated with soil ACP and ALP activities as well as the abundance of phnK, ppx, phoD, phoX, and pqqC genes but not to the contents of soil P components. In conclusion, the co-application of biochar and organic fertilizer on maize productivity increases was mainly related to the improvement of soil phosphatase activity and P-acquiring gene abundance.

Effects of coal-derived compound fertilizers on soil bacterial community structure in coal mining subsidence areas.

The land damaged by coal mining can be recovered to healthy condition through various reclamation methods. Fertilization is one of the effective methods to improve soil fertility and microbial activity. However, the effects of coal-derived compound fertilizers (SH) on bacterial communities in coal mining subsidence areas still remain unclear. Here, we studied the effects on the nutrient characteristics and bacterial communities in fertilizer-reclaimed soil (CK, without fertilizer; CF, common compound fertilizers; SH, coal-derived compound fertilizers) in coal mining subsidence areas and we applied SH with four different nitrogen application rates (90, 135, 180, and 225 kg/hm2). The results showed that the application of SH significantly increased the contents of available nitrogen (AN), available phosphorus (AP), available potassium (AK), total phosphorus (TP) and soil organic matter (SOM) compared with CK, as well as the bacterial richness (Chao1) and diversity (Shannon) in reclaimed soil that increased first and then decreased with the increase of nitrogen application. Under the same nitrogen application rate (135 kg/hm2), the nutrient content, Chao1 and Shannon of SH2 treatments were higher than those of CF treatment. Meanwhile, SH increased the relative abundance of Proteobacteria, Actinobacteria and Gemmatimonadetes. LEfSe analysis indicated that the taxa of Acidobacteria and Actinobacteria were significantly improved under SH treatments. Canonical correspondence analysis (CCA) and Variance partitioning analysis (VPA) showed that SOM was the most important factor affecting the change of bacterial community structure in reclaimed soil. In conclusion, application of SH can not only increase nutrient content and bacterial diversity of reclaimed soil, but also improve bacterial community structure by increasing bacterial abundance.