Soil salinization has emerged as a major factor with an adverse influence on agricultural green development worldwide. It is necessary to develop high-efficiency and ecologically beneficial management measures for alleviating soil salinization. The experiment of application for cow manure (CM), biochar (BC), and bio-organic fertilizer (BIO) in soil with light salinity was conducted to investigate the remediation of organic materials on soil salinization with melon (Cucumis melo L.) by reducing the availability of saline ions and shifting the soil microbial community. Results showed that BC treatment significantly decreased the EC values of the soil and soil solution by 19.23% and 27.02% and the concentrations of Na⁺, K⁺, and Cl^- by 13.28%, 13.08%, and 15.21%, respectively, followed by CM and BIO treatments. High-throughput sequencing identified that organic amendments significantly improved the richness of the soil bacterial community and increased the relative abundances of Acidobacteria and Firmicutes by 33.11% and 111.2%, respectively, and the beneficial salt-tolerant bacterial genera Flavobacterium, Bacillus and Arthrobacter by 32.04%, 38.92% and 35.67%, respectively. Additionally, soil Na⁺, Ca²⁺, K⁺ and Cl^- were significantly negatively correlated with Acidobacteria and Flavobacterium and were also the most important factors driving the changes in the structure of the soil bacterial communities. The bacterial networks were more complex in the organic amendments treatments than in CK, reflecting through more nodes and links and a higher average clustering coefficient, density and modularity. This study provided a comprehensive understanding of the application of organic amendments in alleviating soil salinization and improving soil bacterial and fungal communities and provides scientific support for agriculture green development.

The excessive input of nitrogen (N) fertilizer and irrigation water to greenhouse vegetable production systems leads to N losses via nitrate ( ) leaching, ammonia (NH₃) volatilization and nitrous oxide (N₂O) emissions. Besides management of N fertilizer and irrigation inputs, the addition of the nitrification inhibitor dicyandiamide (DCD) has also been shown to mitigate N losses from soils. A greenhouse experiment was set up to identify the effects of combining DCD with recommended N and irrigation management on leaching, NH₃ volatilization and N₂O emissions under intensive vegetable production of tomatoes (Lycopersicon esculentum Mill.). The five treatments were: (A) control + TMI (traditional managed irrigation); (B) TN (traditional N rate applied at 410 kg N ha⁻¹) + TMI; (C) RN (recommended N rate applied at 210 kg N ha⁻¹) + DCD (21 kg ha⁻¹) + OMI (optimum managed irrigation); (D) 80%RN (N rate applied at 80% of the recommended N rate, 168 kg N ha⁻¹) + DCD (16.8 kg ha⁻¹) + OMI; and (E) 120%RN (N rate applied at 120% of the recommend N rate, 252 kg N ha⁻¹) + DCD (25.2 kg ha⁻¹) + OMI. DCD was applied at the rate of 10% of the N application rate. The results showed that the recommended N rate and irrigation with the addition of DCD (RN + DCD + OMI, 80%RN + DCD + OMI, and 120%RN + DCD + OMI) can significantly reduce N loss as , NH₃ and N₂O. The average concentrations in the top soil depth were decreased by 49.34–55.54%, total NH₃ volatilization were decreased by 20.61–41.51%, and N₂O emission factors were reduced by 84.07–96.19%. In addition, the utilization efficiency of N was enhanced. However, there was no significant effect of the recommended N rate and DCD plus optimum managed irrigation on tomato yield. Overall, these results suggest that applying 80%RN + DCD + OMI may provide a practicable option for both mitigating N losses and improving utilization efficiency of N under intensive greenhouse vegetable production systems.

Optimizing the culture conditions of DBP degradation by bacteria and investigating its biodegradation pathways have a great importance to develop effective PAEs pollution control strategies. In this study, we investigated the cultivation condition optimization, degradation kinetics, and degradation pathways of a newly isolated dibutyl phthalate (DBP) degradation strain, which was isolated from activated sludge and identified as Acinetobacter baumannii DP-2 via morphological observation, biochemical identification, and 16S rDNA sequence analysis. The degradation conditions were optimized based on the results of single-factor experiments and response surface optimization experiments. The DBP degradation rate of Acinetobacter baumannii DP-2 reached up to 85.86% when the inoculation amount was 17.14%, the DBP concentration was 9.81 mg·L⁻¹ and the NaCl concentration was 5 g·L⁻¹. The GC-MS analysis results indicated that the intermediate metabolites of Acinetobacter baumannii DP-2 mainly consisted of DMP, MBP, PA, and benzoic acid derivatives, which confirmed the degradation pathway from DBP to PA under aerobic pathway and then to BA under anaerobic pathway. In summary, Acinetobacter baumannii DP-2 shows great potential for the degradation of DBP in contaminated soils.