Soil type and wetting intensity control the enhancement extent of N_(2)O efflux in soil with drought and rewetting cycles

Climate change alters the intensity and frequency of drought and rewetting(D/W)events;however,the influence patterns of D/W on soil N_(2)O efflux in the water-limited area were not fully understood.Therefore,the impacts of D/W cycles varying in different extent of rewetting and frequency to N_(2)O efflux in two kinds of soil on the Loess Plateau were investigated.The incubation conditions consisted of 1)D/W treatments with four 7-day cycles from 10%water holding capacity(WHC)to 60%WHC or 90%WHC,2)constant moisture of 60%WHC and 90%WHC.The pulse of N_(2)O efflux rate under 10-60%WHC treatment was higher than that under 10-90%WHC treatment in calcic cambisols,while opposite trend was observed in earth-cumuli-orthic anthrosols.Meanwhile,the pulse of N_(2)O efflux rate decreased as cycle number increased for different wetting intensities and soil types.The direct N_(2)O efflux under 10-60%WHC and 10-90%WHC treatments were 5.49 and 1.89μg N_(2)O-N g^(-1)soil in calcic cambisols,with those being 1.92 and 10.85μg N_(2)O-N g^(-1)soil in earth-cumuli-orthic anthrosols,respectively.The N loss in earth-cumuli-orthic anthrosols was approximately 5.74 times greater than that in calcic cambisols under 10-90%WHC treatment,whereas the N loss under 10-60%WHC treatment was about 2.86 times greater in calcic cambisols than that in earth-cumuli-orthic anthrosols.This study suggested that extreme rainfall events can enhance the N_(2)O efflux and N loss in agricultural soils on the Loess Plateau in terms of soil type and wetting intensity,which should not be ignored in the N fertilizer management.

Drying-rewetting cycles reduce bacterial diversity and carbon loss in soil on the Loess Plateau of China

With global climate change, soil drying-rewetting(DRW) events have intensified and occurred frequently on the Loess Plateau of China. However, the extent to which the DRW cycles with different wetting intensities and cycle numbers alter microbial community and respiration is barely understood. Here,indoor DRW one and four cycles treatments were implemented on soil samples obtained from the Loess Plateau, involving increase of soil moisture from10% water-holding capacity(WHC) to 60% and 90% WHC(i.e., 10%–60% and 10%–90% WHC, respectively). Constant soil moistures of 10%, 60%,and 90% WHC were used as the controls. The results showed that bacterial diversity and richness decreased and those of fungi remained unchanged under DRW treatments compared to the controls. Under all moisture levels, Actinobacteriota and Ascomycota were the most dominant bacterial and fungal phyla,respectively. The bacterial network was more complex than that of fungi, indicating that bacteria had a greater potential for interaction and niche sharing under DRW treatments. The pulse of respiration rate declined as the DRW cycle increased under 10%–60% WHC, but remained similar for different cycles under 10%–90% WHC. Moreover, the DRW treatments reduced the overall carbon loss, and the direct carbon release under 10%–60% WHC was larger than that under 10%–90% WHC. The cumulative CO_(2) emissions after four DRW cycles were significantly positively correlated with microbial biomass carbon and negatively correlated with fungal richness(Chao 1).

Dependence of cumulative CO_(2) emission and microbial diversity on the wetting intensity in drying-rewetting cycles in agriculture soil on the Loess Plateau

Altered drying-rewetting(DRW)procedures due to climate change may influence soil microbial properties and microbially-mediated carbon cycling in arid and semi-arid regions.However,the effects of DRW of different intensities on the microbial properties and respiration are not well understood.Thus,the responsive patterns of microbial communities and carbon mineralization in agriculture soil on the Chinese Loess Plateau to DRW treatments with different wetting intensities(5%-25% and 5%-36%)and frequency(1-cycle to 4-cycle)were investigated.Continuous moisture levels of 5%,25% and 36% were used as control.Results revealed that the reduction of bacterial diversity and richness were greater for 5%-36% than 5%-25% treatment,while diversity of fungi was similar for different wetting intensities.Bacterial communities became clustered by wetting intensity rather than cycle number,however fungal community was unaffected by DRW.The complexity of bacterial co-occurrence network increased because of higher nodes,edges,average degree,diameter and average cluster coefficient after 4-cycles,and the interaction was more complex after 1-cycle for fungi.Rewetting caused a pulse-like increase of respiration rate,and the pulse amplitude was greater for DRW with high rewetting intensity and decreased with the increase of cycle number.The cumulative CO_(2) emission for DRW treatments was lower than that for the continuous moisture conditions.The net reduction of carbon release for 5%-36% treatment was 1.18 times higher than that for 5%-25% treatment.Our study provides experimental evidence of the positive potential of DRW processes for maintaining soil carbon stock in an agriculture system on the Loess Plateau.

The SUPER reporting guideline suggested for reporting of surgical technique

Background:Existing reporting guidelines pay insufficient attention to the detail and comprehensiveness reporting of surgical technique.The Surgical techniqUe rePorting chEcklist and standaRds(SUPER)aims to address this gap by defining reporting standards for surgical technique.The SUPER guideline intends to apply to articles that encompass surgical technique in any study design,surgical discipline,and stage of surgical innovation.Methods:Following the EQUATOR(Enhancing the QUAlity and Transparency Of health Research)Network approach,16 surgeons,journal editors,and methodologists reviewed existing reporting guidelines relating to surgical technique,reviewed papers from 15 top journals,and brainstormed to draft initial items for the SUPER.The initial items were revised through a three-round Delphi survey from 21 multidisciplinary Delphi panel experts from 13 countries and regions.The final SUPER items were formed after an online consensus meeting to resolve disagreements and a three-round wording refinement by all 16 SUPER working group members and five SUPER consultants.Results:The SUPER reporting guideline includes 22 items that are considered essential for good and informative surgical technique reporting.The items are divided into six sections:background,rationale,and objectives(items 1 to 5);preoperative preparations and requirements(items 6 to 9);surgical technique details(items 10 to 15);postoperative considerations and tasks(items 16 to 19);summary and prospect(items 20 and 21);and other information(item 22).Conclusions:The SUPER reporting guideline has the potential to guide detailed,comprehensive,and transparent surgical technique reporting for surgeons.It may also assist journal editors,peer reviewers,systematic reviewers,and guideline developers in the evaluation of surgical technique papers and help practitioners to better understand and reproduce surgical technique.

Biodegradation of 3,5-dimethyl-2,4-dichlorophenol in saline wastewater by newly isolated Penicillium sp.yz11-22N2

In this study,the performance of 3,5-dimethyl-2,4-dichlorophenol（DCMX） degradation by a screened strain was investigated.18 S r DNA and the neighbor-joining method were used for identification of the isolated strain.The results of phylogenetic analysis and scanning electron micrographs showed that the most probable identity of the screened strain should be Penicillium sp.Growth characteristics of Penicillium sp.and degradation processes of DCMX were examined.Fourier transform infrared spectroscopy of the inoculated DCMX solution was recorded,which supported the capacity of DCMX degradation by the screened Penicillium sp.Under different salinity conditions,the highest growth rate and removal efficiency for DCMX were obtained at p H 6.0.The removal efficiency decreased from 100%to 66% when the DCMX concentration increased from 5 to 60 mg/L,respectively.Using a Box–Behnken design,the maximum DCMX removal efficiency was determined to be 98.4%.With acclimation to salinity,higher removal efficiency could be achieved.The results demonstrate that the screened Penicillium sp.has the capability for degradation of DCMX.