The long-term uncertainty of biodegradable mulch film residues and associated microplastics pollution on plant-soil health.

Biodegradable mulch film potentially offers an encouraging alternative to conventional (petroleum-based) plastic films. Since biodegradable films are more susceptible to rapid degradation, more microplastics (MPs) are likely to be generated than conventional films within the same time frame, probably leading to more severe MPs pollution and associated effects. However, the effect of biodegradable mulch film residues and associated MPs pollution on plant-soil health remains uncertainty. Here, we evaluated the potential effect of bio-MPs pollution on soil carbon (C) and nutrient (i.e., N and P) cycling, soil biology (microorganisms and mesofauna), and plant health, as these are crucial to agroecosystem functioning and the delivery of key ecosystem services. Unlike the inert (and therefore recalcitrant) C contained within petroleum-based MPs, at least 80% of the C from bio-MPs is converted to CO2, with up to 20% immobilized in living microbial biomass (i.e., < 0.05 t C ha-1). Although biodegradable films are unlikely to be important in promoting soil C storage, they may accelerate microbial biomass turnover in the short term, as well as CO2 production. Compared to conventional MPs, bio-MPs degradation is more pronounced, thereby inducing greater alterations in microbial diversity and community composition. This may further alter N2O and CH4 emissions, and ultimately resulting in unpredictable consequences for global climate warming. The extent to which this may occur, however, has yet to be shown in either laboratory or field studies. In addition, bio-MPs have a large chance of forming nanoplastics, potentially causing a stronger toxic effect on plants relative to conventional MPs. Consequently, this would influence plant health, crop productivity, and food safety, leading to potential health risks. It is unclear, however, if these are direct effects on key plant processes (e.g. signaling, cell expansion) or indirect effects (e.g. nutrient deficiency or acidification). Overall, the question as to whether biodegradable mulch films offer a promising alternative to solve the conventional plastic legacy in soil over the long term remains unclear.

Efficacy and safety of Reduning injection in the treatment of COVID-19: a randomized, multicenter clinical study.

BACKGROUND: Reduning injection is a traditional Chinese medicine (TCM) with known efficacy against a variety of viral infections, but there is no data about its efficacy against coronavirus disease 2019 (COVID-19). METHODS: To explore the efficacy and safety of Reduning injection in the treatment of COVID-19, a randomized, open-labeled, multicenter, controlled trial was conducted from 12 general hospitals between 2020.02.06 and 2020.03.23. Patients with COVID-19 who met the diagnostic criteria of the "Diagnosis and Treatment Program for Novel Coronavirus Infection Pneumonia (Trial Fifth Edition)". Patients were randomized to routine treatment with or without Reduning injection (20 mL/day for 14 days) (ChiCTR2000029589). The primary endpoint was the rate of achieving clinical symptom recovery on day 14 of treatment. RESULTS: There were 77 and 80 participants in the Reduning and control groups. The symptom resolution rate at 14 days was higher in the Reduning injection than in controls [full-analysis set (FAS): 84.4% vs. 60.0%, P=0.0004]. Compared with controls, the Reduning group showed shorter median time to resolution of the clinical symptoms (143 vs. 313.5 h, P<0.001), shorter to nucleic acid test turning negative (146.5 vs. 255.5 h, P<0.001), shorter hospital stay (14.1 vs. 18.1 days, P<0.001), and shorter time to defervescence (29 vs. 71 h, P<0.001). There was no difference in AEs (3.9% vs. 8.8%, P=0.383). CONCLUSIONS: This preliminary trial suggests that Reduning injection might be effective and safe in patients with symptomatic COVID-19.

Enhancing naked oat (Avena nuda L.) productivity with minimal indirect nitrogen loss and maximum nitrogen use efficiency through integrated use of different nitrogen sources.

Oat (Avena nuda L.) is a nutritious grain crop, rich in dietary fibers and phytochemicals. Application of efficient nitrogen (N) sources and dose is very important to obtain higher crop productivity and to achieve environmental sustainability. The exploitation of natural beneficial microbes and organic nitrogen in combination with chemical nitrogen would be effective to boost soil N for plant uptake. Hence, a field experiment was conducted during 2016 and 2017 with the aim to ameliorate the use of chemical N (CN) with organic nitrogen (ON) and microbial fertilizer (MBF) without compromising the productivity of oat. T1 = control, T2 = 100% CN, T3 = 100% CN+MBF, T4 = 75% CN+ 25% ON+MBF, T5 = 50% CN+ 50% ON+MBF, T6 = 100% ON+MBF, T7 = 100% ON were the treatments. 50% CN + 50% ON + MBF treatment proved to be an efficient combination regarding enhanced biomass and grain yield, nitrogen uptake and NUE as compared to rest of the treatments in both years. During the critical stages of the crop, when most of the applied CN was leached from the top 20 cm soil depth, a substantial N came from the PM mineralization through enhanced microbial activity by the addition of MBF. Lastly, the application of ON supplemented with MBF improved the rhizosphere soil properties, i.e. mineral N concentration, total N (TN), soil organic carbon (SOC), microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), soil respiration rate and enzymatic activity. A balanced and source conscious application of CN, ON and MBF reduced N losses and added a substantial amount of N into the soil N pool. We concluded that organic N combined with chemical N and MBF proved to be effective in improving soil properties ensuring less N loss and increasing oat production in the semi-arid region.