Metal oxide nanoparticles inhibit nitrogen fixation and rhizosphere colonization by inducing ROS in associative nitrogen-fixing bacteria Pseudomonas stutzeri A1501.

The potential effects of engineered metal oxide nanoparticles (MONPs) on bacterial nitrogen fixation are of great concern. Herein, the impact and mechanism of the increasing-used MONPs, including TiO, AlO, and ZnO nanoparticles (TiONP, AlONP, and ZnONP, respectively), on nitrogenase activity was studied at the concentrations ranging from 0 to 10 mg L using associative rhizosphere nitrogen-fixing bacteria Pseudomonas stutzeri A1501. Nitrogen fixation capacity was inhibited by MONPs in an increasing degree of TiONP < AlONP < ZnONP.

Matured compost amendment improves compost nutrient content by changing the bacterial community during the composting of Chinese herb residues.

Composting is a sustainable strategy to deal with organic waste. Our research aimed to study the influence of an amendment of 10% matured compost (MC) during Chinese herb residue (CHR) compost. Here, a 60-day CHR compost was performed, and MC application was able to reduce the nitrogen loss and enhance the humic acid accumulation during the composting as compared with the non-inoculated control (NC), by 25 and 19%, respectively.

Decreased Methane Emissions Associated with Methanogenic and Methanotrophic Communities in a Pig Manure Windrow Composting System under Calcium Superphosphate Amendment.

With the rapid growth of livestock breeding, manure composting has evolved to be an important source of atmospheric methane (CH) which accelerates global warming. Calcium superphosphate (CaSSP), as a commonly used fertilizer, was proposed to be effective in reducing CH emissions from manure composting, but the intrinsic biological mechanism remains unknown. Methanogens and methanotrophs both play a key role in mediating CH fluxes, therefore we hypothesized that the CaSSP-mediated reduction in CH emissions was attributed to the shift of methanogens and methanotrophs, which was regulated by physicochemical parameter changes.

Calcium Superphosphate-Mediated Reshaping of Denitrifying Bacteria Community Contributed to NO Mitigation in Pig Manure Windrow Composting.

Composting is recognized as an effective strategy for the sustainable use of organic wastes, but also as an important emission source of nitrous oxide (NO) contributing to global warming. The effects of calcium superphosphate (CaSSP) on NO production during composting are reported to be controversial, and the intrinsic microbial mechanism remains unclear. Here, a pig manure windrow composting experiment lasting for ~60 days was performed to evaluate the effects of CaSSP amendment (5%, /) on NO fluxes in situ, and to determine the denitrifiers' response, and their driving factors.

The continuous application of biochar in field: effects on P fraction, P sorption and release.

It is unclear how biochar can affect P availability in soil, especially in field under continuous application. In this study, a field experiment was conducted to study the effect of 2-years application of biochar on P availability, P fractionation, P sorption and release in a clay soil. The biochar in this study was produced from rice straw through pyrolysis at 700°C.

Heavy metal and nutrient changes during vermicomposting animal manure spiked with mushroom residues.

A pilot-scale trial of four months was conducted to investigate the responses of heavy metal and nutrient to composting animal manure spiked with mushroom residues with and without earthworms. Results showed that earthworm activities accelerated organic matter mineralization (e.g.

[Effects of fluctuating thermal regime on cold tolerance of parasitoid wasp Aphidius gifuensis].

In order to understand the effects of fluctuating thermal regime (FTR) on the cold tolerance of female and male Aphidius gifuensis adults in the mummies of Schizaphis graminum and to explore the variation patterns of the biochemical substances in the adult body, this paper determined the supercooling point (SCP), freezing point (FP), and the water, fat, protein, and carbohydrate contents of the adults after FTR treatments. Compared with that at constant temperature (20 degrees C), the cold tolerance of the adults at 4 degrees C 22 h/20 degrees C 2 h and 4 degrees C 46 h/20 degrees C 2 h after 1 week enhanced significantly. The SCP and FP after FTR presented a downtrend, being the lowest (-26.