Impact of Weed Management Practices on Soil Microflora and Dehydrogenase Enzyme Activity Under Varying Levels of Nitrogen in Winter Season Onion (Allium cepa L.).

The study was conducted to evaluate the suitability of different weed management practices under influence of varying levels of N doses to test their effects on the various soil microflora and dehydrogenase enzyme activity in the winter onion field during 2016-2017 and 2017-2018. There were a total of twenty eight treatments replicated three times under the split-plot design (SPD). The treatments associated with weed management practices were applied to the main plots and the different N doses were given in each subplot. Microbial population and dehydrogenase enzyme activity in soil and crop weed competition index were determined. The two-hand weeding (HW) at 20 and 40 days after transplanting (DAT) of onion seedlings as well as preplant application of oxyfluorfen along with one HW at 40 DAT, exhibited a significant increase in dehydrogenase activity and microbial population in the soil when the N was applied at 100 kg ha-1. The study suggests that suitable weed management practices for the winter onion exerts a transient impact on soil microbial population, maintained good soil health and reduced crop-weed competition (CWC) with relatively less environmental hazards.

Artificial night light alters ecosystem services provided by biotic components.

The global catastrophe of natural biodiversity and ecosystem services are expedited with the growing human population. Repercussions of artificial light at night ALAN are much wider, as it varies from unicellular to higher organism. Subsequently, hastened pollution and over exploitation of natural resources accelerate the expeditious transformation of climatic phenomenon and further cause global biodiversity losses. Moreover, it has a crucial role in global biodiversity and ecosystem services losses via influencing the ecosystem biodiversity by modulating abundance, number and aggregation at every levels as from individual to biome levels. Along with these affects, it disturbs the population, genetics and landscape structures by interfering inter- and intra-species interactions and landscape formation processes. Furthermore, alterations in normal light/dark (diurnal) signalling disrupt the stable physiological, biochemical, and molecular processes and modulate the regulating, cultural and provisioning ecosystem services and ultimately disorganize the stable ecosystem structure and functions. Moreover, ALAN reshapes the abiotic component of the ecosystem, and as a key component of global warming via producing greenhouse gases via emitting light. By taking together the above facts, this review highlights the impact of ALAN on the ecosystem and its living and non-living components, emphasizing to the terrestrial and aquatic ecosystem. Further, we summarize the means of minimizing strategies of ALAN in the environment, which are very crucial to reduce the further spread of night light contamination in the environment and can be useful to minimize the drastic impacts on the ecosystem.