Responses of weed community, soil nutrients, and microbes to different weed management practices in a fallow field in Northern China

A novel Zn2+-coordination fluorescence probe for sensing HPPD inhibitors and its application in environmental media and biological imaging

Mesotrione, topramezone, tembotrione, and sulcotrione are four types of 4-hydroxyphenylpyruvate dioxidase (HPPD) inhibitor herbicides that are extensively employed in agricultural practices, but their usage also leads to environmental pollution and poses risks to human health. A probe (E)-1-((2-(pyridin-2-yl) hydrazineylidene) methyl) naphthalen-2-ol (CHMN) based on chelation enhancement (CHEF) effect synthesized. CHMN was first chelated with Zn2+ to form a probe system with green, which can be further used to detect mesotrione, topramezone, tembotrione and sulcotrione in complicated environment. CHMN-Zn2+ detection of four pesticides was accurate, with an excellent linear relationship between 0 and 100 μM. The detection limits were LODmesotrione = 7.79 μM, LODtopramezone = 1.91 μM, LODtembotrione = 1.38 μM and LODsulcotrione = 2.43 μM. The detection time is 1 min, and it is successfully applied in real water sample and bioimaging. This work can provide a novel method for studying the migration and behavior of environmental pollutants.

Invasive Johnsongrass, a threat to native grasslands and agriculture

Among the weedy plant species, Johnsongrass (Sorghum halepense) is one of the most destructive. Johnsongrass has invaded new habitats beyond its native Eurasian origin by outcompeting native flora and cultivated crops. The Johnsongrass habitat is expanding continuously due to clonal and self-pollinating reproduction strategy, accelerated growth and the progressing climate change. As a result, Johnsongrass has reduced native plant diversity in grasslands and inflicted economic damage to agriculture on every continent. Johnsongrass is a growing threat to crop production, as it serves as a refuge for a variety of agricultural pests and plant viral diseases. Over the past decades, herbicides extensively applied to control Johnsongrass have boosted selection pressure, resulting in the independent evolution of herbicide-resistant ecotypes across multiple locations. The apparent threat to native flora and agriculture caused by the invasive Johnsongrass is a subject to a long and ongoing research. This review provides a historical and research overview on Johnsongrass expansion, its current as well future impact particularly on North American and European grasslands and agriculture.

Identifying potential threats to soil biodiversity

A decline in soil biodiversity is generally considered to be the reduction of forms of life living in soils, both in terms of quantity and variety. Where soil biodiversity decline occurs, it can significantly affect the soils' ability to function, respond to perturbations and recover from a disturbance. Several soil threats have been identified as having negative effects on soil biodiversity, including human intensive exploitation, land-use change and soil organic matter decline. In this review we consider what we mean by soil biodiversity, and why it is important to monitor. After a thorough review of the literature identified on a Web of Science search concerning threats to soil biodiversity (topic search: threat* "soil biodiversity"), we compiled a table of biodiversity threats considered in each paper including climate change, land use change, intensive human exploitation, decline in soil health or plastic; followed by detailed listings of threats studied. This we compared to a previously published expert assessment of threats to soil biodiversity. In addition, we identified emerging threats, particularly microplastics, in the 10 years following these knowledge based rankings. We found that many soil biodiversity studies do not focus on biodiversity sensu stricto, rather these studies examined either changes in abundance and/or diversity of individual groups of soil biota, instead of soil biodiversity as a whole, encompassing all levels of the soil food web. This highlights the complexity of soil biodiversity which is often impractical to assess in all but the largest studies. Published global scientific activity was only partially related to the threats identified by the expert panel assessment. The number of threats and the priority given to the threats (by number of publications) were quite different, indicating a disparity between research actions versus perceived threats. The lack of research effort in key areas of high priority in the threats to soil biodiversity are a concerning finding and requires some consideration and debate in the research community.