Fire Reduces Soil Nitrate Retention While Increasing Soil Nitrogen Production and Loss Globally.

Elucidating the response of soil gross nitrogen (N) transformations to fires could improve our understanding of how fire affects N availability and loss. Yet, how internal soil gross N transformation rates respond to fires remains unexplored globally. Here, we investigate the general response of gross soil N transformations to fire and its consequences for N availability and loss.

Initial evidence on the effect of copper on global cropland nitrogen cycling: A meta-analysis.

Copper (Cu) is a key cofactor in ammonia monooxygenase functioning responsible for the first step of nitrification, but its excess availability impairs soil microbial functions and plant growth. Yet, the impact of Cu on nitrogen (N) cycling and process-related variables in cropland soils remains unexplored globally. Through a meta-analysis of 1209-paired and 319-single observations from 94 publications, we found that Cu (Cu addition or Cu-polluted soil) reduced soil potential nitrification by 33.

Land Use Change from Natural Tropical Forests to Managed Ecosystems Reduces Gross Nitrogen Production Rates and Increases the Soil Microbial Nitrogen Limitation.

Understanding the underlying mechanisms of soil microbial nitrogen (N) utilization under land use change is critical to evaluating soil N availability or limitation and its environmental consequences. A combination of soil gross N production and ecoenzymatic stoichiometry provides a promising avenue for nutrient limitation assessment in soil microbial metabolism. Gross N production via N tracing and ecoenzymatic stoichiometry through the vector and threshold element ratio (Vector-TER) model were quantified to evaluate the soil microbial N limitation in response to land use changes.

Aridity creates global thresholds in soil nitrogen retention and availability.

Identifying tipping points in the relationship between aridity and gross nitrogen (N) cycling rates could show critical vulnerabilities of terrestrial ecosystems to climate change. Yet, the global pattern of gross N cycling response to aridity across terrestrial ecosystems remains unknown. Here, we collected 14,144 observations from 451 N-labeled studies and used segmented regression to identify the global threshold responses of soil gross N cycling rates and soil process-related variables to aridity index (AI), which decreases as aridity increases.

Effects of Solidago canadensis L. on mineralization-immobilization turnover enhance its nitrogen competitiveness and invasiveness.

The effects of exotic plants on soil nitrogen (N) transformations may influence species invasion success. However, the complex interplay between invasive plant N uptake and N transformation in soils remains unclear. In the present study, a series of N-labeled pot experiments were carried out with Solidago canadensis L.

Soil dissolved organic matters mediate bacterial taxa to enhance nitrification rates under wheat cultivation.

Studies have shown that dissolved organic matters (DOMs) may affect soil nutrient availability to plants due to their effect on microbial communities; however, the relationships of soil DOM-bacterial community-N function in response to root exudates remains poorly understand. Here, we evaluated the DOM composition, bacterial taxonomic variation and nitrogen transformation rates in both acidic and alkaline soils, with or without the typical nitrate preference plant (wheat, Triticum aestivum L.).