We compared gross N fluxes by N pool dilution in a coarse-textured agricultural soil when N was applied to the soil NH4 C pool by either: (i) mixing a NH4NO3 solution into disturbed soil or (ii) injection of NH3 gas into intact soil cores. The two techniques produced similar results for gross N mineralization rates indicating that NH4 C production in soil was not altered by soil disturbance, me...

re-vegetation of bare soil is believed to increase, or at least maintain the organic matter levels of soil. the aim of this study was to investigate the soil characteristics changes, nutrient pool sizes and their availability under mid canopy, and canopy gap positions of saltbush in an area re-vegetated with atriplex lentiformis. some of the physical and chemical soil characteristics (the parti...

SUMMARY *Simulation models indicate that the nitrogen (N) cycle plays a key role in how other ecosystem processes such as plant productivity and carbon (C) sequestration respond to elevated CO(2) and warming. However, combined effects of elevated CO(2) and warming on N cycling have rarely been tested in the field. *Here, we studied N cycling under ambient and elevated CO(2) concentrations (600 ...

In many terrestrial ecosystems nitrogen (N) limits productivity and plant community composition is influenced by N availability. However, vegetation is not only controlled by N; plant species may influence ecosystem N dynamics through positive or negative effects on N cycling. We examined four potential mechanisms of plant species effects on nitrogen (N) cycling. We found no species differences...

Humans have dramatically increased the deposition and availability of nutrients, such as nitrogen (N), worldwide. Soil organic matter (SOM) is a significant global reservoir of carbon (C); however, the effects of N enrichment on this large, heterogeneous C stock are unclear. Nitrogen has variable effects on the biological, chemical, and physical factors that determine SOM pool mean residence ti...

Biochar production and subsequent soil incorporation could provide carbon farming solutions to global climate change and escalating food demand. There is evidence that biochar amendment causes fundamental changes in soil nutrient cycles, often resulting in marked increases in crop production, particularly in acidic and in infertile soils with low soil organic matter contents, although comparabl...

In many terrestrial ecosystems plant productivity is limited by the availability of mineral nitrogen, which is produced by soil microbial transformations of organic N in soil organic matter (SOM-N). Mineral N availability results from two opposing processes, 1) gross mineral N production (gross ammonification/ gross nitrification) and 2) microbial N immobilization. These processes can be influe...

plant biomass production increases in response to burning, quantities of available soil N may not be sufficient The availability of N limits productivity in tallgrass prairie. Spring to meet plant demand. burning is common because it results in greater plant productivity Although the total mass of N in the Konza Prairie in despite reducing net N mineralization. To better explain how burning Kan...

Elevated anthropogenic nitrogen (N) deposition has greatly altered terrestrial ecosystem functioning, threatening ecosystem health via acidification and eutrophication in temperate and boreal forests across the northern hemisphere. However, response of forest soil acidification to N deposition has been less studied in humid tropics compared to other forest types. This study was designed to expl...