The southern Brazilian highland plateau is a mosaic of two contrasting plant communities, Araucaria forests and grasslands, both differing in the relative abundances and spatial patterns of soil nitrate and ammonium. However, we still do not know the inorganic N preferences of one key species in this mosaic, Araucaria angustifolia, the dominant tree species in the Araucaria forests and an impor...

Plants mainly utilize inorganic forms of nitrogen (N), such as nitrate (NO3-) and ammonium (NH4+). However, the composition of the N source is important, because excess of NH4+ promotes morphological disorders. Plants cultured on NH4+ as the sole N source exhibit serious growth inhibition, commonly referred to as "ammonium toxicity syndrome." NH4+-mediated suppression of growth may be attributa...

Ammonium was injected from the subseafloor hydrothermal system at the Endeavour Segment, Juan de Fuca Ridge, into the deep-sea water column resulting in an NH4 þ-rich (6177 nM) neutrally buoyant hydrothermal plume. This NH4 was quickly removed by both autotrophic ammonia oxidation and assimilation. The former accounted for at least 93% of total net NH4 þ removal, with its maximum rate in the ne...

a conductance study of the interaction between cs+, rb+, nh4+, k+, t1+ and ag+ ions and18-crown-6 (18c6), benzo-18-crown-6 (b18c6), dicyclohexyl-18-crown-6 (dc18c6),dicyclohexyl-24-crown-8 (dc24c8), dibenzo-24-crown-8 (db24c8) in different binarymixtures of acetonitrile (an) with dimethylsulfoxide (dmso) and dimethylformamide (dmf)at 25 °c has been carried out. formation constants of the result...

Biochar produced by pyrolysis of biomass can be used to counter nitrogen (N) pollution. The present study investigated the effects of feedstock and temperature on characteristics of biochars and their adsorption ability for ammonium N (NH4(+)-N) and nitrate N (NO3(-)-N). Twelve biochars were produced from wheat-straw (W-BC), corn-straw (C-BC) and peanut-shell (P-BC) at pyrolysis temperatures of...

A review is given of a relatively unknown area of the electronic structures of Rydberg radicals. The primary examples of such structures are H , NH4 and H30. The condensed phase existence of the latter 8wo has long been proposed. Mercury amalgams of organic ammonium radicals, R4N, have been reported. Theoretical studies are reported on some of these species. in liquid ammonia vis-a-vis NH4 + e ...

The vertical distributions of nitrifying bacteria in aerobic fixed biofilm were investigated to evaluate the relationship between nitrification performance and microbial community at different HRT. Fluorescent in situ hybridization (FISH) and portable ion selective microelectrode system were adopted to analyze microbial communities and ions profiles according to the biofilm depth. Cilia media p...