In plants, the uptake of nitrate from the soil is a critical process controlled by complex regulatory networks that target nitrate transporters in the roots. In this issue, Ho et al. (2009) show that phosphorylation of the CHL1 nitrate transporter allows the plant root to sense and respond to different nitrate concentrations in the soil.

Nitrate was formed from ammonium at pH 3.2 to 6.1 in suspensions of a naturally acid forest soil; the maximum rates of formation occurred at ca. pH 4 to 5. Nitrate was also formed from soil nitrogen in suspensions incubated at 50 degrees C. Autotrophic nitrifying bacteria could not be isolated from this soil. Enrichment cultures produced nitrate in a medium with beta-alanine if much soil was ad...

The leachate contains dissolved and suspended organic and inorganic, toxic or chemicals pollutants. Leachate can contaminate groundwater, surface water and soil. It can further have detrimental health effects on human being. This study sets out to investigate the effects of land treatment of municipal landfill’s leachate on the natural reduction of nitrogen and phosphorous density existing in t...

Studies examining the value of switching to a variable rate technologies (VRT) fertilizer program assume producers possess perfect soil nitrate information. In reality, producers estimate soil nitrate levels with soil sampling. The value of switching to a VRT program depends on the quality of the estimates and on how the estimates are used. Larger sample sizes, increased spatial correlation, an...

Slow release of nitrate by charred organic matter used as a soil amendment (i.e. biochar) was recently suggested as potential mechanism of nutrient delivery to plants which may explain some agronomic benefits of biochar. So far, isolated soil-aged and composted biochar particles were shown to release considerable amounts of nitrate only in extended (>1 h) extractions ("slow release"). In this s...

By employing chemical and isotopic tracers ((15)N and (18)O in NO(3)(-)), we investigated the main processes controlling nitrate distribution in the unsaturated zone and aquifer. Soil water was extracted from two soil cores drilled in a typical agricultural cropping area of the North China Plain (NCP), where groundwater was also sampled. The results indicate that evaporation and denitrification...

Nests of the harvester ant Pogonomyrmex barbatus typically contain higher concentrations of organic matter, nitrogen and phosphorus than surrounding soils. The difference between nest soils and surrounding soils is due, at least in part, to ant foraging behavior. Ants retrieve seeds from the environment and concentrate seed nutrients in the vicinity of the nest. But elevated nutrient concentrat...

Abstract Nitrates when found in excess in the groundwater, is a health hazard. Nitrates can easily be transported by groundwater movement and may eventually reach aquifers located far away from the contamination location. It is important to monitor the nitrate movement in the groundwater to predict the extent of nitrate contamination. Traditionally, nitrate movement is monitored by sampling gro...

Background: Highly-concentrated phosphate and nitrate anions from sugarcane wastewater are often discharged into public waters without standardized treatments. This study assessed the effects of electrical coagulation, initial pH and reaction time in the removal of phosphate and nitrate pollutants. Methods: We used aluminum electrodes to remove the pollutants at Hakhim Farabi Agricultural and ...