Mulching and nitrogen are critical drivers of crop production for smallholders of the Loess Plateau in China. The purpose of this study was to investigate the effect of mulching and nitrogen fertilizer on the soil water content, soil nitrate-N content and vertical distribution in maize root-zone. The experiment was conducted over two consecutive years and used randomly assigned field plots with...

The effect of nitrate, acetate, and hydrogen on native perchlorate-reducing bacteria (PRB) was examined by conducting microcosm tests using vadose soil collected from a perchlorate-contaminated site. The rate of perchlorate reduction was enhanced by hydrogen amendment and inhibited by acetate amendment, compared with unamendment. Nitrate was reduced before perchlorate in all amendments. In hydr...

Forest harvesting disrupts the nitrogen cycle, which may affect stream water quality by increasing nitrate concentrations, reducing pH and acid neutralizing capacity, and mobilizing aluminum and base cations. We tested the application of wood chips derived from logging slash to increase immobilization of N after harvesting, which should reduce nitrate flux to streams. In August 2004, a stand of...

This study aimed at examining effective sample treatments and spectral processing for an alternate method of soil nitrate determination using the attenuated total reflectance (ATR) of Fourier transform infrared (FTIR) spectroscopy. Prior to FTIR measurements, soil samples were prepared as paste to enhance adhesion between the ATR crystal and sample. The similar nitrate peak heights of soil past...

We studied the effects of adding water, nitrate and sucrose on denitrification in a riparian forest that receives nitrate in drainage from cornfields. We used large (3-6 m2) flow-through chambers to sample N 2 0 emissions from surface soils. N2 emissions were estimated by comparing N 2 0 efflux in chambers with or without acetylene addition. Water and solutions of nitrate or sucrose were sprink...

The aims of the study were to analyse the concentration of nitrate and ammonium ions in soil solutions obtained using MacroRhizon miniaturized composite suction cups under field conditions and to determine potential nitrogen leaching from soil fertilized with three types of fertilizers (standard urea, slow-release urea, and ammonium nitrate) at the doses of 90 and 180 kg ha-1, applied once or d...

Th ere is noticeable negative impact on soil and water quality caused by nutrient leaching, especially nitrate. Five regions in Croatia are preliminary delineated as nitrate vulnerable zones, including potentially vulnerable zones (PVZ) and vulnerable zones (VZ), one of them being Varaždin County. Agricultural land spreads on 59% of its total area. Th e survey was carried out to analyze two ava...

We assessed the effects of canopy position and feral pig disturbance on soil moisture, pH, and inorganic nitrogen concentrations beneath canopies of Quercus agrifolia and surrounding grasslands on Santa Cruz Island, California. Percent soil moisture, pH, nitrate-N, and total inorganic nitrogen varied significantly with canopy position. Soil moisture decreased, and pH increased along transects f...

Unpublished studies in the files of the Pineapple Research Institute of Hawaii indicate that under present cultural conditions the .pineapp1e plant displays superior performance with a foliar applied combination of ammonium and nitrate nitrogen than with either form of nitrogen alone. The studies presented here were undertaken to evaluate ammonium nitrate as a nitrogen source under different so...

The microbial processes of denitrification and dissimilatory nitrate reduction to ammonium (DNRA) are two important nitrate reducing mechanisms in soil, which are responsible for the loss of nitrate ([Formula: see text]) and production of the potent greenhouse gas, nitrous oxide (N(2)O). A number of factors are known to control these processes, including O(2) concentrations and moisture content...