Intensive vegetable production in southern Australia is characterised by high inputs of nitrogen (N) fertiliser, water, and occasionally animal manures, which creates the potential for high nitrous oxide (N2O) emissions. Three field experiments were conducted to investigate the effects of the nitrification inhibitors 3, 4-dimethylpyrazole phosphate (DMPP), 3-methyl pyrazole plus 1H-1,2,4 triazo...

A method was developed to determine the contributions of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) to the nitrification potentials (NPs) of soils taken from forest, pasture, cropped, and fallowed (19 years) lands. Soil slurries were exposed to acetylene to irreversibly inactivate ammonia monooxygenase, and upon the removal of acetylene, the recovery of nitrification p...

In order to examine how fundamental soil N cycling processes are affected by elevated N inputs to temperate forest ecosystems, we made concurrent laboratory measurements of gross rates of nitrogen (N) mineralization, nitrification, nitrate (NO3 ) consumption, ammonium (NH4 þ) immobilization, nitrous oxide (N2O) and nitric oxide (NO) production, and NO consumption in soils from the Harvard Fores...

Shifts in nitrogen (N) mineralization and nitrification rates due to global changes can influence nutrient availability, which can affect terrestrial productivity and climate change feedbacks. While many single-factor studies have examined the effects of environmental changes on N mineralization and nitrification, few have examined these effects in a multifactor context or recorded how these ef...

Most studies on soil N2O emissions have focused either on the quantifying of agricultural N2O fluxes or on the effect of environmental factors on N2O emissions. However, very limited information is available on how land-use will affect N2O production, and nitrifiers involved in N2O emissions in agricultural soil ecosystems. Therefore, this study aimed at evaluating the relative importance of ni...

In addition to N load, cold weather nitrification is an important consideration for stabilized performance of biological processes applied to continuous animal production systems. A winter simulation experiment was conducted in the laboratory to evaluate performance of immobilized bacteria for treatment of swine wastewater under cold weather conditions. Bench fluidized reactors (1.2 L) containi...

Potential nitrogen mineralization and nitrification were measured in soils from a primary successional sequence developed on sand dunes and from a secondary successional sequence on old fields. Potential nitrogen mineralization in soils from the primary sere increased through the first five stages and then leveled off. Nitrogen mineralization was relatively constant in soils from the secondary ...