This paper reports a soil-based bioassay of rice husk bio-ash impacts on redox properties and rice production. Bio-ash was produced during the pyrolytic process of rice husk as a boiler fuel, after which it was applied as an amendment to a flooded soil. Bio-ash was amended before rice transplanting at different mass rates including 0%, 0.1%, 1% and 5%, which was defined as T1, T2, T3, and T4 re...

Thirty-seven surface soil samples varying in physico-chemical properties were incubated under reduced (anaerobic) conditions to study the factors influencing oxygen consumption rates. Oxygen consumption rates were measured after introduction of a known amount of oxygen into a reduced (anaerobic) soil system and following the disappearance of oxygen as a function of time. The time dependence of ...

Flooding/waterlogging is a major factor responsible for hypoxic stress in agriculture. The aim of this study was to develop an effective oxygen buffer with magnesium peroxide (MgO2) to generate hydrogen peroxide (H2O2) and release bioavailable oxygen. MgO2 provided a relatively stable level (approx. 300 mM) of bioavailable oxygen. The oxygen-buffer system is adjustable and controllable by addin...

Water flow in the soil–root–stem system was studied in a flooded riparian hardwood forest in the upper Rhine floodplain. The study was undertaken to identify the vertical distribution of water uptake by trees in a system where the groundwater is at a depth of less than 1 m. The three dominant ligneous species (Quercus robur, Fraxinus excelsior and Populus alba) were investigated for root struct...

Saproxylic arthropods are thought to play an important role in wood decomposition but very few efforts have been made to quantify their contributions to the process and the factors controlling their activities are not well understood. In the current study, mesh exclusion bags were used to quantify how arthropods affect loblolly pine (Pinus taeda L.) decomposition rates in both seasonally floode...

The nitrate (NO(3)(-)) removal capacity of riparian zones is well documented, but information is lacking with regard to N(2)O emission from riparian ecosystems and factors controlling temporal dynamics of this potent greenhouse gas. We monitored N(2)O fluxes (static chambers) and measured denitrification (C(2)H(2) block using soil cores) at six riparian sites along a fourth-order stretch of the...

AbstruclFloodplain inundation and vegetation along the Negro and Amazon rivers near Manaus, Brazil were accurately delineated using multi-frequency, polarimetric synthetic aperture radar (SAR) data from the April and October 1994 SIR-C missions. A decision-tree model was used to formulate rules for a supervised classification into five categories: water, clearing (pasture), aquatic macrophyte (...

Lepidium latifolium L. is an invasive exotic crucifer that has spread explosively in wetlands and riparian areas of the western United States. To understand the ecophysiological characteristics of L. latifolium that affect its ability to invade riparian areas and wetlands, we examined photosynthesis, chlorophyll concentration, carbohydrate partitioning and nutrient uptake in L. latifolium in re...

Nitrogen fixation (C(2)H(2) reduction) by algae in flooded soil was limited by interactions within the algal community. Nitrogen fixation by either indigenous algae or Tolypothrix tenuis was reduced severalfold by a dense suspension of the green alga Nephrocytium sp. Similarly, interactions between the nitrogen-fixing alga (cyanobacterium) Aulosira 68 and natural densities of indigenous algae l...

Lowland rice roots have a unique physiological response to drought because of their adaptation to flooded soil. Rice root attributes that facilitate growth under flooded conditions may affect rice response to drought, but the relative roles of root structural and functional characteristics for water uptake under drought in rice are not known. Morphological, anatomical, biochemical, and molecula...