HR: 11:20h
AN: H42A-03    [Abstracts]
TI: Soil Moisture, Plant Nutrient Uptake, and Computer Simulation of Nutrient Export
AU: * Wang, P
EM: pwang@chesapeakebay.net
AF: Uinversity of Maryland Center for Environmental Science, 410 Severn Avenue, Suite 109, Annapolis, MD 21403 United States
AU: Linker, L C
EM: linker.lewis@epa.gov
AF: US Environmental Protection Agency, 410 Severn Avenue, Annapolis, MD 21403 United States
AB: Correct estimate of nutrient discharge from soil is important in nutrient management for protecting water quality of receiving water. Solute property, soil physical and chemical property, climatic factors, water supplies, microorganism activities, and plant uptake play important rolls in sub-ground nutrient cycle. Soil water movement provides forcing for transport of dissolved nutrients within the soil and their discharge from land to a receiving water. Solute export is proportional to water discharge and solute concentration in the soil pool. Plant uptake reduces the amount of nutrient in the soil and reduces export potential. Soil moisture level has a significant effect on the uptake of nutrient by plant, which involves both solute transport and complex physiological responses of plant. Plant nutrient uptake is not a monotonic function with soil moisture. Experiments show that plant uptake increases from a dry soil to moist soil, hence, reducing the potential of nutrient export. However, when moisture is over-sufficient in a wet soil, then more moisture would not cause higher nutrient uptake but increase export potential due to higher water discharge. This paper discusses the relationship among soil moisture, nutrient concentration, evapotranspiration, plant nutrient uptake and nutrient export from land, and presents a computer model on these processes, providing a method to simulate plant nutrient uptake and nutrient export under various moisture conditions.
DE: 1615 Biogeochemical processes (4805)
DE: 1866 Soil moisture
DE: 1871 Surface water quality
SC: Hydrology [H]
MN: 2005 Joint Assembly