Uptake Processes
Plant Uptake: Plant uptake is another means by which chemicals in the soil can be removed from the pool available for leaching. The importance of planet uptake will clearly depend upon the chemical of interest. Plant uptake of pesticides is generally ignored. However, modeling major plant nutrients will likely require modeling plant uptake. Nitrogen can be taken up in very large quantities. Therefore modeling leaching of nitrate must deal with N uptake if a realistic estimate of the quantity leaching to groundwater is needed. Moreover the model must be able to estimate the uptake over time and for different irrigation practices if vulnerability is to be assesseds for those practices.
The CMLS model used in this vulnerability assessment does not deal with plant uptake so it can not be used for assessing the concentration of nitrate entering groundwater. It can be used to estimate the time required to leach the a non-adsorbed chemical such as nitrate through the root zone and the drainage or recharge associated with different management practices.
