Using a capacity model to quantify nitrate leaching from agricultural soils and its validation through lysimeter studies
Abstract:
The leaching of nitrate from agriculturally used soils still represents a risk to groundwater. Temporally and spatially flexible control methods to assess the impact of agriculture on groundwater are thus far missing, however.
During a DVGW research project conducted between 2001 and 2003 a relatively simple control method, using only few soil characteristics and climatic input parameters, was developed and validated. Nmin-data (mineral nitrogen in soil) levels were raised several times at the pilot-site and resulting data was used to calculate nitrate losses from the soil. Calculations were done using the simple numeric capacity model INVAM, which was developed at the TZW in 1991.
This indirect quantification of nitrate leaching was validated using soil-water-samplers and monolithic lysimeters. Tracer tests with bromide gave information on water and solute movement in the soil.
The validation of lysimeter investigations confirms that the combination of soil controls and a functional model is a method well suited for the quantification of nitrate leaching. This DVGW research project thus represents a suitable tool for ensuring groundwater protection through land management.
The leaching of nitrate from agriculturally used soils still represents a risk to groundwater. Temporally and spatially flexible control methods to assess the impact of agriculture on groundwater are thus far missing, however.
During a DVGW research project conducted between 2001 and 2003 a relatively simple control method, using only few soil characteristics and climatic input parameters, was developed and validated. Nmin-data (mineral nitrogen in soil) levels were raised several times at the pilot-site and resulting data was used to calculate nitrate losses from the soil. Calculations were done using the simple numeric capacity model INVAM, which was developed at the TZW in 1991.
This indirect quantification of nitrate leaching was validated using soil-water-samplers and monolithic lysimeters. Tracer tests with bromide gave information on water and solute movement in the soil.
The validation of lysimeter investigations confirms that the combination of soil controls and a functional model is a method well suited for the quantification of nitrate leaching. This DVGW research project thus represents a suitable tool for ensuring groundwater protection through land management.
Project duration
Mai 2001 - Dezember 2003
