As the groundwater percolates downward, it frequently moves laterally toward streams. Nitrate that is carried with the groundwater eventually discharges into a surface-water body. The amount of nitrate entering the surface water can be reduced if the groundwater flows through a riparian buffer or discharges into a controlled drainage system, or if the amount of nitrogen that reaches the groundwater is reduced as a result of good management practices. Managing nitrogen is important to ensure that only the amount needed by the crop is added. Although nitrogen management will not prevent nitrate from leaching into the groundwater, it will reduce the amount.
Riparian buffers are trees, shrubs, or grass next to streams.
Nitrate in groundwater that passes through a riparian buffer may either be taken up by the riparian vegetation or converted to a gas, through a process called denitrification, by bacteria found in the soil. In riparian soils, denitrification is an extremely important process for removing nitrate from groundwater flowing from fertilized fields. Nitrogen is denitrified as it moves from the field into the ditch. Because nitrogen is essential for high crop yields, strategies to control it must involve either nitrogen management and controlled drainage or nitrogen management and riparian buffers. Circle the answer that best describes your use of nitrogen management.