Grazing is no exception, management is the key.
Managed rotational grazing on deep silt-loam soils does not appear to contribute to groundwater contamination, say researchers from the U.S. Dairy Forage Research Center. The researchers buried 12 plastic tubes, called lysimeters, randomly in each paddock. The lysimeters captured moisture and dissolved nutrients seeping through the soil, including nitrate. Nitrate leaching losses averaged only 1 to 3 pounds per acre. However, directly under urine spots the amount of nitrate in the lysimeters increased to 20 pounds per acre.