Nitrate leaching may be greater when a fertilizer contains the nitrate compared to the situations where ammoniacal nitrogen is the major component of a fertilizer. Nitrate losses are likely to be more when all the nitrogen is applied in one application compared to when nitrogen is applied in split applications. Fall-application of fertilizers or manures will cause high nitrate losses during early spring. Nitrate losses from fertilizer use can be reduced by matching fertilizer application with nitrogen needs of a crop. Nitrogen fertilizers or manure used on a sandy soil are more vulnerable to leaching to groundwater than nitrogen used on a clay soil.
Water moves rapidly through sandy or other coarse-textured soils.
Nitrates move along with the water in a soil. Nitrogen loss to the groundwater from clay soils is smaller than those for the coarse-textured soils. Clay soils do not specifically retain nitrates. Water movement through clay soils is very slow and small. Water does not pass easily through clay soils so nitrates, which only move with water, do not leach to groundwater.