Lysimeter Studies of Nitrogen Leaching and Nitrogen Balances as Affected by Agricultural Practices

Abstract

Three types of simple lysimeters are described and discussed, including a “topsoil lysimeter”. The leaching losses were more dependent on conditions after harvest than on nitrogen level. Leaching was reduced by (in order of importance) cover crops, late growing crops, straw incorporation. For slurry and farmyard manure early application in the autumn resulted in large nitrate losses which, however, could be almost prevented by a good cover crop. It is concluded that lysimeters can be used efficiently for studies of how agricultural practices affect leaching losses and further that adjustments in agricultural practices can give large improvements of the nitrogen efficiency of agricultural systems.