Leaching of organic nitrogen (DON) and carbon (DOC) was measured after cultivating grass-clover of different age. It was found that DON and escpecially DOC was lost in considerable amounts, and that the leaching depends upon crop and management. The highest concentrations of DON were measured in the bare soil treatment, whereas concen-trations in catch crop treatments were between 1.2 and 3.2 mg N L-1. The leaching of DOC showed opposite trends compared to leaching of DON with higher values in the catch crop treatments (296 - 310 kg DOC ha-1) than in bare soil treatments (174 - 217 kg DOC ha-1)
