Use of an N-functionalized alkoxy pyrazole compound of formula I or a salt, stereoisomer, tautomer, or N-oxide thereof as a nitrification inhibitor, wherein R 1 is C 1 -C 6 -alkyl, benzyl, or allyl; R 2 is halogen, C 1 -C 6 -alkyl, C 3 -C 6 -cycloalkyl, benzyl, allyl, propargyl, or phenyl, wherein said phenyl group is unsubstituted or substituted by one or more, same or different substituents R x ; R N is CHR a C(=O)OR b , CHR a C(=O)NR b R c , CH(C(=O)OR b )CH 2 (C(=O)OR b ); C(=O)R d , C(=O)NR b R c , or CHR a NR e (C=O)R f ; and wherein R a is H, C 1 -C 4 -alkyl, C 1 -C 4 -haloalkyl, C 3 -C 8 -cycloalkyl, phenyl, or phenyl-C 1 -C 2 -alkyl; R b is H, C 1 -C 4 -alkyl, C 1 -C 4 -haloalkyl, C 3 -C 8 -cycloalkyl, phenyl, or phenyl-C 1 -C 2 -alkyl; R c is H, C 1 -C 4 -alkyl, C 1 -C 4 -haloalkyl, or phenyl; R d is H, C 1 -C 8 -alkyl, C 2 -C 8 -alkenyl, C 2 -C 8 -alkynyl, phenyl, or phenyl-C 1 -C 2 -alkyl, wherein these groups are unsubstituted or substituted by a group COOH; R e is H, C 1 -C 4 -alkyl, C 3 -C 8 -cycloalkyl, or C 6 -C 10 -aryl; R f is H, or C 1 -C 4 -alkyl; R x is halogen, C 1 -C 4 -alkyl, C 1 -C 4 -haloalkyl, C 1 -C 4 -alkoxy, or C 1 -C 4 -haloalkoxy; n is 0, 1, or 2. or a salt, stereoisomer, tautomer, or N-oxide thereof as a nitrification inhibitor, wherein R 1 is C 1 -C 6 -alkyl, benzyl, or allyl; R 2 is halogen, C 1 -C 6 -alkyl, C 3 -C 6 -cycloalkyl, benzyl, allyl, propargyl, or phenyl, wherein said phenyl group is unsubstituted or substituted by one or more, same or different substituents R x ; R N is CHR a C(=O)OR b , CHR a C(=O)NR b R c , CH(C(=O)OR b )CH 2 (C(=O)OR b ); C(=O)R d , C(=O)NR b R c , or CHR a NR e (C=O)R f ; R 1 is C 1 -C 6 -alkyl, benzyl, or allyl; R 2 is halogen, C 1 -C 6 -alkyl, C 3 -C 6 -cycloalkyl, benzyl, allyl, propargyl, or phenyl, wherein said phenyl group is unsubstituted or substituted by one or more, same or different substituents R x ; R N is CHR a C(=O)OR b , CHR a C(=O)NR b R c , CH(C(=O)OR b )CH 2 (C(=O)OR b ); C(=O)R d , C(=O)NR b R c , or CHR a NR e (C=O)R f ; and wherein R a is H, C 1 -C 4 -alkyl, C 1 -C 4 -haloalkyl, C 3 -C 8 -cycloalkyl, phenyl, or phenyl-C 1 -C 2 -alkyl; R b is H, C 1 -C 4 -alkyl, C 1 -C 4 -haloalkyl, C 3 -C 8 -cycloalkyl, phenyl, or phenyl-C 1 -C 2 -alkyl; R c is H, C 1 -C 4 -alkyl, C 1 -C 4 -haloalkyl, or phenyl; R d is H, C 1 -C 8 -alkyl, C 2 -C 8 -alkenyl, C 2 -C 8 -alkynyl, phenyl, or phenyl-C 1 -C 2 -alkyl, wherein these groups are unsubstituted or substituted by a group COOH; R e is H, C 1 -C 4 -alkyl, C 3 -C 8 -cycloalkyl, or C 6 -C 10 -aryl; R f is H, or C 1 -C 4 -alkyl; R x is halogen, C 1 -C 4 -alkyl, C 1 -C 4 -haloalkyl, C 1 -C 4 -alkoxy, or C 1 -C 4 -haloalkoxy; n is 0, 1, or 2. R a is H, C 1 -C 4 -alkyl, C 1 -C 4 -haloalkyl, C 3 -C 8 -cycloalkyl, phenyl, or phenyl-C 1 -C 2 -alkyl; R b is H, C 1 -C 4 -alkyl, C 1 -C 4 -haloalkyl, C 3 -C 8 -cycloalkyl, phenyl, or phenyl-C 1 -C 2 -alkyl; R c is H, C 1 -C 4 -alkyl, C 1 -C 4 -haloalkyl, or phenyl; R d is H, C 1 -C 8 -alkyl, C 2 -C 8 -alkenyl, C 2 -C 8 -alkynyl, phenyl, or phenyl-C 1 -C 2 -alkyl, wherein these groups are unsubstituted or substituted by a group COOH; R e is H, C 1 -C 4 -alkyl, C 3 -C 8 -cycloalkyl, or C 6 -C 10 -aryl; R f is H, or C 1 -C 4 -alkyl; R x is halogen, C 1 -C 4 -alkyl, C 1 -C 4 -haloalkyl, C 1 -C 4 -alkoxy, or C 1 -C 4 -haloalkoxy; n is 0, 1, or 2. <EOS>