Use of a substituted thiazolidine compound as nitrification inhibitor

A substituted thiazolidine compound of formula I

• or a salt, stereoisomer, tautomer, N-oxide, or S-oxide thereof for use as a nitrification inhibitor,
• wherein
• R1, R2, R3 and R4 are independently of each other selected from H, halogen, C1-C6-alkyl, C1-C6-haloalkyl, C1-C6-alkoxy, C1-C6-haloalkoxy, C2-C6-alkenyl, C3-C6-cycloalkyl, C1-C4-alkylsulfonyl, benzyl, and phenyl, wherein said groups are unsubstituted or substituted by one or more, same or different substituents Rx;
• or
• R1 and R2 or R3 and R4 together form ═O;
• and wherein
• RN is H, C1-C6-alkyl, C3-C6-cycloalkyl, benzyl, allyl, propargyl, or phenyl, wherein said groups are unsubstituted or substituted by one or more, same or different substituents Ry;
• CHRaC(═O)ORb, CHRaC(═O)O−-Q+, CHRaC(═O)Rd, CHRaC(═O)NRbRc, C(═O)Rd, C(═O)ORb, C(═O)NRbRc, CHRaORb, C(═O)(CH2)2C(═O)ORb, or CSNRbRc;
• Ra is H, halogen, C1-C6-alkyl, C1-C6-alkoxy, C1-C4-haloalkyl, C3-C6-cycloalkyl, phenyl, or phenyl-C1-C2-alkyl;
• Rb is H, C1-C6-alkyl, C1-C6-alkoxy, C3-C6-cycloalkyl, aryl, phenyl, or phenyl-C1-C2-alkyl;
• Rc is H, C1-C6-alkyl, C1-C6-alkoxy, C3-C6-cycloalkyl, aryl, phenyl, or phenyl-C1-C2-alkyl;
• Rd is H, C1-C3-alkyl, C1-C6-haloalkyl, C2-C6-alkenyl, C2-C6-alkynyl, phenyl, phenyl-C1-C2-alkyl, hetaryl, or hetaryl-C2-C3-alkenyl, wherein these groups are unsubstituted or substituted by one or more, same or different substituents selected from halogen, OH, OCH3, and CH3;
• Rx is halogen, OH, C1-C6-alkyl, C1-C6-haloalkyl, C1-C6-alkoxy, C1-C6-haloalkoxy, C1-C6-alkylthio, C1-C6-alkylcarbonyl, or C1-C6-alkylcarboxy;
• Ry is halogen, OH, C1-C6-alkyl, C1-C6-haloalkyl, C1-C6-alkoxy, C1-C6-haloalkoxy, or phenyl;
• and
• Q+ is selected from the group consisting of Na+, K+, Ca2+, and NH4+.