Patent ID: 7846416

Claim:
Anitrate-nitrogen-reducing agent for a farm product, comprising as an active ingredient a hydroxide solid solution represented by the formula (1), [(M 1 2+ ) 1-x (M 2 2+ ) x ] 1-z (M 3+ )(OH) 2 (A n− ) z/n ·mH 2 O (1) wherein M 1 2+ represents Ca and/or Mg, M 2 2+ represents Fe, Mn, Zn, Cu, M 3+ represents at least one trivalent metal, A n− represents an anion having a valence of n, x is a positive number in the range of 0<x<0.5, m is 0 or a positive number in the range of 0≦m<10, z is a positive number in the range of 0<z<0.4, and n is a positive number in the range of 1≦n≦10, and/or the formula (2), (M 1 2+ ) 1-x (M 2 2+ ) x (OH) 2 (2) wherein M 1 2+ , x and M 2 2+ are as defined in the formula (1), wherein the nitrate-nitrogen-reducing agent contains Fe in an of from 5 to 12 mol %, Mn in an amount of from 1 to 5 mol %, Zn in an amount of from 2 to 5 mol % and Cu in an amount of 0.2 to 1 mol %.