Use of layered double hydroxides (LDH) of the hydrotalcite group as reservoir minerals for nitrate in soils - Examination of the chemical and mechanical stability

Abstract

The leaching of nitrate resulting from both fertilizer application in agricultural production and also from natural transformation of nitrogen from organic compounds and/or ammonium into the nitrate form is an important way of nitrogen losses in crop production particularly during autumn and winter. Since nitrate as an anion is not adsorbed to the soil particles, it remains mobile in the soil. An efficient way to reduce nitrate leaching would be to control its movement in the soil by adsorbing it from the soil solution in the same way as clay minerals do it for cations like potassium and ammonium. The addition of an anion exchanging material to the soil could reduce this nitrate loss in the soil and the nitrate load in groundwater. The material should have a high selectivity and a high storage capacity for nitrate, and should be stable and active in the soil for several growing periods.