Nitrification inhibition effect of dicyandiamide on ammonium bicarbonate in red soils with different textures Comparative studies on soil nitrification inhibition by pyridine compounds Nitrification inhibition and dose-dependent effect of dicyandiamide on sandy, loamy and clayey soils Effects of different nitrogen regulators on nitrogen transformation in different soil types. Nitrification inhibition of dicyandiamide on urea in the red soil of different textures