Affiliations: Punjab Agricultural University, Ludhiana 141 004, Punjab, India | Sant Longowal Institute of Engineering & Technology, Longowal, Punjab, India
Abstract: Nitrification acts as a key process in determining fertilizer use efficiency by crops as well as nitrogen losses from soils. Metal dithiocarbamates in addition to their pesticidal properties can also inhibit biological oxidation of ammonium (nitrification) in soil. Metal [M=V(III), Cr(III), Mn(II), Fe(III), Ni(II), Cu(II), Zn(II) and Pt(IV)] diethyldithiocarbamates (DEDTC) were synthesized by the reaction of sodium diethyldithiocarbamate with metal chloride in dichloromethane/water mixture. These metal diethyldithiocarbamates were screened for their ability to inhibit nitrification at different concentrations(10 µg/g soil, 50 µg/g soil and 100 µg/g soil). With increasing concentration of the complex, capacity to retard nitrification increased but the extent of increase varied for different metals. At 100 µg/g soil, different complexes showed nitrification inhibition from 22.36% to 46.45%. Among the diethyldithiocarbamates tested, Zn(DEDTC)_{2} proved to be the most effective nitrification inhibitor at 100 µg/g soil. Manganese, iron and chromium diethyldithiocarbamates also proved to be effective nitrification inhibitors than the others at 100 µg/g soil. The order of percent nitrification inhibition in soil by metal diethyldithiocarbamates was: Zn(II)>Mn(II)>Fe(III)>Cr(III)>V(III)>Co(II)>Ni(II)>Cu(II).
Keywords: nitrification inhibitor, diethyldithiocarbamate, metal complexes, nitrogenous fertilizers, pesticides
