title: Medicinal and aromatic plant materials as nitrification inhibitors for augmenting yield and nitrogen uptake of Japanese mint (Mentha arvensis L. Var. Piperascens).
abstract: Pot experiments were conducted to evaluate the relative performance of medicinal and aromatic plant materials and dicyandiamide (DCD) as nitrification inhibitors to regulate transformation of N from urea. Their effect on the efficiencies of use of N by Japanese mint (Mentha arvensis cv. Hy 77) was tested. Urea was coated with these materials viz., Mentha spicata, Artemisia annua or DCD at the rate of 5% (w/w) of fertilizer urea using an appropriate coating technique. Nimin (tetranortriterpenoids, an ethanol extract of neem (Azadirachta indica Juss) coating was done at the rate of 1% w/w of urea. Fertilizer nitrogen was applied at 100 and 200 mg kg(-1) soil. These natural coating materials significantly increased the herb and essential oil yields of the crop at both rates of fertilizer nitrogen compared to urea alone and were found to be as effective as DCD in retarding NO3- formation in soil. Herb yield increased by 6-81% when compared to uncoated urea. The increase in essential oil yield ranged between 3% and 68% due to coating. The effectiveness of the nitrification-inhibitor--coated urea, however, varied with the soils used and the rate of fertilizer nitrogen applied. The results suggest that the natural products could be potential nitrification inhibitors for increasing fertilizer N use efficiency.
authors.affiliation: Division of Soil Science and Water Technology, Central Institute of Medicinal and Aromatic Plants, PO CIMAP, Lucknow 226 015, Uttar Pradesh, India.
authors.forename: Usha
authors.initials: U
authors.lastname: Kiran
authors.forename: D D
authors.initials: DD
authors.lastname: Patra
mesh_terms: D001682:Biological Availability; D005308:Fertilizers; D027541:Mentha / Q000502:physiology*; D009584:Nitrogen / Q000378:metabolism / Q000493:pharmacokinetics*; D012987:Soil; D014508:Urea / Q000378:metabolism*
chemical_list: D005308:Fertilizers; D012987:Soil; D014508:Urea; D009584:Nitrogen