Kumar, Rajesh and DEVAKUMAR, C and SHARMA, V and KAKKAR, G and KUMAR, DINESH and PANNEERSELVAM, P (2007) Influence of Physicochemical Parameters of Neem (Azadirachta indica A Juss) Oils on Nitrification Inhibition in Soil. Journal of Agricultural and Food Chemistry, 55 (4). pp. 1389-1393.
Restricted to Repository staff only
The technology for the production of neem oil coated urea (NOCU) developed by the Indian Agricultural Research Institute is in the pipeline for adaption by several Indian fertilizer industries. Use of nitrification inhibitors is one of the methods of improving the nitrogen use efficiency (NUE) of nitrogenous fertilizers in agriculture. However, standard specifications for the neem oil as a raw material of NOCU are desired. Accordingly, the present study was undertaken to evaluate 25 samples of neem oils comprising 11 samples of expeller grade (EG) oils, 8 samples of cold-pressed (CP) oils, 3 samples of solvent-extracted oils, and 2 commercial formulations. NOCU was prepared using these oils (5000 ppm of urea-N). The soils fertilized with NOCUs (200 ppm of urea-N) were incubated at 27 °C and 50% water-holding capacity for a period of 15 days. Nitrapyrin (0.5% of N) coated urea served as the reference and prilled urea as control. Samples were analyzed for NH 4 + -N, NO 2 - -N, and NO 3 - -N using standard methods. The percent nitrification inhibition (NI) was calculated, and the results revealed that all of the neem oils caused NI ranging from 4.0 to 30.9%. Two samples of EG oils and two commercial formulations were found to be the best, causing 27.0-30.9% NI. Iodine, acid, and saponification values and meliacin content of all of the oils were analyzed and correlated with NI. The results revealed the direct influence of meliacin content of the neem oils on NI, which, however, was found to be negatively correlated with saponification and iodine values. There is, therefore, a need to introduce new Bureau of Indian Standards (BIS) specifications for neem oils as raw materials of NOCU.
|Uncontrolled Keywords:||Neem (Azadirachta indica); neem oils; nitrification inhibition; meliacins; NOCU; iodine value; saponification value; acid value|
|Subjects:||Agricultural Sciences and Technology > Agricultural Chemicals|
|Deposited By:||Dr Rajesh Kumar|
|Deposited On:||07 Jul 2010 17:54|
|Last Modified:||07 Jul 2010 18:03|
Repository Staff Only: item control page