Effect of neem (Azadirachta indica Juss.L) products on nitrification in rice growing soil Singh Ashok K., Ram H., Maurya B.R., Singh P.N. *Department of Agricultural Chemistry and Soil Science, SMM Town PG College, Ballia, Uttar Pradesh, India Abstract A pot experiment was conducted, during wet season using three types soils, namely typic haplusters-clay loam, aridic haplustepts-sandy loam and typic haplustalfs-sandy loam with rice as test crop. Four neem (Azadirechta indica) products as neem cake (NC) @ 20% of urea, neem oil (NO) @ 1% volume by weight of urea, Nimco (NI) @ 2% and Neemagold (NG) @ 1% by weight, blended with prilled urea alone were tested in a factorial randomized block design with 3 replication. The nitrifying capacity of soil was significantly decreased due to the application of neem products coated urea than prilled (control) in typic haplusterts, aridic haplustepts and typic haplustalfs at tillering, booting and harvesting stages of paddy. Among the neem products, neem oil coated urea treatment significantly proved superior to reduce the activity followed by neemgold nimco and neem cake also. All soils were found to have significantly reduced the nitrification among the neem products. Irrespective soil types the mineralizable N in soils was higher in control at tillering stage than the later stages. The coating of urea with neem oil @ 1.0 per cent would be promising to reduces the nitrifying capacity of soil and control the mineralization of N in typic haplusterts, aridic haplustepts and typic haplustalfs as compared to neemgold, nimco and neem cake, respectively. Top Keywords nitrifying capacity, rice soil, neem products, and available nitrogen. Top |