Nitrogen transformation, Urea, Vermicompost, Pendimethalin, Lateritic soil.

An experiment was conducted to study the effect of pendimethalin on nitrogen transformation of vermicompost and urea in lateritic soil of West Bengal. There was continuous decrease in NH4 N + content in soil, irrespective of treatments. The rate of decrease was gradual during the initial period (up to 3rd week), while it was sharp during the later part of incubation. NO3N - content showed a decreasing trend up to 4th week of incubation both in control and urea treated soil, irrespective of pendimethalin application. Thereafter, there was a sharp increase. However, such decrease in NO3N - content was not observed during the initial period in soil where vermicompost was applied. The results also suggest that on an average, vermicompost was as efficient as urea in releasing NO3N - . The mean results indicated that the urea treatments released much higher amount of mineral nitrogen (NH4 N + + NO N 3 - ) compared to vermicompost.