A representative rice growing rural area (10,000 ha) of Sonitpur district, Assam (India) is considered for the present investigation. Geographical location of the study area is in between 9254015.1900E (upper left longitude), 2646040.8200N (upper left latitude) and 930017.1300E (lower right longitude), 2641015.9300N (lower right latitude). The climate of the study
area is sub-tropical type with average summer (March to September) and winter (October to February) temperature is
29 C and 16 C respectively.