Abstract

                                Field experiments were conducted at Agricultural college and Research Institute, Coimbatore to study the impact of weed management options on the nitrogen dynamics in the rhizosphere soil of two rice hybrids CORH2 and ADTRHI during 2001-02. Manual hand weeding was tested against conoweeding in which weeds were incorporated insitu in the field. Conoweeding set a favourable impact on the nitrogen fractions of the rhizosphere soil owing to the aeration of the soil rendered by the mechanical weeder due to soil stirring resulting in greater mobility of nitrogen in the rhizosphere region.

Key words : Rice hybrids, hand weeding, conoweeding, ammoniacal nitrogen, nitrate nitrogen, nitrogen fractions