Planting, irrigation, weeding and nutritional methods on available silica in the rhizosphere of CORH 2 Rice Hybrid

Field experiment was designed in the wetlands of Agricultural College and Research Institute, Coimbatore during samba 2001 with the rice (Oryza sativa) hybrid CORH 2 (125 days duration) to study the impact of modified crop management options on the available silica content of the rhizosphere soil. The treatments included planting of 14 day old dapog seedlings, limited irrigation, weed management aided by insitu weed incorporation using conoweeder, green manuring along with chemical fertilizers verses conventional planting, irrigation, weeding and nutritional methods. The experiment was laid out in strip plot design with each treatment replicated thrice. Rhizosphere soil was sampled at all the physiological growth stages and the available silica was estimated by neutral normal ammonium acetate method. The research revealed that planting of 14 days old dapog seedlings, limited irrigation and green manuring practices resulted in higher content of available silica in the rhizosphere soil due to enhanced root volume and presence of aerobic microbes.