Effects of Different Compositions of Rice Straw on Nutrient Profile of Vermicompost and Fecundity of Earthworms (Eisenia fetida)

The present investigation was carried out to observe the effects of different compositions of rice straw on fecundity and population of earthworms (Eisenia fetida) using 100%, 90%, 80%, 70% of cow dung with 10%, 20%, 30% rice straw in 80-litre plastic tubs containing 100 adult earthworms for 90 days. At the end of the experiment, the total number of cocoons produced in E. fetida was higher (541±2.65) in 90% cow dung with 10% rice straw. The organic carbon (%) was highest in 100% cow dung (28.22±0.20) and lowest in 10 % rice straw + 90% cow dung (21.49±0.67) but nitrogen % was highest in 10 % rice straw (1.466± 0.009) followed by 20 % rice straw (1.37± 0.015), 30 % rice straw (1.33± 0.0057) and control (1.28 ±0.01). The C/N ratio was maximum in control (22.05± 0.33), followed by 30 % rice straw (20.38± 0.54), 20 % rice straw (17.41± 0.62) and 10 % rice straw (14.66± 0.37). The total phosphorus (%) was highest in 10 % rice straw (1.363± 0.025), followed by 20 % rice straw (1.18±0.025), 30 % rice straw (0.81± 0.03) and control (0.72± 0.0055). A similar trend was observed in total Potassium, where 10 % rice straw (1.95 ±0.02) had the highest total potassium, followed by 20 % rice straw (1.84± 0.019), 30 % rice straw (1.76 ±0.035) and control (1.46± 0.025). Hence, the addition of rice straw has a significant effect on the total number of cocoons produced and population of E. fetida in comparison to the control. The organic carbon (%) and C/N ratio were recorded highest in the control group and lower in treatments having rice straw and cow dung, but nitrogen %, total potassium and total phosphorus % were highest in 10 % rice straw followed by 20 % rice straw, 30 % rice straw and control.