Nutrient Uptake, Soil Fertility Status and Nutrient Use Efficiency of Rice as Influenced by Inorganic and Bio-fertilizer in New Alluvial Zone of West Bengal

Aims: To study the influence of inorganic and bio-fertilizers on nutrient uptake, soil fertility status and nutrient use efficiency of rice (Oryza sativa L.).

Place and Duration of Study: The field trial was conducted in the experimental farm of Bidhan Chandra Krishi Viswavidyalaya, West Bengal, India during kharif season of 2016.

Methodology: The experiment was carried out in a randomized block design with seven treatments each of which was replicated three times. The experiment was comprised of seven treatments viz. T1: control, T2: chemical fertilizer at 100% recommended dose of NPK, T3: 50% recommended dose of NP + 100% RDK + Bacillus polymyxa, T4: 75% recommended dose of NP + 100% RDK + Azotobacter chroococcum, T5: 75% recommended dose of NP + 100% RDK + Bacillus polymyxa, T6: 50% recommended dose of NP + 100% RDK + Pseudomonas fluorescence and T7: 50% recommended dose of NPK + Bacillus polymyxa. Rice cultivar ‘IET-4786 (Shatabdi)’ was used as test crop.

Results: Results of this study revealed that the maximum nutrient concentration in rice grain and straw; total N, P and K uptake (136.80, 37.07 and 184.65 kg ha-1 respectively); grain and straw yield; were obtained with the application of 100% recommended dose of chemical fertilizer (T2). T2 treatment was followed by 75% recommended dose of NP + 100% RDK + Azotobacter chroococcum (T4) and 75% recommended dose of NP + 100% RDK + Bacillus polymyxa (T5). Treatments T4 and T5 were significant in improving the soil health status including organic carbon content (0.38%), available N (183.29 and 172.43 kg ha-1), P2O5 (44.31 and 41.46 kg ha-1) and K2O (217.89 and 195.82 kg ha-1).

Conclusion: Therefore, treatments T4 and T5 exhibited beneficial effect on improving soil health and nutrient use efficiency leading towards higher rice yield along with reducing soil deterioration and maintaining sustainability.