Evaluating the effect of Bio-fertilizers in mitigating GHGs in Puddled rice (Oryza sativa. L)

Abstract

A field experiment was conducted at Agricultural College & Research Institute, Tamil Nadu Agricultural University, Madurai during 2021to quantify the GHG emission in puddled rice, ADT 54. The experiment was laid out in Randomized Block Design with four replications with the treatments, T₁ - SRI method of rice cultivation with organic farming SOP, T₂ - SRI method of rice cultivation with inorganic farming SOP, T₃ - T₁+BGA application @ 10 kg ha^-1, T₄ - T₂+ BGA application @ 10 kg ha^-1, T₅ -T₁+Azolla application @ 250 kg ha^-1, T₆ -T₂+ Azolla application @ 250 kg ha^-1.Among the treatments, SRI method of rice cultivation with inorganic farming (T₂) has recorded significantly taller plants (133 cm), higher number of tillers plant ^-1(19.8), maximum LAI (5.73), more productive tillers (328 m^-2) and maximum grain yield (5285 kg ha^-1). However, with regard to methane emission, SRI with inorganic farming + Azolla 250 kg ha^-1(T₆) recorded with very less methane during active tillering (4.14 mg m^-2 hr^-1)and flowering stage (2.77 mg m^-2 hr^-1) with higher post-harvest soil fertility status.  As regards BCR, it was maximum at SRI with inorganic farming and was closely followed by SRI with inorganic farming + Azolla 250 kg ha^-1. Hence, SRI with inorganic farming + Azolla 250 kg ha^-1(T₆) may be recommended for getting higher yield, reduced methane emission, higher post-harvest soil fertility status and higher BCR (2.37) for rice variety, ADT 54.