Green manuring management in combination with inorganic nitrogen in rice-wheat cropping system under calcareous soil of Bihar

Field study was conducted during the kharif-rabi season of 2016–17 to 2019–20 for 4 consecutive years at research farm of Dr. Rajendra Prasad Central Agricultural University, Pusa, Samastipur (Bihar) to assess the effect of green manuring and nitrogen on rice and its residual effect on succeeding wheat. This was laid out in RBD, comprising seven treatments of green manuring (three age of sesbania with two seed rate along with one control) and five levels of nitrogen with three replications. Green manuring with sesbania at the age of 45 days with 30 kg seed rate recorded the maximum grain and straw yield of rice. This treatment recorded the maximum uptake of NPK by rice crop. This treatment also maintained the superiority in terms of B:C ratio. Application of graded level of nitrogen increased the grain and straw yield upto 120 kg/ha. However, interaction effect revealed that green manuring at 45 DAS with 30 kg seed rate coupled with 60 kg N/ha gave significantly maximum grain yield. Residual effect on succeeding wheat was maximum when age of sesbania for green manuring in rice was 65 days with 30 kg seed rate. This treatment also excelled in terms of NPK uptake by wheat crop along with higher B:C ratio.