Residual effect of foliar applied nanofertilisers on rice fallow green gram for sustainable rice intensification

Sustainable crop intensification through rice-green gram cropping system utilises the residual benefits of fertilisers, particularly through foliar application of nanofertilisers. Therefore, the present study aimed to assess the residual effects of foliar-applied nanofertilisers especially nitrogen (N), zinc (Zn) and copper (Cu) on rice fallow green gram. The field trial was conducted using a randomised block design with 12 treatments and 3 replications, integrating soil and nano foliar applied fertilisers. The results indicated that in experiment I, 100 % nitrogen, phosphorus and potassium (NPK) + nano N, Zn and Cu at active tillering, each at 4 mL L-1 of water showed significantly higher green gram yield by 12.69 %, nitrogen uptake by 8.45 % and net returns by 23 % compared to conventional fertilisation (100 % NPK). In experiment II, foliar application of nano N at active tillering at 8 mL L-1 of water, combined with either 100 % NPK or 75 % N + 100 % PK, significantly enhanced yield by 13.05 %, nitrogen uptake by 15.6 % and net returns by 28.5 %. System indices also showed similar trend with respect to rice equivalent yield, system productivity and profitability. In conclusion, application of either 100 % NPK or 75 % N + 100 % PK along with foliar application of nano N at 8 mL L-1 during active tillering proved effective in enhancing green gram performance and sustaining soil and environmental health in rice-fallow systems.