The researchers studied how using bio fertilizers and zinc affects the growth and yield of lentils. They conducted a field experiment with different treatments and measured plant height, number of nodules, pods per plant, seed yield, and more. The results showed that the combination of Rhizobium bio fertilizer and zinc at a certain level led to the highest plant height, dry weight, number of nodules, pods per plant, seeds per pod, seed yield, and Stover yield. This combination also resulted in the highest gross return, net returns, and benefit cost.