The researchers studied how using vermicompost along with different amounts of NPK fertilizer affects wheat yield. They found that applying 3 tonnes of vermicompost with 100% NPK resulted in the highest grain yield. Using 50% NPK along with 1 tonne of vermicompost gave similar results to using 100% NPK alone. Overall, combining vermicompost with NPK fertilizer can improve wheat yield, with certain combinations showing better results than others.