The researchers conducted field experiments to find a better cropping system than rice-wheat for higher productivity and profit. They tested four systems and found that growing maize, potato, and onion together gave the best results, with 150% more productivity than other systems. The second-best system was growing fodder maize, cowpea, wheat, and mungbean together. Overall, the maize-potato-onion system showed the highest productivity and profit potential, suggesting it could replace the traditional rice-wheat system in the Indo-Gangetic Plains.