What were the advantages of the use of mechanical harvesting machines in the USA?

(i) The mid-western prairie was covered with a thick mat of grass with tough roots. New ploughs broke the sod and turned the soil over. By the early twentieth century, farmers in Great Plains broke the ground with tractors and disk ploughs, cleared vast stretches for wheat cultivation.
(ii) Mechanical harvesting machines helped in cutting grain quickly. Earlier hundreds of men and women could be seen in the fields. By the early twentieth century, most farmers were using combined harvesters to cut grain.
(iii) New machines allowed big farmers to rapidly clear large tracts, break up soil, remove the grass and prepare the ground for cultivation. With power-driven machinery, four men could plough, seed and harvest 2000 to 4000 acres of wheat in a season.