Machinery has made it possible for the work of a dozen farm workers to be done twice as quickly by one worker. There are fewer people working on the land in developed countries than ever before.
Machinery also has a large effect on the environment well, as hedges ditches are removed to allow larger machines to work the enormous fields. Crops have also been bred for the machine age ago. They need to ripen together, not over a period of time, so that machinery can harvest them in one operation.
There are still many parts of the world where traditional farming methods are used, but the use of machinery is increasing year by year.