sentence: Many farms also use machines, which cut down on the number of people needed to farm the land.
sentences_before: In rich countries, farms are often much larger. The yield on farms has gotten bigger in the last one hundred years because farmers are able to grow better varieties of plants, use more fertilizer, use more water, and more easily control weeds and pests.
sentences_after: This results in fewer farmers in rich countries, but the farmers are able to eat more. This kind of intensive agriculture comes with its own set of problems. These chemicals can pollute the soil or the water. They can also create bugs and weeds that are more resistant to the chemicals, causing outbreaks of these pests. Having fewer farmers also changes society and can make a country less able to feed itself in bad times.
concept_name: farm
headings: Farming Overview