Thomas Jefferson was the first to suggest what practice?
1. plowing legumes into the soil
2.adding a bacteria filled powder to the land while planting
3. alternating their crops between different fields each year
4.planting legumes every year in the same field

alternation of crops

Explanation:

Common legumes include clover, beans, peas, alfalfa, and peanuts. Thomas Jefferson suggested that farmers alternate their crops between different fields each year. They range from single cells up to large organisms measuring 50 centimeters or more.

it should be p1 v1 = p2 v2