Terrace is built by taking earth from the top of the slope and moving it down to an area farther down. This allows you to turn sloped fields into flat fields. Once the terrace is ready, build a low earthen wall about 6-10 inches high around it to increase the amount of water that enters the ground. Leave one or two gaps in the wall to prevent water logging of the field. Try to drain fields away from other agricultural lands to prevent damaging it. This technique can even allow the creation of rice paddies on hillsides