The balloon was airborne for approximately 30 minutes prior to the pilot setting up for a landing in a grassy area alongside a road. The pilot reported the ground crew informed him that there was a ditch running parallel to the side of the road. However, the pilot reported he did not know the depth of the ditch. The local winds were 6 to 7 miles per hour at the time of the landing. The pilot reported he briefed the passengers for the landing. The balloon touched down in a bean field, about 20 feet from the grass area, and the ground crew grabbed the basket as it moved into the grass. The ground crew was not able to stop the basket and it traveled into the 10-foot deep ditch. The balloon came to rest at the bottom of the ditch with the ground crew still hanging on. One of the two passengers on board suffered a fractured leg. The injured passenger stated that she thought that either the other passenger or the pilot hit her leg during the landing. There was no damage to the balloon envelope or basket.